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linux_dsm_epyc7002/drivers/hv/vmbus_drv.c
Vitaly Kuznetsov cd95aad557 Drivers: hv: vmbus: handle various crash scenarios 
Kdump keeps biting. Turns out CHANNELMSG_UNLOAD_RESPONSE is always
delivered to the CPU which was used for initial contact or to CPU0
depending on host version. vmbus_wait_for_unload() doesn't account for
the fact that in case we're crashing on some other CPU we won't get the
CHANNELMSG_UNLOAD_RESPONSE message and our wait on the current CPU will
never end.

Do the following:
1) Check for completion_done() in the loop. In case interrupt handler is
   still alive we'll get the confirmation we need.

2) Read message pages for all CPUs message page as we're unsure where
   CHANNELMSG_UNLOAD_RESPONSE is going to be delivered to. We can race with
   still-alive interrupt handler doing the same, add cmpxchg() to
   vmbus_signal_eom() to not lose CHANNELMSG_UNLOAD_RESPONSE message.

3) Cleanup message pages on all CPUs. This is required (at least for the
   current CPU as we're clearing CPU0 messages now but we may want to bring
   up additional CPUs on crash) as new messages won't be delivered till we
   consume what's pending. On boot we'll place message pages somewhere else
   and we won't be able to read stale messages.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00

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/*
* Copyright (c) 2009, Microsoft Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* 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 <asm/hyperv.h>
#include <asm/hypervisor.h>
#include <asm/mshyperv.h>
#include <linux/notifier.h>
#include <linux/ptrace.h>
#include <linux/screen_info.h>
#include <linux/kdebug.h>
#include <linux/efi.h>
#include "hyperv_vmbus.h"
static struct acpi_device *hv_acpi_dev;
static struct completion probe_event;
static void hyperv_report_panic(struct pt_regs *regs)
{
static bool panic_reported;
/*
* We prefer to report panic on 'die' chain as we have proper
* registers to report, but if we miss it (e.g. on BUG()) we need
* to report it on 'panic'.
*/
if (panic_reported)
return;
panic_reported = true;
wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
/*
* Let Hyper-V know there is crash data available
*/
wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
}
static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct pt_regs *regs;
regs = current_pt_regs();
hyperv_report_panic(regs);
return NOTIFY_DONE;
}
static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
void *args)
{
struct die_args *die = (struct die_args *)args;
struct pt_regs *regs = die->regs;
hyperv_report_panic(regs);
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;
struct resource *hyperv_mmio;
DEFINE_SEMAPHORE(hyperv_mmio_lock);
static int vmbus_exists(void)
{
if (hv_acpi_dev == NULL)
return -ENODEV;
return 0;
}
#define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
{
int i;
for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
}
static u8 channel_monitor_group(struct vmbus_channel *channel)
{
return (u8)channel->offermsg.monitorid / 32;
}
static u8 channel_monitor_offset(struct vmbus_channel *channel)
{
return (u8)channel->offermsg.monitorid % 32;
}
static u32 channel_pending(struct vmbus_channel *channel,
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(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->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.b);
}
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.b);
}
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);
char alias_name[VMBUS_ALIAS_LEN + 1];
print_alias_name(hv_dev, alias_name);
return sprintf(buf, "vmbus:%s\n", alias_name);
}
static DEVICE_ATTR_RO(modalias);
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[1]));
}
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
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;
if (!hv_dev->channel)
return -ENODEV;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
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;
unsigned long flags;
int buf_size = PAGE_SIZE, n_written, tot_written;
struct list_head *cur;
if (!channel)
return -ENODEV;
tot_written = snprintf(buf, buf_size, "%u:%u\n",
channel->offermsg.child_relid, channel->target_cpu);
spin_lock_irqsave(&channel->lock, flags);
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;
}
spin_unlock_irqrestore(&channel->lock, flags);
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);
/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
static struct attribute *vmbus_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,
&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,
NULL,
};
ATTRIBUTE_GROUPS(vmbus);
/*
* 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);
int ret;
char alias_name[VMBUS_ALIAS_LEN + 1];
print_alias_name(dev, alias_name);
ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
return ret;
}
static const uuid_le null_guid;
static inline bool is_null_guid(const uuid_le *guid)
{
if (uuid_le_cmp(*guid, null_guid))
return false;
return true;
}
/*
* 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(
const struct hv_vmbus_device_id *id,
const uuid_le *guid)
{
for (; !is_null_guid(&id->guid); id++)
if (!uuid_le_cmp(id->guid, *guid))
return id;
return NULL;
}
/*
* 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->id_table, &hv_dev->dev_type))
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->id_table, &dev->dev_type);
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_remove - Remove a vmbus device
*/
static int 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);
}
return 0;
}
/*
* 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);
return;
}
/*
* 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_process_channel_removal(channel,
channel->offermsg.child_relid);
kfree(hv_dev);
}
/* 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,
.dev_groups = vmbus_groups,
};
struct onmessage_work_context {
struct work_struct work;
struct hv_message 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(&ctx->msg);
kfree(ctx);
}
static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
{
struct clock_event_device *dev = hv_context.clk_evt[cpu];
if (dev->event_handler)
dev->event_handler(dev);
vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
}
void vmbus_on_msg_dpc(unsigned long data)
{
int cpu = smp_processor_id();
void *page_addr = hv_context.synic_message_page[cpu];
struct hv_message *msg = (struct hv_message *)page_addr +
VMBUS_MESSAGE_SINT;
struct vmbus_channel_message_header *hdr;
struct vmbus_channel_message_table_entry *entry;
struct onmessage_work_context *ctx;
u32 message_type = msg->header.message_type;
if (message_type == HVMSG_NONE)
/* no msg */
return;
hdr = (struct vmbus_channel_message_header *)msg->u.payload;
if (hdr->msgtype >= CHANNELMSG_COUNT) {
WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
goto msg_handled;
}
entry = &channel_message_table[hdr->msgtype];
if (entry->handler_type == VMHT_BLOCKING) {
ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
if (ctx == NULL)
return;
INIT_WORK(&ctx->work, vmbus_onmessage_work);
memcpy(&ctx->msg, msg, sizeof(*msg));
queue_work(vmbus_connection.work_queue, &ctx->work);
} else
entry->message_handler(hdr);
msg_handled:
vmbus_signal_eom(msg, message_type);
}
static void vmbus_isr(void)
{
int cpu = smp_processor_id();
void *page_addr;
struct hv_message *msg;
union hv_synic_event_flags *event;
bool handled = false;
page_addr = hv_context.synic_event_page[cpu];
if (page_addr == NULL)
return;
event = (union hv_synic_event_flags *)page_addr +
VMBUS_MESSAGE_SINT;
/*
* Check for events before checking for messages. This is the order
* in which events and messages are checked in Windows guests on
* Hyper-V, and the Windows team suggested we do the same.
*/
if ((vmbus_proto_version == VERSION_WS2008) ||
(vmbus_proto_version == VERSION_WIN7)) {
/* Since we are a child, we only need to check bit 0 */
if (sync_test_and_clear_bit(0,
(unsigned long *) &event->flags32[0])) {
handled = true;
}
} else {
/*
* Our host is win8 or above. The signaling mechanism
* has changed and we can directly look at the event page.
* If bit n is set then we have an interrup on the channel
* whose id is n.
*/
handled = true;
}
if (handled)
tasklet_schedule(hv_context.event_dpc[cpu]);
page_addr = hv_context.synic_message_page[cpu];
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_process_timer_expiration(msg, cpu);
else
tasklet_schedule(hv_context.msg_dpc[cpu]);
}
}
/*
* 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;
/* Hypervisor initialization...setup hypercall page..etc */
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)
goto err_cleanup;
hv_setup_vmbus_irq(vmbus_isr);
ret = hv_synic_alloc();
if (ret)
goto err_alloc;
/*
* Initialize the per-cpu interrupt state and
* connect to the host.
*/
on_each_cpu(hv_synic_init, NULL, 1);
ret = vmbus_connect();
if (ret)
goto err_connect;
if (vmbus_proto_version > VERSION_WIN7)
cpu_hotplug_disable();
/*
* Only register if the crash MSRs are available
*/
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
register_die_notifier(&hyperv_die_block);
atomic_notifier_chain_register(&panic_notifier_list,
&hyperv_panic_block);
}
vmbus_request_offers();
return 0;
err_connect:
on_each_cpu(hv_synic_cleanup, NULL, 1);
err_alloc:
hv_synic_free();
hv_remove_vmbus_irq();
bus_unregister(&hv_bus);
err_cleanup:
hv_cleanup();
return ret;
}
/**
* __vmbus_child_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;
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);
}
EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
/*
* vmbus_device_create - Creates and registers a new child device
* on the vmbus.
*/
struct hv_device *vmbus_device_create(const uuid_le *type,
const uuid_le *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;
memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
memcpy(&child_device_obj->dev_instance, instance,
sizeof(uuid_le));
child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
return child_device_obj;
}
/*
* vmbus_device_register - Register the child device
*/
int vmbus_device_register(struct hv_device *child_device_obj)
{
int ret = 0;
dev_set_name(&child_device_obj->device, "vmbus_%d",
child_device_obj->channel->id);
child_device_obj->device.bus = &hv_bus;
child_device_obj->device.parent = &hv_acpi_dev->dev;
child_device_obj->device.release = vmbus_device_release;
/*
* 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");
else
pr_debug("child device %s registered\n",
dev_name(&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));
/*
* 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;
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;
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)
{
int size;
/*
* 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.
*/
if (screen_info.lfb_base) {
if (efi_enabled(EFI_BOOT))
size = max_t(__u32, screen_info.lfb_size, 0x800000);
else
size = max_t(__u32, screen_info.lfb_size, 0x4000000);
for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
fb_mmio = __request_region(hyperv_mmio,
screen_info.lfb_base, 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;
const char *dev_n = dev_name(&device_obj->device);
int retval;
retval = -ENXIO;
down(&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) {
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:
up(&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;
down(&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);
up(&hyperv_mmio_lock);
}
EXPORT_SYMBOL_GPL(vmbus_free_mmio);
/**
* vmbus_cpu_number_to_vp_number() - Map CPU to VP.
* @cpu_number: CPU number in Linux terms
*
* This function returns the mapping between the Linux processor
* number and the hypervisor's virtual processor number, useful
* in making hypercalls and such that talk about specific
* processors.
*
* Return: Virtual processor number in Hyper-V terms
*/
int vmbus_cpu_number_to_vp_number(int cpu_number)
{
return hv_context.vp_index[cpu_number];
}
EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
static int vmbus_acpi_add(struct acpi_device *device)
{
acpi_status result;
int ret_val = -ENODEV;
struct acpi_device *ancestor;
hv_acpi_dev = device;
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 = device->parent; ancestor; ancestor = ancestor->parent) {
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:
complete(&probe_event);
if (ret_val)
vmbus_acpi_remove(device);
return ret_val;
}
static const struct acpi_device_id vmbus_acpi_device_ids[] = {
{"VMBUS", 0},
{"VMBus", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
static struct acpi_driver vmbus_acpi_driver = {
.name = "vmbus",
.ids = vmbus_acpi_device_ids,
.ops = {
.add = vmbus_acpi_add,
.remove = vmbus_acpi_remove,
},
};
static void hv_kexec_handler(void)
{
int cpu;
hv_synic_clockevents_cleanup();
vmbus_initiate_unload(false);
for_each_online_cpu(cpu)
smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
hv_cleanup();
};
static void hv_crash_handler(struct pt_regs *regs)
{
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.
*/
hv_synic_cleanup(NULL);
hv_cleanup();
};
static int __init hv_acpi_init(void)
{
int ret, t;
if (x86_hyper != &x86_hyper_ms_hyperv)
return -ENODEV;
init_completion(&probe_event);
/*
* Get ACPI resources first.
*/
ret = acpi_bus_register_driver(&vmbus_acpi_driver);
if (ret)
return ret;
t = wait_for_completion_timeout(&probe_event, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
goto cleanup;
}
ret = vmbus_bus_init();
if (ret)
goto cleanup;
hv_setup_kexec_handler(hv_kexec_handler);
hv_setup_crash_handler(hv_crash_handler);
return 0;
cleanup:
acpi_bus_unregister_driver(&vmbus_acpi_driver);
hv_acpi_dev = NULL;
return ret;
}
static void __exit vmbus_exit(void)
{
int cpu;
hv_remove_kexec_handler();
hv_remove_crash_handler();
vmbus_connection.conn_state = DISCONNECTED;
hv_synic_clockevents_cleanup();
vmbus_disconnect();
hv_remove_vmbus_irq();
for_each_online_cpu(cpu)
tasklet_kill(hv_context.msg_dpc[cpu]);
vmbus_free_channels();
if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
unregister_die_notifier(&hyperv_die_block);
atomic_notifier_chain_unregister(&panic_notifier_list,
&hyperv_panic_block);
}
bus_unregister(&hv_bus);
hv_cleanup();
for_each_online_cpu(cpu) {
tasklet_kill(hv_context.event_dpc[cpu]);
smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
}
hv_synic_free();
acpi_bus_unregister_driver(&vmbus_acpi_driver);
if (vmbus_proto_version > VERSION_WIN7)
cpu_hotplug_enable();
}
MODULE_LICENSE("GPL");
subsys_initcall(hv_acpi_init);
module_exit(vmbus_exit);
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