With _F_DESC_ASID backend feature, the device can now support the VHOST_VDPA_GET_VRING_DESC_GROUP ioctl, and it may expose the descriptor table (including avail and used ring) in a different group than the buffers it contains. This new uAPI will fetch the group ID of the descriptor table. Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx> --- drivers/vhost/vdpa.c | 10 ++++++++++ include/uapi/linux/vhost.h | 8 ++++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index f2e5dce..eabac06 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -602,6 +602,16 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, else if (copy_to_user(argp, &s, sizeof(s))) return -EFAULT; return 0; + case VHOST_VDPA_GET_VRING_DESC_GROUP: + if (!vhost_vdpa_has_desc_group(v)) + return -EOPNOTSUPP; + s.index = idx; + s.num = ops->get_vq_desc_group(vdpa, idx); + if (s.num >= vdpa->ngroups) + return -EIO; + else if (copy_to_user(argp, &s, sizeof(s))) + return -EFAULT; + return 0; case VHOST_VDPA_SET_GROUP_ASID: if (copy_from_user(&s, argp, sizeof(s))) return -EFAULT; diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h index f5c48b6..05faad2 100644 --- a/include/uapi/linux/vhost.h +++ b/include/uapi/linux/vhost.h @@ -219,4 +219,12 @@ */ #define VHOST_VDPA_RESUME _IO(VHOST_VIRTIO, 0x7E) +/* Get the dedicated group for the descriptor table of a virtqueue: + * read index, write group in num. + * The virtqueue index is stored in the index field of vhost_vring_state. + * The group id for the descriptor table of this specific virtqueue + * is returned via num field of vhost_vring_state. + */ +#define VHOST_VDPA_GET_VRING_DESC_GROUP _IOWR(VHOST_VIRTIO, 0x7F, \ + struct vhost_vring_state) #endif -- 1.8.3.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
