On Wed, 23 Sep 2020 04:54:10 +0530
Kirti Wankhede <kwankh...@nvidia.com> wrote:
> Added .save_live_pending, .save_live_iterate and .save_live_complete_precopy
> functions. These functions handles pre-copy and stop-and-copy phase.
>
> In _SAVING|_RUNNING device state or pre-copy phase:
> - read pending_bytes. If pending_bytes > 0, go through below steps.
> - read data_offset - indicates kernel driver to write data to staging
> buffer.
> - read data_size - amount of data in bytes written by vendor driver in
> migration region.
> - read data_size bytes of data from data_offset in the migration region.
> - Write data packet to file stream as below:
> {VFIO_MIG_FLAG_DEV_DATA_STATE, data_size, actual data,
> VFIO_MIG_FLAG_END_OF_STATE }
>
> In _SAVING device state or stop-and-copy phase
> a. read config space of device and save to migration file stream. This
> doesn't need to be from vendor driver. Any other special config state
> from driver can be saved as data in following iteration.
> b. read pending_bytes. If pending_bytes > 0, go through below steps.
> c. read data_offset - indicates kernel driver to write data to staging
> buffer.
> d. read data_size - amount of data in bytes written by vendor driver in
> migration region.
> e. read data_size bytes of data from data_offset in the migration region.
> f. Write data packet as below:
> {VFIO_MIG_FLAG_DEV_DATA_STATE, data_size, actual data}
> g. iterate through steps b to f while (pending_bytes > 0)
> h. Write {VFIO_MIG_FLAG_END_OF_STATE}
>
> When data region is mapped, its user's responsibility to read data from
> data_offset of data_size before moving to next steps.
>
> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> Reviewed-by: Neo Jia <c...@nvidia.com>
> ---
> hw/vfio/migration.c | 273
> ++++++++++++++++++++++++++++++++++++++++++
> hw/vfio/trace-events | 6 +
> include/hw/vfio/vfio-common.h | 1 +
> 3 files changed, 280 insertions(+)
>
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index 8e8adaa25779..4611bb972228 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -180,6 +180,154 @@ static int vfio_migration_set_state(VFIODevice
> *vbasedev, uint32_t mask,
> return 0;
> }
>
> +static void *get_data_section_size(VFIORegion *region, uint64_t data_offset,
> + uint64_t data_size, uint64_t *size)
> +{
> + void *ptr = NULL;
> + uint64_t limit = 0;
> + int i;
> +
> + if (!region->mmaps) {
> + if (size) {
> + *size = data_size;
> + }
> + return ptr;
> + }
> +
> + for (i = 0; i < region->nr_mmaps; i++) {
> + VFIOMmap *map = region->mmaps + i;
> +
> + if ((data_offset >= map->offset) &&
> + (data_offset < map->offset + map->size)) {
> +
> + /* check if data_offset is within sparse mmap areas */
> + ptr = map->mmap + data_offset - map->offset;
> + if (size) {
> + *size = MIN(data_size, map->offset + map->size -
> data_offset);
> + }
> + break;
> + } else if ((data_offset < map->offset) &&
> + (!limit || limit > map->offset)) {
> + /*
> + * data_offset is not within sparse mmap areas, find size of
> + * non-mapped area. Check through all list since region->mmaps
> list
> + * is not sorted.
> + */
> + limit = map->offset;
> + }
> + }
> +
> + if (!ptr && size) {
> + *size = limit ? limit - data_offset : data_size;
'limit - data_offset' doesn't take data_size into account, this should
be MIN(data_size, limit - data_offset).
> + }
> + return ptr;
> +}
> +
> +static int vfio_save_buffer(QEMUFile *f, VFIODevice *vbasedev, uint64_t
> *size)
> +{
> + VFIOMigration *migration = vbasedev->migration;
> + VFIORegion *region = &migration->region;
> + uint64_t data_offset = 0, data_size = 0, sz;
> + int ret;
> +
> + ret = vfio_mig_read(vbasedev, &data_offset, sizeof(data_offset),
> + region->fd_offset + offsetof(struct
> vfio_device_migration_info,
> + data_offset));
> + if (ret < 0) {
> + return ret;
> + }
> +
> + ret = vfio_mig_read(vbasedev, &data_size, sizeof(data_size),
> + region->fd_offset + offsetof(struct
> vfio_device_migration_info,
> + data_size));
> + if (ret < 0) {
> + return ret;
> + }
> +
> + trace_vfio_save_buffer(vbasedev->name, data_offset, data_size,
> + migration->pending_bytes);
> +
> + qemu_put_be64(f, data_size);
> + sz = data_size;
> +
> + while (sz) {
> + void *buf = NULL;
Unnecessary initialization.
> + uint64_t sec_size;
> + bool buf_allocated = false;
> +
> + buf = get_data_section_size(region, data_offset, sz, &sec_size);
> +
> + if (!buf) {
> + buf = g_try_malloc(sec_size);
> + if (!buf) {
> + error_report("%s: Error allocating buffer ", __func__);
> + return -ENOMEM;
> + }
> + buf_allocated = true;
> +
> + ret = vfio_mig_read(vbasedev, buf, sec_size,
> + region->fd_offset + data_offset);
> + if (ret < 0) {
> + g_free(buf);
> + return ret;
> + }
> + }
> +
> + qemu_put_buffer(f, buf, sec_size);
> +
> + if (buf_allocated) {
> + g_free(buf);
> + }
> + sz -= sec_size;
> + data_offset += sec_size;
> + }
> +
> + ret = qemu_file_get_error(f);
> +
> + if (!ret && size) {
> + *size = data_size;
> + }
> +
> + return ret;
> +}
> +
> +static int vfio_update_pending(VFIODevice *vbasedev)
> +{
> + VFIOMigration *migration = vbasedev->migration;
> + VFIORegion *region = &migration->region;
> + uint64_t pending_bytes = 0;
> + int ret;
> +
> + ret = vfio_mig_read(vbasedev, &pending_bytes, sizeof(pending_bytes),
> + region->fd_offset + offsetof(struct
> vfio_device_migration_info,
> + pending_bytes));
> + if (ret < 0) {
> + migration->pending_bytes = 0;
> + return ret;
> + }
> +
> + migration->pending_bytes = pending_bytes;
> + trace_vfio_update_pending(vbasedev->name, pending_bytes);
> + return 0;
> +}
> +
> +static int vfio_save_device_config_state(QEMUFile *f, void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_CONFIG_STATE);
> +
> + if (vbasedev->ops && vbasedev->ops->vfio_save_config) {
> + vbasedev->ops->vfio_save_config(vbasedev, f);
> + }
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
> +
> + trace_vfio_save_device_config_state(vbasedev->name);
> +
> + return qemu_file_get_error(f);
> +}
> +
> /* ---------------------------------------------------------------------- */
>
> static int vfio_save_setup(QEMUFile *f, void *opaque)
> @@ -232,9 +380,134 @@ static void vfio_save_cleanup(void *opaque)
> trace_vfio_save_cleanup(vbasedev->name);
> }
>
> +static void vfio_save_pending(QEMUFile *f, void *opaque,
> + uint64_t threshold_size,
> + uint64_t *res_precopy_only,
> + uint64_t *res_compatible,
> + uint64_t *res_postcopy_only)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> + int ret;
> +
> + ret = vfio_update_pending(vbasedev);
> + if (ret) {
> + return;
> + }
> +
> + *res_precopy_only += migration->pending_bytes;
> +
> + trace_vfio_save_pending(vbasedev->name, *res_precopy_only,
> + *res_postcopy_only, *res_compatible);
> +}
> +
> +static int vfio_save_iterate(QEMUFile *f, void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> + uint64_t data_size;
> + int ret;
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE);
> +
> + if (migration->pending_bytes == 0) {
> + ret = vfio_update_pending(vbasedev);
> + if (ret) {
> + return ret;
> + }
> +
> + if (migration->pending_bytes == 0) {
> + /* indicates data finished, goto complete phase */
> + return 1;
> + }
> + }
> +
> + ret = vfio_save_buffer(f, vbasedev, &data_size);
> +
> + if (ret) {
> + error_report("%s: vfio_save_buffer failed %s", vbasedev->name,
> + strerror(errno));
> + return ret;
> + }
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
> +
> + ret = qemu_file_get_error(f);
> + if (ret) {
> + return ret;
> + }
> +
> + trace_vfio_save_iterate(vbasedev->name, data_size);
> +
> + return 0;
> +}
> +
> +static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> + uint64_t data_size;
> + int ret;
> +
> + ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_RUNNING,
> + VFIO_DEVICE_STATE_SAVING);
> + if (ret) {
> + error_report("%s: Failed to set state STOP and SAVING",
> + vbasedev->name);
> + return ret;
> + }
This also assumes success implies desired state.
> +
> + ret = vfio_save_device_config_state(f, opaque);
> + if (ret) {
> + return ret;
> + }
> +
> + ret = vfio_update_pending(vbasedev);
> + if (ret) {
> + return ret;
> + }
> +
> + while (migration->pending_bytes > 0) {
> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE);
> + ret = vfio_save_buffer(f, vbasedev, &data_size);
> + if (ret < 0) {
> + error_report("%s: Failed to save buffer", vbasedev->name);
> + return ret;
> + }
> +
> + if (data_size == 0) {
> + break;
> + }
> +
> + ret = vfio_update_pending(vbasedev);
> + if (ret) {
> + return ret;
> + }
> + }
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
> +
> + ret = qemu_file_get_error(f);
> + if (ret) {
> + return ret;
> + }
> +
> + ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_SAVING, 0);
> + if (ret) {
> + error_report("%s: Failed to set state STOPPED", vbasedev->name);
> + return ret;
> + }
And another. Thanks,
Alex
> +
> + trace_vfio_save_complete_precopy(vbasedev->name);
> + 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,
> };
>
> /* ---------------------------------------------------------------------- */
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index 982d8dccb219..118b5547c921 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -154,3 +154,9 @@ vfio_vmstate_change(const char *name, int running, const
> char *reason, uint32_t
> 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)"
> +vfio_save_buffer(const char *name, uint64_t data_offset, uint64_t data_size,
> uint64_t pending) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64" pending
> 0x%"PRIx64
> +vfio_update_pending(const char *name, uint64_t pending) " (%s) pending
> 0x%"PRIx64
> +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)"
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 49c7c7a0e29a..471e444a364c 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -60,6 +60,7 @@ typedef struct VFIORegion {
>
> typedef struct VFIOMigration {
> VFIORegion region;
> + uint64_t pending_bytes;
> } VFIOMigration;
>
> typedef struct VFIOAddressSpace {
