[PATCH] vdpa: fix cannot get vring base when stopping a vhost-vdpa device with multiple queues

[PATCH] vdpa: fix cannot get vring base when stopping a vhost-vdpa device with multiple queues

[Wafer Xie]

When stopping a vhost-vdpa device, only the first queue pair is marked as suspended,
while the remaining queues are not updated to the suspended state.
As a result, when stopping a multi-queue vhost-vdpa device,
the following error message will be printed.

qemu-system-x86_64:vhost VQ 2 ring restore failed: -1: Operation not permitted (1)

qemu-system-x86_64:vhost VQ 3 ring restore failed: -1: Operation not permitted (1)

Fixes: b6662cb7 ("vdpa: add vhost_vdpa->suspended parameter")

Signed-off-by: Wafer Xie <wafer@jaguarmicro.com>
---
 hw/virtio/vhost-vdpa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 7061b6e1a3..2d5e6aca74 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -1481,7 +1481,7 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
         return 0;
     }
 
-    if (!v->suspended) {
+    if (!v->suspended && vhost_vdpa_first_dev(dev)) {
         /*
          * Cannot trust in value returned by device, let vhost recover used
          * idx from guest.
-- 
2.34.1

Re: [PATCH] vdpa: fix cannot get vring base when stopping a vhost-vdpa device with multiple queues

[Jason Wang]

On Wed, Oct 29, 2025 at 8:50 PM Wafer Xie <wafer@jaguarmicro.com> wrote:
>
> When stopping a vhost-vdpa device, only the first queue pair is marked as suspended,
> while the remaining queues are not updated to the suspended state.

This looks like a bug, no?

> As a result, when stopping a multi-queue vhost-vdpa device,
> the following error message will be printed.
>
> qemu-system-x86_64:vhost VQ 2 ring restore failed: -1: Operation not permitted (1)
>
> qemu-system-x86_64:vhost VQ 3 ring restore failed: -1: Operation not permitted (1)
>
> Fixes: b6662cb7 ("vdpa: add vhost_vdpa->suspended parameter")
>
> Signed-off-by: Wafer Xie <wafer@jaguarmicro.com>
> ---
>  hw/virtio/vhost-vdpa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 7061b6e1a3..2d5e6aca74 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -1481,7 +1481,7 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
>          return 0;
>      }
>
> -    if (!v->suspended) {
> +    if (!v->suspended && vhost_vdpa_first_dev(dev)) {
>          /*
>           * Cannot trust in value returned by device, let vhost recover used
>           * idx from guest.
> --
> 2.34.1
>

Thanks

Re: [PATCH] vdpa: fix cannot get vring base when stopping a vhost-vdpa device with multiple queues

[Eugenio Perez Martin]

On Wed, Oct 29, 2025 at 1:50 PM Wafer Xie <wafer@jaguarmicro.com> wrote:
>
> When stopping a vhost-vdpa device, only the first queue pair is marked as suspended,
> while the remaining queues are not updated to the suspended state.
> As a result, when stopping a multi-queue vhost-vdpa device,
> the following error message will be printed.
>
> qemu-system-x86_64:vhost VQ 2 ring restore failed: -1: Operation not permitted (1)
>
> qemu-system-x86_64:vhost VQ 3 ring restore failed: -1: Operation not permitted (1)
>
> Fixes: b6662cb7 ("vdpa: add vhost_vdpa->suspended parameter")
>
> Signed-off-by: Wafer Xie <wafer@jaguarmicro.com>
> ---
>  hw/virtio/vhost-vdpa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 7061b6e1a3..2d5e6aca74 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -1481,7 +1481,7 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
>          return 0;
>      }
>
> -    if (!v->suspended) {
> +    if (!v->suspended && vhost_vdpa_first_dev(dev)) {

I'm sorry I missed this fix!

Good catch, thank you very much! But the right fix is to move
v->suspended to v->shared, and then all the vhost_vdpa devices cannot
have different suspended states.

Apart from that, please include the tag

Fixes: 0bb302a9960a ("vdpa: add vhost_vdpa_suspend")

In the patch description.

Thanks!

>          /*
>           * Cannot trust in value returned by device, let vhost recover used
>           * idx from guest.
> --
> 2.34.1
>