[PATCH vhost 04/16] vhost-vdpa: uAPI to get dedicated descriptor group id
From: Dragos Tatulea <dtatulea@nvidia.com>
Date: 2023-09-28 16:50:04
Also in:
kvm, lkml, virtualization
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
From: Si-Wei Liu <redacted> 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 <redacted> Acked-by: Eugenio Pérez <eperezma@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> --- 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 2f21798a37ee..851535f57b95 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c@@ -613,6 +613,16 @@ 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 f5c48b61ab62..649560c685f1 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 group for the descriptor table including driver & device areas + * 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 of the descriptor table for 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
--
2.41.0