On Fri, Jul 7, 2023 at 12:18 PM Zhu Lingshan <lingshan....@intel.com> wrote:
>
> In the poweroff routine, no need to fetch last available index.
>
> This commit also provides a better debug message in the vhost
> caller vhost_virtqueue_stop, 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.
>
> Signed-off-by: Zhu Lingshan <lingshan....@intel.com>
CCing MST.
> ---
> hw/virtio/vhost-vdpa.c | 4 ++++
> hw/virtio/vhost.c | 2 +-
> 2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 3c575a9a6e..f62952e1c7 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 +1392,9 @@ 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))
> + return 0;
> +
QEMU coding style mandates braces around the "if" body (CODING_STYLE.rst file).
Apart from that I think we should add a comment here. Something in the line of:
Some devices do not support the call properly, and we don't need to
retrieve the indexes if we're not migrating. Skip it in this case.
> 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..84712743e0 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 used idx for vhost VQ
> %u", idx);
Guest's used idx? Also, maybe it is worth splitting this in a separated patch.
Apart from the nitpicking, I think the general line of the patch is
the way to go :).
Thanks!
> /* Connection to the backend is broken, so let's sync internal
> * last avail idx to the device used idx.
> */
> --
> 2.39.3
>
