diff options
Diffstat (limited to 'drivers/xen/xen-pciback')
| -rw-r--r-- | drivers/xen/xen-pciback/Makefile | 8 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space.c | 431 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space.h | 129 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space_capability.c | 207 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space_header.c | 424 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space_quirks.c | 140 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space_quirks.h | 34 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/passthrough.c | 197 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/pci_stub.c | 1652 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/pciback.h | 202 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/pciback_ops.c | 464 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/vpci.c | 273 | ||||
| -rw-r--r-- | drivers/xen/xen-pciback/xenbus.c | 755 |
13 files changed, 4916 insertions, 0 deletions
diff --git a/drivers/xen/xen-pciback/Makefile b/drivers/xen/xen-pciback/Makefile new file mode 100644 index 000000000..e8d981d43 --- /dev/null +++ b/drivers/xen/xen-pciback/Makefile @@ -0,0 +1,8 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback.o + +xen-pciback-y := pci_stub.o pciback_ops.o xenbus.o +xen-pciback-y += conf_space.o conf_space_header.o \ + conf_space_capability.o \ + conf_space_quirks.o vpci.o \ + passthrough.o diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c new file mode 100644 index 000000000..60111719b --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space.c @@ -0,0 +1,431 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend - Functions for creating a virtual configuration space for + * exported PCI Devices. + * It's dangerous to allow PCI Driver Domains to change their + * device's resources (memory, i/o ports, interrupts). We need to + * restrict changes to certain PCI Configuration registers: + * BARs, INTERRUPT_PIN, most registers in the header... + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#include <linux/kernel.h> +#include <linux/moduleparam.h> +#include <linux/pci.h> +#include "pciback.h" +#include "conf_space.h" +#include "conf_space_quirks.h" + +bool xen_pcibk_permissive; +module_param_named(permissive, xen_pcibk_permissive, bool, 0644); + +/* This is where xen_pcibk_read_config_byte, xen_pcibk_read_config_word, + * xen_pcibk_write_config_word, and xen_pcibk_write_config_byte are created. */ +#define DEFINE_PCI_CONFIG(op, size, type) \ +int xen_pcibk_##op##_config_##size \ +(struct pci_dev *dev, int offset, type value, void *data) \ +{ \ + return pci_##op##_config_##size(dev, offset, value); \ +} + +DEFINE_PCI_CONFIG(read, byte, u8 *) +DEFINE_PCI_CONFIG(read, word, u16 *) +DEFINE_PCI_CONFIG(read, dword, u32 *) + +DEFINE_PCI_CONFIG(write, byte, u8) +DEFINE_PCI_CONFIG(write, word, u16) +DEFINE_PCI_CONFIG(write, dword, u32) + +static int conf_space_read(struct pci_dev *dev, + const struct config_field_entry *entry, + int offset, u32 *value) +{ + int ret = 0; + const struct config_field *field = entry->field; + + *value = 0; + + switch (field->size) { + case 1: + if (field->u.b.read) + ret = field->u.b.read(dev, offset, (u8 *) value, + entry->data); + break; + case 2: + if (field->u.w.read) + ret = field->u.w.read(dev, offset, (u16 *) value, + entry->data); + break; + case 4: + if (field->u.dw.read) + ret = field->u.dw.read(dev, offset, value, entry->data); + break; + } + return ret; +} + +static int conf_space_write(struct pci_dev *dev, + const struct config_field_entry *entry, + int offset, u32 value) +{ + int ret = 0; + const struct config_field *field = entry->field; + + switch (field->size) { + case 1: + if (field->u.b.write) + ret = field->u.b.write(dev, offset, (u8) value, + entry->data); + break; + case 2: + if (field->u.w.write) + ret = field->u.w.write(dev, offset, (u16) value, + entry->data); + break; + case 4: + if (field->u.dw.write) + ret = field->u.dw.write(dev, offset, value, + entry->data); + break; + } + return ret; +} + +static inline u32 get_mask(int size) +{ + if (size == 1) + return 0xff; + else if (size == 2) + return 0xffff; + else + return 0xffffffff; +} + +static inline int valid_request(int offset, int size) +{ + /* Validate request (no un-aligned requests) */ + if ((size == 1 || size == 2 || size == 4) && (offset % size) == 0) + return 1; + return 0; +} + +static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask, + int offset) +{ + if (offset >= 0) { + new_val_mask <<= (offset * 8); + new_val <<= (offset * 8); + } else { + new_val_mask >>= (offset * -8); + new_val >>= (offset * -8); + } + val = (val & ~new_val_mask) | (new_val & new_val_mask); + + return val; +} + +static int xen_pcibios_err_to_errno(int err) +{ + switch (err) { + case PCIBIOS_SUCCESSFUL: + return XEN_PCI_ERR_success; + case PCIBIOS_DEVICE_NOT_FOUND: + return XEN_PCI_ERR_dev_not_found; + case PCIBIOS_BAD_REGISTER_NUMBER: + return XEN_PCI_ERR_invalid_offset; + case PCIBIOS_FUNC_NOT_SUPPORTED: + return XEN_PCI_ERR_not_implemented; + case PCIBIOS_SET_FAILED: + return XEN_PCI_ERR_access_denied; + } + return err; +} + +int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size, + u32 *ret_val) +{ + int err = 0; + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + const struct config_field_entry *cfg_entry; + const struct config_field *field; + int field_start, field_end; + /* if read fails for any reason, return 0 + * (as if device didn't respond) */ + u32 value = 0, tmp_val; + + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: read %d bytes at 0x%x\n", + pci_name(dev), size, offset); + + if (!valid_request(offset, size)) { + err = XEN_PCI_ERR_invalid_offset; + goto out; + } + + /* Get the real value first, then modify as appropriate */ + switch (size) { + case 1: + err = pci_read_config_byte(dev, offset, (u8 *) &value); + break; + case 2: + err = pci_read_config_word(dev, offset, (u16 *) &value); + break; + case 4: + err = pci_read_config_dword(dev, offset, &value); + break; + } + + list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { + field = cfg_entry->field; + + field_start = OFFSET(cfg_entry); + field_end = OFFSET(cfg_entry) + field->size; + + if (offset + size > field_start && field_end > offset) { + err = conf_space_read(dev, cfg_entry, field_start, + &tmp_val); + if (err) + goto out; + + value = merge_value(value, tmp_val, + get_mask(field->size), + field_start - offset); + } + } + +out: + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: read %d bytes at 0x%x = %x\n", + pci_name(dev), size, offset, value); + + *ret_val = value; + return xen_pcibios_err_to_errno(err); +} + +int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value) +{ + int err = 0, handled = 0; + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + const struct config_field_entry *cfg_entry; + const struct config_field *field; + u32 tmp_val; + int field_start, field_end; + + if (unlikely(verbose_request)) + printk(KERN_DEBUG + DRV_NAME ": %s: write request %d bytes at 0x%x = %x\n", + pci_name(dev), size, offset, value); + + if (!valid_request(offset, size)) + return XEN_PCI_ERR_invalid_offset; + + list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { + field = cfg_entry->field; + + field_start = OFFSET(cfg_entry); + field_end = OFFSET(cfg_entry) + field->size; + + if (offset + size > field_start && field_end > offset) { + err = conf_space_read(dev, cfg_entry, field_start, + &tmp_val); + if (err) + break; + + tmp_val = merge_value(tmp_val, value, get_mask(size), + offset - field_start); + + err = conf_space_write(dev, cfg_entry, field_start, + tmp_val); + + /* handled is set true here, but not every byte + * may have been written! Properly detecting if + * every byte is handled is unnecessary as the + * flag is used to detect devices that need + * special helpers to work correctly. + */ + handled = 1; + } + } + + if (!handled && !err) { + /* By default, anything not specificially handled above is + * read-only. The permissive flag changes this behavior so + * that anything not specifically handled above is writable. + * This means that some fields may still be read-only because + * they have entries in the config_field list that intercept + * the write and do nothing. */ + if (dev_data->permissive || xen_pcibk_permissive) { + switch (size) { + case 1: + err = pci_write_config_byte(dev, offset, + (u8) value); + break; + case 2: + err = pci_write_config_word(dev, offset, + (u16) value); + break; + case 4: + err = pci_write_config_dword(dev, offset, + (u32) value); + break; + } + } else if (!dev_data->warned_on_write) { + dev_data->warned_on_write = 1; + dev_warn(&dev->dev, "Driver tried to write to a " + "read-only configuration space field at offset" + " 0x%x, size %d. This may be harmless, but if " + "you have problems with your device:\n" + "1) see permissive attribute in sysfs\n" + "2) report problems to the xen-devel " + "mailing list along with details of your " + "device obtained from lspci.\n", offset, size); + } + } + + return xen_pcibios_err_to_errno(err); +} + +void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev) +{ + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + struct config_field_entry *cfg_entry, *t; + const struct config_field *field; + + dev_dbg(&dev->dev, "free-ing dynamically allocated virtual " + "configuration space fields\n"); + if (!dev_data) + return; + + list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) { + field = cfg_entry->field; + + if (field->clean) { + field->clean((struct config_field *)field); + + kfree(cfg_entry->data); + + list_del(&cfg_entry->list); + kfree(cfg_entry); + } + + } +} + +void xen_pcibk_config_reset_dev(struct pci_dev *dev) +{ + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + const struct config_field_entry *cfg_entry; + const struct config_field *field; + + dev_dbg(&dev->dev, "resetting virtual configuration space\n"); + if (!dev_data) + return; + + list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { + field = cfg_entry->field; + + if (field->reset) + field->reset(dev, OFFSET(cfg_entry), cfg_entry->data); + } +} + +void xen_pcibk_config_free_dev(struct pci_dev *dev) +{ + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + struct config_field_entry *cfg_entry, *t; + const struct config_field *field; + + dev_dbg(&dev->dev, "free-ing virtual configuration space fields\n"); + if (!dev_data) + return; + + list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) { + list_del(&cfg_entry->list); + + field = cfg_entry->field; + + if (field->release) + field->release(dev, OFFSET(cfg_entry), cfg_entry->data); + + kfree(cfg_entry); + } +} + +int xen_pcibk_config_add_field_offset(struct pci_dev *dev, + const struct config_field *field, + unsigned int base_offset) +{ + int err = 0; + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + struct config_field_entry *cfg_entry; + void *tmp; + + cfg_entry = kmalloc(sizeof(*cfg_entry), GFP_KERNEL); + if (!cfg_entry) { + err = -ENOMEM; + goto out; + } + + cfg_entry->data = NULL; + cfg_entry->field = field; + cfg_entry->base_offset = base_offset; + + /* silently ignore duplicate fields */ + err = xen_pcibk_field_is_dup(dev, OFFSET(cfg_entry)); + if (err) + goto out; + + if (field->init) { + tmp = field->init(dev, OFFSET(cfg_entry)); + + if (IS_ERR(tmp)) { + err = PTR_ERR(tmp); + goto out; + } + + cfg_entry->data = tmp; + } + + dev_dbg(&dev->dev, "added config field at offset 0x%02x\n", + OFFSET(cfg_entry)); + list_add_tail(&cfg_entry->list, &dev_data->config_fields); + +out: + if (err) + kfree(cfg_entry); + + return err; +} + +/* This sets up the device's virtual configuration space to keep track of + * certain registers (like the base address registers (BARs) so that we can + * keep the client from manipulating them directly. + */ +int xen_pcibk_config_init_dev(struct pci_dev *dev) +{ + int err = 0; + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + + dev_dbg(&dev->dev, "initializing virtual configuration space\n"); + + INIT_LIST_HEAD(&dev_data->config_fields); + + err = xen_pcibk_config_header_add_fields(dev); + if (err) + goto out; + + err = xen_pcibk_config_capability_add_fields(dev); + if (err) + goto out; + + err = xen_pcibk_config_quirks_init(dev); + +out: + return err; +} + +int xen_pcibk_config_init(void) +{ + return xen_pcibk_config_capability_init(); +} diff --git a/drivers/xen/xen-pciback/conf_space.h b/drivers/xen/xen-pciback/conf_space.h new file mode 100644 index 000000000..22db63071 --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space.h @@ -0,0 +1,129 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * PCI Backend - Common data structures for overriding the configuration space + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#ifndef __XEN_PCIBACK_CONF_SPACE_H__ +#define __XEN_PCIBACK_CONF_SPACE_H__ + +#include <linux/list.h> +#include <linux/err.h> + +/* conf_field_init can return an errno in a ptr with ERR_PTR() */ +typedef void *(*conf_field_init) (struct pci_dev *dev, int offset); +typedef void (*conf_field_reset) (struct pci_dev *dev, int offset, void *data); +typedef void (*conf_field_free) (struct pci_dev *dev, int offset, void *data); + +typedef int (*conf_dword_write) (struct pci_dev *dev, int offset, u32 value, + void *data); +typedef int (*conf_word_write) (struct pci_dev *dev, int offset, u16 value, + void *data); +typedef int (*conf_byte_write) (struct pci_dev *dev, int offset, u8 value, + void *data); +typedef int (*conf_dword_read) (struct pci_dev *dev, int offset, u32 *value, + void *data); +typedef int (*conf_word_read) (struct pci_dev *dev, int offset, u16 *value, + void *data); +typedef int (*conf_byte_read) (struct pci_dev *dev, int offset, u8 *value, + void *data); + +/* These are the fields within the configuration space which we + * are interested in intercepting reads/writes to and changing their + * values. + */ +struct config_field { + unsigned int offset; + unsigned int size; + unsigned int mask; + conf_field_init init; + conf_field_reset reset; + conf_field_free release; + void (*clean) (struct config_field *field); + union { + struct { + conf_dword_write write; + conf_dword_read read; + } dw; + struct { + conf_word_write write; + conf_word_read read; + } w; + struct { + conf_byte_write write; + conf_byte_read read; + } b; + } u; + struct list_head list; +}; + +struct config_field_entry { + struct list_head list; + const struct config_field *field; + unsigned int base_offset; + void *data; +}; + +extern bool xen_pcibk_permissive; + +#define OFFSET(cfg_entry) ((cfg_entry)->base_offset+(cfg_entry)->field->offset) + +/* Add fields to a device - the add_fields macro expects to get a pointer to + * the first entry in an array (of which the ending is marked by size==0) + */ +int xen_pcibk_config_add_field_offset(struct pci_dev *dev, + const struct config_field *field, + unsigned int offset); + +static inline int xen_pcibk_config_add_field(struct pci_dev *dev, + const struct config_field *field) +{ + return xen_pcibk_config_add_field_offset(dev, field, 0); +} + +static inline int xen_pcibk_config_add_fields(struct pci_dev *dev, + const struct config_field *field) +{ + int i, err = 0; + for (i = 0; field[i].size != 0; i++) { + err = xen_pcibk_config_add_field(dev, &field[i]); + if (err) + break; + } + return err; +} + +static inline int xen_pcibk_config_add_fields_offset(struct pci_dev *dev, + const struct config_field *field, + unsigned int offset) +{ + int i, err = 0; + for (i = 0; field[i].size != 0; i++) { + err = xen_pcibk_config_add_field_offset(dev, &field[i], offset); + if (err) + break; + } + return err; +} + +/* Read/Write the real configuration space */ +int xen_pcibk_read_config_byte(struct pci_dev *dev, int offset, u8 *value, + void *data); +int xen_pcibk_read_config_word(struct pci_dev *dev, int offset, u16 *value, + void *data); +int xen_pcibk_read_config_dword(struct pci_dev *dev, int offset, u32 *value, + void *data); +int xen_pcibk_write_config_byte(struct pci_dev *dev, int offset, u8 value, + void *data); +int xen_pcibk_write_config_word(struct pci_dev *dev, int offset, u16 value, + void *data); +int xen_pcibk_write_config_dword(struct pci_dev *dev, int offset, u32 value, + void *data); + +int xen_pcibk_config_capability_init(void); + +int xen_pcibk_config_header_add_fields(struct pci_dev *dev); +int xen_pcibk_config_capability_add_fields(struct pci_dev *dev); + +#endif /* __XEN_PCIBACK_CONF_SPACE_H__ */ diff --git a/drivers/xen/xen-pciback/conf_space_capability.c b/drivers/xen/xen-pciback/conf_space_capability.c new file mode 100644 index 000000000..42f0f64fc --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space_capability.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend - Handles the virtual fields found on the capability lists + * in the configuration space. + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include "pciback.h" +#include "conf_space.h" + +static LIST_HEAD(capabilities); +struct xen_pcibk_config_capability { + struct list_head cap_list; + + int capability; + + /* If the device has the capability found above, add these fields */ + const struct config_field *fields; +}; + +static const struct config_field caplist_header[] = { + { + .offset = PCI_CAP_LIST_ID, + .size = 2, /* encompass PCI_CAP_LIST_ID & PCI_CAP_LIST_NEXT */ + .u.w.read = xen_pcibk_read_config_word, + .u.w.write = NULL, + }, + {} +}; + +static inline void register_capability(struct xen_pcibk_config_capability *cap) +{ + list_add_tail(&cap->cap_list, &capabilities); +} + +int xen_pcibk_config_capability_add_fields(struct pci_dev *dev) +{ + int err = 0; + struct xen_pcibk_config_capability *cap; + int cap_offset; + + list_for_each_entry(cap, &capabilities, cap_list) { + cap_offset = pci_find_capability(dev, cap->capability); + if (cap_offset) { + dev_dbg(&dev->dev, "Found capability 0x%x at 0x%x\n", + cap->capability, cap_offset); + + err = xen_pcibk_config_add_fields_offset(dev, + caplist_header, + cap_offset); + if (err) + goto out; + err = xen_pcibk_config_add_fields_offset(dev, + cap->fields, + cap_offset); + if (err) + goto out; + } + } + +out: + return err; +} + +static int vpd_address_write(struct pci_dev *dev, int offset, u16 value, + void *data) +{ + /* Disallow writes to the vital product data */ + if (value & PCI_VPD_ADDR_F) + return PCIBIOS_SET_FAILED; + else + return pci_write_config_word(dev, offset, value); +} + +static const struct config_field caplist_vpd[] = { + { + .offset = PCI_VPD_ADDR, + .size = 2, + .u.w.read = xen_pcibk_read_config_word, + .u.w.write = vpd_address_write, + }, + { + .offset = PCI_VPD_DATA, + .size = 4, + .u.dw.read = xen_pcibk_read_config_dword, + .u.dw.write = NULL, + }, + {} +}; + +static int pm_caps_read(struct pci_dev *dev, int offset, u16 *value, + void *data) +{ + int err; + u16 real_value; + + err = pci_read_config_word(dev, offset, &real_value); + if (err) + goto out; + + *value = real_value & ~PCI_PM_CAP_PME_MASK; + +out: + return err; +} + +/* PM_OK_BITS specifies the bits that the driver domain is allowed to change. + * Can't allow driver domain to enable PMEs - they're shared */ +#define PM_OK_BITS (PCI_PM_CTRL_PME_STATUS|PCI_PM_CTRL_DATA_SEL_MASK) + +static int pm_ctrl_write(struct pci_dev *dev, int offset, u16 new_value, + void *data) +{ + int err; + u16 old_value; + pci_power_t new_state; + + err = pci_read_config_word(dev, offset, &old_value); + if (err) + goto out; + + new_state = (pci_power_t)(new_value & PCI_PM_CTRL_STATE_MASK); + + new_value &= PM_OK_BITS; + if ((old_value & PM_OK_BITS) != new_value) { + new_value = (old_value & ~PM_OK_BITS) | new_value; + err = pci_write_config_word(dev, offset, new_value); + if (err) + goto out; + } + + /* Let pci core handle the power management change */ + dev_dbg(&dev->dev, "set power state to %x\n", new_state); + err = pci_set_power_state(dev, new_state); + if (err) { + err = PCIBIOS_SET_FAILED; + goto out; + } + + out: + return err; +} + +/* Ensure PMEs are disabled */ +static void *pm_ctrl_init(struct pci_dev *dev, int offset) +{ + int err; + u16 value; + + err = pci_read_config_word(dev, offset, &value); + if (err) + goto out; + + if (value & PCI_PM_CTRL_PME_ENABLE) { + value &= ~PCI_PM_CTRL_PME_ENABLE; + err = pci_write_config_word(dev, offset, value); + } + +out: + return err ? ERR_PTR(err) : NULL; +} + +static const struct config_field caplist_pm[] = { + { + .offset = PCI_PM_PMC, + .size = 2, + .u.w.read = pm_caps_read, + }, + { + .offset = PCI_PM_CTRL, + .size = 2, + .init = pm_ctrl_init, + .u.w.read = xen_pcibk_read_config_word, + .u.w.write = pm_ctrl_write, + }, + { + .offset = PCI_PM_PPB_EXTENSIONS, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + }, + { + .offset = PCI_PM_DATA_REGISTER, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + }, + {} +}; + +static struct xen_pcibk_config_capability xen_pcibk_config_capability_pm = { + .capability = PCI_CAP_ID_PM, + .fields = caplist_pm, +}; +static struct xen_pcibk_config_capability xen_pcibk_config_capability_vpd = { + .capability = PCI_CAP_ID_VPD, + .fields = caplist_vpd, +}; + +int xen_pcibk_config_capability_init(void) +{ + register_capability(&xen_pcibk_config_capability_vpd); + register_capability(&xen_pcibk_config_capability_pm); + + return 0; +} diff --git a/drivers/xen/xen-pciback/conf_space_header.c b/drivers/xen/xen-pciback/conf_space_header.c new file mode 100644 index 000000000..10ae24b5a --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space_header.c @@ -0,0 +1,424 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend - Handles the virtual fields in the configuration space headers. + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/pci.h> +#include "pciback.h" +#include "conf_space.h" + +struct pci_cmd_info { + u16 val; +}; + +struct pci_bar_info { + u32 val; + u32 len_val; + int which; +}; + +#define is_enable_cmd(value) ((value)&(PCI_COMMAND_MEMORY|PCI_COMMAND_IO)) +#define is_master_cmd(value) ((value)&PCI_COMMAND_MASTER) + +/* Bits guests are allowed to control in permissive mode. */ +#define PCI_COMMAND_GUEST (PCI_COMMAND_MASTER|PCI_COMMAND_SPECIAL| \ + PCI_COMMAND_INVALIDATE|PCI_COMMAND_VGA_PALETTE| \ + PCI_COMMAND_WAIT|PCI_COMMAND_FAST_BACK) + +static void *command_init(struct pci_dev *dev, int offset) +{ + struct pci_cmd_info *cmd = kmalloc(sizeof(*cmd), GFP_KERNEL); + int err; + + if (!cmd) + return ERR_PTR(-ENOMEM); + + err = pci_read_config_word(dev, PCI_COMMAND, &cmd->val); + if (err) { + kfree(cmd); + return ERR_PTR(err); + } + + return cmd; +} + +static int command_read(struct pci_dev *dev, int offset, u16 *value, void *data) +{ + int ret = pci_read_config_word(dev, offset, value); + const struct pci_cmd_info *cmd = data; + + *value &= PCI_COMMAND_GUEST; + *value |= cmd->val & ~PCI_COMMAND_GUEST; + + return ret; +} + +static int command_write(struct pci_dev *dev, int offset, u16 value, void *data) +{ + struct xen_pcibk_dev_data *dev_data; + int err; + u16 val; + struct pci_cmd_info *cmd = data; + + dev_data = pci_get_drvdata(dev); + if (!pci_is_enabled(dev) && is_enable_cmd(value)) { + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: enable\n", + pci_name(dev)); + err = pci_enable_device(dev); + if (err) + return err; + if (dev_data) + dev_data->enable_intx = 1; + } else if (pci_is_enabled(dev) && !is_enable_cmd(value)) { + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: disable\n", + pci_name(dev)); + pci_disable_device(dev); + if (dev_data) + dev_data->enable_intx = 0; + } + + if (!dev->is_busmaster && is_master_cmd(value)) { + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: set bus master\n", + pci_name(dev)); + pci_set_master(dev); + } else if (dev->is_busmaster && !is_master_cmd(value)) { + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: clear bus master\n", + pci_name(dev)); + pci_clear_master(dev); + } + + if (!(cmd->val & PCI_COMMAND_INVALIDATE) && + (value & PCI_COMMAND_INVALIDATE)) { + if (unlikely(verbose_request)) + printk(KERN_DEBUG + DRV_NAME ": %s: enable memory-write-invalidate\n", + pci_name(dev)); + err = pci_set_mwi(dev); + if (err) { + pr_warn("%s: cannot enable memory-write-invalidate (%d)\n", + pci_name(dev), err); + value &= ~PCI_COMMAND_INVALIDATE; + } + } else if ((cmd->val & PCI_COMMAND_INVALIDATE) && + !(value & PCI_COMMAND_INVALIDATE)) { + if (unlikely(verbose_request)) + printk(KERN_DEBUG + DRV_NAME ": %s: disable memory-write-invalidate\n", + pci_name(dev)); + pci_clear_mwi(dev); + } + + cmd->val = value; + + if (!xen_pcibk_permissive && (!dev_data || !dev_data->permissive)) + return 0; + + /* Only allow the guest to control certain bits. */ + err = pci_read_config_word(dev, offset, &val); + if (err || val == value) + return err; + + value &= PCI_COMMAND_GUEST; + value |= val & ~PCI_COMMAND_GUEST; + + return pci_write_config_word(dev, offset, value); +} + +static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data) +{ + struct pci_bar_info *bar = data; + + if (unlikely(!bar)) { + pr_warn(DRV_NAME ": driver data not found for %s\n", + pci_name(dev)); + return XEN_PCI_ERR_op_failed; + } + + /* A write to obtain the length must happen as a 32-bit write. + * This does not (yet) support writing individual bytes + */ + if ((value | ~PCI_ROM_ADDRESS_MASK) == ~0U) + bar->which = 1; + else { + u32 tmpval; + pci_read_config_dword(dev, offset, &tmpval); + if (tmpval != bar->val && value == bar->val) { + /* Allow restoration of bar value. */ + pci_write_config_dword(dev, offset, bar->val); + } + bar->which = 0; + } + + /* Do we need to support enabling/disabling the rom address here? */ + + return 0; +} + +/* For the BARs, only allow writes which write ~0 or + * the correct resource information + * (Needed for when the driver probes the resource usage) + */ +static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data) +{ + struct pci_bar_info *bar = data; + unsigned int pos = (offset - PCI_BASE_ADDRESS_0) / 4; + const struct resource *res = dev->resource; + u32 mask; + + if (unlikely(!bar)) { + pr_warn(DRV_NAME ": driver data not found for %s\n", + pci_name(dev)); + return XEN_PCI_ERR_op_failed; + } + + /* A write to obtain the length must happen as a 32-bit write. + * This does not (yet) support writing individual bytes + */ + if (res[pos].flags & IORESOURCE_IO) + mask = ~PCI_BASE_ADDRESS_IO_MASK; + else if (pos && (res[pos - 1].flags & IORESOURCE_MEM_64)) + mask = 0; + else + mask = ~PCI_BASE_ADDRESS_MEM_MASK; + if ((value | mask) == ~0U) + bar->which = 1; + else { + u32 tmpval; + pci_read_config_dword(dev, offset, &tmpval); + if (tmpval != bar->val && value == bar->val) { + /* Allow restoration of bar value. */ + pci_write_config_dword(dev, offset, bar->val); + } + bar->which = 0; + } + + return 0; +} + +static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data) +{ + struct pci_bar_info *bar = data; + + if (unlikely(!bar)) { + pr_warn(DRV_NAME ": driver data not found for %s\n", + pci_name(dev)); + return XEN_PCI_ERR_op_failed; + } + + *value = bar->which ? bar->len_val : bar->val; + + return 0; +} + +static void *bar_init(struct pci_dev *dev, int offset) +{ + unsigned int pos; + const struct resource *res = dev->resource; + struct pci_bar_info *bar = kzalloc(sizeof(*bar), GFP_KERNEL); + + if (!bar) + return ERR_PTR(-ENOMEM); + + if (offset == PCI_ROM_ADDRESS || offset == PCI_ROM_ADDRESS1) + pos = PCI_ROM_RESOURCE; + else { + pos = (offset - PCI_BASE_ADDRESS_0) / 4; + if (pos && (res[pos - 1].flags & IORESOURCE_MEM_64)) { + bar->val = res[pos - 1].start >> 32; + bar->len_val = -resource_size(&res[pos - 1]) >> 32; + return bar; + } + } + + if (!res[pos].flags || + (res[pos].flags & (IORESOURCE_DISABLED | IORESOURCE_UNSET | + IORESOURCE_BUSY))) + return bar; + + bar->val = res[pos].start | + (res[pos].flags & PCI_REGION_FLAG_MASK); + bar->len_val = -resource_size(&res[pos]) | + (res[pos].flags & PCI_REGION_FLAG_MASK); + + return bar; +} + +static void bar_reset(struct pci_dev *dev, int offset, void *data) +{ + struct pci_bar_info *bar = data; + + bar->which = 0; +} + +static void bar_release(struct pci_dev *dev, int offset, void *data) +{ + kfree(data); +} + +static int xen_pcibk_read_vendor(struct pci_dev *dev, int offset, + u16 *value, void *data) +{ + *value = dev->vendor; + + return 0; +} + +static int xen_pcibk_read_device(struct pci_dev *dev, int offset, + u16 *value, void *data) +{ + *value = dev->device; + + return 0; +} + +static int interrupt_read(struct pci_dev *dev, int offset, u8 * value, + void *data) +{ + *value = (u8) dev->irq; + + return 0; +} + +static int bist_write(struct pci_dev *dev, int offset, u8 value, void *data) +{ + u8 cur_value; + int err; + + err = pci_read_config_byte(dev, offset, &cur_value); + if (err) + goto out; + + if ((cur_value & ~PCI_BIST_START) == (value & ~PCI_BIST_START) + || value == PCI_BIST_START) + err = pci_write_config_byte(dev, offset, value); + +out: + return err; +} + +static const struct config_field header_common[] = { + { + .offset = PCI_VENDOR_ID, + .size = 2, + .u.w.read = xen_pcibk_read_vendor, + }, + { + .offset = PCI_DEVICE_ID, + .size = 2, + .u.w.read = xen_pcibk_read_device, + }, + { + .offset = PCI_COMMAND, + .size = 2, + .init = command_init, + .release = bar_release, + .u.w.read = command_read, + .u.w.write = command_write, + }, + { + .offset = PCI_INTERRUPT_LINE, + .size = 1, + .u.b.read = interrupt_read, + }, + { + .offset = PCI_INTERRUPT_PIN, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + }, + { + /* Any side effects of letting driver domain control cache line? */ + .offset = PCI_CACHE_LINE_SIZE, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + .u.b.write = xen_pcibk_write_config_byte, + }, + { + .offset = PCI_LATENCY_TIMER, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + }, + { + .offset = PCI_BIST, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + .u.b.write = bist_write, + }, + {} +}; + +#define CFG_FIELD_BAR(reg_offset) \ + { \ + .offset = reg_offset, \ + .size = 4, \ + .init = bar_init, \ + .reset = bar_reset, \ + .release = bar_release, \ + .u.dw.read = bar_read, \ + .u.dw.write = bar_write, \ + } + +#define CFG_FIELD_ROM(reg_offset) \ + { \ + .offset = reg_offset, \ + .size = 4, \ + .init = bar_init, \ + .reset = bar_reset, \ + .release = bar_release, \ + .u.dw.read = bar_read, \ + .u.dw.write = rom_write, \ + } + +static const struct config_field header_0[] = { + CFG_FIELD_BAR(PCI_BASE_ADDRESS_0), + CFG_FIELD_BAR(PCI_BASE_ADDRESS_1), + CFG_FIELD_BAR(PCI_BASE_ADDRESS_2), + CFG_FIELD_BAR(PCI_BASE_ADDRESS_3), + CFG_FIELD_BAR(PCI_BASE_ADDRESS_4), + CFG_FIELD_BAR(PCI_BASE_ADDRESS_5), + CFG_FIELD_ROM(PCI_ROM_ADDRESS), + {} +}; + +static const struct config_field header_1[] = { + CFG_FIELD_BAR(PCI_BASE_ADDRESS_0), + CFG_FIELD_BAR(PCI_BASE_ADDRESS_1), + CFG_FIELD_ROM(PCI_ROM_ADDRESS1), + {} +}; + +int xen_pcibk_config_header_add_fields(struct pci_dev *dev) +{ + int err; + + err = xen_pcibk_config_add_fields(dev, header_common); + if (err) + goto out; + + switch (dev->hdr_type) { + case PCI_HEADER_TYPE_NORMAL: + err = xen_pcibk_config_add_fields(dev, header_0); + break; + + case PCI_HEADER_TYPE_BRIDGE: + err = xen_pcibk_config_add_fields(dev, header_1); + break; + + default: + err = -EINVAL; + pr_err("%s: Unsupported header type %d!\n", + pci_name(dev), dev->hdr_type); + break; + } + +out: + return err; +} diff --git a/drivers/xen/xen-pciback/conf_space_quirks.c b/drivers/xen/xen-pciback/conf_space_quirks.c new file mode 100644 index 000000000..ed593d104 --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space_quirks.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend - Handle special overlays for broken devices. + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + * Author: Chris Bookholt <hap10@epoch.ncsc.mil> + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include "pciback.h" +#include "conf_space.h" +#include "conf_space_quirks.h" + +LIST_HEAD(xen_pcibk_quirks); +static inline const struct pci_device_id * +match_one_device(const struct pci_device_id *id, const struct pci_dev *dev) +{ + if ((id->vendor == PCI_ANY_ID || id->vendor == dev->vendor) && + (id->device == PCI_ANY_ID || id->device == dev->device) && + (id->subvendor == PCI_ANY_ID || + id->subvendor == dev->subsystem_vendor) && + (id->subdevice == PCI_ANY_ID || + id->subdevice == dev->subsystem_device) && + !((id->class ^ dev->class) & id->class_mask)) + return id; + return NULL; +} + +static struct xen_pcibk_config_quirk *xen_pcibk_find_quirk(struct pci_dev *dev) +{ + struct xen_pcibk_config_quirk *tmp_quirk; + + list_for_each_entry(tmp_quirk, &xen_pcibk_quirks, quirks_list) + if (match_one_device(&tmp_quirk->devid, dev) != NULL) + goto out; + tmp_quirk = NULL; + printk(KERN_DEBUG DRV_NAME + ": quirk didn't match any device known\n"); +out: + return tmp_quirk; +} + +static inline void register_quirk(struct xen_pcibk_config_quirk *quirk) +{ + list_add_tail(&quirk->quirks_list, &xen_pcibk_quirks); +} + +int xen_pcibk_field_is_dup(struct pci_dev *dev, unsigned int reg) +{ + int ret = 0; + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + struct config_field_entry *cfg_entry; + + list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { + if (OFFSET(cfg_entry) == reg) { + ret = 1; + break; + } + } + return ret; +} + +int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field + *field) +{ + int err = 0; + + switch (field->size) { + case 1: + field->u.b.read = xen_pcibk_read_config_byte; + field->u.b.write = xen_pcibk_write_config_byte; + break; + case 2: + field->u.w.read = xen_pcibk_read_config_word; + field->u.w.write = xen_pcibk_write_config_word; + break; + case 4: + field->u.dw.read = xen_pcibk_read_config_dword; + field->u.dw.write = xen_pcibk_write_config_dword; + break; + default: + err = -EINVAL; + goto out; + } + + xen_pcibk_config_add_field(dev, field); + +out: + return err; +} + +int xen_pcibk_config_quirks_init(struct pci_dev *dev) +{ + struct xen_pcibk_config_quirk *quirk; + int ret = 0; + + quirk = kzalloc(sizeof(*quirk), GFP_KERNEL); + if (!quirk) { + ret = -ENOMEM; + goto out; + } + + quirk->devid.vendor = dev->vendor; + quirk->devid.device = dev->device; + quirk->devid.subvendor = dev->subsystem_vendor; + quirk->devid.subdevice = dev->subsystem_device; + quirk->devid.class = 0; + quirk->devid.class_mask = 0; + quirk->devid.driver_data = 0UL; + + quirk->pdev = dev; + + register_quirk(quirk); +out: + return ret; +} + +void xen_pcibk_config_field_free(struct config_field *field) +{ + kfree(field); +} + +int xen_pcibk_config_quirk_release(struct pci_dev *dev) +{ + struct xen_pcibk_config_quirk *quirk; + int ret = 0; + + quirk = xen_pcibk_find_quirk(dev); + if (!quirk) { + ret = -ENXIO; + goto out; + } + + list_del(&quirk->quirks_list); + kfree(quirk); + +out: + return ret; +} diff --git a/drivers/xen/xen-pciback/conf_space_quirks.h b/drivers/xen/xen-pciback/conf_space_quirks.h new file mode 100644 index 000000000..d873abe35 --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space_quirks.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * PCI Backend - Data structures for special overlays for broken devices. + * + * Ryan Wilson <hap9@epoch.ncsc.mil> + * Chris Bookholt <hap10@epoch.ncsc.mil> + */ + +#ifndef __XEN_PCIBACK_CONF_SPACE_QUIRKS_H__ +#define __XEN_PCIBACK_CONF_SPACE_QUIRKS_H__ + +#include <linux/pci.h> +#include <linux/list.h> + +struct xen_pcibk_config_quirk { + struct list_head quirks_list; + struct pci_device_id devid; + struct pci_dev *pdev; +}; + +int xen_pcibk_config_quirks_add_field(struct pci_dev *dev, struct config_field + *field); + +int xen_pcibk_config_quirks_remove_field(struct pci_dev *dev, int reg); + +int xen_pcibk_config_quirks_init(struct pci_dev *dev); + +void xen_pcibk_config_field_free(struct config_field *field); + +int xen_pcibk_config_quirk_release(struct pci_dev *dev); + +int xen_pcibk_field_is_dup(struct pci_dev *dev, unsigned int reg); + +#endif diff --git a/drivers/xen/xen-pciback/passthrough.c b/drivers/xen/xen-pciback/passthrough.c new file mode 100644 index 000000000..66e9b814c --- /dev/null +++ b/drivers/xen/xen-pciback/passthrough.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend - Provides restricted access to the real PCI bus topology + * to the frontend + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#include <linux/list.h> +#include <linux/pci.h> +#include <linux/mutex.h> +#include "pciback.h" + +struct passthrough_dev_data { + /* Access to dev_list must be protected by lock */ + struct list_head dev_list; + struct mutex lock; +}; + +static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, + unsigned int domain, + unsigned int bus, + unsigned int devfn) +{ + struct passthrough_dev_data *dev_data = pdev->pci_dev_data; + struct pci_dev_entry *dev_entry; + struct pci_dev *dev = NULL; + + mutex_lock(&dev_data->lock); + + list_for_each_entry(dev_entry, &dev_data->dev_list, list) { + if (domain == (unsigned int)pci_domain_nr(dev_entry->dev->bus) + && bus == (unsigned int)dev_entry->dev->bus->number + && devfn == dev_entry->dev->devfn) { + dev = dev_entry->dev; + break; + } + } + + mutex_unlock(&dev_data->lock); + + return dev; +} + +static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev, + int devid, publish_pci_dev_cb publish_cb) +{ + struct passthrough_dev_data *dev_data = pdev->pci_dev_data; + struct pci_dev_entry *dev_entry; + unsigned int domain, bus, devfn; + int err; + + dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL); + if (!dev_entry) + return -ENOMEM; + dev_entry->dev = dev; + + mutex_lock(&dev_data->lock); + list_add_tail(&dev_entry->list, &dev_data->dev_list); + mutex_unlock(&dev_data->lock); + + /* Publish this device. */ + domain = (unsigned int)pci_domain_nr(dev->bus); + bus = (unsigned int)dev->bus->number; + devfn = dev->devfn; + err = publish_cb(pdev, domain, bus, devfn, devid); + + return err; +} + +static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev, bool lock) +{ + struct passthrough_dev_data *dev_data = pdev->pci_dev_data; + struct pci_dev_entry *dev_entry, *t; + struct pci_dev *found_dev = NULL; + + mutex_lock(&dev_data->lock); + + list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) { + if (dev_entry->dev == dev) { + list_del(&dev_entry->list); + found_dev = dev_entry->dev; + kfree(dev_entry); + } + } + + mutex_unlock(&dev_data->lock); + + if (found_dev) { + if (lock) + device_lock(&found_dev->dev); + pcistub_put_pci_dev(found_dev); + if (lock) + device_unlock(&found_dev->dev); + } +} + +static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev) +{ + struct passthrough_dev_data *dev_data; + + dev_data = kmalloc(sizeof(*dev_data), GFP_KERNEL); + if (!dev_data) + return -ENOMEM; + + mutex_init(&dev_data->lock); + + INIT_LIST_HEAD(&dev_data->dev_list); + + pdev->pci_dev_data = dev_data; + + return 0; +} + +static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev, + publish_pci_root_cb publish_root_cb) +{ + int err = 0; + struct passthrough_dev_data *dev_data = pdev->pci_dev_data; + struct pci_dev_entry *dev_entry, *e; + struct pci_dev *dev; + int found; + unsigned int domain, bus; + + mutex_lock(&dev_data->lock); + + list_for_each_entry(dev_entry, &dev_data->dev_list, list) { + /* Only publish this device as a root if none of its + * parent bridges are exported + */ + found = 0; + dev = dev_entry->dev->bus->self; + for (; !found && dev != NULL; dev = dev->bus->self) { + list_for_each_entry(e, &dev_data->dev_list, list) { + if (dev == e->dev) { + found = 1; + break; + } + } + } + + domain = (unsigned int)pci_domain_nr(dev_entry->dev->bus); + bus = (unsigned int)dev_entry->dev->bus->number; + + if (!found) { + err = publish_root_cb(pdev, domain, bus); + if (err) + break; + } + } + + mutex_unlock(&dev_data->lock); + + return err; +} + +static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev) +{ + struct passthrough_dev_data *dev_data = pdev->pci_dev_data; + struct pci_dev_entry *dev_entry, *t; + + list_for_each_entry_safe(dev_entry, t, &dev_data->dev_list, list) { + struct pci_dev *dev = dev_entry->dev; + list_del(&dev_entry->list); + device_lock(&dev->dev); + pcistub_put_pci_dev(dev); + device_unlock(&dev->dev); + kfree(dev_entry); + } + + kfree(dev_data); + pdev->pci_dev_data = NULL; +} + +static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev, + struct xen_pcibk_device *pdev, + unsigned int *domain, unsigned int *bus, + unsigned int *devfn) +{ + *domain = pci_domain_nr(pcidev->bus); + *bus = pcidev->bus->number; + *devfn = pcidev->devfn; + return 1; +} + +const struct xen_pcibk_backend xen_pcibk_passthrough_backend = { + .name = "passthrough", + .init = __xen_pcibk_init_devices, + .free = __xen_pcibk_release_devices, + .find = __xen_pcibk_get_pcifront_dev, + .publish = __xen_pcibk_publish_pci_roots, + .release = __xen_pcibk_release_pci_dev, + .add = __xen_pcibk_add_pci_dev, + .get = __xen_pcibk_get_pci_dev, +}; diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c new file mode 100644 index 000000000..adf3aae29 --- /dev/null +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -0,0 +1,1652 @@ +/* + * PCI Stub Driver - Grabs devices in backend to be exported later + * + * Ryan Wilson <hap9@epoch.ncsc.mil> + * Chris Bookholt <hap10@epoch.ncsc.mil> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/rwsem.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/kref.h> +#include <linux/pci.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/atomic.h> +#include <xen/events.h> +#include <asm/xen/pci.h> +#include <asm/xen/hypervisor.h> +#include <xen/interface/physdev.h> +#include "pciback.h" +#include "conf_space.h" +#include "conf_space_quirks.h" + +#define PCISTUB_DRIVER_NAME "pciback" + +static char *pci_devs_to_hide; +wait_queue_head_t xen_pcibk_aer_wait_queue; +/*Add sem for sync AER handling and xen_pcibk remove/reconfigue ops, +* We want to avoid in middle of AER ops, xen_pcibk devices is being removed +*/ +static DECLARE_RWSEM(pcistub_sem); +module_param_named(hide, pci_devs_to_hide, charp, 0444); + +struct pcistub_device_id { + struct list_head slot_list; + int domain; + unsigned char bus; + unsigned int devfn; +}; +static LIST_HEAD(pcistub_device_ids); +static DEFINE_SPINLOCK(device_ids_lock); + +struct pcistub_device { + struct kref kref; + struct list_head dev_list; + spinlock_t lock; + + struct pci_dev *dev; + struct xen_pcibk_device *pdev;/* non-NULL if struct pci_dev is in use */ +}; + +/* Access to pcistub_devices & seized_devices lists and the initialize_devices + * flag must be locked with pcistub_devices_lock + */ +static DEFINE_SPINLOCK(pcistub_devices_lock); +static LIST_HEAD(pcistub_devices); + +/* wait for device_initcall before initializing our devices + * (see pcistub_init_devices_late) + */ +static int initialize_devices; +static LIST_HEAD(seized_devices); + +static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev) +{ + struct pcistub_device *psdev; + + dev_dbg(&dev->dev, "pcistub_device_alloc\n"); + + psdev = kzalloc(sizeof(*psdev), GFP_KERNEL); + if (!psdev) + return NULL; + + psdev->dev = pci_dev_get(dev); + if (!psdev->dev) { + kfree(psdev); + return NULL; + } + + kref_init(&psdev->kref); + spin_lock_init(&psdev->lock); + + return psdev; +} + +/* Don't call this directly as it's called by pcistub_device_put */ +static void pcistub_device_release(struct kref *kref) +{ + struct pcistub_device *psdev; + struct pci_dev *dev; + struct xen_pcibk_dev_data *dev_data; + + psdev = container_of(kref, struct pcistub_device, kref); + dev = psdev->dev; + dev_data = pci_get_drvdata(dev); + + dev_dbg(&dev->dev, "pcistub_device_release\n"); + + xen_unregister_device_domain_owner(dev); + + /* Call the reset function which does not take lock as this + * is called from "unbind" which takes a device_lock mutex. + */ + __pci_reset_function_locked(dev); + if (dev_data && + pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state)) + dev_info(&dev->dev, "Could not reload PCI state\n"); + else + pci_restore_state(dev); + + if (dev->msix_cap) { + struct physdev_pci_device ppdev = { + .seg = pci_domain_nr(dev->bus), + .bus = dev->bus->number, + .devfn = dev->devfn + }; + int err = HYPERVISOR_physdev_op(PHYSDEVOP_release_msix, + &ppdev); + + if (err && err != -ENOSYS) + dev_warn(&dev->dev, "MSI-X release failed (%d)\n", + err); + } + + /* Disable the device */ + xen_pcibk_reset_device(dev); + + kfree(dev_data); + pci_set_drvdata(dev, NULL); + + /* Clean-up the device */ + xen_pcibk_config_free_dyn_fields(dev); + xen_pcibk_config_free_dev(dev); + + pci_clear_dev_assigned(dev); + pci_dev_put(dev); + + kfree(psdev); +} + +static inline void pcistub_device_get(struct pcistub_device *psdev) +{ + kref_get(&psdev->kref); +} + +static inline void pcistub_device_put(struct pcistub_device *psdev) +{ + kref_put(&psdev->kref, pcistub_device_release); +} + +static struct pcistub_device *pcistub_device_find_locked(int domain, int bus, + int slot, int func) +{ + struct pcistub_device *psdev; + + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (psdev->dev != NULL + && domain == pci_domain_nr(psdev->dev->bus) + && bus == psdev->dev->bus->number + && slot == PCI_SLOT(psdev->dev->devfn) + && func == PCI_FUNC(psdev->dev->devfn)) { + return psdev; + } + } + + return NULL; +} + +static struct pcistub_device *pcistub_device_find(int domain, int bus, + int slot, int func) +{ + struct pcistub_device *psdev; + unsigned long flags; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + psdev = pcistub_device_find_locked(domain, bus, slot, func); + if (psdev) + pcistub_device_get(psdev); + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + return psdev; +} + +static struct pci_dev *pcistub_device_get_pci_dev(struct xen_pcibk_device *pdev, + struct pcistub_device *psdev) +{ + struct pci_dev *pci_dev = NULL; + unsigned long flags; + + pcistub_device_get(psdev); + + spin_lock_irqsave(&psdev->lock, flags); + if (!psdev->pdev) { + psdev->pdev = pdev; + pci_dev = psdev->dev; + } + spin_unlock_irqrestore(&psdev->lock, flags); + + if (!pci_dev) + pcistub_device_put(psdev); + + return pci_dev; +} + +struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev, + int domain, int bus, + int slot, int func) +{ + struct pcistub_device *psdev; + struct pci_dev *found_dev = NULL; + unsigned long flags; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + psdev = pcistub_device_find_locked(domain, bus, slot, func); + if (psdev) + found_dev = pcistub_device_get_pci_dev(pdev, psdev); + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + return found_dev; +} + +struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev) +{ + struct pcistub_device *psdev; + struct pci_dev *found_dev = NULL; + unsigned long flags; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (psdev->dev == dev) { + found_dev = pcistub_device_get_pci_dev(pdev, psdev); + break; + } + } + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + return found_dev; +} + +/* + * Called when: + * - XenBus state has been reconfigure (pci unplug). See xen_pcibk_remove_device + * - XenBus state has been disconnected (guest shutdown). See xen_pcibk_xenbus_remove + * - 'echo BDF > unbind' on pciback module with no guest attached. See pcistub_remove + * - 'echo BDF > unbind' with a guest still using it. See pcistub_remove + * + * As such we have to be careful. + * + * To make this easier, the caller has to hold the device lock. + */ +void pcistub_put_pci_dev(struct pci_dev *dev) +{ + struct pcistub_device *psdev, *found_psdev = NULL; + unsigned long flags; + struct xen_pcibk_dev_data *dev_data; + int ret; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (psdev->dev == dev) { + found_psdev = psdev; + break; + } + } + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + if (WARN_ON(!found_psdev)) + return; + + /*hold this lock for avoiding breaking link between + * pcistub and xen_pcibk when AER is in processing + */ + down_write(&pcistub_sem); + /* Cleanup our device + * (so it's ready for the next domain) + */ + device_lock_assert(&dev->dev); + __pci_reset_function_locked(dev); + + dev_data = pci_get_drvdata(dev); + ret = pci_load_saved_state(dev, dev_data->pci_saved_state); + if (!ret) { + /* + * The usual sequence is pci_save_state & pci_restore_state + * but the guest might have messed the configuration space up. + * Use the initial version (when device was bound to us). + */ + pci_restore_state(dev); + } else + dev_info(&dev->dev, "Could not reload PCI state\n"); + /* This disables the device. */ + xen_pcibk_reset_device(dev); + + /* And cleanup up our emulated fields. */ + xen_pcibk_config_reset_dev(dev); + xen_pcibk_config_free_dyn_fields(dev); + + xen_unregister_device_domain_owner(dev); + + spin_lock_irqsave(&found_psdev->lock, flags); + found_psdev->pdev = NULL; + spin_unlock_irqrestore(&found_psdev->lock, flags); + + pcistub_device_put(found_psdev); + up_write(&pcistub_sem); +} + +static int pcistub_match_one(struct pci_dev *dev, + struct pcistub_device_id *pdev_id) +{ + /* Match the specified device by domain, bus, slot, func and also if + * any of the device's parent bridges match. + */ + for (; dev != NULL; dev = dev->bus->self) { + if (pci_domain_nr(dev->bus) == pdev_id->domain + && dev->bus->number == pdev_id->bus + && dev->devfn == pdev_id->devfn) + return 1; + + /* Sometimes topmost bridge links to itself. */ + if (dev == dev->bus->self) + break; + } + + return 0; +} + +static int pcistub_match(struct pci_dev *dev) +{ + struct pcistub_device_id *pdev_id; + unsigned long flags; + int found = 0; + + spin_lock_irqsave(&device_ids_lock, flags); + list_for_each_entry(pdev_id, &pcistub_device_ids, slot_list) { + if (pcistub_match_one(dev, pdev_id)) { + found = 1; + break; + } + } + spin_unlock_irqrestore(&device_ids_lock, flags); + + return found; +} + +static int pcistub_init_device(struct pci_dev *dev) +{ + struct xen_pcibk_dev_data *dev_data; + int err = 0; + + dev_dbg(&dev->dev, "initializing...\n"); + + /* The PCI backend is not intended to be a module (or to work with + * removable PCI devices (yet). If it were, xen_pcibk_config_free() + * would need to be called somewhere to free the memory allocated + * here and then to call kfree(pci_get_drvdata(psdev->dev)). + */ + dev_data = kzalloc(sizeof(*dev_data) + strlen(DRV_NAME "[]") + + strlen(pci_name(dev)) + 1, GFP_KERNEL); + if (!dev_data) { + err = -ENOMEM; + goto out; + } + pci_set_drvdata(dev, dev_data); + + /* + * Setup name for fake IRQ handler. It will only be enabled + * once the device is turned on by the guest. + */ + sprintf(dev_data->irq_name, DRV_NAME "[%s]", pci_name(dev)); + + dev_dbg(&dev->dev, "initializing config\n"); + + init_waitqueue_head(&xen_pcibk_aer_wait_queue); + err = xen_pcibk_config_init_dev(dev); + if (err) + goto out; + + /* HACK: Force device (& ACPI) to determine what IRQ it's on - we + * must do this here because pcibios_enable_device may specify + * the pci device's true irq (and possibly its other resources) + * if they differ from what's in the configuration space. + * This makes the assumption that the device's resources won't + * change after this point (otherwise this code may break!) + */ + dev_dbg(&dev->dev, "enabling device\n"); + err = pci_enable_device(dev); + if (err) + goto config_release; + + if (dev->msix_cap) { + struct physdev_pci_device ppdev = { + .seg = pci_domain_nr(dev->bus), + .bus = dev->bus->number, + .devfn = dev->devfn + }; + + err = HYPERVISOR_physdev_op(PHYSDEVOP_prepare_msix, &ppdev); + if (err && err != -ENOSYS) + dev_err(&dev->dev, "MSI-X preparation failed (%d)\n", + err); + } + + /* We need the device active to save the state. */ + dev_dbg(&dev->dev, "save state of device\n"); + pci_save_state(dev); + dev_data->pci_saved_state = pci_store_saved_state(dev); + if (!dev_data->pci_saved_state) + dev_err(&dev->dev, "Could not store PCI conf saved state!\n"); + else { + dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n"); + __pci_reset_function_locked(dev); + pci_restore_state(dev); + } + /* Now disable the device (this also ensures some private device + * data is setup before we export) + */ + dev_dbg(&dev->dev, "reset device\n"); + xen_pcibk_reset_device(dev); + + pci_set_dev_assigned(dev); + return 0; + +config_release: + xen_pcibk_config_free_dev(dev); + +out: + pci_set_drvdata(dev, NULL); + kfree(dev_data); + return err; +} + +/* + * Because some initialization still happens on + * devices during fs_initcall, we need to defer + * full initialization of our devices until + * device_initcall. + */ +static int __init pcistub_init_devices_late(void) +{ + struct pcistub_device *psdev; + unsigned long flags; + int err = 0; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + while (!list_empty(&seized_devices)) { + psdev = container_of(seized_devices.next, + struct pcistub_device, dev_list); + list_del(&psdev->dev_list); + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + + err = pcistub_init_device(psdev->dev); + if (err) { + dev_err(&psdev->dev->dev, + "error %d initializing device\n", err); + kfree(psdev); + psdev = NULL; + } + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + if (psdev) + list_add_tail(&psdev->dev_list, &pcistub_devices); + } + + initialize_devices = 1; + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + + return 0; +} + +static void pcistub_device_id_add_list(struct pcistub_device_id *new, + int domain, int bus, unsigned int devfn) +{ + struct pcistub_device_id *pci_dev_id; + unsigned long flags; + int found = 0; + + spin_lock_irqsave(&device_ids_lock, flags); + + list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) { + if (pci_dev_id->domain == domain && pci_dev_id->bus == bus && + pci_dev_id->devfn == devfn) { + found = 1; + break; + } + } + + if (!found) { + new->domain = domain; + new->bus = bus; + new->devfn = devfn; + list_add_tail(&new->slot_list, &pcistub_device_ids); + } + + spin_unlock_irqrestore(&device_ids_lock, flags); + + if (found) + kfree(new); +} + +static int pcistub_seize(struct pci_dev *dev, + struct pcistub_device_id *pci_dev_id) +{ + struct pcistub_device *psdev; + unsigned long flags; + int err = 0; + + psdev = pcistub_device_alloc(dev); + if (!psdev) { + kfree(pci_dev_id); + return -ENOMEM; + } + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + if (initialize_devices) { + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + + /* don't want irqs disabled when calling pcistub_init_device */ + err = pcistub_init_device(psdev->dev); + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + if (!err) + list_add(&psdev->dev_list, &pcistub_devices); + } else { + dev_dbg(&dev->dev, "deferring initialization\n"); + list_add(&psdev->dev_list, &seized_devices); + } + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + + if (err) { + kfree(pci_dev_id); + pcistub_device_put(psdev); + } else if (pci_dev_id) + pcistub_device_id_add_list(pci_dev_id, pci_domain_nr(dev->bus), + dev->bus->number, dev->devfn); + + return err; +} + +/* Called when 'bind'. This means we must _NOT_ call pci_reset_function or + * other functions that take the sysfs lock. */ +static int pcistub_probe(struct pci_dev *dev, const struct pci_device_id *id) +{ + int err = 0, match; + struct pcistub_device_id *pci_dev_id = NULL; + + dev_dbg(&dev->dev, "probing...\n"); + + match = pcistub_match(dev); + + if ((dev->driver_override && + !strcmp(dev->driver_override, PCISTUB_DRIVER_NAME)) || + match) { + + if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL + && dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) { + dev_err(&dev->dev, "can't export pci devices that " + "don't have a normal (0) or bridge (1) " + "header type!\n"); + err = -ENODEV; + goto out; + } + + if (!match) { + pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL); + if (!pci_dev_id) { + err = -ENOMEM; + goto out; + } + } + + dev_info(&dev->dev, "seizing device\n"); + err = pcistub_seize(dev, pci_dev_id); + } else + /* Didn't find the device */ + err = -ENODEV; + +out: + return err; +} + +/* Called when 'unbind'. This means we must _NOT_ call pci_reset_function or + * other functions that take the sysfs lock. */ +static void pcistub_remove(struct pci_dev *dev) +{ + struct pcistub_device *psdev, *found_psdev = NULL; + unsigned long flags; + + dev_dbg(&dev->dev, "removing\n"); + + spin_lock_irqsave(&pcistub_devices_lock, flags); + + xen_pcibk_config_quirk_release(dev); + + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (psdev->dev == dev) { + found_psdev = psdev; + break; + } + } + + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + + if (found_psdev) { + dev_dbg(&dev->dev, "found device to remove %s\n", + found_psdev->pdev ? "- in-use" : ""); + + if (found_psdev->pdev) { + int domid = xen_find_device_domain_owner(dev); + + pr_warn("****** removing device %s while still in-use by domain %d! ******\n", + pci_name(found_psdev->dev), domid); + pr_warn("****** driver domain may still access this device's i/o resources!\n"); + pr_warn("****** shutdown driver domain before binding device\n"); + pr_warn("****** to other drivers or domains\n"); + + /* N.B. This ends up calling pcistub_put_pci_dev which ends up + * doing the FLR. */ + xen_pcibk_release_pci_dev(found_psdev->pdev, + found_psdev->dev, + false /* caller holds the lock. */); + } + + spin_lock_irqsave(&pcistub_devices_lock, flags); + list_del(&found_psdev->dev_list); + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + + /* the final put for releasing from the list */ + pcistub_device_put(found_psdev); + } +} + +static const struct pci_device_id pcistub_ids[] = { + { + .vendor = PCI_ANY_ID, + .device = PCI_ANY_ID, + .subvendor = PCI_ANY_ID, + .subdevice = PCI_ANY_ID, + }, + {0,}, +}; + +#define PCI_NODENAME_MAX 40 +static void kill_domain_by_device(struct pcistub_device *psdev) +{ + struct xenbus_transaction xbt; + int err; + char nodename[PCI_NODENAME_MAX]; + + BUG_ON(!psdev); + snprintf(nodename, PCI_NODENAME_MAX, "/local/domain/0/backend/pci/%d/0", + psdev->pdev->xdev->otherend_id); + +again: + err = xenbus_transaction_start(&xbt); + if (err) { + dev_err(&psdev->dev->dev, + "error %d when start xenbus transaction\n", err); + return; + } + /*PV AER handlers will set this flag*/ + xenbus_printf(xbt, nodename, "aerState" , "aerfail"); + err = xenbus_transaction_end(xbt, 0); + if (err) { + if (err == -EAGAIN) + goto again; + dev_err(&psdev->dev->dev, + "error %d when end xenbus transaction\n", err); + return; + } +} + +/* For each aer recovery step error_detected, mmio_enabled, etc, front_end and + * backend need to have cooperation. In xen_pcibk, those steps will do similar + * jobs: send service request and waiting for front_end response. +*/ +static pci_ers_result_t common_process(struct pcistub_device *psdev, + pci_channel_state_t state, int aer_cmd, + pci_ers_result_t result) +{ + pci_ers_result_t res = result; + struct xen_pcie_aer_op *aer_op; + struct xen_pcibk_device *pdev = psdev->pdev; + struct xen_pci_sharedinfo *sh_info = pdev->sh_info; + int ret; + + /*with PV AER drivers*/ + aer_op = &(sh_info->aer_op); + aer_op->cmd = aer_cmd ; + /*useful for error_detected callback*/ + aer_op->err = state; + /*pcifront_end BDF*/ + ret = xen_pcibk_get_pcifront_dev(psdev->dev, psdev->pdev, + &aer_op->domain, &aer_op->bus, &aer_op->devfn); + if (!ret) { + dev_err(&psdev->dev->dev, + DRV_NAME ": failed to get pcifront device\n"); + return PCI_ERS_RESULT_NONE; + } + wmb(); + + dev_dbg(&psdev->dev->dev, + DRV_NAME ": aer_op %x dom %x bus %x devfn %x\n", + aer_cmd, aer_op->domain, aer_op->bus, aer_op->devfn); + /*local flag to mark there's aer request, xen_pcibk callback will use + * this flag to judge whether we need to check pci-front give aer + * service ack signal + */ + set_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags); + + /*It is possible that a pcifront conf_read_write ops request invokes + * the callback which cause the spurious execution of wake_up. + * Yet it is harmless and better than a spinlock here + */ + set_bit(_XEN_PCIB_active, + (unsigned long *)&sh_info->flags); + wmb(); + notify_remote_via_irq(pdev->evtchn_irq); + + /* Enable IRQ to signal "request done". */ + xen_pcibk_lateeoi(pdev, 0); + + ret = wait_event_timeout(xen_pcibk_aer_wait_queue, + !(test_bit(_XEN_PCIB_active, (unsigned long *) + &sh_info->flags)), 300*HZ); + + /* Enable IRQ for pcifront request if not already active. */ + if (!test_bit(_PDEVF_op_active, &pdev->flags)) + xen_pcibk_lateeoi(pdev, 0); + + if (!ret) { + if (test_bit(_XEN_PCIB_active, + (unsigned long *)&sh_info->flags)) { + dev_err(&psdev->dev->dev, + "pcifront aer process not responding!\n"); + clear_bit(_XEN_PCIB_active, + (unsigned long *)&sh_info->flags); + aer_op->err = PCI_ERS_RESULT_NONE; + return res; + } + } + clear_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags); + + res = (pci_ers_result_t)aer_op->err; + return res; +} + +/* +* xen_pcibk_slot_reset: it will send the slot_reset request to pcifront in case +* of the device driver could provide this service, and then wait for pcifront +* ack. +* @dev: pointer to PCI devices +* return value is used by aer_core do_recovery policy +*/ +static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev) +{ + struct pcistub_device *psdev; + pci_ers_result_t result; + + result = PCI_ERS_RESULT_RECOVERED; + dev_dbg(&dev->dev, "xen_pcibk_slot_reset(bus:%x,devfn:%x)\n", + dev->bus->number, dev->devfn); + + down_write(&pcistub_sem); + psdev = pcistub_device_find(pci_domain_nr(dev->bus), + dev->bus->number, + PCI_SLOT(dev->devfn), + PCI_FUNC(dev->devfn)); + + if (!psdev || !psdev->pdev) { + dev_err(&dev->dev, + DRV_NAME " device is not found/assigned\n"); + goto end; + } + + if (!psdev->pdev->sh_info) { + dev_err(&dev->dev, DRV_NAME " device is not connected or owned" + " by HVM, kill it\n"); + kill_domain_by_device(psdev); + goto end; + } + + if (!test_bit(_XEN_PCIB_AERHANDLER, + (unsigned long *)&psdev->pdev->sh_info->flags)) { + dev_err(&dev->dev, + "guest with no AER driver should have been killed\n"); + goto end; + } + result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result); + + if (result == PCI_ERS_RESULT_NONE || + result == PCI_ERS_RESULT_DISCONNECT) { + dev_dbg(&dev->dev, + "No AER slot_reset service or disconnected!\n"); + kill_domain_by_device(psdev); + } +end: + if (psdev) + pcistub_device_put(psdev); + up_write(&pcistub_sem); + return result; + +} + + +/*xen_pcibk_mmio_enabled: it will send the mmio_enabled request to pcifront +* in case of the device driver could provide this service, and then wait +* for pcifront ack +* @dev: pointer to PCI devices +* return value is used by aer_core do_recovery policy +*/ + +static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev) +{ + struct pcistub_device *psdev; + pci_ers_result_t result; + + result = PCI_ERS_RESULT_RECOVERED; + dev_dbg(&dev->dev, "xen_pcibk_mmio_enabled(bus:%x,devfn:%x)\n", + dev->bus->number, dev->devfn); + + down_write(&pcistub_sem); + psdev = pcistub_device_find(pci_domain_nr(dev->bus), + dev->bus->number, + PCI_SLOT(dev->devfn), + PCI_FUNC(dev->devfn)); + + if (!psdev || !psdev->pdev) { + dev_err(&dev->dev, + DRV_NAME " device is not found/assigned\n"); + goto end; + } + + if (!psdev->pdev->sh_info) { + dev_err(&dev->dev, DRV_NAME " device is not connected or owned" + " by HVM, kill it\n"); + kill_domain_by_device(psdev); + goto end; + } + + if (!test_bit(_XEN_PCIB_AERHANDLER, + (unsigned long *)&psdev->pdev->sh_info->flags)) { + dev_err(&dev->dev, + "guest with no AER driver should have been killed\n"); + goto end; + } + result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result); + + if (result == PCI_ERS_RESULT_NONE || + result == PCI_ERS_RESULT_DISCONNECT) { + dev_dbg(&dev->dev, + "No AER mmio_enabled service or disconnected!\n"); + kill_domain_by_device(psdev); + } +end: + if (psdev) + pcistub_device_put(psdev); + up_write(&pcistub_sem); + return result; +} + +/*xen_pcibk_error_detected: it will send the error_detected request to pcifront +* in case of the device driver could provide this service, and then wait +* for pcifront ack. +* @dev: pointer to PCI devices +* @error: the current PCI connection state +* return value is used by aer_core do_recovery policy +*/ + +static pci_ers_result_t xen_pcibk_error_detected(struct pci_dev *dev, + pci_channel_state_t error) +{ + struct pcistub_device *psdev; + pci_ers_result_t result; + + result = PCI_ERS_RESULT_CAN_RECOVER; + dev_dbg(&dev->dev, "xen_pcibk_error_detected(bus:%x,devfn:%x)\n", + dev->bus->number, dev->devfn); + + down_write(&pcistub_sem); + psdev = pcistub_device_find(pci_domain_nr(dev->bus), + dev->bus->number, + PCI_SLOT(dev->devfn), + PCI_FUNC(dev->devfn)); + + if (!psdev || !psdev->pdev) { + dev_err(&dev->dev, + DRV_NAME " device is not found/assigned\n"); + goto end; + } + + if (!psdev->pdev->sh_info) { + dev_err(&dev->dev, DRV_NAME " device is not connected or owned" + " by HVM, kill it\n"); + kill_domain_by_device(psdev); + goto end; + } + + /*Guest owns the device yet no aer handler regiested, kill guest*/ + if (!test_bit(_XEN_PCIB_AERHANDLER, + (unsigned long *)&psdev->pdev->sh_info->flags)) { + dev_dbg(&dev->dev, "guest may have no aer driver, kill it\n"); + kill_domain_by_device(psdev); + goto end; + } + result = common_process(psdev, error, XEN_PCI_OP_aer_detected, result); + + if (result == PCI_ERS_RESULT_NONE || + result == PCI_ERS_RESULT_DISCONNECT) { + dev_dbg(&dev->dev, + "No AER error_detected service or disconnected!\n"); + kill_domain_by_device(psdev); + } +end: + if (psdev) + pcistub_device_put(psdev); + up_write(&pcistub_sem); + return result; +} + +/*xen_pcibk_error_resume: it will send the error_resume request to pcifront +* in case of the device driver could provide this service, and then wait +* for pcifront ack. +* @dev: pointer to PCI devices +*/ + +static void xen_pcibk_error_resume(struct pci_dev *dev) +{ + struct pcistub_device *psdev; + + dev_dbg(&dev->dev, "xen_pcibk_error_resume(bus:%x,devfn:%x)\n", + dev->bus->number, dev->devfn); + + down_write(&pcistub_sem); + psdev = pcistub_device_find(pci_domain_nr(dev->bus), + dev->bus->number, + PCI_SLOT(dev->devfn), + PCI_FUNC(dev->devfn)); + + if (!psdev || !psdev->pdev) { + dev_err(&dev->dev, + DRV_NAME " device is not found/assigned\n"); + goto end; + } + + if (!psdev->pdev->sh_info) { + dev_err(&dev->dev, DRV_NAME " device is not connected or owned" + " by HVM, kill it\n"); + kill_domain_by_device(psdev); + goto end; + } + + if (!test_bit(_XEN_PCIB_AERHANDLER, + (unsigned long *)&psdev->pdev->sh_info->flags)) { + dev_err(&dev->dev, + "guest with no AER driver should have been killed\n"); + kill_domain_by_device(psdev); + goto end; + } + common_process(psdev, 1, XEN_PCI_OP_aer_resume, + PCI_ERS_RESULT_RECOVERED); +end: + if (psdev) + pcistub_device_put(psdev); + up_write(&pcistub_sem); + return; +} + +/*add xen_pcibk AER handling*/ +static const struct pci_error_handlers xen_pcibk_error_handler = { + .error_detected = xen_pcibk_error_detected, + .mmio_enabled = xen_pcibk_mmio_enabled, + .slot_reset = xen_pcibk_slot_reset, + .resume = xen_pcibk_error_resume, +}; + +/* + * Note: There is no MODULE_DEVICE_TABLE entry here because this isn't + * for a normal device. I don't want it to be loaded automatically. + */ + +static struct pci_driver xen_pcibk_pci_driver = { + /* The name should be xen_pciback, but until the tools are updated + * we will keep it as pciback. */ + .name = PCISTUB_DRIVER_NAME, + .id_table = pcistub_ids, + .probe = pcistub_probe, + .remove = pcistub_remove, + .err_handler = &xen_pcibk_error_handler, +}; + +static inline int str_to_slot(const char *buf, int *domain, int *bus, + int *slot, int *func) +{ + int parsed = 0; + + switch (sscanf(buf, " %x:%x:%x.%x %n", domain, bus, slot, func, + &parsed)) { + case 3: + *func = -1; + sscanf(buf, " %x:%x:%x.* %n", domain, bus, slot, &parsed); + break; + case 2: + *slot = *func = -1; + sscanf(buf, " %x:%x:*.* %n", domain, bus, &parsed); + break; + } + if (parsed && !buf[parsed]) + return 0; + + /* try again without domain */ + *domain = 0; + switch (sscanf(buf, " %x:%x.%x %n", bus, slot, func, &parsed)) { + case 2: + *func = -1; + sscanf(buf, " %x:%x.* %n", bus, slot, &parsed); + break; + case 1: + *slot = *func = -1; + sscanf(buf, " %x:*.* %n", bus, &parsed); + break; + } + if (parsed && !buf[parsed]) + return 0; + + return -EINVAL; +} + +static inline int str_to_quirk(const char *buf, int *domain, int *bus, int + *slot, int *func, int *reg, int *size, int *mask) +{ + int parsed = 0; + + sscanf(buf, " %x:%x:%x.%x-%x:%x:%x %n", domain, bus, slot, func, + reg, size, mask, &parsed); + if (parsed && !buf[parsed]) + return 0; + + /* try again without domain */ + *domain = 0; + sscanf(buf, " %x:%x.%x-%x:%x:%x %n", bus, slot, func, reg, size, + mask, &parsed); + if (parsed && !buf[parsed]) + return 0; + + return -EINVAL; +} + +static int pcistub_device_id_add(int domain, int bus, int slot, int func) +{ + struct pcistub_device_id *pci_dev_id; + int rc = 0, devfn = PCI_DEVFN(slot, func); + + if (slot < 0) { + for (slot = 0; !rc && slot < 32; ++slot) + rc = pcistub_device_id_add(domain, bus, slot, func); + return rc; + } + + if (func < 0) { + for (func = 0; !rc && func < 8; ++func) + rc = pcistub_device_id_add(domain, bus, slot, func); + return rc; + } + + if (( +#if !defined(MODULE) /* pci_domains_supported is not being exported */ \ + || !defined(CONFIG_PCI_DOMAINS) + !pci_domains_supported ? domain : +#endif + domain < 0 || domain > 0xffff) + || bus < 0 || bus > 0xff + || PCI_SLOT(devfn) != slot + || PCI_FUNC(devfn) != func) + return -EINVAL; + + pci_dev_id = kmalloc(sizeof(*pci_dev_id), GFP_KERNEL); + if (!pci_dev_id) + return -ENOMEM; + + pr_debug("wants to seize %04x:%02x:%02x.%d\n", + domain, bus, slot, func); + + pcistub_device_id_add_list(pci_dev_id, domain, bus, devfn); + + return 0; +} + +static int pcistub_device_id_remove(int domain, int bus, int slot, int func) +{ + struct pcistub_device_id *pci_dev_id, *t; + int err = -ENOENT; + unsigned long flags; + + spin_lock_irqsave(&device_ids_lock, flags); + list_for_each_entry_safe(pci_dev_id, t, &pcistub_device_ids, + slot_list) { + if (pci_dev_id->domain == domain && pci_dev_id->bus == bus + && (slot < 0 || PCI_SLOT(pci_dev_id->devfn) == slot) + && (func < 0 || PCI_FUNC(pci_dev_id->devfn) == func)) { + /* Don't break; here because it's possible the same + * slot could be in the list more than once + */ + list_del(&pci_dev_id->slot_list); + kfree(pci_dev_id); + + err = 0; + + pr_debug("removed %04x:%02x:%02x.%d from seize list\n", + domain, bus, slot, func); + } + } + spin_unlock_irqrestore(&device_ids_lock, flags); + + return err; +} + +static int pcistub_reg_add(int domain, int bus, int slot, int func, + unsigned int reg, unsigned int size, + unsigned int mask) +{ + int err = 0; + struct pcistub_device *psdev; + struct pci_dev *dev; + struct config_field *field; + + if (reg > 0xfff || (size < 4 && (mask >> (size * 8)))) + return -EINVAL; + + psdev = pcistub_device_find(domain, bus, slot, func); + if (!psdev) { + err = -ENODEV; + goto out; + } + dev = psdev->dev; + + field = kzalloc(sizeof(*field), GFP_KERNEL); + if (!field) { + err = -ENOMEM; + goto out; + } + + field->offset = reg; + field->size = size; + field->mask = mask; + field->init = NULL; + field->reset = NULL; + field->release = NULL; + field->clean = xen_pcibk_config_field_free; + + err = xen_pcibk_config_quirks_add_field(dev, field); + if (err) + kfree(field); +out: + if (psdev) + pcistub_device_put(psdev); + return err; +} + +static ssize_t new_slot_store(struct device_driver *drv, const char *buf, + size_t count) +{ + int domain, bus, slot, func; + int err; + + err = str_to_slot(buf, &domain, &bus, &slot, &func); + if (err) + goto out; + + err = pcistub_device_id_add(domain, bus, slot, func); + +out: + if (!err) + err = count; + return err; +} +static DRIVER_ATTR_WO(new_slot); + +static ssize_t remove_slot_store(struct device_driver *drv, const char *buf, + size_t count) +{ + int domain, bus, slot, func; + int err; + + err = str_to_slot(buf, &domain, &bus, &slot, &func); + if (err) + goto out; + + err = pcistub_device_id_remove(domain, bus, slot, func); + +out: + if (!err) + err = count; + return err; +} +static DRIVER_ATTR_WO(remove_slot); + +static ssize_t slots_show(struct device_driver *drv, char *buf) +{ + struct pcistub_device_id *pci_dev_id; + size_t count = 0; + unsigned long flags; + + spin_lock_irqsave(&device_ids_lock, flags); + list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) { + if (count >= PAGE_SIZE) + break; + + count += scnprintf(buf + count, PAGE_SIZE - count, + "%04x:%02x:%02x.%d\n", + pci_dev_id->domain, pci_dev_id->bus, + PCI_SLOT(pci_dev_id->devfn), + PCI_FUNC(pci_dev_id->devfn)); + } + spin_unlock_irqrestore(&device_ids_lock, flags); + + return count; +} +static DRIVER_ATTR_RO(slots); + +static ssize_t irq_handlers_show(struct device_driver *drv, char *buf) +{ + struct pcistub_device *psdev; + struct xen_pcibk_dev_data *dev_data; + size_t count = 0; + unsigned long flags; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (count >= PAGE_SIZE) + break; + if (!psdev->dev) + continue; + dev_data = pci_get_drvdata(psdev->dev); + if (!dev_data) + continue; + count += + scnprintf(buf + count, PAGE_SIZE - count, + "%s:%s:%sing:%ld\n", + pci_name(psdev->dev), + dev_data->isr_on ? "on" : "off", + dev_data->ack_intr ? "ack" : "not ack", + dev_data->handled); + } + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + return count; +} +static DRIVER_ATTR_RO(irq_handlers); + +static ssize_t irq_handler_state_store(struct device_driver *drv, + const char *buf, size_t count) +{ + struct pcistub_device *psdev; + struct xen_pcibk_dev_data *dev_data; + int domain, bus, slot, func; + int err; + + err = str_to_slot(buf, &domain, &bus, &slot, &func); + if (err) + return err; + + psdev = pcistub_device_find(domain, bus, slot, func); + if (!psdev) { + err = -ENOENT; + goto out; + } + + dev_data = pci_get_drvdata(psdev->dev); + if (!dev_data) { + err = -ENOENT; + goto out; + } + + dev_dbg(&psdev->dev->dev, "%s fake irq handler: %d->%d\n", + dev_data->irq_name, dev_data->isr_on, + !dev_data->isr_on); + + dev_data->isr_on = !(dev_data->isr_on); + if (dev_data->isr_on) + dev_data->ack_intr = 1; +out: + if (psdev) + pcistub_device_put(psdev); + if (!err) + err = count; + return err; +} +static DRIVER_ATTR_WO(irq_handler_state); + +static ssize_t quirks_store(struct device_driver *drv, const char *buf, + size_t count) +{ + int domain, bus, slot, func, reg, size, mask; + int err; + + err = str_to_quirk(buf, &domain, &bus, &slot, &func, ®, &size, + &mask); + if (err) + goto out; + + err = pcistub_reg_add(domain, bus, slot, func, reg, size, mask); + +out: + if (!err) + err = count; + return err; +} + +static ssize_t quirks_show(struct device_driver *drv, char *buf) +{ + int count = 0; + unsigned long flags; + struct xen_pcibk_config_quirk *quirk; + struct xen_pcibk_dev_data *dev_data; + const struct config_field *field; + const struct config_field_entry *cfg_entry; + + spin_lock_irqsave(&device_ids_lock, flags); + list_for_each_entry(quirk, &xen_pcibk_quirks, quirks_list) { + if (count >= PAGE_SIZE) + goto out; + + count += scnprintf(buf + count, PAGE_SIZE - count, + "%02x:%02x.%01x\n\t%04x:%04x:%04x:%04x\n", + quirk->pdev->bus->number, + PCI_SLOT(quirk->pdev->devfn), + PCI_FUNC(quirk->pdev->devfn), + quirk->devid.vendor, quirk->devid.device, + quirk->devid.subvendor, + quirk->devid.subdevice); + + dev_data = pci_get_drvdata(quirk->pdev); + + list_for_each_entry(cfg_entry, &dev_data->config_fields, list) { + field = cfg_entry->field; + if (count >= PAGE_SIZE) + goto out; + + count += scnprintf(buf + count, PAGE_SIZE - count, + "\t\t%08x:%01x:%08x\n", + cfg_entry->base_offset + + field->offset, field->size, + field->mask); + } + } + +out: + spin_unlock_irqrestore(&device_ids_lock, flags); + + return count; +} +static DRIVER_ATTR_RW(quirks); + +static ssize_t permissive_store(struct device_driver *drv, const char *buf, + size_t count) +{ + int domain, bus, slot, func; + int err; + struct pcistub_device *psdev; + struct xen_pcibk_dev_data *dev_data; + + err = str_to_slot(buf, &domain, &bus, &slot, &func); + if (err) + goto out; + + psdev = pcistub_device_find(domain, bus, slot, func); + if (!psdev) { + err = -ENODEV; + goto out; + } + + dev_data = pci_get_drvdata(psdev->dev); + /* the driver data for a device should never be null at this point */ + if (!dev_data) { + err = -ENXIO; + goto release; + } + if (!dev_data->permissive) { + dev_data->permissive = 1; + /* Let user know that what they're doing could be unsafe */ + dev_warn(&psdev->dev->dev, "enabling permissive mode " + "configuration space accesses!\n"); + dev_warn(&psdev->dev->dev, + "permissive mode is potentially unsafe!\n"); + } +release: + pcistub_device_put(psdev); +out: + if (!err) + err = count; + return err; +} + +static ssize_t permissive_show(struct device_driver *drv, char *buf) +{ + struct pcistub_device *psdev; + struct xen_pcibk_dev_data *dev_data; + size_t count = 0; + unsigned long flags; + spin_lock_irqsave(&pcistub_devices_lock, flags); + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (count >= PAGE_SIZE) + break; + if (!psdev->dev) + continue; + dev_data = pci_get_drvdata(psdev->dev); + if (!dev_data || !dev_data->permissive) + continue; + count += + scnprintf(buf + count, PAGE_SIZE - count, "%s\n", + pci_name(psdev->dev)); + } + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + return count; +} +static DRIVER_ATTR_RW(permissive); + +static void pcistub_exit(void) +{ + driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_new_slot); + driver_remove_file(&xen_pcibk_pci_driver.driver, + &driver_attr_remove_slot); + driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_slots); + driver_remove_file(&xen_pcibk_pci_driver.driver, &driver_attr_quirks); + driver_remove_file(&xen_pcibk_pci_driver.driver, + &driver_attr_permissive); + driver_remove_file(&xen_pcibk_pci_driver.driver, + &driver_attr_irq_handlers); + driver_remove_file(&xen_pcibk_pci_driver.driver, + &driver_attr_irq_handler_state); + pci_unregister_driver(&xen_pcibk_pci_driver); +} + +static int __init pcistub_init(void) +{ + int pos = 0; + int err = 0; + int domain, bus, slot, func; + int parsed; + + if (pci_devs_to_hide && *pci_devs_to_hide) { + do { + parsed = 0; + + err = sscanf(pci_devs_to_hide + pos, + " (%x:%x:%x.%x) %n", + &domain, &bus, &slot, &func, &parsed); + switch (err) { + case 3: + func = -1; + sscanf(pci_devs_to_hide + pos, + " (%x:%x:%x.*) %n", + &domain, &bus, &slot, &parsed); + break; + case 2: + slot = func = -1; + sscanf(pci_devs_to_hide + pos, + " (%x:%x:*.*) %n", + &domain, &bus, &parsed); + break; + } + + if (!parsed) { + domain = 0; + err = sscanf(pci_devs_to_hide + pos, + " (%x:%x.%x) %n", + &bus, &slot, &func, &parsed); + switch (err) { + case 2: + func = -1; + sscanf(pci_devs_to_hide + pos, + " (%x:%x.*) %n", + &bus, &slot, &parsed); + break; + case 1: + slot = func = -1; + sscanf(pci_devs_to_hide + pos, + " (%x:*.*) %n", + &bus, &parsed); + break; + } + } + + if (parsed <= 0) + goto parse_error; + + err = pcistub_device_id_add(domain, bus, slot, func); + if (err) + goto out; + + pos += parsed; + } while (pci_devs_to_hide[pos]); + } + + /* If we're the first PCI Device Driver to register, we're the + * first one to get offered PCI devices as they become + * available (and thus we can be the first to grab them) + */ + err = pci_register_driver(&xen_pcibk_pci_driver); + if (err < 0) + goto out; + + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_new_slot); + if (!err) + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_remove_slot); + if (!err) + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_slots); + if (!err) + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_quirks); + if (!err) + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_permissive); + + if (!err) + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_irq_handlers); + if (!err) + err = driver_create_file(&xen_pcibk_pci_driver.driver, + &driver_attr_irq_handler_state); + if (err) + pcistub_exit(); + +out: + return err; + +parse_error: + pr_err("Error parsing pci_devs_to_hide at \"%s\"\n", + pci_devs_to_hide + pos); + return -EINVAL; +} + +#ifndef MODULE +/* + * fs_initcall happens before device_initcall + * so xen_pcibk *should* get called first (b/c we + * want to suck up any device before other drivers + * get a chance by being the first pci device + * driver to register) + */ +fs_initcall(pcistub_init); +#endif + +#ifdef CONFIG_PCI_IOV +static struct pcistub_device *find_vfs(const struct pci_dev *pdev) +{ + struct pcistub_device *psdev = NULL; + unsigned long flags; + bool found = false; + + spin_lock_irqsave(&pcistub_devices_lock, flags); + list_for_each_entry(psdev, &pcistub_devices, dev_list) { + if (!psdev->pdev && psdev->dev != pdev + && pci_physfn(psdev->dev) == pdev) { + found = true; + break; + } + } + spin_unlock_irqrestore(&pcistub_devices_lock, flags); + if (found) + return psdev; + return NULL; +} + +static int pci_stub_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + const struct pci_dev *pdev = to_pci_dev(dev); + + if (action != BUS_NOTIFY_UNBIND_DRIVER) + return NOTIFY_DONE; + + if (!pdev->is_physfn) + return NOTIFY_DONE; + + for (;;) { + struct pcistub_device *psdev = find_vfs(pdev); + if (!psdev) + break; + device_release_driver(&psdev->dev->dev); + } + return NOTIFY_DONE; +} + +static struct notifier_block pci_stub_nb = { + .notifier_call = pci_stub_notifier, +}; +#endif + +static int __init xen_pcibk_init(void) +{ + int err; + + if (!xen_initial_domain()) + return -ENODEV; + + err = xen_pcibk_config_init(); + if (err) + return err; + +#ifdef MODULE + err = pcistub_init(); + if (err < 0) + return err; +#endif + + pcistub_init_devices_late(); + err = xen_pcibk_xenbus_register(); + if (err) + pcistub_exit(); +#ifdef CONFIG_PCI_IOV + else + bus_register_notifier(&pci_bus_type, &pci_stub_nb); +#endif + + return err; +} + +static void __exit xen_pcibk_cleanup(void) +{ +#ifdef CONFIG_PCI_IOV + bus_unregister_notifier(&pci_bus_type, &pci_stub_nb); +#endif + xen_pcibk_xenbus_unregister(); + pcistub_exit(); +} + +module_init(xen_pcibk_init); +module_exit(xen_pcibk_cleanup); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS("xen-backend:pci"); diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h new file mode 100644 index 000000000..235cdfe13 --- /dev/null +++ b/drivers/xen/xen-pciback/pciback.h @@ -0,0 +1,202 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * PCI Backend Common Data Structures & Function Declarations + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ +#ifndef __XEN_PCIBACK_H__ +#define __XEN_PCIBACK_H__ + +#include <linux/pci.h> +#include <linux/interrupt.h> +#include <xen/xenbus.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> +#include <linux/atomic.h> +#include <xen/events.h> +#include <xen/interface/io/pciif.h> + +#define DRV_NAME "xen-pciback" + +struct pci_dev_entry { + struct list_head list; + struct pci_dev *dev; +}; + +#define _PDEVF_op_active (0) +#define PDEVF_op_active (1<<(_PDEVF_op_active)) +#define _PCIB_op_pending (1) +#define PCIB_op_pending (1<<(_PCIB_op_pending)) +#define _EOI_pending (2) +#define EOI_pending (1<<(_EOI_pending)) + +struct xen_pcibk_device { + void *pci_dev_data; + struct mutex dev_lock; + struct xenbus_device *xdev; + struct xenbus_watch be_watch; + u8 be_watching; + int evtchn_irq; + struct xen_pci_sharedinfo *sh_info; + unsigned long flags; + struct work_struct op_work; + struct xen_pci_op op; +}; + +struct xen_pcibk_dev_data { + struct list_head config_fields; + struct pci_saved_state *pci_saved_state; + unsigned int permissive:1; + unsigned int warned_on_write:1; + unsigned int enable_intx:1; + unsigned int isr_on:1; /* Whether the IRQ handler is installed. */ + unsigned int ack_intr:1; /* .. and ACK-ing */ + unsigned long handled; + unsigned int irq; /* Saved in case device transitions to MSI/MSI-X */ + char irq_name[0]; /* xen-pcibk[000:04:00.0] */ +}; + +/* Used by XenBus and xen_pcibk_ops.c */ +extern wait_queue_head_t xen_pcibk_aer_wait_queue; +/* Used by pcistub.c and conf_space_quirks.c */ +extern struct list_head xen_pcibk_quirks; + +/* Get/Put PCI Devices that are hidden from the PCI Backend Domain */ +struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev, + int domain, int bus, + int slot, int func); +struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev); +void pcistub_put_pci_dev(struct pci_dev *dev); + +/* Ensure a device is turned off or reset */ +void xen_pcibk_reset_device(struct pci_dev *pdev); + +/* Access a virtual configuration space for a PCI device */ +int xen_pcibk_config_init(void); +int xen_pcibk_config_init_dev(struct pci_dev *dev); +void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev); +void xen_pcibk_config_reset_dev(struct pci_dev *dev); +void xen_pcibk_config_free_dev(struct pci_dev *dev); +int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size, + u32 *ret_val); +int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, + u32 value); + +/* Handle requests for specific devices from the frontend */ +typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev, + unsigned int domain, unsigned int bus, + unsigned int devfn, unsigned int devid); +typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev, + unsigned int domain, unsigned int bus); + +/* Backend registration for the two types of BDF representation: + * vpci - BDFs start at 00 + * passthrough - BDFs are exactly like in the host. + */ +struct xen_pcibk_backend { + const char *name; + int (*init)(struct xen_pcibk_device *pdev); + void (*free)(struct xen_pcibk_device *pdev); + int (*find)(struct pci_dev *pcidev, struct xen_pcibk_device *pdev, + unsigned int *domain, unsigned int *bus, + unsigned int *devfn); + int (*publish)(struct xen_pcibk_device *pdev, publish_pci_root_cb cb); + void (*release)(struct xen_pcibk_device *pdev, struct pci_dev *dev, + bool lock); + int (*add)(struct xen_pcibk_device *pdev, struct pci_dev *dev, + int devid, publish_pci_dev_cb publish_cb); + struct pci_dev *(*get)(struct xen_pcibk_device *pdev, + unsigned int domain, unsigned int bus, + unsigned int devfn); +}; + +extern const struct xen_pcibk_backend xen_pcibk_vpci_backend; +extern const struct xen_pcibk_backend xen_pcibk_passthrough_backend; +extern const struct xen_pcibk_backend *xen_pcibk_backend; + +static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev, + int devid, + publish_pci_dev_cb publish_cb) +{ + if (xen_pcibk_backend && xen_pcibk_backend->add) + return xen_pcibk_backend->add(pdev, dev, devid, publish_cb); + return -1; +} + +static inline void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev, bool lock) +{ + if (xen_pcibk_backend && xen_pcibk_backend->release) + return xen_pcibk_backend->release(pdev, dev, lock); +} + +static inline struct pci_dev * +xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain, + unsigned int bus, unsigned int devfn) +{ + if (xen_pcibk_backend && xen_pcibk_backend->get) + return xen_pcibk_backend->get(pdev, domain, bus, devfn); + return NULL; +} + +/** +* Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk +* before sending aer request to pcifront, so that guest could identify +* device, coopearte with xen_pcibk to finish aer recovery job if device driver +* has the capability +*/ +static inline int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev, + struct xen_pcibk_device *pdev, + unsigned int *domain, + unsigned int *bus, + unsigned int *devfn) +{ + if (xen_pcibk_backend && xen_pcibk_backend->find) + return xen_pcibk_backend->find(pcidev, pdev, domain, bus, + devfn); + return -1; +} + +static inline int xen_pcibk_init_devices(struct xen_pcibk_device *pdev) +{ + if (xen_pcibk_backend && xen_pcibk_backend->init) + return xen_pcibk_backend->init(pdev); + return -1; +} + +static inline int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev, + publish_pci_root_cb cb) +{ + if (xen_pcibk_backend && xen_pcibk_backend->publish) + return xen_pcibk_backend->publish(pdev, cb); + return -1; +} + +static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev) +{ + if (xen_pcibk_backend && xen_pcibk_backend->free) + return xen_pcibk_backend->free(pdev); +} + +/* Handles events from front-end */ +irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id); +void xen_pcibk_do_op(struct work_struct *data); + +static inline void xen_pcibk_lateeoi(struct xen_pcibk_device *pdev, + unsigned int eoi_flag) +{ + if (test_and_clear_bit(_EOI_pending, &pdev->flags)) + xen_irq_lateeoi(pdev->evtchn_irq, eoi_flag); +} + +int xen_pcibk_xenbus_register(void); +void xen_pcibk_xenbus_unregister(void); + +extern int verbose_request; +#endif + +/* Handles shared IRQs that can to device domain and control domain. */ +void xen_pcibk_irq_handler(struct pci_dev *dev, int reset); diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c new file mode 100644 index 000000000..c4ed2c634 --- /dev/null +++ b/drivers/xen/xen-pciback/pciback_ops.c @@ -0,0 +1,464 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend Operations - respond to PCI requests from Frontend + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/moduleparam.h> +#include <linux/wait.h> +#include <linux/bitops.h> +#include <xen/events.h> +#include <linux/sched.h> +#include "pciback.h" + +int verbose_request; +module_param(verbose_request, int, 0644); + +static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id); + +/* Ensure a device is has the fake IRQ handler "turned on/off" and is + * ready to be exported. This MUST be run after xen_pcibk_reset_device + * which does the actual PCI device enable/disable. + */ +static void xen_pcibk_control_isr(struct pci_dev *dev, int reset) +{ + struct xen_pcibk_dev_data *dev_data; + int rc; + int enable = 0; + + dev_data = pci_get_drvdata(dev); + if (!dev_data) + return; + + /* We don't deal with bridges */ + if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL) + return; + + if (reset) { + dev_data->enable_intx = 0; + dev_data->ack_intr = 0; + } + enable = dev_data->enable_intx; + + /* Asked to disable, but ISR isn't runnig */ + if (!enable && !dev_data->isr_on) + return; + + /* Squirrel away the IRQs in the dev_data. We need this + * b/c when device transitions to MSI, the dev->irq is + * overwritten with the MSI vector. + */ + if (enable) + dev_data->irq = dev->irq; + + /* + * SR-IOV devices in all use MSI-X and have no legacy + * interrupts, so inhibit creating a fake IRQ handler for them. + */ + if (dev_data->irq == 0) + goto out; + + dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n", + dev_data->irq_name, + dev_data->irq, + pci_is_enabled(dev) ? "on" : "off", + dev->msi_enabled ? "MSI" : "", + dev->msix_enabled ? "MSI/X" : "", + dev_data->isr_on ? "enable" : "disable", + enable ? "enable" : "disable"); + + if (enable) { + /* + * The MSI or MSI-X should not have an IRQ handler. Otherwise + * if the guest terminates we BUG_ON in free_msi_irqs. + */ + if (dev->msi_enabled || dev->msix_enabled) + goto out; + + rc = request_irq(dev_data->irq, + xen_pcibk_guest_interrupt, IRQF_SHARED, + dev_data->irq_name, dev); + if (rc) { + dev_err(&dev->dev, "%s: failed to install fake IRQ " \ + "handler for IRQ %d! (rc:%d)\n", + dev_data->irq_name, dev_data->irq, rc); + goto out; + } + } else { + free_irq(dev_data->irq, dev); + dev_data->irq = 0; + } + dev_data->isr_on = enable; + dev_data->ack_intr = enable; +out: + dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n", + dev_data->irq_name, + dev_data->irq, + pci_is_enabled(dev) ? "on" : "off", + dev->msi_enabled ? "MSI" : "", + dev->msix_enabled ? "MSI/X" : "", + enable ? (dev_data->isr_on ? "enabled" : "failed to enable") : + (dev_data->isr_on ? "failed to disable" : "disabled")); +} + +/* Ensure a device is "turned off" and ready to be exported. + * (Also see xen_pcibk_config_reset to ensure virtual configuration space is + * ready to be re-exported) + */ +void xen_pcibk_reset_device(struct pci_dev *dev) +{ + u16 cmd; + + xen_pcibk_control_isr(dev, 1 /* reset device */); + + /* Disable devices (but not bridges) */ + if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) { +#ifdef CONFIG_PCI_MSI + /* The guest could have been abruptly killed without + * disabling MSI/MSI-X interrupts.*/ + if (dev->msix_enabled) + pci_disable_msix(dev); + if (dev->msi_enabled) + pci_disable_msi(dev); +#endif + if (pci_is_enabled(dev)) + pci_disable_device(dev); + + dev->is_busmaster = 0; + } else { + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & (PCI_COMMAND_INVALIDATE)) { + cmd &= ~(PCI_COMMAND_INVALIDATE); + pci_write_config_word(dev, PCI_COMMAND, cmd); + + dev->is_busmaster = 0; + } + } +} + +#ifdef CONFIG_PCI_MSI +static +int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev, + struct pci_dev *dev, struct xen_pci_op *op) +{ + struct xen_pcibk_dev_data *dev_data; + int status; + + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev)); + + if (dev->msi_enabled) + status = -EALREADY; + else if (dev->msix_enabled) + status = -ENXIO; + else + status = pci_enable_msi(dev); + + if (status) { + pr_warn_ratelimited("%s: error enabling MSI for guest %u: err %d\n", + pci_name(dev), pdev->xdev->otherend_id, + status); + op->value = 0; + return XEN_PCI_ERR_op_failed; + } + + /* The value the guest needs is actually the IDT vector, not the + * the local domain's IRQ number. */ + + op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0; + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev), + op->value); + + dev_data = pci_get_drvdata(dev); + if (dev_data) + dev_data->ack_intr = 0; + + return 0; +} + +static +int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev, + struct pci_dev *dev, struct xen_pci_op *op) +{ + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n", + pci_name(dev)); + + if (dev->msi_enabled) { + struct xen_pcibk_dev_data *dev_data; + + pci_disable_msi(dev); + + dev_data = pci_get_drvdata(dev); + if (dev_data) + dev_data->ack_intr = 1; + } + op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0; + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev), + op->value); + return 0; +} + +static +int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev, + struct pci_dev *dev, struct xen_pci_op *op) +{ + struct xen_pcibk_dev_data *dev_data; + int i, result; + struct msix_entry *entries; + u16 cmd; + + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n", + pci_name(dev)); + + if (op->value > SH_INFO_MAX_VEC) + return -EINVAL; + + if (dev->msix_enabled) + return -EALREADY; + + /* + * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able + * to access the BARs where the MSI-X entries reside. + * But VF devices are unique in which the PF needs to be checked. + */ + pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd); + if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY)) + return -ENXIO; + + entries = kmalloc_array(op->value, sizeof(*entries), GFP_KERNEL); + if (entries == NULL) + return -ENOMEM; + + for (i = 0; i < op->value; i++) { + entries[i].entry = op->msix_entries[i].entry; + entries[i].vector = op->msix_entries[i].vector; + } + + result = pci_enable_msix_exact(dev, entries, op->value); + if (result == 0) { + for (i = 0; i < op->value; i++) { + op->msix_entries[i].entry = entries[i].entry; + if (entries[i].vector) { + op->msix_entries[i].vector = + xen_pirq_from_irq(entries[i].vector); + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: " \ + "MSI-X[%d]: %d\n", + pci_name(dev), i, + op->msix_entries[i].vector); + } + } + } else + pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: err %d!\n", + pci_name(dev), pdev->xdev->otherend_id, + result); + kfree(entries); + + op->value = result; + dev_data = pci_get_drvdata(dev); + if (dev_data) + dev_data->ack_intr = 0; + + return result > 0 ? 0 : result; +} + +static +int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev, + struct pci_dev *dev, struct xen_pci_op *op) +{ + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n", + pci_name(dev)); + + if (dev->msix_enabled) { + struct xen_pcibk_dev_data *dev_data; + + pci_disable_msix(dev); + + dev_data = pci_get_drvdata(dev); + if (dev_data) + dev_data->ack_intr = 1; + } + /* + * SR-IOV devices (which don't have any legacy IRQ) have + * an undefined IRQ value of zero. + */ + op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0; + if (unlikely(verbose_request)) + printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", + pci_name(dev), op->value); + return 0; +} +#endif + +static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev) +{ + return test_bit(_XEN_PCIF_active, + (unsigned long *)&pdev->sh_info->flags) && + !test_and_set_bit(_PDEVF_op_active, &pdev->flags); +} + +/* +* Now the same evtchn is used for both pcifront conf_read_write request +* as well as pcie aer front end ack. We use a new work_queue to schedule +* xen_pcibk conf_read_write service for avoiding confict with aer_core +* do_recovery job which also use the system default work_queue +*/ +static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev) +{ + bool eoi = true; + + /* Check that frontend is requesting an operation and that we are not + * already processing a request */ + if (xen_pcibk_test_op_pending(pdev)) { + schedule_work(&pdev->op_work); + eoi = false; + } + /*_XEN_PCIB_active should have been cleared by pcifront. And also make + sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/ + if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags) + && test_bit(_PCIB_op_pending, &pdev->flags)) { + wake_up(&xen_pcibk_aer_wait_queue); + eoi = false; + } + + /* EOI if there was nothing to do. */ + if (eoi) + xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS); +} + +/* Performing the configuration space reads/writes must not be done in atomic + * context because some of the pci_* functions can sleep (mostly due to ACPI + * use of semaphores). This function is intended to be called from a work + * queue in process context taking a struct xen_pcibk_device as a parameter */ + +static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev) +{ + struct pci_dev *dev; + struct xen_pcibk_dev_data *dev_data = NULL; + struct xen_pci_op *op = &pdev->op; + int test_intx = 0; +#ifdef CONFIG_PCI_MSI + unsigned int nr = 0; +#endif + + *op = pdev->sh_info->op; + barrier(); + dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn); + + if (dev == NULL) + op->err = XEN_PCI_ERR_dev_not_found; + else { + dev_data = pci_get_drvdata(dev); + if (dev_data) + test_intx = dev_data->enable_intx; + switch (op->cmd) { + case XEN_PCI_OP_conf_read: + op->err = xen_pcibk_config_read(dev, + op->offset, op->size, &op->value); + break; + case XEN_PCI_OP_conf_write: + op->err = xen_pcibk_config_write(dev, + op->offset, op->size, op->value); + break; +#ifdef CONFIG_PCI_MSI + case XEN_PCI_OP_enable_msi: + op->err = xen_pcibk_enable_msi(pdev, dev, op); + break; + case XEN_PCI_OP_disable_msi: + op->err = xen_pcibk_disable_msi(pdev, dev, op); + break; + case XEN_PCI_OP_enable_msix: + nr = op->value; + op->err = xen_pcibk_enable_msix(pdev, dev, op); + break; + case XEN_PCI_OP_disable_msix: + op->err = xen_pcibk_disable_msix(pdev, dev, op); + break; +#endif + default: + op->err = XEN_PCI_ERR_not_implemented; + break; + } + } + if (!op->err && dev && dev_data) { + /* Transition detected */ + if ((dev_data->enable_intx != test_intx)) + xen_pcibk_control_isr(dev, 0 /* no reset */); + } + pdev->sh_info->op.err = op->err; + pdev->sh_info->op.value = op->value; +#ifdef CONFIG_PCI_MSI + if (op->cmd == XEN_PCI_OP_enable_msix && op->err == 0) { + unsigned int i; + + for (i = 0; i < nr; i++) + pdev->sh_info->op.msix_entries[i].vector = + op->msix_entries[i].vector; + } +#endif + /* Tell the driver domain that we're done. */ + wmb(); + clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags); + notify_remote_via_irq(pdev->evtchn_irq); + + /* Mark that we're done. */ + smp_mb__before_atomic(); /* /after/ clearing PCIF_active */ + clear_bit(_PDEVF_op_active, &pdev->flags); + smp_mb__after_atomic(); /* /before/ final check for work */ +} + +void xen_pcibk_do_op(struct work_struct *data) +{ + struct xen_pcibk_device *pdev = + container_of(data, struct xen_pcibk_device, op_work); + + do { + xen_pcibk_do_one_op(pdev); + } while (xen_pcibk_test_op_pending(pdev)); + + xen_pcibk_lateeoi(pdev, 0); +} + +irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id) +{ + struct xen_pcibk_device *pdev = dev_id; + bool eoi; + + /* IRQs might come in before pdev->evtchn_irq is written. */ + if (unlikely(pdev->evtchn_irq != irq)) + pdev->evtchn_irq = irq; + + eoi = test_and_set_bit(_EOI_pending, &pdev->flags); + WARN(eoi, "IRQ while EOI pending\n"); + + xen_pcibk_test_and_schedule_op(pdev); + + return IRQ_HANDLED; +} +static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id) +{ + struct pci_dev *dev = (struct pci_dev *)dev_id; + struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev); + + if (dev_data->isr_on && dev_data->ack_intr) { + dev_data->handled++; + if ((dev_data->handled % 1000) == 0) { + if (xen_test_irq_shared(irq)) { + pr_info("%s IRQ line is not shared " + "with other domains. Turning ISR off\n", + dev_data->irq_name); + dev_data->ack_intr = 0; + } + } + return IRQ_HANDLED; + } + return IRQ_NONE; +} diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c new file mode 100644 index 000000000..30313084f --- /dev/null +++ b/drivers/xen/xen-pciback/vpci.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend - Provides a Virtual PCI bus (with real devices) + * to the frontend + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/pci.h> +#include <linux/mutex.h> +#include "pciback.h" + +#define PCI_SLOT_MAX 32 + +struct vpci_dev_data { + /* Access to dev_list must be protected by lock */ + struct list_head dev_list[PCI_SLOT_MAX]; + struct mutex lock; +}; + +static inline struct list_head *list_first(struct list_head *head) +{ + return head->next; +} + +static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, + unsigned int domain, + unsigned int bus, + unsigned int devfn) +{ + struct pci_dev_entry *entry; + struct pci_dev *dev = NULL; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + + if (domain != 0 || bus != 0) + return NULL; + + if (PCI_SLOT(devfn) < PCI_SLOT_MAX) { + mutex_lock(&vpci_dev->lock); + + list_for_each_entry(entry, + &vpci_dev->dev_list[PCI_SLOT(devfn)], + list) { + if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) { + dev = entry->dev; + break; + } + } + + mutex_unlock(&vpci_dev->lock); + } + return dev; +} + +static inline int match_slot(struct pci_dev *l, struct pci_dev *r) +{ + if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus) + && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn)) + return 1; + + return 0; +} + +static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev, int devid, + publish_pci_dev_cb publish_cb) +{ + int err = 0, slot, func = PCI_FUNC(dev->devfn); + struct pci_dev_entry *t, *dev_entry; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + + if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) { + err = -EFAULT; + xenbus_dev_fatal(pdev->xdev, err, + "Can't export bridges on the virtual PCI bus"); + goto out; + } + + dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL); + if (!dev_entry) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "Error adding entry to virtual PCI bus"); + goto out; + } + + dev_entry->dev = dev; + + mutex_lock(&vpci_dev->lock); + + /* + * Keep multi-function devices together on the virtual PCI bus, except + * that we want to keep virtual functions at func 0 on their own. They + * aren't multi-function devices and hence their presence at func 0 + * may cause guests to not scan the other functions. + */ + if (!dev->is_virtfn || func) { + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + if (list_empty(&vpci_dev->dev_list[slot])) + continue; + + t = list_entry(list_first(&vpci_dev->dev_list[slot]), + struct pci_dev_entry, list); + if (t->dev->is_virtfn && !PCI_FUNC(t->dev->devfn)) + continue; + + if (match_slot(dev, t->dev)) { + pr_info("vpci: %s: assign to virtual slot %d func %d\n", + pci_name(dev), slot, + func); + list_add_tail(&dev_entry->list, + &vpci_dev->dev_list[slot]); + goto unlock; + } + } + } + + /* Assign to a new slot on the virtual PCI bus */ + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + if (list_empty(&vpci_dev->dev_list[slot])) { + pr_info("vpci: %s: assign to virtual slot %d\n", + pci_name(dev), slot); + list_add_tail(&dev_entry->list, + &vpci_dev->dev_list[slot]); + goto unlock; + } + } + + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "No more space on root virtual PCI bus"); + +unlock: + mutex_unlock(&vpci_dev->lock); + + /* Publish this device. */ + if (!err) + err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid); + else + kfree(dev_entry); + +out: + return err; +} + +static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev, + struct pci_dev *dev, bool lock) +{ + int slot; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + struct pci_dev *found_dev = NULL; + + mutex_lock(&vpci_dev->lock); + + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + struct pci_dev_entry *e; + + list_for_each_entry(e, &vpci_dev->dev_list[slot], list) { + if (e->dev == dev) { + list_del(&e->list); + found_dev = e->dev; + kfree(e); + goto out; + } + } + } + +out: + mutex_unlock(&vpci_dev->lock); + + if (found_dev) { + if (lock) + device_lock(&found_dev->dev); + pcistub_put_pci_dev(found_dev); + if (lock) + device_unlock(&found_dev->dev); + } +} + +static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev) +{ + int slot; + struct vpci_dev_data *vpci_dev; + + vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL); + if (!vpci_dev) + return -ENOMEM; + + mutex_init(&vpci_dev->lock); + + for (slot = 0; slot < PCI_SLOT_MAX; slot++) + INIT_LIST_HEAD(&vpci_dev->dev_list[slot]); + + pdev->pci_dev_data = vpci_dev; + + return 0; +} + +static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev, + publish_pci_root_cb publish_cb) +{ + /* The Virtual PCI bus has only one root */ + return publish_cb(pdev, 0, 0); +} + +static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev) +{ + int slot; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + struct pci_dev_entry *e, *tmp; + list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot], + list) { + struct pci_dev *dev = e->dev; + list_del(&e->list); + device_lock(&dev->dev); + pcistub_put_pci_dev(dev); + device_unlock(&dev->dev); + kfree(e); + } + } + + kfree(vpci_dev); + pdev->pci_dev_data = NULL; +} + +static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev, + struct xen_pcibk_device *pdev, + unsigned int *domain, unsigned int *bus, + unsigned int *devfn) +{ + struct pci_dev_entry *entry; + struct pci_dev *dev = NULL; + struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; + int found = 0, slot; + + mutex_lock(&vpci_dev->lock); + for (slot = 0; slot < PCI_SLOT_MAX; slot++) { + list_for_each_entry(entry, + &vpci_dev->dev_list[slot], + list) { + dev = entry->dev; + if (dev && dev->bus->number == pcidev->bus->number + && pci_domain_nr(dev->bus) == + pci_domain_nr(pcidev->bus) + && dev->devfn == pcidev->devfn) { + found = 1; + *domain = 0; + *bus = 0; + *devfn = PCI_DEVFN(slot, + PCI_FUNC(pcidev->devfn)); + } + } + } + mutex_unlock(&vpci_dev->lock); + return found; +} + +const struct xen_pcibk_backend xen_pcibk_vpci_backend = { + .name = "vpci", + .init = __xen_pcibk_init_devices, + .free = __xen_pcibk_release_devices, + .find = __xen_pcibk_get_pcifront_dev, + .publish = __xen_pcibk_publish_pci_roots, + .release = __xen_pcibk_release_pci_dev, + .add = __xen_pcibk_add_pci_dev, + .get = __xen_pcibk_get_pci_dev, +}; diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c new file mode 100644 index 000000000..4fb6aacf9 --- /dev/null +++ b/drivers/xen/xen-pciback/xenbus.c @@ -0,0 +1,755 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Backend Xenbus Setup - handles setup with frontend and xend + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/moduleparam.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/vmalloc.h> +#include <linux/workqueue.h> +#include <xen/xenbus.h> +#include <xen/events.h> +#include <asm/xen/pci.h> +#include "pciback.h" + +#define INVALID_EVTCHN_IRQ (-1) + +static bool __read_mostly passthrough; +module_param(passthrough, bool, S_IRUGO); +MODULE_PARM_DESC(passthrough, + "Option to specify how to export PCI topology to guest:\n"\ + " 0 - (default) Hide the true PCI topology and makes the frontend\n"\ + " there is a single PCI bus with only the exported devices on it.\n"\ + " For example, a device at 03:05.0 will be re-assigned to 00:00.0\n"\ + " while second device at 02:1a.1 will be re-assigned to 00:01.1.\n"\ + " 1 - Passthrough provides a real view of the PCI topology to the\n"\ + " frontend (for example, a device at 06:01.b will still appear at\n"\ + " 06:01.b to the frontend). This is similar to how Xen 2.0.x\n"\ + " exposed PCI devices to its driver domains. This may be required\n"\ + " for drivers which depend on finding their hardward in certain\n"\ + " bus/slot locations."); + +static struct xen_pcibk_device *alloc_pdev(struct xenbus_device *xdev) +{ + struct xen_pcibk_device *pdev; + + pdev = kzalloc(sizeof(struct xen_pcibk_device), GFP_KERNEL); + if (pdev == NULL) + goto out; + dev_dbg(&xdev->dev, "allocated pdev @ 0x%p\n", pdev); + + pdev->xdev = xdev; + + mutex_init(&pdev->dev_lock); + + pdev->sh_info = NULL; + pdev->evtchn_irq = INVALID_EVTCHN_IRQ; + pdev->be_watching = 0; + + INIT_WORK(&pdev->op_work, xen_pcibk_do_op); + + if (xen_pcibk_init_devices(pdev)) { + kfree(pdev); + pdev = NULL; + } + + dev_set_drvdata(&xdev->dev, pdev); + +out: + return pdev; +} + +static void xen_pcibk_disconnect(struct xen_pcibk_device *pdev) +{ + mutex_lock(&pdev->dev_lock); + /* Ensure the guest can't trigger our handler before removing devices */ + if (pdev->evtchn_irq != INVALID_EVTCHN_IRQ) { + unbind_from_irqhandler(pdev->evtchn_irq, pdev); + pdev->evtchn_irq = INVALID_EVTCHN_IRQ; + } + + /* If the driver domain started an op, make sure we complete it + * before releasing the shared memory */ + + flush_work(&pdev->op_work); + + if (pdev->sh_info != NULL) { + xenbus_unmap_ring_vfree(pdev->xdev, pdev->sh_info); + pdev->sh_info = NULL; + } + mutex_unlock(&pdev->dev_lock); +} + +static void free_pdev(struct xen_pcibk_device *pdev) +{ + if (pdev->be_watching) { + unregister_xenbus_watch(&pdev->be_watch); + pdev->be_watching = 0; + } + + xen_pcibk_disconnect(pdev); + + /* N.B. This calls pcistub_put_pci_dev which does the FLR on all + * of the PCIe devices. */ + xen_pcibk_release_devices(pdev); + + dev_set_drvdata(&pdev->xdev->dev, NULL); + pdev->xdev = NULL; + + kfree(pdev); +} + +static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref, + int remote_evtchn) +{ + int err = 0; + void *vaddr; + + dev_dbg(&pdev->xdev->dev, + "Attaching to frontend resources - gnt_ref=%d evtchn=%d\n", + gnt_ref, remote_evtchn); + + err = xenbus_map_ring_valloc(pdev->xdev, &gnt_ref, 1, &vaddr); + if (err < 0) { + xenbus_dev_fatal(pdev->xdev, err, + "Error mapping other domain page in ours."); + goto out; + } + + pdev->sh_info = vaddr; + + err = bind_interdomain_evtchn_to_irqhandler_lateeoi( + pdev->xdev->otherend_id, remote_evtchn, xen_pcibk_handle_event, + 0, DRV_NAME, pdev); + if (err < 0) { + xenbus_dev_fatal(pdev->xdev, err, + "Error binding event channel to IRQ"); + goto out; + } + pdev->evtchn_irq = err; + err = 0; + + dev_dbg(&pdev->xdev->dev, "Attached!\n"); +out: + return err; +} + +static int xen_pcibk_attach(struct xen_pcibk_device *pdev) +{ + int err = 0; + int gnt_ref, remote_evtchn; + char *magic = NULL; + + + mutex_lock(&pdev->dev_lock); + /* Make sure we only do this setup once */ + if (xenbus_read_driver_state(pdev->xdev->nodename) != + XenbusStateInitialised) + goto out; + + /* Wait for frontend to state that it has published the configuration */ + if (xenbus_read_driver_state(pdev->xdev->otherend) != + XenbusStateInitialised) + goto out; + + dev_dbg(&pdev->xdev->dev, "Reading frontend config\n"); + + err = xenbus_gather(XBT_NIL, pdev->xdev->otherend, + "pci-op-ref", "%u", &gnt_ref, + "event-channel", "%u", &remote_evtchn, + "magic", NULL, &magic, NULL); + if (err) { + /* If configuration didn't get read correctly, wait longer */ + xenbus_dev_fatal(pdev->xdev, err, + "Error reading configuration from frontend"); + goto out; + } + + if (magic == NULL || strcmp(magic, XEN_PCI_MAGIC) != 0) { + xenbus_dev_fatal(pdev->xdev, -EFAULT, + "version mismatch (%s/%s) with pcifront - " + "halting " DRV_NAME, + magic, XEN_PCI_MAGIC); + err = -EFAULT; + goto out; + } + + err = xen_pcibk_do_attach(pdev, gnt_ref, remote_evtchn); + if (err) + goto out; + + dev_dbg(&pdev->xdev->dev, "Connecting...\n"); + + err = xenbus_switch_state(pdev->xdev, XenbusStateConnected); + if (err) + xenbus_dev_fatal(pdev->xdev, err, + "Error switching to connected state!"); + + dev_dbg(&pdev->xdev->dev, "Connected? %d\n", err); +out: + mutex_unlock(&pdev->dev_lock); + + kfree(magic); + + return err; +} + +static int xen_pcibk_publish_pci_dev(struct xen_pcibk_device *pdev, + unsigned int domain, unsigned int bus, + unsigned int devfn, unsigned int devid) +{ + int err; + int len; + char str[64]; + + len = snprintf(str, sizeof(str), "vdev-%d", devid); + if (unlikely(len >= (sizeof(str) - 1))) { + err = -ENOMEM; + goto out; + } + + /* Note: The PV protocol uses %02x, don't change it */ + err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, str, + "%04x:%02x:%02x.%02x", domain, bus, + PCI_SLOT(devfn), PCI_FUNC(devfn)); + +out: + return err; +} + +static int xen_pcibk_export_device(struct xen_pcibk_device *pdev, + int domain, int bus, int slot, int func, + int devid) +{ + struct pci_dev *dev; + int err = 0; + + dev_dbg(&pdev->xdev->dev, "exporting dom %x bus %x slot %x func %x\n", + domain, bus, slot, func); + + dev = pcistub_get_pci_dev_by_slot(pdev, domain, bus, slot, func); + if (!dev) { + err = -EINVAL; + xenbus_dev_fatal(pdev->xdev, err, + "Couldn't locate PCI device " + "(%04x:%02x:%02x.%d)! " + "perhaps already in-use?", + domain, bus, slot, func); + goto out; + } + + err = xen_pcibk_add_pci_dev(pdev, dev, devid, + xen_pcibk_publish_pci_dev); + if (err) + goto out; + + dev_info(&dev->dev, "registering for %d\n", pdev->xdev->otherend_id); + if (xen_register_device_domain_owner(dev, + pdev->xdev->otherend_id) != 0) { + dev_err(&dev->dev, "Stealing ownership from dom%d.\n", + xen_find_device_domain_owner(dev)); + xen_unregister_device_domain_owner(dev); + xen_register_device_domain_owner(dev, pdev->xdev->otherend_id); + } + + /* TODO: It'd be nice to export a bridge and have all of its children + * get exported with it. This may be best done in xend (which will + * have to calculate resource usage anyway) but we probably want to + * put something in here to ensure that if a bridge gets given to a + * driver domain, that all devices under that bridge are not given + * to other driver domains (as he who controls the bridge can disable + * it and stop the other devices from working). + */ +out: + return err; +} + +static int xen_pcibk_remove_device(struct xen_pcibk_device *pdev, + int domain, int bus, int slot, int func) +{ + int err = 0; + struct pci_dev *dev; + + dev_dbg(&pdev->xdev->dev, "removing dom %x bus %x slot %x func %x\n", + domain, bus, slot, func); + + dev = xen_pcibk_get_pci_dev(pdev, domain, bus, PCI_DEVFN(slot, func)); + if (!dev) { + err = -EINVAL; + dev_dbg(&pdev->xdev->dev, "Couldn't locate PCI device " + "(%04x:%02x:%02x.%d)! not owned by this domain\n", + domain, bus, slot, func); + goto out; + } + + dev_dbg(&dev->dev, "unregistering for %d\n", pdev->xdev->otherend_id); + xen_unregister_device_domain_owner(dev); + + /* N.B. This ends up calling pcistub_put_pci_dev which ends up + * doing the FLR. */ + xen_pcibk_release_pci_dev(pdev, dev, true /* use the lock. */); + +out: + return err; +} + +static int xen_pcibk_publish_pci_root(struct xen_pcibk_device *pdev, + unsigned int domain, unsigned int bus) +{ + unsigned int d, b; + int i, root_num, len, err; + char str[64]; + + dev_dbg(&pdev->xdev->dev, "Publishing pci roots\n"); + + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, + "root_num", "%d", &root_num); + if (err == 0 || err == -ENOENT) + root_num = 0; + else if (err < 0) + goto out; + + /* Verify that we haven't already published this pci root */ + for (i = 0; i < root_num; i++) { + len = snprintf(str, sizeof(str), "root-%d", i); + if (unlikely(len >= (sizeof(str) - 1))) { + err = -ENOMEM; + goto out; + } + + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, + str, "%x:%x", &d, &b); + if (err < 0) + goto out; + if (err != 2) { + err = -EINVAL; + goto out; + } + + if (d == domain && b == bus) { + err = 0; + goto out; + } + } + + len = snprintf(str, sizeof(str), "root-%d", root_num); + if (unlikely(len >= (sizeof(str) - 1))) { + err = -ENOMEM; + goto out; + } + + dev_dbg(&pdev->xdev->dev, "writing root %d at %04x:%02x\n", + root_num, domain, bus); + + err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, str, + "%04x:%02x", domain, bus); + if (err) + goto out; + + err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, + "root_num", "%d", (root_num + 1)); + +out: + return err; +} + +static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev, + enum xenbus_state state) +{ + int err = 0; + int num_devs; + int domain, bus, slot, func; + unsigned int substate; + int i, len; + char state_str[64]; + char dev_str[64]; + + + dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n"); + + mutex_lock(&pdev->dev_lock); + if (xenbus_read_driver_state(pdev->xdev->nodename) != state) + goto out; + + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d", + &num_devs); + if (err != 1) { + if (err >= 0) + err = -EINVAL; + xenbus_dev_fatal(pdev->xdev, err, + "Error reading number of devices"); + goto out; + } + + for (i = 0; i < num_devs; i++) { + len = snprintf(state_str, sizeof(state_str), "state-%d", i); + if (unlikely(len >= (sizeof(state_str) - 1))) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "String overflow while reading " + "configuration"); + goto out; + } + substate = xenbus_read_unsigned(pdev->xdev->nodename, state_str, + XenbusStateUnknown); + + switch (substate) { + case XenbusStateInitialising: + dev_dbg(&pdev->xdev->dev, "Attaching dev-%d ...\n", i); + + len = snprintf(dev_str, sizeof(dev_str), "dev-%d", i); + if (unlikely(len >= (sizeof(dev_str) - 1))) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "String overflow while " + "reading configuration"); + goto out; + } + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, + dev_str, "%x:%x:%x.%x", + &domain, &bus, &slot, &func); + if (err < 0) { + xenbus_dev_fatal(pdev->xdev, err, + "Error reading device " + "configuration"); + goto out; + } + if (err != 4) { + err = -EINVAL; + xenbus_dev_fatal(pdev->xdev, err, + "Error parsing pci device " + "configuration"); + goto out; + } + + err = xen_pcibk_export_device(pdev, domain, bus, slot, + func, i); + if (err) + goto out; + + /* Publish pci roots. */ + err = xen_pcibk_publish_pci_roots(pdev, + xen_pcibk_publish_pci_root); + if (err) { + xenbus_dev_fatal(pdev->xdev, err, + "Error while publish PCI root" + "buses for frontend"); + goto out; + } + + err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, + state_str, "%d", + XenbusStateInitialised); + if (err) { + xenbus_dev_fatal(pdev->xdev, err, + "Error switching substate of " + "dev-%d\n", i); + goto out; + } + break; + + case XenbusStateClosing: + dev_dbg(&pdev->xdev->dev, "Detaching dev-%d ...\n", i); + + len = snprintf(dev_str, sizeof(dev_str), "vdev-%d", i); + if (unlikely(len >= (sizeof(dev_str) - 1))) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "String overflow while " + "reading configuration"); + goto out; + } + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, + dev_str, "%x:%x:%x.%x", + &domain, &bus, &slot, &func); + if (err < 0) { + xenbus_dev_fatal(pdev->xdev, err, + "Error reading device " + "configuration"); + goto out; + } + if (err != 4) { + err = -EINVAL; + xenbus_dev_fatal(pdev->xdev, err, + "Error parsing pci device " + "configuration"); + goto out; + } + + err = xen_pcibk_remove_device(pdev, domain, bus, slot, + func); + if (err) + goto out; + + /* TODO: If at some point we implement support for pci + * root hot-remove on pcifront side, we'll need to + * remove unnecessary xenstore nodes of pci roots here. + */ + + break; + + default: + break; + } + } + + if (state != XenbusStateReconfiguring) + /* Make sure we only reconfigure once. */ + goto out; + + err = xenbus_switch_state(pdev->xdev, XenbusStateReconfigured); + if (err) { + xenbus_dev_fatal(pdev->xdev, err, + "Error switching to reconfigured state!"); + goto out; + } + +out: + mutex_unlock(&pdev->dev_lock); + return 0; +} + +static void xen_pcibk_frontend_changed(struct xenbus_device *xdev, + enum xenbus_state fe_state) +{ + struct xen_pcibk_device *pdev = dev_get_drvdata(&xdev->dev); + + dev_dbg(&xdev->dev, "fe state changed %d\n", fe_state); + + switch (fe_state) { + case XenbusStateInitialised: + xen_pcibk_attach(pdev); + break; + + case XenbusStateReconfiguring: + xen_pcibk_reconfigure(pdev, XenbusStateReconfiguring); + break; + + case XenbusStateConnected: + /* pcifront switched its state from reconfiguring to connected. + * Then switch to connected state. + */ + xenbus_switch_state(xdev, XenbusStateConnected); + break; + + case XenbusStateClosing: + xen_pcibk_disconnect(pdev); + xenbus_switch_state(xdev, XenbusStateClosing); + break; + + case XenbusStateClosed: + xen_pcibk_disconnect(pdev); + xenbus_switch_state(xdev, XenbusStateClosed); + if (xenbus_dev_is_online(xdev)) + break; + /* fall through if not online */ + case XenbusStateUnknown: + dev_dbg(&xdev->dev, "frontend is gone! unregister device\n"); + device_unregister(&xdev->dev); + break; + + default: + break; + } +} + +static int xen_pcibk_setup_backend(struct xen_pcibk_device *pdev) +{ + /* Get configuration from xend (if available now) */ + int domain, bus, slot, func; + int err = 0; + int i, num_devs; + char dev_str[64]; + char state_str[64]; + + mutex_lock(&pdev->dev_lock); + /* It's possible we could get the call to setup twice, so make sure + * we're not already connected. + */ + if (xenbus_read_driver_state(pdev->xdev->nodename) != + XenbusStateInitWait) + goto out; + + dev_dbg(&pdev->xdev->dev, "getting be setup\n"); + + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d", + &num_devs); + if (err != 1) { + if (err >= 0) + err = -EINVAL; + xenbus_dev_fatal(pdev->xdev, err, + "Error reading number of devices"); + goto out; + } + + for (i = 0; i < num_devs; i++) { + int l = snprintf(dev_str, sizeof(dev_str), "dev-%d", i); + if (unlikely(l >= (sizeof(dev_str) - 1))) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "String overflow while reading " + "configuration"); + goto out; + } + + err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, dev_str, + "%x:%x:%x.%x", &domain, &bus, &slot, &func); + if (err < 0) { + xenbus_dev_fatal(pdev->xdev, err, + "Error reading device configuration"); + goto out; + } + if (err != 4) { + err = -EINVAL; + xenbus_dev_fatal(pdev->xdev, err, + "Error parsing pci device " + "configuration"); + goto out; + } + + err = xen_pcibk_export_device(pdev, domain, bus, slot, func, i); + if (err) + goto out; + + /* Switch substate of this device. */ + l = snprintf(state_str, sizeof(state_str), "state-%d", i); + if (unlikely(l >= (sizeof(state_str) - 1))) { + err = -ENOMEM; + xenbus_dev_fatal(pdev->xdev, err, + "String overflow while reading " + "configuration"); + goto out; + } + err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, state_str, + "%d", XenbusStateInitialised); + if (err) { + xenbus_dev_fatal(pdev->xdev, err, "Error switching " + "substate of dev-%d\n", i); + goto out; + } + } + + err = xen_pcibk_publish_pci_roots(pdev, xen_pcibk_publish_pci_root); + if (err) { + xenbus_dev_fatal(pdev->xdev, err, + "Error while publish PCI root buses " + "for frontend"); + goto out; + } + + err = xenbus_switch_state(pdev->xdev, XenbusStateInitialised); + if (err) + xenbus_dev_fatal(pdev->xdev, err, + "Error switching to initialised state!"); + +out: + mutex_unlock(&pdev->dev_lock); + if (!err) + /* see if pcifront is already configured (if not, we'll wait) */ + xen_pcibk_attach(pdev); + return err; +} + +static void xen_pcibk_be_watch(struct xenbus_watch *watch, + const char *path, const char *token) +{ + struct xen_pcibk_device *pdev = + container_of(watch, struct xen_pcibk_device, be_watch); + + switch (xenbus_read_driver_state(pdev->xdev->nodename)) { + case XenbusStateInitWait: + xen_pcibk_setup_backend(pdev); + break; + + case XenbusStateInitialised: + /* + * We typically move to Initialised when the first device was + * added. Hence subsequent devices getting added may need + * reconfiguring. + */ + xen_pcibk_reconfigure(pdev, XenbusStateInitialised); + break; + + default: + break; + } +} + +static int xen_pcibk_xenbus_probe(struct xenbus_device *dev, + const struct xenbus_device_id *id) +{ + int err = 0; + struct xen_pcibk_device *pdev = alloc_pdev(dev); + + if (pdev == NULL) { + err = -ENOMEM; + xenbus_dev_fatal(dev, err, + "Error allocating xen_pcibk_device struct"); + goto out; + } + + /* wait for xend to configure us */ + err = xenbus_switch_state(dev, XenbusStateInitWait); + if (err) + goto out; + + /* watch the backend node for backend configuration information */ + err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch, + NULL, xen_pcibk_be_watch); + if (err) + goto out; + + pdev->be_watching = 1; + + /* We need to force a call to our callback here in case + * xend already configured us! + */ + xen_pcibk_be_watch(&pdev->be_watch, NULL, 0); + +out: + return err; +} + +static int xen_pcibk_xenbus_remove(struct xenbus_device *dev) +{ + struct xen_pcibk_device *pdev = dev_get_drvdata(&dev->dev); + + if (pdev != NULL) + free_pdev(pdev); + + return 0; +} + +static const struct xenbus_device_id xen_pcibk_ids[] = { + {"pci"}, + {""}, +}; + +static struct xenbus_driver xen_pcibk_driver = { + .name = DRV_NAME, + .ids = xen_pcibk_ids, + .probe = xen_pcibk_xenbus_probe, + .remove = xen_pcibk_xenbus_remove, + .otherend_changed = xen_pcibk_frontend_changed, +}; + +const struct xen_pcibk_backend *__read_mostly xen_pcibk_backend; + +int __init xen_pcibk_xenbus_register(void) +{ + xen_pcibk_backend = &xen_pcibk_vpci_backend; + if (passthrough) + xen_pcibk_backend = &xen_pcibk_passthrough_backend; + pr_info("backend is %s\n", xen_pcibk_backend->name); + return xenbus_register_backend(&xen_pcibk_driver); +} + +void __exit xen_pcibk_xenbus_unregister(void) +{ + xenbus_unregister_driver(&xen_pcibk_driver); +} |