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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/hv/vmbus_drv.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
-rw-r--r--drivers/hv/vmbus_drv.c2828
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);