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vfio: Register SaveVMHandlers for VFIO device 

Define flags to be used as delimiter in migration stream for VFIO devices.
Added .save_setup and .save_cleanup functions. Map & unmap migration
region from these functions at source during saving or pre-copy phase.

Set VFIO device state depending on VM's state. During live migration, VM is
running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO
device. During save-restore, VM is paused, _SAVING state is set for VFIO device.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Kirti Wankhede 2020-10-26 15:06:17 +05:30 committed by Alex Williamson
parent 050c588c2e
commit 7c2f5f75f9
2 changed files with 104 additions and 0 deletions
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102
hw/vfio/migration.c
View File

@ -8,12 +8,15 @@
*/
#include "qemu/osdep.h"
#include "qemu/main-loop.h"
#include "qemu/cutils.h"
#include <linux/vfio.h>
#include "sysemu/runstate.h"
#include "hw/vfio/vfio-common.h"
#include "cpu.h"
#include "migration/migration.h"
#include "migration/vmstate.h"
#include "migration/qemu-file.h"
#include "migration/register.h"
#include "migration/blocker.h"
@ -25,6 +28,22 @@
#include "trace.h"
#include "hw/hw.h"
/*
* Flags to be used as unique delimiters for VFIO devices in the migration
* stream. These flags are composed as:
* 0xffffffff => MSB 32-bit all 1s
* 0xef10 => Magic ID, represents emulated (virtual) function IO
* 0x0000 => 16-bits reserved for flags
*
* The beginning of state information is marked by _DEV_CONFIG_STATE,
* _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a
* certain state information is marked by _END_OF_STATE.
*/
#define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL)
#define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL)
#define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL)
#define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL)
static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count,
off_t off, bool iswrite)
{
@ -129,6 +148,75 @@ static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask,
return 0;
}
static void vfio_migration_cleanup(VFIODevice *vbasedev)
{
VFIOMigration *migration = vbasedev->migration;
if (migration->region.mmaps) {
vfio_region_unmap(&migration->region);
}
}
/* ---------------------------------------------------------------------- */
static int vfio_save_setup(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
int ret;
trace_vfio_save_setup(vbasedev->name);
qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE);
if (migration->region.mmaps) {
/*
* Calling vfio_region_mmap() from migration thread. Memory API called
* from this function require locking the iothread when called from
* outside the main loop thread.
*/
qemu_mutex_lock_iothread();
ret = vfio_region_mmap(&migration->region);
qemu_mutex_unlock_iothread();
if (ret) {
error_report("%s: Failed to mmap VFIO migration region: %s",
vbasedev->name, strerror(-ret));
error_report("%s: Falling back to slow path", vbasedev->name);
}
}
ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_MASK,
VFIO_DEVICE_STATE_SAVING);
if (ret) {
error_report("%s: Failed to set state SAVING", vbasedev->name);
return ret;
}
qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
ret = qemu_file_get_error(f);
if (ret) {
return ret;
}
return 0;
}
static void vfio_save_cleanup(void *opaque)
{
VFIODevice *vbasedev = opaque;
vfio_migration_cleanup(vbasedev);
trace_vfio_save_cleanup(vbasedev->name);
}
static SaveVMHandlers savevm_vfio_handlers = {
.save_setup = vfio_save_setup,
.save_cleanup = vfio_save_cleanup,
};
/* ---------------------------------------------------------------------- */
static void vfio_vmstate_change(void *opaque, int running, RunState state)
{
VFIODevice *vbasedev = opaque;
@ -215,6 +303,8 @@ static int vfio_migration_init(VFIODevice *vbasedev,
int ret;
Object *obj;
VFIOMigration *migration;
char id[256] = "";
g_autofree char *path = NULL, *oid = NULL;
if (!vbasedev->ops->vfio_get_object) {
return -EINVAL;
@ -244,6 +334,18 @@ static int vfio_migration_init(VFIODevice *vbasedev,
migration = vbasedev->migration;
migration->vbasedev = vbasedev;
oid = vmstate_if_get_id(VMSTATE_IF(DEVICE(obj)));
if (oid) {
path = g_strdup_printf("%s/vfio", oid);
} else {
path = g_strdup("vfio");
}
strpadcpy(id, sizeof(id), path, '\0');
register_savevm_live(id, VMSTATE_INSTANCE_ID_ANY, 1, &savevm_vfio_handlers,
vbasedev);
migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
vbasedev);
migration->migration_state.notify = vfio_migration_state_notifier;

2
hw/vfio/trace-events
View File

@ -151,3 +151,5 @@ vfio_migration_probe(const char *name, uint32_t index) " (%s) Region %d"
vfio_migration_set_state(const char *name, uint32_t state) " (%s) state %d"
vfio_vmstate_change(const char *name, int running, const char *reason, uint32_t dev_state) " (%s) running %d reason %s device state %d"
vfio_migration_state_notifier(const char *name, const char *state) " (%s) state %s"
vfio_save_setup(const char *name) " (%s)"
vfio_save_cleanup(const char *name) " (%s)"