Re: [RFC PATCH 23/27] vhost: unmap qemu's shadow virtqueues on sw live migration

[Stefano Garzarella]

On Fri, Nov 20, 2020 at 07:51:01PM +0100, Eugenio Pérez wrote:
> Since vhost does not need to access it, it has no sense to keep it
> mapped.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
> hw/virtio/vhost.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index f640d4edf0..eebfac4455 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1124,6 +1124,7 @@ static int vhost_sw_live_migration_start(struct vhost_dev 
> *dev)
>
>         dev->sw_lm_shadow_vq[idx] = vhost_sw_lm_shadow_vq(dev, idx);
>         event_notifier_set_handler(&vq->masked_notifier, vhost_handle_call);
> +        vhost_virtqueue_memory_unmap(dev, &dev->vqs[idx], true);

IIUC vhost_virtqueue_memory_unmap() is already called at the end of 
vhost_virtqueue_stop(), so we can skip this call, right?

>         vhost_vring_write_addr(dev->sw_lm_shadow_vq[idx], &addr);
>         r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
> -- 2.18.4