Re: [PATCH] vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE

From: Stefano Garzarella
Date: Wed Apr 03 2024 - 05:58:25 EST


On Tue, Apr 02, 2024 at 05:21:39PM -0400, Michael S. Tsirkin wrote:
VDPA_GET_VRING_SIZE by mistake uses the already occupied
ioctl # 0x80 and we never noticed - it happens to work
because the direction and size are different, but confuses
tools such as perf which like to look at just the number,
and breaks the extra robustness of the ioctl numbering macros.

To fix, sort the entries and renumber the ioctl - not too late
since it wasn't in any released kernels yet.

Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Reported-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Fixes: 1496c47065f9 ("vhost-vdpa: uapi to support reporting per vq size")
Cc: "Zhu Lingshan" <lingshan.zhu@xxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---

Build tested only - userspace patches using this will have to adjust.
I will merge this in a week or so unless I hear otherwise,
and afterwards perf can update there header.

Fortunately, we haven't released any kernels with this yet, right?
(other than v6.9-rc*)

LGTM:

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>


include/uapi/linux/vhost.h | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index bea697390613..b95dd84eef2d 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -179,12 +179,6 @@
/* Get the config size */
#define VHOST_VDPA_GET_CONFIG_SIZE _IOR(VHOST_VIRTIO, 0x79, __u32)

-/* Get the count of all virtqueues */
-#define VHOST_VDPA_GET_VQS_COUNT _IOR(VHOST_VIRTIO, 0x80, __u32)
-
-/* Get the number of virtqueue groups. */
-#define VHOST_VDPA_GET_GROUP_NUM _IOR(VHOST_VIRTIO, 0x81, __u32)
-
/* Get the number of address spaces. */
#define VHOST_VDPA_GET_AS_NUM _IOR(VHOST_VIRTIO, 0x7A, unsigned int)

@@ -228,10 +222,17 @@
#define VHOST_VDPA_GET_VRING_DESC_GROUP _IOWR(VHOST_VIRTIO, 0x7F, \
struct vhost_vring_state)

+
+/* Get the count of all virtqueues */
+#define VHOST_VDPA_GET_VQS_COUNT _IOR(VHOST_VIRTIO, 0x80, __u32)
+
+/* Get the number of virtqueue groups. */
+#define VHOST_VDPA_GET_GROUP_NUM _IOR(VHOST_VIRTIO, 0x81, __u32)
+
/* Get the queue size of a specific virtqueue.
* userspace set the vring index in vhost_vring_state.index
* kernel set the queue size in vhost_vring_state.num
*/
-#define VHOST_VDPA_GET_VRING_SIZE _IOWR(VHOST_VIRTIO, 0x80, \
+#define VHOST_VDPA_GET_VRING_SIZE _IOWR(VHOST_VIRTIO, 0x82, \
struct vhost_vring_state)
#endif
--
MST