diff options
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 2828 |
1 files changed, 2828 insertions, 0 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c new file mode 100644 index 000000000..e9c3f1e82 --- /dev/null +++ b/drivers/hv/vmbus_drv.c @@ -0,0 +1,2828 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2009, Microsoft Corporation. + * + * Authors: + * Haiyang Zhang <haiyangz@microsoft.com> + * Hank Janssen <hjanssen@microsoft.com> + * K. Y. Srinivasan <kys@microsoft.com> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/sysctl.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/completion.h> +#include <linux/hyperv.h> +#include <linux/kernel_stat.h> +#include <linux/clockchips.h> +#include <linux/cpu.h> +#include <linux/sched/isolation.h> +#include <linux/sched/task_stack.h> + +#include <linux/delay.h> +#include <linux/notifier.h> +#include <linux/panic_notifier.h> +#include <linux/ptrace.h> +#include <linux/screen_info.h> +#include <linux/kdebug.h> +#include <linux/efi.h> +#include <linux/random.h> +#include <linux/kernel.h> +#include <linux/syscore_ops.h> +#include <linux/dma-map-ops.h> +#include <linux/pci.h> +#include <clocksource/hyperv_timer.h> +#include "hyperv_vmbus.h" + +struct vmbus_dynid { + struct list_head node; + struct hv_vmbus_device_id id; +}; + +static struct acpi_device *hv_acpi_dev; + +static int hyperv_cpuhp_online; + +static void *hv_panic_page; + +static long __percpu *vmbus_evt; + +/* Values parsed from ACPI DSDT */ +int vmbus_irq; +int vmbus_interrupt; + +/* + * Boolean to control whether to report panic messages over Hyper-V. + * + * It can be set via /proc/sys/kernel/hyperv_record_panic_msg + */ +static int sysctl_record_panic_msg = 1; + +static int hyperv_report_reg(void) +{ + return !sysctl_record_panic_msg || !hv_panic_page; +} + +static int hyperv_panic_event(struct notifier_block *nb, unsigned long val, + void *args) +{ + struct pt_regs *regs; + + vmbus_initiate_unload(true); + + /* + * Hyper-V should be notified only once about a panic. If we will be + * doing hv_kmsg_dump() with kmsg data later, don't do the notification + * here. + */ + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE + && hyperv_report_reg()) { + regs = current_pt_regs(); + hyperv_report_panic(regs, val, false); + } + return NOTIFY_DONE; +} + +static int hyperv_die_event(struct notifier_block *nb, unsigned long val, + void *args) +{ + struct die_args *die = args; + struct pt_regs *regs = die->regs; + + /* Don't notify Hyper-V if the die event is other than oops */ + if (val != DIE_OOPS) + return NOTIFY_DONE; + + /* + * Hyper-V should be notified only once about a panic. If we will be + * doing hv_kmsg_dump() with kmsg data later, don't do the notification + * here. + */ + if (hyperv_report_reg()) + hyperv_report_panic(regs, val, true); + return NOTIFY_DONE; +} + +static struct notifier_block hyperv_die_block = { + .notifier_call = hyperv_die_event, +}; +static struct notifier_block hyperv_panic_block = { + .notifier_call = hyperv_panic_event, +}; + +static const char *fb_mmio_name = "fb_range"; +static struct resource *fb_mmio; +static struct resource *hyperv_mmio; +static DEFINE_MUTEX(hyperv_mmio_lock); + +static int vmbus_exists(void) +{ + if (hv_acpi_dev == NULL) + return -ENODEV; + + return 0; +} + +static u8 channel_monitor_group(const struct vmbus_channel *channel) +{ + return (u8)channel->offermsg.monitorid / 32; +} + +static u8 channel_monitor_offset(const struct vmbus_channel *channel) +{ + return (u8)channel->offermsg.monitorid % 32; +} + +static u32 channel_pending(const struct vmbus_channel *channel, + const struct hv_monitor_page *monitor_page) +{ + u8 monitor_group = channel_monitor_group(channel); + + return monitor_page->trigger_group[monitor_group].pending; +} + +static u32 channel_latency(const struct vmbus_channel *channel, + const struct hv_monitor_page *monitor_page) +{ + u8 monitor_group = channel_monitor_group(channel); + u8 monitor_offset = channel_monitor_offset(channel); + + return monitor_page->latency[monitor_group][monitor_offset]; +} + +static u32 channel_conn_id(struct vmbus_channel *channel, + struct hv_monitor_page *monitor_page) +{ + u8 monitor_group = channel_monitor_group(channel); + u8 monitor_offset = channel_monitor_offset(channel); + + return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id; +} + +static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid); +} +static DEVICE_ATTR_RO(id); + +static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", hv_dev->channel->state); +} +static DEVICE_ATTR_RO(state); + +static ssize_t monitor_id_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid); +} +static DEVICE_ATTR_RO(monitor_id); + +static ssize_t class_id_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "{%pUl}\n", + &hv_dev->channel->offermsg.offer.if_type); +} +static DEVICE_ATTR_RO(class_id); + +static ssize_t device_id_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "{%pUl}\n", + &hv_dev->channel->offermsg.offer.if_instance); +} +static DEVICE_ATTR_RO(device_id); + +static ssize_t modalias_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type); +} +static DEVICE_ATTR_RO(modalias); + +#ifdef CONFIG_NUMA +static ssize_t numa_node_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + + return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu)); +} +static DEVICE_ATTR_RO(numa_node); +#endif + +static ssize_t server_monitor_pending_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", + channel_pending(hv_dev->channel, + vmbus_connection.monitor_pages[0])); +} +static DEVICE_ATTR_RO(server_monitor_pending); + +static ssize_t client_monitor_pending_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", + channel_pending(hv_dev->channel, + vmbus_connection.monitor_pages[1])); +} +static DEVICE_ATTR_RO(client_monitor_pending); + +static ssize_t server_monitor_latency_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", + channel_latency(hv_dev->channel, + vmbus_connection.monitor_pages[0])); +} +static DEVICE_ATTR_RO(server_monitor_latency); + +static ssize_t client_monitor_latency_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", + channel_latency(hv_dev->channel, + vmbus_connection.monitor_pages[1])); +} +static DEVICE_ATTR_RO(client_monitor_latency); + +static ssize_t server_monitor_conn_id_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", + channel_conn_id(hv_dev->channel, + vmbus_connection.monitor_pages[0])); +} +static DEVICE_ATTR_RO(server_monitor_conn_id); + +static ssize_t client_monitor_conn_id_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + if (!hv_dev->channel) + return -ENODEV; + return sprintf(buf, "%d\n", + channel_conn_id(hv_dev->channel, + vmbus_connection.monitor_pages[1])); +} +static DEVICE_ATTR_RO(client_monitor_conn_id); + +static ssize_t out_intr_mask_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info outbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, + &outbound); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", outbound.current_interrupt_mask); +} +static DEVICE_ATTR_RO(out_intr_mask); + +static ssize_t out_read_index_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info outbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, + &outbound); + if (ret < 0) + return ret; + return sprintf(buf, "%d\n", outbound.current_read_index); +} +static DEVICE_ATTR_RO(out_read_index); + +static ssize_t out_write_index_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info outbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, + &outbound); + if (ret < 0) + return ret; + return sprintf(buf, "%d\n", outbound.current_write_index); +} +static DEVICE_ATTR_RO(out_write_index); + +static ssize_t out_read_bytes_avail_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info outbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, + &outbound); + if (ret < 0) + return ret; + return sprintf(buf, "%d\n", outbound.bytes_avail_toread); +} +static DEVICE_ATTR_RO(out_read_bytes_avail); + +static ssize_t out_write_bytes_avail_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info outbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, + &outbound); + if (ret < 0) + return ret; + return sprintf(buf, "%d\n", outbound.bytes_avail_towrite); +} +static DEVICE_ATTR_RO(out_write_bytes_avail); + +static ssize_t in_intr_mask_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info inbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", inbound.current_interrupt_mask); +} +static DEVICE_ATTR_RO(in_intr_mask); + +static ssize_t in_read_index_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info inbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", inbound.current_read_index); +} +static DEVICE_ATTR_RO(in_read_index); + +static ssize_t in_write_index_show(struct device *dev, + struct device_attribute *dev_attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info inbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", inbound.current_write_index); +} +static DEVICE_ATTR_RO(in_write_index); + +static ssize_t in_read_bytes_avail_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info inbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", inbound.bytes_avail_toread); +} +static DEVICE_ATTR_RO(in_read_bytes_avail); + +static ssize_t in_write_bytes_avail_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct hv_ring_buffer_debug_info inbound; + int ret; + + if (!hv_dev->channel) + return -ENODEV; + + ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound); + if (ret < 0) + return ret; + + return sprintf(buf, "%d\n", inbound.bytes_avail_towrite); +} +static DEVICE_ATTR_RO(in_write_bytes_avail); + +static ssize_t channel_vp_mapping_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + struct vmbus_channel *channel = hv_dev->channel, *cur_sc; + int buf_size = PAGE_SIZE, n_written, tot_written; + struct list_head *cur; + + if (!channel) + return -ENODEV; + + mutex_lock(&vmbus_connection.channel_mutex); + + tot_written = snprintf(buf, buf_size, "%u:%u\n", + channel->offermsg.child_relid, channel->target_cpu); + + list_for_each(cur, &channel->sc_list) { + if (tot_written >= buf_size - 1) + break; + + cur_sc = list_entry(cur, struct vmbus_channel, sc_list); + n_written = scnprintf(buf + tot_written, + buf_size - tot_written, + "%u:%u\n", + cur_sc->offermsg.child_relid, + cur_sc->target_cpu); + tot_written += n_written; + } + + mutex_unlock(&vmbus_connection.channel_mutex); + + return tot_written; +} +static DEVICE_ATTR_RO(channel_vp_mapping); + +static ssize_t vendor_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + return sprintf(buf, "0x%x\n", hv_dev->vendor_id); +} +static DEVICE_ATTR_RO(vendor); + +static ssize_t device_show(struct device *dev, + struct device_attribute *dev_attr, + char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + + return sprintf(buf, "0x%x\n", hv_dev->device_id); +} +static DEVICE_ATTR_RO(device); + +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + int ret; + + ret = driver_set_override(dev, &hv_dev->driver_override, buf, count); + if (ret) + return ret; + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct hv_device *hv_dev = device_to_hv_device(dev); + ssize_t len; + + device_lock(dev); + len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override); + device_unlock(dev); + + return len; +} +static DEVICE_ATTR_RW(driver_override); + +/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */ +static struct attribute *vmbus_dev_attrs[] = { + &dev_attr_id.attr, + &dev_attr_state.attr, + &dev_attr_monitor_id.attr, + &dev_attr_class_id.attr, + &dev_attr_device_id.attr, + &dev_attr_modalias.attr, +#ifdef CONFIG_NUMA + &dev_attr_numa_node.attr, +#endif + &dev_attr_server_monitor_pending.attr, + &dev_attr_client_monitor_pending.attr, + &dev_attr_server_monitor_latency.attr, + &dev_attr_client_monitor_latency.attr, + &dev_attr_server_monitor_conn_id.attr, + &dev_attr_client_monitor_conn_id.attr, + &dev_attr_out_intr_mask.attr, + &dev_attr_out_read_index.attr, + &dev_attr_out_write_index.attr, + &dev_attr_out_read_bytes_avail.attr, + &dev_attr_out_write_bytes_avail.attr, + &dev_attr_in_intr_mask.attr, + &dev_attr_in_read_index.attr, + &dev_attr_in_write_index.attr, + &dev_attr_in_read_bytes_avail.attr, + &dev_attr_in_write_bytes_avail.attr, + &dev_attr_channel_vp_mapping.attr, + &dev_attr_vendor.attr, + &dev_attr_device.attr, + &dev_attr_driver_override.attr, + NULL, +}; + +/* + * Device-level attribute_group callback function. Returns the permission for + * each attribute, and returns 0 if an attribute is not visible. + */ +static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int idx) +{ + struct device *dev = kobj_to_dev(kobj); + const struct hv_device *hv_dev = device_to_hv_device(dev); + + /* Hide the monitor attributes if the monitor mechanism is not used. */ + if (!hv_dev->channel->offermsg.monitor_allocated && + (attr == &dev_attr_monitor_id.attr || + attr == &dev_attr_server_monitor_pending.attr || + attr == &dev_attr_client_monitor_pending.attr || + attr == &dev_attr_server_monitor_latency.attr || + attr == &dev_attr_client_monitor_latency.attr || + attr == &dev_attr_server_monitor_conn_id.attr || + attr == &dev_attr_client_monitor_conn_id.attr)) + return 0; + + return attr->mode; +} + +static const struct attribute_group vmbus_dev_group = { + .attrs = vmbus_dev_attrs, + .is_visible = vmbus_dev_attr_is_visible +}; +__ATTRIBUTE_GROUPS(vmbus_dev); + +/* Set up the attribute for /sys/bus/vmbus/hibernation */ +static ssize_t hibernation_show(struct bus_type *bus, char *buf) +{ + return sprintf(buf, "%d\n", !!hv_is_hibernation_supported()); +} + +static BUS_ATTR_RO(hibernation); + +static struct attribute *vmbus_bus_attrs[] = { + &bus_attr_hibernation.attr, + NULL, +}; +static const struct attribute_group vmbus_bus_group = { + .attrs = vmbus_bus_attrs, +}; +__ATTRIBUTE_GROUPS(vmbus_bus); + +/* + * vmbus_uevent - add uevent for our device + * + * This routine is invoked when a device is added or removed on the vmbus to + * generate a uevent to udev in the userspace. The udev will then look at its + * rule and the uevent generated here to load the appropriate driver + * + * The alias string will be of the form vmbus:guid where guid is the string + * representation of the device guid (each byte of the guid will be + * represented with two hex characters. + */ +static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env) +{ + struct hv_device *dev = device_to_hv_device(device); + const char *format = "MODALIAS=vmbus:%*phN"; + + return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type); +} + +static const struct hv_vmbus_device_id * +hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid) +{ + if (id == NULL) + return NULL; /* empty device table */ + + for (; !guid_is_null(&id->guid); id++) + if (guid_equal(&id->guid, guid)) + return id; + + return NULL; +} + +static const struct hv_vmbus_device_id * +hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid) +{ + const struct hv_vmbus_device_id *id = NULL; + struct vmbus_dynid *dynid; + + spin_lock(&drv->dynids.lock); + list_for_each_entry(dynid, &drv->dynids.list, node) { + if (guid_equal(&dynid->id.guid, guid)) { + id = &dynid->id; + break; + } + } + spin_unlock(&drv->dynids.lock); + + return id; +} + +static const struct hv_vmbus_device_id vmbus_device_null; + +/* + * Return a matching hv_vmbus_device_id pointer. + * If there is no match, return NULL. + */ +static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv, + struct hv_device *dev) +{ + const guid_t *guid = &dev->dev_type; + const struct hv_vmbus_device_id *id; + + /* When driver_override is set, only bind to the matching driver */ + if (dev->driver_override && strcmp(dev->driver_override, drv->name)) + return NULL; + + /* Look at the dynamic ids first, before the static ones */ + id = hv_vmbus_dynid_match(drv, guid); + if (!id) + id = hv_vmbus_dev_match(drv->id_table, guid); + + /* driver_override will always match, send a dummy id */ + if (!id && dev->driver_override) + id = &vmbus_device_null; + + return id; +} + +/* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */ +static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid) +{ + struct vmbus_dynid *dynid; + + dynid = kzalloc(sizeof(*dynid), GFP_KERNEL); + if (!dynid) + return -ENOMEM; + + dynid->id.guid = *guid; + + spin_lock(&drv->dynids.lock); + list_add_tail(&dynid->node, &drv->dynids.list); + spin_unlock(&drv->dynids.lock); + + return driver_attach(&drv->driver); +} + +static void vmbus_free_dynids(struct hv_driver *drv) +{ + struct vmbus_dynid *dynid, *n; + + spin_lock(&drv->dynids.lock); + list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { + list_del(&dynid->node); + kfree(dynid); + } + spin_unlock(&drv->dynids.lock); +} + +/* + * store_new_id - sysfs frontend to vmbus_add_dynid() + * + * Allow GUIDs to be added to an existing driver via sysfs. + */ +static ssize_t new_id_store(struct device_driver *driver, const char *buf, + size_t count) +{ + struct hv_driver *drv = drv_to_hv_drv(driver); + guid_t guid; + ssize_t retval; + + retval = guid_parse(buf, &guid); + if (retval) + return retval; + + if (hv_vmbus_dynid_match(drv, &guid)) + return -EEXIST; + + retval = vmbus_add_dynid(drv, &guid); + if (retval) + return retval; + return count; +} +static DRIVER_ATTR_WO(new_id); + +/* + * store_remove_id - remove a PCI device ID from this driver + * + * Removes a dynamic pci device ID to this driver. + */ +static ssize_t remove_id_store(struct device_driver *driver, const char *buf, + size_t count) +{ + struct hv_driver *drv = drv_to_hv_drv(driver); + struct vmbus_dynid *dynid, *n; + guid_t guid; + ssize_t retval; + + retval = guid_parse(buf, &guid); + if (retval) + return retval; + + retval = -ENODEV; + spin_lock(&drv->dynids.lock); + list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { + struct hv_vmbus_device_id *id = &dynid->id; + + if (guid_equal(&id->guid, &guid)) { + list_del(&dynid->node); + kfree(dynid); + retval = count; + break; + } + } + spin_unlock(&drv->dynids.lock); + + return retval; +} +static DRIVER_ATTR_WO(remove_id); + +static struct attribute *vmbus_drv_attrs[] = { + &driver_attr_new_id.attr, + &driver_attr_remove_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(vmbus_drv); + + +/* + * vmbus_match - Attempt to match the specified device to the specified driver + */ +static int vmbus_match(struct device *device, struct device_driver *driver) +{ + struct hv_driver *drv = drv_to_hv_drv(driver); + struct hv_device *hv_dev = device_to_hv_device(device); + + /* The hv_sock driver handles all hv_sock offers. */ + if (is_hvsock_channel(hv_dev->channel)) + return drv->hvsock; + + if (hv_vmbus_get_id(drv, hv_dev)) + return 1; + + return 0; +} + +/* + * vmbus_probe - Add the new vmbus's child device + */ +static int vmbus_probe(struct device *child_device) +{ + int ret = 0; + struct hv_driver *drv = + drv_to_hv_drv(child_device->driver); + struct hv_device *dev = device_to_hv_device(child_device); + const struct hv_vmbus_device_id *dev_id; + + dev_id = hv_vmbus_get_id(drv, dev); + if (drv->probe) { + ret = drv->probe(dev, dev_id); + if (ret != 0) + pr_err("probe failed for device %s (%d)\n", + dev_name(child_device), ret); + + } else { + pr_err("probe not set for driver %s\n", + dev_name(child_device)); + ret = -ENODEV; + } + return ret; +} + +/* + * vmbus_dma_configure -- Configure DMA coherence for VMbus device + */ +static int vmbus_dma_configure(struct device *child_device) +{ + /* + * On ARM64, propagate the DMA coherence setting from the top level + * VMbus ACPI device to the child VMbus device being added here. + * On x86/x64 coherence is assumed and these calls have no effect. + */ + hv_setup_dma_ops(child_device, + device_get_dma_attr(&hv_acpi_dev->dev) == DEV_DMA_COHERENT); + return 0; +} + +/* + * vmbus_remove - Remove a vmbus device + */ +static void vmbus_remove(struct device *child_device) +{ + struct hv_driver *drv; + struct hv_device *dev = device_to_hv_device(child_device); + + if (child_device->driver) { + drv = drv_to_hv_drv(child_device->driver); + if (drv->remove) + drv->remove(dev); + } +} + +/* + * vmbus_shutdown - Shutdown a vmbus device + */ +static void vmbus_shutdown(struct device *child_device) +{ + struct hv_driver *drv; + struct hv_device *dev = device_to_hv_device(child_device); + + + /* The device may not be attached yet */ + if (!child_device->driver) + return; + + drv = drv_to_hv_drv(child_device->driver); + + if (drv->shutdown) + drv->shutdown(dev); +} + +#ifdef CONFIG_PM_SLEEP +/* + * vmbus_suspend - Suspend a vmbus device + */ +static int vmbus_suspend(struct device *child_device) +{ + struct hv_driver *drv; + struct hv_device *dev = device_to_hv_device(child_device); + + /* The device may not be attached yet */ + if (!child_device->driver) + return 0; + + drv = drv_to_hv_drv(child_device->driver); + if (!drv->suspend) + return -EOPNOTSUPP; + + return drv->suspend(dev); +} + +/* + * vmbus_resume - Resume a vmbus device + */ +static int vmbus_resume(struct device *child_device) +{ + struct hv_driver *drv; + struct hv_device *dev = device_to_hv_device(child_device); + + /* The device may not be attached yet */ + if (!child_device->driver) + return 0; + + drv = drv_to_hv_drv(child_device->driver); + if (!drv->resume) + return -EOPNOTSUPP; + + return drv->resume(dev); +} +#else +#define vmbus_suspend NULL +#define vmbus_resume NULL +#endif /* CONFIG_PM_SLEEP */ + +/* + * vmbus_device_release - Final callback release of the vmbus child device + */ +static void vmbus_device_release(struct device *device) +{ + struct hv_device *hv_dev = device_to_hv_device(device); + struct vmbus_channel *channel = hv_dev->channel; + + hv_debug_rm_dev_dir(hv_dev); + + mutex_lock(&vmbus_connection.channel_mutex); + hv_process_channel_removal(channel); + mutex_unlock(&vmbus_connection.channel_mutex); + kfree(hv_dev); +} + +/* + * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm. + * + * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we + * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there + * is no way to wake up a Generation-2 VM. + * + * The other 4 ops are for hibernation. + */ + +static const struct dev_pm_ops vmbus_pm = { + .suspend_noirq = NULL, + .resume_noirq = NULL, + .freeze_noirq = vmbus_suspend, + .thaw_noirq = vmbus_resume, + .poweroff_noirq = vmbus_suspend, + .restore_noirq = vmbus_resume, +}; + +/* The one and only one */ +static struct bus_type hv_bus = { + .name = "vmbus", + .match = vmbus_match, + .shutdown = vmbus_shutdown, + .remove = vmbus_remove, + .probe = vmbus_probe, + .uevent = vmbus_uevent, + .dma_configure = vmbus_dma_configure, + .dev_groups = vmbus_dev_groups, + .drv_groups = vmbus_drv_groups, + .bus_groups = vmbus_bus_groups, + .pm = &vmbus_pm, +}; + +struct onmessage_work_context { + struct work_struct work; + struct { + struct hv_message_header header; + u8 payload[]; + } msg; +}; + +static void vmbus_onmessage_work(struct work_struct *work) +{ + struct onmessage_work_context *ctx; + + /* Do not process messages if we're in DISCONNECTED state */ + if (vmbus_connection.conn_state == DISCONNECTED) + return; + + ctx = container_of(work, struct onmessage_work_context, + work); + vmbus_onmessage((struct vmbus_channel_message_header *) + &ctx->msg.payload); + kfree(ctx); +} + +void vmbus_on_msg_dpc(unsigned long data) +{ + struct hv_per_cpu_context *hv_cpu = (void *)data; + void *page_addr = hv_cpu->synic_message_page; + struct hv_message msg_copy, *msg = (struct hv_message *)page_addr + + VMBUS_MESSAGE_SINT; + struct vmbus_channel_message_header *hdr; + enum vmbus_channel_message_type msgtype; + const struct vmbus_channel_message_table_entry *entry; + struct onmessage_work_context *ctx; + __u8 payload_size; + u32 message_type; + + /* + * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as + * it is being used in 'struct vmbus_channel_message_header' definition + * which is supposed to match hypervisor ABI. + */ + BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32)); + + /* + * Since the message is in memory shared with the host, an erroneous or + * malicious Hyper-V could modify the message while vmbus_on_msg_dpc() + * or individual message handlers are executing; to prevent this, copy + * the message into private memory. + */ + memcpy(&msg_copy, msg, sizeof(struct hv_message)); + + message_type = msg_copy.header.message_type; + if (message_type == HVMSG_NONE) + /* no msg */ + return; + + hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload; + msgtype = hdr->msgtype; + + trace_vmbus_on_msg_dpc(hdr); + + if (msgtype >= CHANNELMSG_COUNT) { + WARN_ONCE(1, "unknown msgtype=%d\n", msgtype); + goto msg_handled; + } + + payload_size = msg_copy.header.payload_size; + if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) { + WARN_ONCE(1, "payload size is too large (%d)\n", payload_size); + goto msg_handled; + } + + entry = &channel_message_table[msgtype]; + + if (!entry->message_handler) + goto msg_handled; + + if (payload_size < entry->min_payload_len) { + WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size); + goto msg_handled; + } + + if (entry->handler_type == VMHT_BLOCKING) { + ctx = kmalloc(struct_size(ctx, msg.payload, payload_size), GFP_ATOMIC); + if (ctx == NULL) + return; + + INIT_WORK(&ctx->work, vmbus_onmessage_work); + ctx->msg.header = msg_copy.header; + memcpy(&ctx->msg.payload, msg_copy.u.payload, payload_size); + + /* + * The host can generate a rescind message while we + * may still be handling the original offer. We deal with + * this condition by relying on the synchronization provided + * by offer_in_progress and by channel_mutex. See also the + * inline comments in vmbus_onoffer_rescind(). + */ + switch (msgtype) { + case CHANNELMSG_RESCIND_CHANNELOFFER: + /* + * If we are handling the rescind message; + * schedule the work on the global work queue. + * + * The OFFER message and the RESCIND message should + * not be handled by the same serialized work queue, + * because the OFFER handler may call vmbus_open(), + * which tries to open the channel by sending an + * OPEN_CHANNEL message to the host and waits for + * the host's response; however, if the host has + * rescinded the channel before it receives the + * OPEN_CHANNEL message, the host just silently + * ignores the OPEN_CHANNEL message; as a result, + * the guest's OFFER handler hangs for ever, if we + * handle the RESCIND message in the same serialized + * work queue: the RESCIND handler can not start to + * run before the OFFER handler finishes. + */ + if (vmbus_connection.ignore_any_offer_msg) + break; + queue_work(vmbus_connection.rescind_work_queue, &ctx->work); + break; + + case CHANNELMSG_OFFERCHANNEL: + /* + * The host sends the offer message of a given channel + * before sending the rescind message of the same + * channel. These messages are sent to the guest's + * connect CPU; the guest then starts processing them + * in the tasklet handler on this CPU: + * + * VMBUS_CONNECT_CPU + * + * [vmbus_on_msg_dpc()] + * atomic_inc() // CHANNELMSG_OFFERCHANNEL + * queue_work() + * ... + * [vmbus_on_msg_dpc()] + * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER + * + * We rely on the memory-ordering properties of the + * queue_work() and schedule_work() primitives, which + * guarantee that the atomic increment will be visible + * to the CPUs which will execute the offer & rescind + * works by the time these works will start execution. + */ + if (vmbus_connection.ignore_any_offer_msg) + break; + atomic_inc(&vmbus_connection.offer_in_progress); + fallthrough; + + default: + queue_work(vmbus_connection.work_queue, &ctx->work); + } + } else + entry->message_handler(hdr); + +msg_handled: + vmbus_signal_eom(msg, message_type); +} + +#ifdef CONFIG_PM_SLEEP +/* + * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for + * hibernation, because hv_sock connections can not persist across hibernation. + */ +static void vmbus_force_channel_rescinded(struct vmbus_channel *channel) +{ + struct onmessage_work_context *ctx; + struct vmbus_channel_rescind_offer *rescind; + + WARN_ON(!is_hvsock_channel(channel)); + + /* + * Allocation size is small and the allocation should really not fail, + * otherwise the state of the hv_sock connections ends up in limbo. + */ + ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind), + GFP_KERNEL | __GFP_NOFAIL); + + /* + * So far, these are not really used by Linux. Just set them to the + * reasonable values conforming to the definitions of the fields. + */ + ctx->msg.header.message_type = 1; + ctx->msg.header.payload_size = sizeof(*rescind); + + /* These values are actually used by Linux. */ + rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload; + rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER; + rescind->child_relid = channel->offermsg.child_relid; + + INIT_WORK(&ctx->work, vmbus_onmessage_work); + + queue_work(vmbus_connection.work_queue, &ctx->work); +} +#endif /* CONFIG_PM_SLEEP */ + +/* + * Schedule all channels with events pending + */ +static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu) +{ + unsigned long *recv_int_page; + u32 maxbits, relid; + + /* + * The event page can be directly checked to get the id of + * the channel that has the interrupt pending. + */ + void *page_addr = hv_cpu->synic_event_page; + union hv_synic_event_flags *event + = (union hv_synic_event_flags *)page_addr + + VMBUS_MESSAGE_SINT; + + maxbits = HV_EVENT_FLAGS_COUNT; + recv_int_page = event->flags; + + if (unlikely(!recv_int_page)) + return; + + for_each_set_bit(relid, recv_int_page, maxbits) { + void (*callback_fn)(void *context); + struct vmbus_channel *channel; + + if (!sync_test_and_clear_bit(relid, recv_int_page)) + continue; + + /* Special case - vmbus channel protocol msg */ + if (relid == 0) + continue; + + /* + * Pairs with the kfree_rcu() in vmbus_chan_release(). + * Guarantees that the channel data structure doesn't + * get freed while the channel pointer below is being + * dereferenced. + */ + rcu_read_lock(); + + /* Find channel based on relid */ + channel = relid2channel(relid); + if (channel == NULL) + goto sched_unlock_rcu; + + if (channel->rescind) + goto sched_unlock_rcu; + + /* + * Make sure that the ring buffer data structure doesn't get + * freed while we dereference the ring buffer pointer. Test + * for the channel's onchannel_callback being NULL within a + * sched_lock critical section. See also the inline comments + * in vmbus_reset_channel_cb(). + */ + spin_lock(&channel->sched_lock); + + callback_fn = channel->onchannel_callback; + if (unlikely(callback_fn == NULL)) + goto sched_unlock; + + trace_vmbus_chan_sched(channel); + + ++channel->interrupts; + + switch (channel->callback_mode) { + case HV_CALL_ISR: + (*callback_fn)(channel->channel_callback_context); + break; + + case HV_CALL_BATCHED: + hv_begin_read(&channel->inbound); + fallthrough; + case HV_CALL_DIRECT: + tasklet_schedule(&channel->callback_event); + } + +sched_unlock: + spin_unlock(&channel->sched_lock); +sched_unlock_rcu: + rcu_read_unlock(); + } +} + +static void vmbus_isr(void) +{ + struct hv_per_cpu_context *hv_cpu + = this_cpu_ptr(hv_context.cpu_context); + void *page_addr; + struct hv_message *msg; + + vmbus_chan_sched(hv_cpu); + + page_addr = hv_cpu->synic_message_page; + msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; + + /* Check if there are actual msgs to be processed */ + if (msg->header.message_type != HVMSG_NONE) { + if (msg->header.message_type == HVMSG_TIMER_EXPIRED) { + hv_stimer0_isr(); + vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED); + } else + tasklet_schedule(&hv_cpu->msg_dpc); + } + + add_interrupt_randomness(vmbus_interrupt); +} + +static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id) +{ + vmbus_isr(); + return IRQ_HANDLED; +} + +/* + * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg + * buffer and call into Hyper-V to transfer the data. + */ +static void hv_kmsg_dump(struct kmsg_dumper *dumper, + enum kmsg_dump_reason reason) +{ + struct kmsg_dump_iter iter; + size_t bytes_written; + + /* We are only interested in panics. */ + if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg)) + return; + + /* + * Write dump contents to the page. No need to synchronize; panic should + * be single-threaded. + */ + kmsg_dump_rewind(&iter); + kmsg_dump_get_buffer(&iter, false, hv_panic_page, HV_HYP_PAGE_SIZE, + &bytes_written); + if (!bytes_written) + return; + /* + * P3 to contain the physical address of the panic page & P4 to + * contain the size of the panic data in that page. Rest of the + * registers are no-op when the NOTIFY_MSG flag is set. + */ + hv_set_register(HV_REGISTER_CRASH_P0, 0); + hv_set_register(HV_REGISTER_CRASH_P1, 0); + hv_set_register(HV_REGISTER_CRASH_P2, 0); + hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page)); + hv_set_register(HV_REGISTER_CRASH_P4, bytes_written); + + /* + * Let Hyper-V know there is crash data available along with + * the panic message. + */ + hv_set_register(HV_REGISTER_CRASH_CTL, + (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG)); +} + +static struct kmsg_dumper hv_kmsg_dumper = { + .dump = hv_kmsg_dump, +}; + +static void hv_kmsg_dump_register(void) +{ + int ret; + + hv_panic_page = hv_alloc_hyperv_zeroed_page(); + if (!hv_panic_page) { + pr_err("Hyper-V: panic message page memory allocation failed\n"); + return; + } + + ret = kmsg_dump_register(&hv_kmsg_dumper); + if (ret) { + pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret); + hv_free_hyperv_page((unsigned long)hv_panic_page); + hv_panic_page = NULL; + } +} + +static struct ctl_table_header *hv_ctl_table_hdr; + +/* + * sysctl option to allow the user to control whether kmsg data should be + * reported to Hyper-V on panic. + */ +static struct ctl_table hv_ctl_table[] = { + { + .procname = "hyperv_record_panic_msg", + .data = &sysctl_record_panic_msg, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE + }, + {} +}; + +static struct ctl_table hv_root_table[] = { + { + .procname = "kernel", + .mode = 0555, + .child = hv_ctl_table + }, + {} +}; + +/* + * vmbus_bus_init -Main vmbus driver initialization routine. + * + * Here, we + * - initialize the vmbus driver context + * - invoke the vmbus hv main init routine + * - retrieve the channel offers + */ +static int vmbus_bus_init(void) +{ + int ret; + + ret = hv_init(); + if (ret != 0) { + pr_err("Unable to initialize the hypervisor - 0x%x\n", ret); + return ret; + } + + ret = bus_register(&hv_bus); + if (ret) + return ret; + + /* + * VMbus interrupts are best modeled as per-cpu interrupts. If + * on an architecture with support for per-cpu IRQs (e.g. ARM64), + * allocate a per-cpu IRQ using standard Linux kernel functionality. + * If not on such an architecture (e.g., x86/x64), then rely on + * code in the arch-specific portion of the code tree to connect + * the VMbus interrupt handler. + */ + + if (vmbus_irq == -1) { + hv_setup_vmbus_handler(vmbus_isr); + } else { + vmbus_evt = alloc_percpu(long); + ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr, + "Hyper-V VMbus", vmbus_evt); + if (ret) { + pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d", + vmbus_irq, ret); + free_percpu(vmbus_evt); + goto err_setup; + } + } + + ret = hv_synic_alloc(); + if (ret) + goto err_alloc; + + /* + * Initialize the per-cpu interrupt state and stimer state. + * Then connect to the host. + */ + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online", + hv_synic_init, hv_synic_cleanup); + if (ret < 0) + goto err_alloc; + hyperv_cpuhp_online = ret; + + ret = vmbus_connect(); + if (ret) + goto err_connect; + + if (hv_is_isolation_supported()) + sysctl_record_panic_msg = 0; + + /* + * Only register if the crash MSRs are available + */ + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { + u64 hyperv_crash_ctl; + /* + * Panic message recording (sysctl_record_panic_msg) + * is enabled by default in non-isolated guests and + * disabled by default in isolated guests; the panic + * message recording won't be available in isolated + * guests should the following registration fail. + */ + hv_ctl_table_hdr = register_sysctl_table(hv_root_table); + if (!hv_ctl_table_hdr) + pr_err("Hyper-V: sysctl table register error"); + + /* + * Register for panic kmsg callback only if the right + * capability is supported by the hypervisor. + */ + hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL); + if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) + hv_kmsg_dump_register(); + + register_die_notifier(&hyperv_die_block); + } + + /* + * Always register the panic notifier because we need to unload + * the VMbus channel connection to prevent any VMbus + * activity after the VM panics. + */ + atomic_notifier_chain_register(&panic_notifier_list, + &hyperv_panic_block); + + vmbus_request_offers(); + + return 0; + +err_connect: + cpuhp_remove_state(hyperv_cpuhp_online); +err_alloc: + hv_synic_free(); + if (vmbus_irq == -1) { + hv_remove_vmbus_handler(); + } else { + free_percpu_irq(vmbus_irq, vmbus_evt); + free_percpu(vmbus_evt); + } +err_setup: + bus_unregister(&hv_bus); + unregister_sysctl_table(hv_ctl_table_hdr); + hv_ctl_table_hdr = NULL; + return ret; +} + +/** + * __vmbus_driver_register() - Register a vmbus's driver + * @hv_driver: Pointer to driver structure you want to register + * @owner: owner module of the drv + * @mod_name: module name string + * + * Registers the given driver with Linux through the 'driver_register()' call + * and sets up the hyper-v vmbus handling for this driver. + * It will return the state of the 'driver_register()' call. + * + */ +int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name) +{ + int ret; + + pr_info("registering driver %s\n", hv_driver->name); + + ret = vmbus_exists(); + if (ret < 0) + return ret; + + hv_driver->driver.name = hv_driver->name; + hv_driver->driver.owner = owner; + hv_driver->driver.mod_name = mod_name; + hv_driver->driver.bus = &hv_bus; + + spin_lock_init(&hv_driver->dynids.lock); + INIT_LIST_HEAD(&hv_driver->dynids.list); + + ret = driver_register(&hv_driver->driver); + + return ret; +} +EXPORT_SYMBOL_GPL(__vmbus_driver_register); + +/** + * vmbus_driver_unregister() - Unregister a vmbus's driver + * @hv_driver: Pointer to driver structure you want to + * un-register + * + * Un-register the given driver that was previous registered with a call to + * vmbus_driver_register() + */ +void vmbus_driver_unregister(struct hv_driver *hv_driver) +{ + pr_info("unregistering driver %s\n", hv_driver->name); + + if (!vmbus_exists()) { + driver_unregister(&hv_driver->driver); + vmbus_free_dynids(hv_driver); + } +} +EXPORT_SYMBOL_GPL(vmbus_driver_unregister); + + +/* + * Called when last reference to channel is gone. + */ +static void vmbus_chan_release(struct kobject *kobj) +{ + struct vmbus_channel *channel + = container_of(kobj, struct vmbus_channel, kobj); + + kfree_rcu(channel, rcu); +} + +struct vmbus_chan_attribute { + struct attribute attr; + ssize_t (*show)(struct vmbus_channel *chan, char *buf); + ssize_t (*store)(struct vmbus_channel *chan, + const char *buf, size_t count); +}; +#define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \ + struct vmbus_chan_attribute chan_attr_##_name \ + = __ATTR(_name, _mode, _show, _store) +#define VMBUS_CHAN_ATTR_RW(_name) \ + struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name) +#define VMBUS_CHAN_ATTR_RO(_name) \ + struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name) +#define VMBUS_CHAN_ATTR_WO(_name) \ + struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name) + +static ssize_t vmbus_chan_attr_show(struct kobject *kobj, + struct attribute *attr, char *buf) +{ + const struct vmbus_chan_attribute *attribute + = container_of(attr, struct vmbus_chan_attribute, attr); + struct vmbus_channel *chan + = container_of(kobj, struct vmbus_channel, kobj); + + if (!attribute->show) + return -EIO; + + return attribute->show(chan, buf); +} + +static ssize_t vmbus_chan_attr_store(struct kobject *kobj, + struct attribute *attr, const char *buf, + size_t count) +{ + const struct vmbus_chan_attribute *attribute + = container_of(attr, struct vmbus_chan_attribute, attr); + struct vmbus_channel *chan + = container_of(kobj, struct vmbus_channel, kobj); + + if (!attribute->store) + return -EIO; + + return attribute->store(chan, buf, count); +} + +static const struct sysfs_ops vmbus_chan_sysfs_ops = { + .show = vmbus_chan_attr_show, + .store = vmbus_chan_attr_store, +}; + +static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf) +{ + struct hv_ring_buffer_info *rbi = &channel->outbound; + ssize_t ret; + + mutex_lock(&rbi->ring_buffer_mutex); + if (!rbi->ring_buffer) { + mutex_unlock(&rbi->ring_buffer_mutex); + return -EINVAL; + } + + ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); + mutex_unlock(&rbi->ring_buffer_mutex); + return ret; +} +static VMBUS_CHAN_ATTR_RO(out_mask); + +static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf) +{ + struct hv_ring_buffer_info *rbi = &channel->inbound; + ssize_t ret; + + mutex_lock(&rbi->ring_buffer_mutex); + if (!rbi->ring_buffer) { + mutex_unlock(&rbi->ring_buffer_mutex); + return -EINVAL; + } + + ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); + mutex_unlock(&rbi->ring_buffer_mutex); + return ret; +} +static VMBUS_CHAN_ATTR_RO(in_mask); + +static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf) +{ + struct hv_ring_buffer_info *rbi = &channel->inbound; + ssize_t ret; + + mutex_lock(&rbi->ring_buffer_mutex); + if (!rbi->ring_buffer) { + mutex_unlock(&rbi->ring_buffer_mutex); + return -EINVAL; + } + + ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi)); + mutex_unlock(&rbi->ring_buffer_mutex); + return ret; +} +static VMBUS_CHAN_ATTR_RO(read_avail); + +static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf) +{ + struct hv_ring_buffer_info *rbi = &channel->outbound; + ssize_t ret; + + mutex_lock(&rbi->ring_buffer_mutex); + if (!rbi->ring_buffer) { + mutex_unlock(&rbi->ring_buffer_mutex); + return -EINVAL; + } + + ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi)); + mutex_unlock(&rbi->ring_buffer_mutex); + return ret; +} +static VMBUS_CHAN_ATTR_RO(write_avail); + +static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf) +{ + return sprintf(buf, "%u\n", channel->target_cpu); +} +static ssize_t target_cpu_store(struct vmbus_channel *channel, + const char *buf, size_t count) +{ + u32 target_cpu, origin_cpu; + ssize_t ret = count; + + if (vmbus_proto_version < VERSION_WIN10_V4_1) + return -EIO; + + if (sscanf(buf, "%uu", &target_cpu) != 1) + return -EIO; + + /* Validate target_cpu for the cpumask_test_cpu() operation below. */ + if (target_cpu >= nr_cpumask_bits) + return -EINVAL; + + if (!cpumask_test_cpu(target_cpu, housekeeping_cpumask(HK_TYPE_MANAGED_IRQ))) + return -EINVAL; + + /* No CPUs should come up or down during this. */ + cpus_read_lock(); + + if (!cpu_online(target_cpu)) { + cpus_read_unlock(); + return -EINVAL; + } + + /* + * Synchronizes target_cpu_store() and channel closure: + * + * { Initially: state = CHANNEL_OPENED } + * + * CPU1 CPU2 + * + * [target_cpu_store()] [vmbus_disconnect_ring()] + * + * LOCK channel_mutex LOCK channel_mutex + * LOAD r1 = state LOAD r2 = state + * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED) + * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN + * [...] SEND CLOSECHANNEL + * UNLOCK channel_mutex UNLOCK channel_mutex + * + * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes + * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND + * + * Note. The host processes the channel messages "sequentially", in + * the order in which they are received on a per-partition basis. + */ + mutex_lock(&vmbus_connection.channel_mutex); + + /* + * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels; + * avoid sending the message and fail here for such channels. + */ + if (channel->state != CHANNEL_OPENED_STATE) { + ret = -EIO; + goto cpu_store_unlock; + } + + origin_cpu = channel->target_cpu; + if (target_cpu == origin_cpu) + goto cpu_store_unlock; + + if (vmbus_send_modifychannel(channel, + hv_cpu_number_to_vp_number(target_cpu))) { + ret = -EIO; + goto cpu_store_unlock; + } + + /* + * For version before VERSION_WIN10_V5_3, the following warning holds: + * + * Warning. At this point, there is *no* guarantee that the host will + * have successfully processed the vmbus_send_modifychannel() request. + * See the header comment of vmbus_send_modifychannel() for more info. + * + * Lags in the processing of the above vmbus_send_modifychannel() can + * result in missed interrupts if the "old" target CPU is taken offline + * before Hyper-V starts sending interrupts to the "new" target CPU. + * But apart from this offlining scenario, the code tolerates such + * lags. It will function correctly even if a channel interrupt comes + * in on a CPU that is different from the channel target_cpu value. + */ + + channel->target_cpu = target_cpu; + + /* See init_vp_index(). */ + if (hv_is_perf_channel(channel)) + hv_update_allocated_cpus(origin_cpu, target_cpu); + + /* Currently set only for storvsc channels. */ + if (channel->change_target_cpu_callback) { + (*channel->change_target_cpu_callback)(channel, + origin_cpu, target_cpu); + } + +cpu_store_unlock: + mutex_unlock(&vmbus_connection.channel_mutex); + cpus_read_unlock(); + return ret; +} +static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store); + +static ssize_t channel_pending_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%d\n", + channel_pending(channel, + vmbus_connection.monitor_pages[1])); +} +static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL); + +static ssize_t channel_latency_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%d\n", + channel_latency(channel, + vmbus_connection.monitor_pages[1])); +} +static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL); + +static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf) +{ + return sprintf(buf, "%llu\n", channel->interrupts); +} +static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL); + +static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf) +{ + return sprintf(buf, "%llu\n", channel->sig_events); +} +static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL); + +static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%llu\n", + (unsigned long long)channel->intr_in_full); +} +static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL); + +static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%llu\n", + (unsigned long long)channel->intr_out_empty); +} +static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL); + +static ssize_t channel_out_full_first_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%llu\n", + (unsigned long long)channel->out_full_first); +} +static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL); + +static ssize_t channel_out_full_total_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%llu\n", + (unsigned long long)channel->out_full_total); +} +static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL); + +static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%u\n", channel->offermsg.monitorid); +} +static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL); + +static ssize_t subchannel_id_show(struct vmbus_channel *channel, + char *buf) +{ + return sprintf(buf, "%u\n", + channel->offermsg.offer.sub_channel_index); +} +static VMBUS_CHAN_ATTR_RO(subchannel_id); + +static struct attribute *vmbus_chan_attrs[] = { + &chan_attr_out_mask.attr, + &chan_attr_in_mask.attr, + &chan_attr_read_avail.attr, + &chan_attr_write_avail.attr, + &chan_attr_cpu.attr, + &chan_attr_pending.attr, + &chan_attr_latency.attr, + &chan_attr_interrupts.attr, + &chan_attr_events.attr, + &chan_attr_intr_in_full.attr, + &chan_attr_intr_out_empty.attr, + &chan_attr_out_full_first.attr, + &chan_attr_out_full_total.attr, + &chan_attr_monitor_id.attr, + &chan_attr_subchannel_id.attr, + NULL +}; + +/* + * Channel-level attribute_group callback function. Returns the permission for + * each attribute, and returns 0 if an attribute is not visible. + */ +static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int idx) +{ + const struct vmbus_channel *channel = + container_of(kobj, struct vmbus_channel, kobj); + + /* Hide the monitor attributes if the monitor mechanism is not used. */ + if (!channel->offermsg.monitor_allocated && + (attr == &chan_attr_pending.attr || + attr == &chan_attr_latency.attr || + attr == &chan_attr_monitor_id.attr)) + return 0; + + return attr->mode; +} + +static struct attribute_group vmbus_chan_group = { + .attrs = vmbus_chan_attrs, + .is_visible = vmbus_chan_attr_is_visible +}; + +static struct kobj_type vmbus_chan_ktype = { + .sysfs_ops = &vmbus_chan_sysfs_ops, + .release = vmbus_chan_release, +}; + +/* + * vmbus_add_channel_kobj - setup a sub-directory under device/channels + */ +int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel) +{ + const struct device *device = &dev->device; + struct kobject *kobj = &channel->kobj; + u32 relid = channel->offermsg.child_relid; + int ret; + + kobj->kset = dev->channels_kset; + ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL, + "%u", relid); + if (ret) { + kobject_put(kobj); + return ret; + } + + ret = sysfs_create_group(kobj, &vmbus_chan_group); + + if (ret) { + /* + * The calling functions' error handling paths will cleanup the + * empty channel directory. + */ + kobject_put(kobj); + dev_err(device, "Unable to set up channel sysfs files\n"); + return ret; + } + + kobject_uevent(kobj, KOBJ_ADD); + + return 0; +} + +/* + * vmbus_remove_channel_attr_group - remove the channel's attribute group + */ +void vmbus_remove_channel_attr_group(struct vmbus_channel *channel) +{ + sysfs_remove_group(&channel->kobj, &vmbus_chan_group); +} + +/* + * vmbus_device_create - Creates and registers a new child device + * on the vmbus. + */ +struct hv_device *vmbus_device_create(const guid_t *type, + const guid_t *instance, + struct vmbus_channel *channel) +{ + struct hv_device *child_device_obj; + + child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL); + if (!child_device_obj) { + pr_err("Unable to allocate device object for child device\n"); + return NULL; + } + + child_device_obj->channel = channel; + guid_copy(&child_device_obj->dev_type, type); + guid_copy(&child_device_obj->dev_instance, instance); + child_device_obj->vendor_id = PCI_VENDOR_ID_MICROSOFT; + + return child_device_obj; +} + +/* + * vmbus_device_register - Register the child device + */ +int vmbus_device_register(struct hv_device *child_device_obj) +{ + struct kobject *kobj = &child_device_obj->device.kobj; + int ret; + + dev_set_name(&child_device_obj->device, "%pUl", + &child_device_obj->channel->offermsg.offer.if_instance); + + child_device_obj->device.bus = &hv_bus; + child_device_obj->device.parent = &hv_acpi_dev->dev; + child_device_obj->device.release = vmbus_device_release; + + child_device_obj->device.dma_parms = &child_device_obj->dma_parms; + child_device_obj->device.dma_mask = &child_device_obj->dma_mask; + dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64)); + + /* + * Register with the LDM. This will kick off the driver/device + * binding...which will eventually call vmbus_match() and vmbus_probe() + */ + ret = device_register(&child_device_obj->device); + if (ret) { + pr_err("Unable to register child device\n"); + put_device(&child_device_obj->device); + return ret; + } + + child_device_obj->channels_kset = kset_create_and_add("channels", + NULL, kobj); + if (!child_device_obj->channels_kset) { + ret = -ENOMEM; + goto err_dev_unregister; + } + + ret = vmbus_add_channel_kobj(child_device_obj, + child_device_obj->channel); + if (ret) { + pr_err("Unable to register primary channeln"); + goto err_kset_unregister; + } + hv_debug_add_dev_dir(child_device_obj); + + return 0; + +err_kset_unregister: + kset_unregister(child_device_obj->channels_kset); + +err_dev_unregister: + device_unregister(&child_device_obj->device); + return ret; +} + +/* + * vmbus_device_unregister - Remove the specified child device + * from the vmbus. + */ +void vmbus_device_unregister(struct hv_device *device_obj) +{ + pr_debug("child device %s unregistered\n", + dev_name(&device_obj->device)); + + kset_unregister(device_obj->channels_kset); + + /* + * Kick off the process of unregistering the device. + * This will call vmbus_remove() and eventually vmbus_device_release() + */ + device_unregister(&device_obj->device); +} + + +/* + * VMBUS is an acpi enumerated device. Get the information we + * need from DSDT. + */ +#define VTPM_BASE_ADDRESS 0xfed40000 +static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx) +{ + resource_size_t start = 0; + resource_size_t end = 0; + struct resource *new_res; + struct resource **old_res = &hyperv_mmio; + struct resource **prev_res = NULL; + struct resource r; + + switch (res->type) { + + /* + * "Address" descriptors are for bus windows. Ignore + * "memory" descriptors, which are for registers on + * devices. + */ + case ACPI_RESOURCE_TYPE_ADDRESS32: + start = res->data.address32.address.minimum; + end = res->data.address32.address.maximum; + break; + + case ACPI_RESOURCE_TYPE_ADDRESS64: + start = res->data.address64.address.minimum; + end = res->data.address64.address.maximum; + break; + + /* + * The IRQ information is needed only on ARM64, which Hyper-V + * sets up in the extended format. IRQ information is present + * on x86/x64 in the non-extended format but it is not used by + * Linux. So don't bother checking for the non-extended format. + */ + case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: + if (!acpi_dev_resource_interrupt(res, 0, &r)) { + pr_err("Unable to parse Hyper-V ACPI interrupt\n"); + return AE_ERROR; + } + /* ARM64 INTID for VMbus */ + vmbus_interrupt = res->data.extended_irq.interrupts[0]; + /* Linux IRQ number */ + vmbus_irq = r.start; + return AE_OK; + + default: + /* Unused resource type */ + return AE_OK; + + } + /* + * Ignore ranges that are below 1MB, as they're not + * necessary or useful here. + */ + if (end < 0x100000) + return AE_OK; + + new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC); + if (!new_res) + return AE_NO_MEMORY; + + /* If this range overlaps the virtual TPM, truncate it. */ + if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS) + end = VTPM_BASE_ADDRESS; + + new_res->name = "hyperv mmio"; + new_res->flags = IORESOURCE_MEM; + new_res->start = start; + new_res->end = end; + + /* + * If two ranges are adjacent, merge them. + */ + do { + if (!*old_res) { + *old_res = new_res; + break; + } + + if (((*old_res)->end + 1) == new_res->start) { + (*old_res)->end = new_res->end; + kfree(new_res); + break; + } + + if ((*old_res)->start == new_res->end + 1) { + (*old_res)->start = new_res->start; + kfree(new_res); + break; + } + + if ((*old_res)->start > new_res->end) { + new_res->sibling = *old_res; + if (prev_res) + (*prev_res)->sibling = new_res; + *old_res = new_res; + break; + } + + prev_res = old_res; + old_res = &(*old_res)->sibling; + + } while (1); + + return AE_OK; +} + +static int vmbus_acpi_remove(struct acpi_device *device) +{ + struct resource *cur_res; + struct resource *next_res; + + if (hyperv_mmio) { + if (fb_mmio) { + __release_region(hyperv_mmio, fb_mmio->start, + resource_size(fb_mmio)); + fb_mmio = NULL; + } + + for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) { + next_res = cur_res->sibling; + kfree(cur_res); + } + } + + return 0; +} + +static void vmbus_reserve_fb(void) +{ + resource_size_t start = 0, size; + struct pci_dev *pdev; + + if (efi_enabled(EFI_BOOT)) { + /* Gen2 VM: get FB base from EFI framebuffer */ + start = screen_info.lfb_base; + size = max_t(__u32, screen_info.lfb_size, 0x800000); + } else { + /* Gen1 VM: get FB base from PCI */ + pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT, + PCI_DEVICE_ID_HYPERV_VIDEO, NULL); + if (!pdev) + return; + + if (pdev->resource[0].flags & IORESOURCE_MEM) { + start = pci_resource_start(pdev, 0); + size = pci_resource_len(pdev, 0); + } + + /* + * Release the PCI device so hyperv_drm or hyperv_fb driver can + * grab it later. + */ + pci_dev_put(pdev); + } + + if (!start) + return; + + /* + * Make a claim for the frame buffer in the resource tree under the + * first node, which will be the one below 4GB. The length seems to + * be underreported, particularly in a Generation 1 VM. So start out + * reserving a larger area and make it smaller until it succeeds. + */ + for (; !fb_mmio && (size >= 0x100000); size >>= 1) + fb_mmio = __request_region(hyperv_mmio, start, size, fb_mmio_name, 0); +} + +/** + * vmbus_allocate_mmio() - Pick a memory-mapped I/O range. + * @new: If successful, supplied a pointer to the + * allocated MMIO space. + * @device_obj: Identifies the caller + * @min: Minimum guest physical address of the + * allocation + * @max: Maximum guest physical address + * @size: Size of the range to be allocated + * @align: Alignment of the range to be allocated + * @fb_overlap_ok: Whether this allocation can be allowed + * to overlap the video frame buffer. + * + * This function walks the resources granted to VMBus by the + * _CRS object in the ACPI namespace underneath the parent + * "bridge" whether that's a root PCI bus in the Generation 1 + * case or a Module Device in the Generation 2 case. It then + * attempts to allocate from the global MMIO pool in a way that + * matches the constraints supplied in these parameters and by + * that _CRS. + * + * Return: 0 on success, -errno on failure + */ +int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, + resource_size_t min, resource_size_t max, + resource_size_t size, resource_size_t align, + bool fb_overlap_ok) +{ + struct resource *iter, *shadow; + resource_size_t range_min, range_max, start, end; + const char *dev_n = dev_name(&device_obj->device); + int retval; + + retval = -ENXIO; + mutex_lock(&hyperv_mmio_lock); + + /* + * If overlaps with frame buffers are allowed, then first attempt to + * make the allocation from within the reserved region. Because it + * is already reserved, no shadow allocation is necessary. + */ + if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) && + !(max < fb_mmio->start)) { + + range_min = fb_mmio->start; + range_max = fb_mmio->end; + start = (range_min + align - 1) & ~(align - 1); + for (; start + size - 1 <= range_max; start += align) { + *new = request_mem_region_exclusive(start, size, dev_n); + if (*new) { + retval = 0; + goto exit; + } + } + } + + for (iter = hyperv_mmio; iter; iter = iter->sibling) { + if ((iter->start >= max) || (iter->end <= min)) + continue; + + range_min = iter->start; + range_max = iter->end; + start = (range_min + align - 1) & ~(align - 1); + for (; start + size - 1 <= range_max; start += align) { + end = start + size - 1; + + /* Skip the whole fb_mmio region if not fb_overlap_ok */ + if (!fb_overlap_ok && fb_mmio && + (((start >= fb_mmio->start) && (start <= fb_mmio->end)) || + ((end >= fb_mmio->start) && (end <= fb_mmio->end)))) + continue; + + shadow = __request_region(iter, start, size, NULL, + IORESOURCE_BUSY); + if (!shadow) + continue; + + *new = request_mem_region_exclusive(start, size, dev_n); + if (*new) { + shadow->name = (char *)*new; + retval = 0; + goto exit; + } + + __release_region(iter, start, size); + } + } + +exit: + mutex_unlock(&hyperv_mmio_lock); + return retval; +} +EXPORT_SYMBOL_GPL(vmbus_allocate_mmio); + +/** + * vmbus_free_mmio() - Free a memory-mapped I/O range. + * @start: Base address of region to release. + * @size: Size of the range to be allocated + * + * This function releases anything requested by + * vmbus_mmio_allocate(). + */ +void vmbus_free_mmio(resource_size_t start, resource_size_t size) +{ + struct resource *iter; + + mutex_lock(&hyperv_mmio_lock); + for (iter = hyperv_mmio; iter; iter = iter->sibling) { + if ((iter->start >= start + size) || (iter->end <= start)) + continue; + + __release_region(iter, start, size); + } + release_mem_region(start, size); + mutex_unlock(&hyperv_mmio_lock); + +} +EXPORT_SYMBOL_GPL(vmbus_free_mmio); + +static int vmbus_acpi_add(struct acpi_device *device) +{ + acpi_status result; + int ret_val = -ENODEV; + struct acpi_device *ancestor; + + hv_acpi_dev = device; + + /* + * Older versions of Hyper-V for ARM64 fail to include the _CCA + * method on the top level VMbus device in the DSDT. But devices + * are hardware coherent in all current Hyper-V use cases, so fix + * up the ACPI device to behave as if _CCA is present and indicates + * hardware coherence. + */ + ACPI_COMPANION_SET(&device->dev, device); + if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) && + device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) { + pr_info("No ACPI _CCA found; assuming coherent device I/O\n"); + device->flags.cca_seen = true; + device->flags.coherent_dma = true; + } + + result = acpi_walk_resources(device->handle, METHOD_NAME__CRS, + vmbus_walk_resources, NULL); + + if (ACPI_FAILURE(result)) + goto acpi_walk_err; + /* + * Some ancestor of the vmbus acpi device (Gen1 or Gen2 + * firmware) is the VMOD that has the mmio ranges. Get that. + */ + for (ancestor = acpi_dev_parent(device); + ancestor && ancestor->handle != ACPI_ROOT_OBJECT; + ancestor = acpi_dev_parent(ancestor)) { + result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS, + vmbus_walk_resources, NULL); + + if (ACPI_FAILURE(result)) + continue; + if (hyperv_mmio) { + vmbus_reserve_fb(); + break; + } + } + ret_val = 0; + +acpi_walk_err: + if (ret_val) + vmbus_acpi_remove(device); + return ret_val; +} + +#ifdef CONFIG_PM_SLEEP +static int vmbus_bus_suspend(struct device *dev) +{ + struct hv_per_cpu_context *hv_cpu = per_cpu_ptr( + hv_context.cpu_context, VMBUS_CONNECT_CPU); + struct vmbus_channel *channel, *sc; + + tasklet_disable(&hv_cpu->msg_dpc); + vmbus_connection.ignore_any_offer_msg = true; + /* The tasklet_enable() takes care of providing a memory barrier */ + tasklet_enable(&hv_cpu->msg_dpc); + + /* Drain all the workqueues as we are in suspend */ + drain_workqueue(vmbus_connection.rescind_work_queue); + drain_workqueue(vmbus_connection.work_queue); + drain_workqueue(vmbus_connection.handle_primary_chan_wq); + drain_workqueue(vmbus_connection.handle_sub_chan_wq); + + mutex_lock(&vmbus_connection.channel_mutex); + list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { + if (!is_hvsock_channel(channel)) + continue; + + vmbus_force_channel_rescinded(channel); + } + mutex_unlock(&vmbus_connection.channel_mutex); + + /* + * Wait until all the sub-channels and hv_sock channels have been + * cleaned up. Sub-channels should be destroyed upon suspend, otherwise + * they would conflict with the new sub-channels that will be created + * in the resume path. hv_sock channels should also be destroyed, but + * a hv_sock channel of an established hv_sock connection can not be + * really destroyed since it may still be referenced by the userspace + * application, so we just force the hv_sock channel to be rescinded + * by vmbus_force_channel_rescinded(), and the userspace application + * will thoroughly destroy the channel after hibernation. + * + * Note: the counter nr_chan_close_on_suspend may never go above 0 if + * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM. + */ + if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0) + wait_for_completion(&vmbus_connection.ready_for_suspend_event); + + if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) { + pr_err("Can not suspend due to a previous failed resuming\n"); + return -EBUSY; + } + + mutex_lock(&vmbus_connection.channel_mutex); + + list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { + /* + * Remove the channel from the array of channels and invalidate + * the channel's relid. Upon resume, vmbus_onoffer() will fix + * up the relid (and other fields, if necessary) and add the + * channel back to the array. + */ + vmbus_channel_unmap_relid(channel); + channel->offermsg.child_relid = INVALID_RELID; + + if (is_hvsock_channel(channel)) { + if (!channel->rescind) { + pr_err("hv_sock channel not rescinded!\n"); + WARN_ON_ONCE(1); + } + continue; + } + + list_for_each_entry(sc, &channel->sc_list, sc_list) { + pr_err("Sub-channel not deleted!\n"); + WARN_ON_ONCE(1); + } + + atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume); + } + + mutex_unlock(&vmbus_connection.channel_mutex); + + vmbus_initiate_unload(false); + + /* Reset the event for the next resume. */ + reinit_completion(&vmbus_connection.ready_for_resume_event); + + return 0; +} + +static int vmbus_bus_resume(struct device *dev) +{ + struct vmbus_channel_msginfo *msginfo; + size_t msgsize; + int ret; + + vmbus_connection.ignore_any_offer_msg = false; + + /* + * We only use the 'vmbus_proto_version', which was in use before + * hibernation, to re-negotiate with the host. + */ + if (!vmbus_proto_version) { + pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version); + return -EINVAL; + } + + msgsize = sizeof(*msginfo) + + sizeof(struct vmbus_channel_initiate_contact); + + msginfo = kzalloc(msgsize, GFP_KERNEL); + + if (msginfo == NULL) + return -ENOMEM; + + ret = vmbus_negotiate_version(msginfo, vmbus_proto_version); + + kfree(msginfo); + + if (ret != 0) + return ret; + + WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0); + + vmbus_request_offers(); + + if (wait_for_completion_timeout( + &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0) + pr_err("Some vmbus device is missing after suspending?\n"); + + /* Reset the event for the next suspend. */ + reinit_completion(&vmbus_connection.ready_for_suspend_event); + + return 0; +} +#else +#define vmbus_bus_suspend NULL +#define vmbus_bus_resume NULL +#endif /* CONFIG_PM_SLEEP */ + +static const struct acpi_device_id vmbus_acpi_device_ids[] = { + {"VMBUS", 0}, + {"VMBus", 0}, + {"", 0}, +}; +MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids); + +/* + * Note: we must use the "no_irq" ops, otherwise hibernation can not work with + * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in + * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see + * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() -> + * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's + * resume callback must also run via the "noirq" ops. + * + * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment + * earlier in this file before vmbus_pm. + */ + +static const struct dev_pm_ops vmbus_bus_pm = { + .suspend_noirq = NULL, + .resume_noirq = NULL, + .freeze_noirq = vmbus_bus_suspend, + .thaw_noirq = vmbus_bus_resume, + .poweroff_noirq = vmbus_bus_suspend, + .restore_noirq = vmbus_bus_resume +}; + +static struct acpi_driver vmbus_acpi_driver = { + .name = "vmbus", + .ids = vmbus_acpi_device_ids, + .ops = { + .add = vmbus_acpi_add, + .remove = vmbus_acpi_remove, + }, + .drv.pm = &vmbus_bus_pm, + .drv.probe_type = PROBE_FORCE_SYNCHRONOUS, +}; + +static void hv_kexec_handler(void) +{ + hv_stimer_global_cleanup(); + vmbus_initiate_unload(false); + /* Make sure conn_state is set as hv_synic_cleanup checks for it */ + mb(); + cpuhp_remove_state(hyperv_cpuhp_online); +}; + +static void hv_crash_handler(struct pt_regs *regs) +{ + int cpu; + + vmbus_initiate_unload(true); + /* + * In crash handler we can't schedule synic cleanup for all CPUs, + * doing the cleanup for current CPU only. This should be sufficient + * for kdump. + */ + cpu = smp_processor_id(); + hv_stimer_cleanup(cpu); + hv_synic_disable_regs(cpu); +}; + +static int hv_synic_suspend(void) +{ + /* + * When we reach here, all the non-boot CPUs have been offlined. + * If we're in a legacy configuration where stimer Direct Mode is + * not enabled, the stimers on the non-boot CPUs have been unbound + * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() -> + * hv_stimer_cleanup() -> clockevents_unbind_device(). + * + * hv_synic_suspend() only runs on CPU0 with interrupts disabled. + * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because: + * 1) it's unnecessary as interrupts remain disabled between + * syscore_suspend() and syscore_resume(): see create_image() and + * resume_target_kernel() + * 2) the stimer on CPU0 is automatically disabled later by + * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ... + * -> clockevents_shutdown() -> ... -> hv_ce_shutdown() + * 3) a warning would be triggered if we call + * clockevents_unbind_device(), which may sleep, in an + * interrupts-disabled context. + */ + + hv_synic_disable_regs(0); + + return 0; +} + +static void hv_synic_resume(void) +{ + hv_synic_enable_regs(0); + + /* + * Note: we don't need to call hv_stimer_init(0), because the timer + * on CPU0 is not unbound in hv_synic_suspend(), and the timer is + * automatically re-enabled in timekeeping_resume(). + */ +} + +/* The callbacks run only on CPU0, with irqs_disabled. */ +static struct syscore_ops hv_synic_syscore_ops = { + .suspend = hv_synic_suspend, + .resume = hv_synic_resume, +}; + +static int __init hv_acpi_init(void) +{ + int ret; + + if (!hv_is_hyperv_initialized()) + return -ENODEV; + + if (hv_root_partition) + return 0; + + /* + * Get ACPI resources first. + */ + ret = acpi_bus_register_driver(&vmbus_acpi_driver); + + if (ret) + return ret; + + if (!hv_acpi_dev) { + ret = -ENODEV; + goto cleanup; + } + + /* + * If we're on an architecture with a hardcoded hypervisor + * vector (i.e. x86/x64), override the VMbus interrupt found + * in the ACPI tables. Ensure vmbus_irq is not set since the + * normal Linux IRQ mechanism is not used in this case. + */ +#ifdef HYPERVISOR_CALLBACK_VECTOR + vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR; + vmbus_irq = -1; +#endif + + hv_debug_init(); + + ret = vmbus_bus_init(); + if (ret) + goto cleanup; + + hv_setup_kexec_handler(hv_kexec_handler); + hv_setup_crash_handler(hv_crash_handler); + + register_syscore_ops(&hv_synic_syscore_ops); + + return 0; + +cleanup: + acpi_bus_unregister_driver(&vmbus_acpi_driver); + hv_acpi_dev = NULL; + return ret; +} + +static void __exit vmbus_exit(void) +{ + int cpu; + + unregister_syscore_ops(&hv_synic_syscore_ops); + + hv_remove_kexec_handler(); + hv_remove_crash_handler(); + vmbus_connection.conn_state = DISCONNECTED; + hv_stimer_global_cleanup(); + vmbus_disconnect(); + if (vmbus_irq == -1) { + hv_remove_vmbus_handler(); + } else { + free_percpu_irq(vmbus_irq, vmbus_evt); + free_percpu(vmbus_evt); + } + for_each_online_cpu(cpu) { + struct hv_per_cpu_context *hv_cpu + = per_cpu_ptr(hv_context.cpu_context, cpu); + + tasklet_kill(&hv_cpu->msg_dpc); + } + hv_debug_rm_all_dir(); + + vmbus_free_channels(); + kfree(vmbus_connection.channels); + + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { + kmsg_dump_unregister(&hv_kmsg_dumper); + unregister_die_notifier(&hyperv_die_block); + } + + /* + * The panic notifier is always registered, hence we should + * also unconditionally unregister it here as well. + */ + atomic_notifier_chain_unregister(&panic_notifier_list, + &hyperv_panic_block); + + free_page((unsigned long)hv_panic_page); + unregister_sysctl_table(hv_ctl_table_hdr); + hv_ctl_table_hdr = NULL; + bus_unregister(&hv_bus); + + cpuhp_remove_state(hyperv_cpuhp_online); + hv_synic_free(); + acpi_bus_unregister_driver(&vmbus_acpi_driver); +} + + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver"); + +subsys_initcall(hv_acpi_init); +module_exit(vmbus_exit); |