Re: [Qemu-devel] [PATCH 08/10] virtio: cache used_idx in a VirtQueue field

[Cornelia Huck]

On Fri, 15 Jan 2016 13:41:56 +0100
Paolo Bonzini <address@hidden> wrote:

> From: Vincenzo Maffione <address@hidden>
> 
> Accessing used_idx in the VQ requires an expensive access to
> guest physical memory. Before this patch, 3 accesses are normally
> done for each pop/push/notify call. However, since the used_idx is
> only written by us, we can track it in our internal data structure.
> 
> Signed-off-by: Vincenzo Maffione <address@hidden>
> Message-Id: <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  hw/virtio/virtio.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)

Reviewed-by: Cornelia Huck <address@hidden>