On Mon, Jul 10, 2023 at 4:53 PM Zhu Lingshan <lingshan....@intel.com> wrote:
>
> In the poweroff routine, no need to fetch last available index.
>
This is because there's no concept of shutdown in the vhost layer, it
only knows start and stop.
> This commit also provides a better debug message in the vhost
> caller vhost_virtqueue_stop,
A separate patch is better.
> because if vhost does not fetch
> the last avail idx successfully, maybe the device does not
> suspend, vhost will sync last avail idx to vring used idx as a
> work around, not a failure.
This only happens if we return a negative value?
>
> Signed-off-by: Zhu Lingshan <lingshan....@intel.com>
> ---
> hw/virtio/vhost-vdpa.c | 10 ++++++++++
> hw/virtio/vhost.c | 2 +-
> 2 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 3c575a9a6e..10b445f64e 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -26,6 +26,7 @@
> #include "cpu.h"
> #include "trace.h"
> #include "qapi/error.h"
> +#include "sysemu/runstate.h"
>
> /*
> * Return one past the end of the end of section. Be careful with uint64_t
> @@ -1391,6 +1392,15 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev
> *dev,
> struct vhost_vdpa *v = dev->opaque;
> int ret;
>
> + if (runstate_check(RUN_STATE_SHUTDOWN)) {
> + /*
> + * Some devices do not support this call properly,
> + * and we don't need to retrieve the indexes
> + * if it is shutting down
> + */
> + return 0;
Checking runstate in the vhost code seems like a layer violation.
What happens without this patch?
Thanks
> + }
> +
> if (v->shadow_vqs_enabled) {
> ring->num = virtio_queue_get_last_avail_idx(dev->vdev, ring->index);
> return 0;
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 82394331bf..7dd90cff3a 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1262,7 +1262,7 @@ void vhost_virtqueue_stop(struct vhost_dev *dev,
>
> r = dev->vhost_ops->vhost_get_vring_base(dev, &state);
> if (r < 0) {
> - VHOST_OPS_DEBUG(r, "vhost VQ %u ring restore failed: %d", idx, r);
> + VHOST_OPS_DEBUG(r, "sync last avail idx to the guest used idx for
> vhost VQ %u", idx);
> /* Connection to the backend is broken, so let's sync internal
> * last avail idx to the device used idx.
> */
> --
> 2.39.3
>
