Re: [PATCH v3 12/13] vfio/migration: Query device dirty page tracking support

[Cédric Le Goater]

On 3/4/23 02:43, Joao Martins wrote:
> Now that everything has been set up for device dirty page tracking,
> query the device for device dirty page tracking support.
>
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.

> ---
>   hw/vfio/migration.c | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
>
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index 3e75868ae7a9..da3aa596b3ec 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -555,6 +555,19 @@ static int vfio_migration_query_flags(VFIODevice 
> *vbasedev, uint64_t *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;
> @@ -589,6 +602,8 @@ static int vfio_migration_init(VFIODevice *vbasedev)
>       migration->device_state = VFIO_DEVICE_STATE_RUNNING;
>       migration->data_fd = -1;
>   
> +    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);