* Alex Williamson (alex.william...@redhat.com) wrote:
> On Sun, 21 Jun 2020 01:51:18 +0530
> Kirti Wankhede <kwankh...@nvidia.com> wrote:
>
> > 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 <kwankh...@nvidia.com>
> > Reviewed-by: Neo Jia <c...@nvidia.com>
> > Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> > ---
> > hw/vfio/migration.c | 177
> > +++++++++++++++++++++++++++++++++++++++++++++++++++
> > hw/vfio/trace-events | 3 +
> > 2 files changed, 180 insertions(+)
> >
> > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> > index ef1150c1ff02..faacea5327cb 100644
> > --- a/hw/vfio/migration.c
> > +++ b/hw/vfio/migration.c
> > @@ -302,6 +302,33 @@ 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 int vfio_save_setup(QEMUFile *f, void *opaque)
> > @@ -472,12 +499,162 @@ 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));
> > + return ret;
>
>
> Not fatal.
>
>
> > + }
> > + }
> > +
> > + 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);
> > + }
> > + return ret;
> > +}
> > +
> > +static int vfio_load_cleanup(void *opaque)
> > +{
> > + vfio_save_cleanup(opaque);
> > + return 0;
> > +}
> > +
> > +static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
> > +{
> > + VFIODevice *vbasedev = opaque;
> > + VFIOMigration *migration = vbasedev->migration;
> > + int ret = 0;
> > + uint64_t data, data_size;
> > +
> > + 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;
>
> This is essentially just a compatibility failure, right? For instance
> some future version of QEMU might include additional data between these
> markers that we don't understand and therefore we fail the migration.
Or any other screwup in data layout; we've found having a canary at the
end of state is quite useful for when we screwup for one reason or
another.
Dave
> Thanks,
>
> Alex
>
> > + }
> > + break;
> > + }
> > + case VFIO_MIG_FLAG_DEV_DATA_STATE:
> > + {
> > + VFIORegion *region = &migration->region;
> > + uint64_t data_offset = 0, size;
> > +
> > + data_size = size = qemu_get_be64(f);
> > + if (data_size == 0) {
> > + break;
> > + }
> > +
> > + ret = pread(vbasedev->fd, &data_offset, sizeof(data_offset),
> > + region->fd_offset +
> > + offsetof(struct vfio_device_migration_info,
> > + data_offset));
> > + if (ret != sizeof(data_offset)) {
> > + error_report("%s:Failed to get migration buffer data
> > offset %d",
> > + vbasedev->name, ret);
> > + return -EINVAL;
> > + }
> > +
> > + trace_vfio_load_state_device_data(vbasedev->name, data_offset,
> > + data_size);
> > +
> > + while (size) {
> > + void *buf = NULL;
> > + uint64_t sec_size;
> > + bool buffer_mmaped;
> > +
> > + buf = get_data_section_size(region, data_offset, size,
> > + &sec_size);
> > +
> > + buffer_mmaped = (buf != NULL);
> > +
> > + if (!buffer_mmaped) {
> > + buf = g_try_malloc(sec_size);
> > + if (!buf) {
> > + error_report("%s: Error allocating buffer ",
> > __func__);
> > + return -ENOMEM;
> > + }
> > + }
> > +
> > + qemu_get_buffer(f, buf, sec_size);
> > +
> > + if (!buffer_mmaped) {
> > + ret = pwrite(vbasedev->fd, buf, sec_size,
> > + region->fd_offset + data_offset);
> > + g_free(buf);
> > +
> > + if (ret != sec_size) {
> > + error_report("%s: Failed to set migration buffer
> > %d",
> > + vbasedev->name, ret);
> > + return -EINVAL;
> > + }
> > + }
> > + size -= sec_size;
> > + data_offset += sec_size;
> > + }
> > +
> > + ret = pwrite(vbasedev->fd, &data_size, sizeof(data_size),
> > + region->fd_offset +
> > + offsetof(struct vfio_device_migration_info,
> > data_size));
> > + if (ret != sizeof(data_size)) {
> > + error_report("%s: Failed to set migration buffer data size
> > %d",
> > + vbasedev->name, ret);
> > + return -EINVAL;
> > + }
> > + 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,
> > };
> >
> > /* ----------------------------------------------------------------------
> > */
> > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> > index 9a1c5e17d97f..4a4bd3ba9a2a 100644
> > --- a/hw/vfio/trace-events
> > +++ b/hw/vfio/trace-events
> > @@ -157,3 +157,6 @@ 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
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
