Re: [Qemu-devel] [RFC v1 7/7] vhost: abort if an emulated iommu is used

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Oct 11, 2012 at 03:27:03PM +0200, Avi Kivity wrote:
> vhost doesn't support guest iommus yet, indicate it to the user
> by gently depositing a core on their disk.
> 
> Signed-off-by: Avi Kivity <avi@redhat.com>

Actually there is no problem. virtio bypasses an IOMMU,
so vhost works fine by writing into guest memory directly.

So I don't think we need this patch.

> ---
>  hw/vhost.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/hw/vhost.c b/hw/vhost.c
> index 0b4ac3f..cd5d9f5 100644
> --- a/hw/vhost.c
> +++ b/hw/vhost.c
> @@ -451,6 +451,8 @@ static void vhost_region_add(MemoryListener *listener,
>      struct vhost_dev *dev = container_of(listener, struct vhost_dev,
>                                           memory_listener);
>  
> +    assert(!memory_region_is_iommu(section.mr));
> +
>      if (!vhost_section(section)) {
>          return;
>      }
> -- 
> 1.7.12