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33dc04b072
qemu/hw/vfio/migration.c
Cédric Le Goater 33dc04b072 vfio: Also trace event failures in vfio_save_complete_precopy() 
vfio_save_complete_precopy() currently returns before doing the trace
event. Change that.

Reviewed-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
2024-05-16 16:59:19 +02:00

1021 lines
31 KiB
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/*
* Migration support for VFIO devices
*
* Copyright NVIDIA, Inc. 2020
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/main-loop.h"
#include "qemu/cutils.h"
#include "qemu/units.h"
#include "qemu/error-report.h"
#include <linux/vfio.h>
#include <sys/ioctl.h>
#include "sysemu/runstate.h"
#include "hw/vfio/vfio-common.h"
#include "migration/misc.h"
#include "migration/savevm.h"
#include "migration/vmstate.h"
#include "migration/qemu-file.h"
#include "migration/register.h"
#include "migration/blocker.h"
#include "qapi/error.h"
#include "exec/ramlist.h"
#include "exec/ram_addr.h"
#include "pci.h"
#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)
#define VFIO_MIG_FLAG_DEV_INIT_DATA_SENT (0xffffffffef100005ULL)
/*
* This is an arbitrary size based on migration of mlx5 devices, where typically
* total device migration size is on the order of 100s of MB. Testing with
* larger values, e.g. 128MB and 1GB, did not show a performance improvement.
*/
#define VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE (1 * MiB)
static int64_t bytes_transferred;
static const char *mig_state_to_str(enum vfio_device_mig_state state)
{
switch (state) {
case VFIO_DEVICE_STATE_ERROR:
return "ERROR";
case VFIO_DEVICE_STATE_STOP:
return "STOP";
case VFIO_DEVICE_STATE_RUNNING:
return "RUNNING";
case VFIO_DEVICE_STATE_STOP_COPY:
return "STOP_COPY";
case VFIO_DEVICE_STATE_RESUMING:
return "RESUMING";
case VFIO_DEVICE_STATE_RUNNING_P2P:
return "RUNNING_P2P";
case VFIO_DEVICE_STATE_PRE_COPY:
return "PRE_COPY";
case VFIO_DEVICE_STATE_PRE_COPY_P2P:
return "PRE_COPY_P2P";
default:
return "UNKNOWN STATE";
}
}
static int vfio_migration_set_state(VFIODevice *vbasedev,
enum vfio_device_mig_state new_state,
enum vfio_device_mig_state recover_state,
Error **errp)
{
VFIOMigration *migration = vbasedev->migration;
uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
sizeof(struct vfio_device_feature_mig_state),
sizeof(uint64_t))] = {};
struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
struct vfio_device_feature_mig_state *mig_state =
(struct vfio_device_feature_mig_state *)feature->data;
int ret;
g_autofree char *error_prefix =
g_strdup_printf("%s: Failed setting device state to %s.",
vbasedev->name, mig_state_to_str(new_state));
feature->argsz = sizeof(buf);
feature->flags =
VFIO_DEVICE_FEATURE_SET | VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE;
mig_state->device_state = new_state;
if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
/* Try to set the device in some good state */
ret = -errno;
if (recover_state == VFIO_DEVICE_STATE_ERROR) {
error_setg_errno(errp, errno,
"%s Recover state is ERROR. Resetting device",
error_prefix);
goto reset_device;
}
error_setg_errno(errp, errno,
"%s Setting device in recover state %s",
error_prefix, mig_state_to_str(recover_state));
mig_state->device_state = recover_state;
if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
ret = -errno;
/*
* If setting the device in recover state fails, report
* the error here and propagate the first error.
*/
error_report(
"%s: Failed setting device in recover state, err: %s. Resetting device",
vbasedev->name, strerror(errno));
goto reset_device;
}
migration->device_state = recover_state;
return ret;
}
migration->device_state = new_state;
if (mig_state->data_fd != -1) {
if (migration->data_fd != -1) {
/*
* This can happen if the device is asynchronously reset and
* terminates a data transfer.
*/
error_setg(errp, "%s: data_fd out of sync", vbasedev->name);
close(mig_state->data_fd);
return -EBADF;
}
migration->data_fd = mig_state->data_fd;
}
trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state));
return 0;
reset_device:
if (ioctl(vbasedev->fd, VFIO_DEVICE_RESET)) {
hw_error("%s: Failed resetting device, err: %s", vbasedev->name,
strerror(errno));
}
migration->device_state = VFIO_DEVICE_STATE_RUNNING;
return ret;
}
/*
* Some device state transitions require resetting the device if they fail.
* This function sets the device in new_state and resets the device if that
* fails. Reset is done by using ERROR as the recover state.
*/
static int
vfio_migration_set_state_or_reset(VFIODevice *vbasedev,
enum vfio_device_mig_state new_state,
Error **errp)
{
return vfio_migration_set_state(vbasedev, new_state,
VFIO_DEVICE_STATE_ERROR, errp);
}
static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev,
uint64_t data_size)
{
VFIOMigration *migration = vbasedev->migration;
int ret;
ret = qemu_file_get_to_fd(f, migration->data_fd, data_size);
trace_vfio_load_state_device_data(vbasedev->name, data_size, ret);
return ret;
}
static int vfio_save_device_config_state(QEMUFile *f, void *opaque,
Error **errp)
{
VFIODevice *vbasedev = opaque;
int ret;
qemu_put_be64(f, VFIO_MIG_FLAG_DEV_CONFIG_STATE);
if (vbasedev->ops && vbasedev->ops->vfio_save_config) {
ret = vbasedev->ops->vfio_save_config(vbasedev, f, errp);
if (ret) {
return ret;
}
}
qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
trace_vfio_save_device_config_state(vbasedev->name);
ret = qemu_file_get_error(f);
if (ret < 0) {
error_setg_errno(errp, -ret, "Failed to save state");
}
return ret;
}
static int vfio_load_device_config_state(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
uint64_t data;
if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
int ret;
ret = vbasedev->ops->vfio_load_config(vbasedev, f);
if (ret) {
error_report("%s: Failed to load device config space",
vbasedev->name);
return ret;
}
}
data = qemu_get_be64(f);
if (data != VFIO_MIG_FLAG_END_OF_STATE) {
error_report("%s: Failed loading device config space, "
"end flag incorrect 0x%"PRIx64, vbasedev->name, data);
return -EINVAL;
}
trace_vfio_load_device_config_state(vbasedev->name);
return qemu_file_get_error(f);
}
static void vfio_migration_cleanup(VFIODevice *vbasedev)
{
VFIOMigration *migration = vbasedev->migration;
close(migration->data_fd);
migration->data_fd = -1;
}
static int vfio_query_stop_copy_size(VFIODevice *vbasedev,
uint64_t *stop_copy_size)
{
uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
sizeof(struct vfio_device_feature_mig_data_size),
sizeof(uint64_t))] = {};
struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
struct vfio_device_feature_mig_data_size *mig_data_size =
(struct vfio_device_feature_mig_data_size *)feature->data;
feature->argsz = sizeof(buf);
feature->flags =
VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIG_DATA_SIZE;
if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
return -errno;
}
*stop_copy_size = mig_data_size->stop_copy_length;
return 0;
}
static int vfio_query_precopy_size(VFIOMigration *migration)
{
struct vfio_precopy_info precopy = {
.argsz = sizeof(precopy),
};
migration->precopy_init_size = 0;
migration->precopy_dirty_size = 0;
if (ioctl(migration->data_fd, VFIO_MIG_GET_PRECOPY_INFO, &precopy)) {
return -errno;
}
migration->precopy_init_size = precopy.initial_bytes;
migration->precopy_dirty_size = precopy.dirty_bytes;
return 0;
}
/* Returns the size of saved data on success and -errno on error */
static ssize_t vfio_save_block(QEMUFile *f, VFIOMigration *migration)
{
ssize_t data_size;
data_size = read(migration->data_fd, migration->data_buffer,
migration->data_buffer_size);
if (data_size < 0) {
/*
* Pre-copy emptied all the device state for now. For more information,
* please refer to the Linux kernel VFIO uAPI.
*/
if (errno == ENOMSG) {
return 0;
}
return -errno;
}
if (data_size == 0) {
return 0;
}
qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE);
qemu_put_be64(f, data_size);
qemu_put_buffer(f, migration->data_buffer, data_size);
bytes_transferred += data_size;
trace_vfio_save_block(migration->vbasedev->name, data_size);
return qemu_file_get_error(f) ?: data_size;
}
static void vfio_update_estimated_pending_data(VFIOMigration *migration,
uint64_t data_size)
{
if (!data_size) {
/*
* Pre-copy emptied all the device state for now, update estimated sizes
* accordingly.
*/
migration->precopy_init_size = 0;
migration->precopy_dirty_size = 0;
return;
}
if (migration->precopy_init_size) {
uint64_t init_size = MIN(migration->precopy_init_size, data_size);
migration->precopy_init_size -= init_size;
data_size -= init_size;
}
migration->precopy_dirty_size -= MIN(migration->precopy_dirty_size,
data_size);
}
static bool vfio_precopy_supported(VFIODevice *vbasedev)
{
VFIOMigration *migration = vbasedev->migration;
return migration->mig_flags & VFIO_MIGRATION_PRE_COPY;
}
/* ---------------------------------------------------------------------- */
static int vfio_save_prepare(void *opaque, Error **errp)
{
VFIODevice *vbasedev = opaque;
/*
* Snapshot doesn't use postcopy nor background snapshot, so allow snapshot
* even if they are on.
*/
if (runstate_check(RUN_STATE_SAVE_VM)) {
return 0;
}
if (migrate_postcopy_ram()) {
error_setg(
errp, "%s: VFIO migration is not supported with postcopy migration",
vbasedev->name);
return -EOPNOTSUPP;
}
if (migrate_background_snapshot()) {
error_setg(
errp,
"%s: VFIO migration is not supported with background snapshot",
vbasedev->name);
return -EOPNOTSUPP;
}
return 0;
}
static int vfio_save_setup(QEMUFile *f, void *opaque, Error **errp)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE;
int ret;
qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE);
vfio_query_stop_copy_size(vbasedev, &stop_copy_size);
migration->data_buffer_size = MIN(VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE,
stop_copy_size);
migration->data_buffer = g_try_malloc0(migration->data_buffer_size);
if (!migration->data_buffer) {
error_setg(errp, "%s: Failed to allocate migration data buffer",
vbasedev->name);
return -ENOMEM;
}
if (vfio_precopy_supported(vbasedev)) {
switch (migration->device_state) {
case VFIO_DEVICE_STATE_RUNNING:
ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_PRE_COPY,
VFIO_DEVICE_STATE_RUNNING, errp);
if (ret) {
return ret;
}
vfio_query_precopy_size(migration);
break;
case VFIO_DEVICE_STATE_STOP:
/* vfio_save_complete_precopy() will go to STOP_COPY */
break;
default:
error_setg(errp, "%s: Invalid device state %d", vbasedev->name,
migration->device_state);
return -EINVAL;
}
}
trace_vfio_save_setup(vbasedev->name, migration->data_buffer_size);
qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
ret = qemu_file_get_error(f);
if (ret < 0) {
error_setg_errno(errp, -ret, "%s: save setup failed", vbasedev->name);
}
return ret;
}
static void vfio_save_cleanup(void *opaque)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
Error *local_err = NULL;
int ret;
/*
* Changing device state from STOP_COPY to STOP can take time. Do it here,
* after migration has completed, so it won't increase downtime.
*/
if (migration->device_state == VFIO_DEVICE_STATE_STOP_COPY) {
ret = vfio_migration_set_state_or_reset(vbasedev,
VFIO_DEVICE_STATE_STOP,
&local_err);
if (ret) {
error_report_err(local_err);
}
}
g_free(migration->data_buffer);
migration->data_buffer = NULL;
migration->precopy_init_size = 0;
migration->precopy_dirty_size = 0;
migration->initial_data_sent = false;
vfio_migration_cleanup(vbasedev);
trace_vfio_save_cleanup(vbasedev->name);
}
static void vfio_state_pending_estimate(void *opaque, uint64_t *must_precopy,
uint64_t *can_postcopy)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
if (!vfio_device_state_is_precopy(vbasedev)) {
return;
}
*must_precopy +=
migration->precopy_init_size + migration->precopy_dirty_size;
trace_vfio_state_pending_estimate(vbasedev->name, *must_precopy,
*can_postcopy,
migration->precopy_init_size,
migration->precopy_dirty_size);
}
/*
* Migration size of VFIO devices can be as little as a few KBs or as big as
* many GBs. This value should be big enough to cover the worst case.
*/
#define VFIO_MIG_STOP_COPY_SIZE (100 * GiB)
static void vfio_state_pending_exact(void *opaque, uint64_t *must_precopy,
uint64_t *can_postcopy)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
uint64_t stop_copy_size = VFIO_MIG_STOP_COPY_SIZE;
/*
* If getting pending migration size fails, VFIO_MIG_STOP_COPY_SIZE is
* reported so downtime limit won't be violated.
*/
vfio_query_stop_copy_size(vbasedev, &stop_copy_size);
*must_precopy += stop_copy_size;
if (vfio_device_state_is_precopy(vbasedev)) {
vfio_query_precopy_size(migration);
*must_precopy +=
migration->precopy_init_size + migration->precopy_dirty_size;
}
trace_vfio_state_pending_exact(vbasedev->name, *must_precopy, *can_postcopy,
stop_copy_size, migration->precopy_init_size,
migration->precopy_dirty_size);
}
static bool vfio_is_active_iterate(void *opaque)
{
VFIODevice *vbasedev = opaque;
return vfio_device_state_is_precopy(vbasedev);
}
/*
* Note about migration rate limiting: VFIO migration buffer size is currently
* limited to 1MB, so there is no need to check if migration rate exceeded (as
* in the worst case it will exceed by 1MB). However, if the buffer size is
* later changed to a bigger value, migration rate should be enforced here.
*/
static int vfio_save_iterate(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
ssize_t data_size;
data_size = vfio_save_block(f, migration);
if (data_size < 0) {
return data_size;
}
vfio_update_estimated_pending_data(migration, data_size);
if (migrate_switchover_ack() && !migration->precopy_init_size &&
!migration->initial_data_sent) {
qemu_put_be64(f, VFIO_MIG_FLAG_DEV_INIT_DATA_SENT);
migration->initial_data_sent = true;
} else {
qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
}
trace_vfio_save_iterate(vbasedev->name, migration->precopy_init_size,
migration->precopy_dirty_size);
return !migration->precopy_init_size && !migration->precopy_dirty_size;
}
static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
ssize_t data_size;
int ret;
Error *local_err = NULL;
/* We reach here with device state STOP or STOP_COPY only */
ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY,
VFIO_DEVICE_STATE_STOP, &local_err);
if (ret) {
error_report_err(local_err);
return ret;
}
do {
data_size = vfio_save_block(f, vbasedev->migration);
if (data_size < 0) {
return data_size;
}
} while (data_size);
qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
ret = qemu_file_get_error(f);
trace_vfio_save_complete_precopy(vbasedev->name, ret);
return ret;
}
static void vfio_save_state(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
Error *local_err = NULL;
int ret;
ret = vfio_save_device_config_state(f, opaque, &local_err);
if (ret) {
error_prepend(&local_err,
"vfio: Failed to save device config space of %s - ",
vbasedev->name);
qemu_file_set_error_obj(f, ret, local_err);
}
}
static int vfio_load_setup(QEMUFile *f, void *opaque, Error **errp)
{
VFIODevice *vbasedev = opaque;
return vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING,
vbasedev->migration->device_state, errp);
}
static int vfio_load_cleanup(void *opaque)
{
VFIODevice *vbasedev = opaque;
vfio_migration_cleanup(vbasedev);
trace_vfio_load_cleanup(vbasedev->name);
return 0;
}
static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
{
VFIODevice *vbasedev = opaque;
int ret = 0;
uint64_t data;
data = qemu_get_be64(f);
while (data != VFIO_MIG_FLAG_END_OF_STATE) {
trace_vfio_load_state(vbasedev->name, data);
switch (data) {
case VFIO_MIG_FLAG_DEV_CONFIG_STATE:
{
return vfio_load_device_config_state(f, opaque);
}
case VFIO_MIG_FLAG_DEV_SETUP_STATE:
{
data = qemu_get_be64(f);
if (data == VFIO_MIG_FLAG_END_OF_STATE) {
return ret;
} else {
error_report("%s: SETUP STATE: EOS not found 0x%"PRIx64,
vbasedev->name, data);
return -EINVAL;
}
break;
}
case VFIO_MIG_FLAG_DEV_DATA_STATE:
{
uint64_t data_size = qemu_get_be64(f);
if (data_size) {
ret = vfio_load_buffer(f, vbasedev, data_size);
if (ret < 0) {
return ret;
}
}
break;
}
case VFIO_MIG_FLAG_DEV_INIT_DATA_SENT:
{
if (!vfio_precopy_supported(vbasedev) ||
!migrate_switchover_ack()) {
error_report("%s: Received INIT_DATA_SENT but switchover ack "
"is not used", vbasedev->name);
return -EINVAL;
}
ret = qemu_loadvm_approve_switchover();
if (ret) {
error_report(
"%s: qemu_loadvm_approve_switchover failed, err=%d (%s)",
vbasedev->name, ret, strerror(-ret));
}
return ret;
}
default:
error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
return -EINVAL;
}
data = qemu_get_be64(f);
ret = qemu_file_get_error(f);
if (ret) {
return ret;
}
}
return ret;
}
static bool vfio_switchover_ack_needed(void *opaque)
{
VFIODevice *vbasedev = opaque;
return vfio_precopy_supported(vbasedev);
}
static const SaveVMHandlers savevm_vfio_handlers = {
.save_prepare = vfio_save_prepare,
.save_setup = vfio_save_setup,
.save_cleanup = vfio_save_cleanup,
.state_pending_estimate = vfio_state_pending_estimate,
.state_pending_exact = vfio_state_pending_exact,
.is_active_iterate = vfio_is_active_iterate,
.save_live_iterate = vfio_save_iterate,
.save_live_complete_precopy = vfio_save_complete_precopy,
.save_state = vfio_save_state,
.load_setup = vfio_load_setup,
.load_cleanup = vfio_load_cleanup,
.load_state = vfio_load_state,
.switchover_ack_needed = vfio_switchover_ack_needed,
};
/* ---------------------------------------------------------------------- */
static void vfio_vmstate_change_prepare(void *opaque, bool running,
RunState state)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
enum vfio_device_mig_state new_state;
Error *local_err = NULL;
int ret;
new_state = migration->device_state == VFIO_DEVICE_STATE_PRE_COPY ?
VFIO_DEVICE_STATE_PRE_COPY_P2P :
VFIO_DEVICE_STATE_RUNNING_P2P;
ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err);
if (ret) {
/*
* Migration should be aborted in this case, but vm_state_notify()
* currently does not support reporting failures.
*/
migration_file_set_error(ret, local_err);
}
trace_vfio_vmstate_change_prepare(vbasedev->name, running,
RunState_str(state),
mig_state_to_str(new_state));
}
static void vfio_vmstate_change(void *opaque, bool running, RunState state)
{
VFIODevice *vbasedev = opaque;
enum vfio_device_mig_state new_state;
Error *local_err = NULL;
int ret;
if (running) {
new_state = VFIO_DEVICE_STATE_RUNNING;
} else {
new_state =
(vfio_device_state_is_precopy(vbasedev) &&
(state == RUN_STATE_FINISH_MIGRATE || state == RUN_STATE_PAUSED)) ?
VFIO_DEVICE_STATE_STOP_COPY :
VFIO_DEVICE_STATE_STOP;
}
ret = vfio_migration_set_state_or_reset(vbasedev, new_state, &local_err);
if (ret) {
/*
* Migration should be aborted in this case, but vm_state_notify()
* currently does not support reporting failures.
*/
migration_file_set_error(ret, local_err);
}
trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),
mig_state_to_str(new_state));
}
static int vfio_migration_state_notifier(NotifierWithReturn *notifier,
MigrationEvent *e, Error **errp)
{
VFIOMigration *migration = container_of(notifier, VFIOMigration,
migration_state);
VFIODevice *vbasedev = migration->vbasedev;
Error *local_err = NULL;
int ret;
trace_vfio_migration_state_notifier(vbasedev->name, e->type);
if (e->type == MIG_EVENT_PRECOPY_FAILED) {
/*
* MigrationNotifyFunc may not return an error code and an Error
* object for MIG_EVENT_PRECOPY_FAILED. Hence, report the error
* locally and ignore the errp argument.
*/
ret = vfio_migration_set_state_or_reset(vbasedev,
VFIO_DEVICE_STATE_RUNNING,
&local_err);
if (ret) {
error_report_err(local_err);
}
}
return 0;
}
static void vfio_migration_free(VFIODevice *vbasedev)
{
g_free(vbasedev->migration);
vbasedev->migration = NULL;
}
static int vfio_migration_query_flags(VFIODevice *vbasedev, uint64_t *mig_flags)
{
uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) +
sizeof(struct vfio_device_feature_migration),
sizeof(uint64_t))] = {};
struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
struct vfio_device_feature_migration *mig =
(struct vfio_device_feature_migration *)feature->data;
feature->argsz = sizeof(buf);
feature->flags = VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_MIGRATION;
if (ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature)) {
return -errno;
}
*mig_flags = mig->flags;
return 0;
}
static bool vfio_dma_logging_supported(VFIODevice *vbasedev)
{
uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature),
sizeof(uint64_t))] = {};
struct vfio_device_feature *feature = (struct vfio_device_feature *)buf;
feature->argsz = sizeof(buf);
feature->flags = VFIO_DEVICE_FEATURE_PROBE |
VFIO_DEVICE_FEATURE_DMA_LOGGING_START;
return !ioctl(vbasedev->fd, VFIO_DEVICE_FEATURE, feature);
}
static int vfio_migration_init(VFIODevice *vbasedev)
{
int ret;
Object *obj;
VFIOMigration *migration;
char id[256] = "";
g_autofree char *path = NULL, *oid = NULL;
uint64_t mig_flags = 0;
VMChangeStateHandler *prepare_cb;
if (!vbasedev->ops->vfio_get_object) {
return -EINVAL;
}
obj = vbasedev->ops->vfio_get_object(vbasedev);
if (!obj) {
return -EINVAL;
}
ret = vfio_migration_query_flags(vbasedev, &mig_flags);
if (ret) {
return ret;
}
/* Basic migration functionality must be supported */
if (!(mig_flags & VFIO_MIGRATION_STOP_COPY)) {
return -EOPNOTSUPP;
}
vbasedev->migration = g_new0(VFIOMigration, 1);
migration = vbasedev->migration;
migration->vbasedev = vbasedev;
migration->device_state = VFIO_DEVICE_STATE_RUNNING;
migration->data_fd = -1;
migration->mig_flags = mig_flags;
vbasedev->dirty_pages_supported = vfio_dma_logging_supported(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);
prepare_cb = migration->mig_flags & VFIO_MIGRATION_P2P ?
vfio_vmstate_change_prepare :
NULL;
migration->vm_state = qdev_add_vm_change_state_handler_full(
vbasedev->dev, vfio_vmstate_change, prepare_cb, vbasedev);
migration_add_notifier(&migration->migration_state,
vfio_migration_state_notifier);
return 0;
}
static void vfio_migration_deinit(VFIODevice *vbasedev)
{
VFIOMigration *migration = vbasedev->migration;
migration_remove_notifier(&migration->migration_state);
qemu_del_vm_change_state_handler(migration->vm_state);
unregister_savevm(VMSTATE_IF(vbasedev->dev), "vfio", vbasedev);
vfio_migration_free(vbasedev);
vfio_unblock_multiple_devices_migration();
}
static int vfio_block_migration(VFIODevice *vbasedev, Error *err, Error **errp)
{
if (vbasedev->enable_migration == ON_OFF_AUTO_ON) {
error_propagate(errp, err);
return -EINVAL;
}
vbasedev->migration_blocker = error_copy(err);
error_free(err);
return migrate_add_blocker_normal(&vbasedev->migration_blocker, errp);
}
/* ---------------------------------------------------------------------- */
int64_t vfio_mig_bytes_transferred(void)
{
return bytes_transferred;
}
void vfio_reset_bytes_transferred(void)
{
bytes_transferred = 0;
}
/*
* Return true when either migration initialized or blocker registered.
* Currently only return false when adding blocker fails which will
* de-register vfio device.
*/
bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp)
{
Error *err = NULL;
int ret;
if (vbasedev->enable_migration == ON_OFF_AUTO_OFF) {
error_setg(&err, "%s: Migration is disabled for VFIO device",
vbasedev->name);
return !vfio_block_migration(vbasedev, err, errp);
}
ret = vfio_migration_init(vbasedev);
if (ret) {
if (ret == -ENOTTY) {
error_setg(&err, "%s: VFIO migration is not supported in kernel",
vbasedev->name);
} else {
error_setg(&err,
"%s: Migration couldn't be initialized for VFIO device, "
"err: %d (%s)",
vbasedev->name, ret, strerror(-ret));
}
return !vfio_block_migration(vbasedev, err, errp);
}
if (!vbasedev->dirty_pages_supported) {
if (vbasedev->enable_migration == ON_OFF_AUTO_AUTO) {
error_setg(&err,
"%s: VFIO device doesn't support device dirty tracking",
vbasedev->name);
goto add_blocker;
}
warn_report("%s: VFIO device doesn't support device dirty tracking",
vbasedev->name);
}
ret = vfio_block_multiple_devices_migration(vbasedev, errp);
if (ret) {
goto out_deinit;
}
if (vfio_viommu_preset(vbasedev)) {
error_setg(&err, "%s: Migration is currently not supported "
"with vIOMMU enabled", vbasedev->name);
goto add_blocker;
}
trace_vfio_migration_realize(vbasedev->name);
return true;
add_blocker:
ret = vfio_block_migration(vbasedev, err, errp);
out_deinit:
if (ret) {
vfio_migration_deinit(vbasedev);
}
return !ret;
}
void vfio_migration_exit(VFIODevice *vbasedev)
{
if (vbasedev->migration) {
vfio_migration_deinit(vbasedev);
}
migrate_del_blocker(&vbasedev->migration_blocker);
}
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