vfio: Add load state functions to SaveVMHandlers

Sequence  during _RESUMING device state:
While data for this device is available, repeat below steps:
a. read data_offset from where user application should write data.
b. write data of data_size to migration region from data_offset.
c. write data_size which indicates vendor driver that data is written in
   staging buffer.

For user, data is opaque. User should write data in the same order as
received.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@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 15:06:19 +05:30 committed by Alex Williamson
parent 1bc3c535ff
commit 3336d21710
2 changed files with 199 additions and 0 deletions

View File

@ -257,6 +257,77 @@ static int vfio_save_buffer(QEMUFile *f, VFIODevice *vbasedev, uint64_t *size)
return ret;
}
static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev,
uint64_t data_size)
{
VFIORegion *region = &vbasedev->migration->region;
uint64_t data_offset = 0, size, report_size;
int ret;
do {
ret = vfio_mig_read(vbasedev, &data_offset, sizeof(data_offset),
region->fd_offset + VFIO_MIG_STRUCT_OFFSET(data_offset));
if (ret < 0) {
return ret;
}
if (data_offset + data_size > region->size) {
/*
* If data_size is greater than the data section of migration region
* then iterate the write buffer operation. This case can occur if
* size of migration region at destination is smaller than size of
* migration region at source.
*/
report_size = size = region->size - data_offset;
data_size -= size;
} else {
report_size = size = data_size;
data_size = 0;
}
trace_vfio_load_state_device_data(vbasedev->name, data_offset, size);
while (size) {
void *buf;
uint64_t sec_size;
bool buf_alloc = false;
buf = get_data_section_size(region, data_offset, size, &sec_size);
if (!buf) {
buf = g_try_malloc(sec_size);
if (!buf) {
error_report("%s: Error allocating buffer ", __func__);
return -ENOMEM;
}
buf_alloc = true;
}
qemu_get_buffer(f, buf, sec_size);
if (buf_alloc) {
ret = vfio_mig_write(vbasedev, buf, sec_size,
region->fd_offset + data_offset);
g_free(buf);
if (ret < 0) {
return ret;
}
}
size -= sec_size;
data_offset += sec_size;
}
ret = vfio_mig_write(vbasedev, &report_size, sizeof(report_size),
region->fd_offset + VFIO_MIG_STRUCT_OFFSET(data_size));
if (ret < 0) {
return ret;
}
} while (data_size);
return 0;
}
static int vfio_update_pending(VFIODevice *vbasedev)
{
VFIOMigration *migration = vbasedev->migration;
@ -293,6 +364,33 @@ static int vfio_save_device_config_state(QEMUFile *f, void *opaque)
return qemu_file_get_error(f);
}
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;
@ -483,12 +581,109 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
return ret;
}
static int vfio_load_setup(QEMUFile *f, void *opaque)
{
VFIODevice *vbasedev = opaque;
VFIOMigration *migration = vbasedev->migration;
int ret = 0;
if (migration->region.mmaps) {
ret = vfio_region_mmap(&migration->region);
if (ret) {
error_report("%s: Failed to mmap VFIO migration region %d: %s",
vbasedev->name, migration->region.nr,
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_RESUMING);
if (ret) {
error_report("%s: Failed to set state RESUMING", vbasedev->name);
if (migration->region.mmaps) {
vfio_region_unmap(&migration->region);
}
}
return ret;
}
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:
{
ret = vfio_load_device_config_state(f, opaque);
if (ret) {
return ret;
}
break;
}
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;
}
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 SaveVMHandlers savevm_vfio_handlers = {
.save_setup = vfio_save_setup,
.save_cleanup = vfio_save_cleanup,
.save_live_pending = vfio_save_pending,
.save_live_iterate = vfio_save_iterate,
.save_live_complete_precopy = vfio_save_complete_precopy,
.load_setup = vfio_load_setup,
.load_cleanup = vfio_load_cleanup,
.load_state = vfio_load_state,
};
/* ---------------------------------------------------------------------- */

View File

@ -159,3 +159,7 @@ vfio_save_device_config_state(const char *name) " (%s)"
vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
vfio_save_complete_precopy(const char *name) " (%s)"
vfio_load_device_config_state(const char *name) " (%s)"
vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
vfio_load_cleanup(const char *name) " (%s)"