On Fri, 15 Jan 2016 13:41:57 +0100 Paolo Bonzini <pbonz...@redhat.com> wrote:
> From: Vincenzo Maffione <v.maffi...@gmail.com> > > The virtqueue_pop() implementation needs to check if the avail ring > contains some pending buffers. To perform this check, it is not > always necessary to fetch the avail_idx in the VQ memory, which is > expensive. This patch introduces a shadow variable tracking avail_idx > and modifies virtio_queue_empty() to access avail_idx in physical > memory only when necessary. > > Signed-off-by: Vincenzo Maffione <v.maffi...@gmail.com> > Message-Id: > <b617d6459902773d9f4ab843bfaca764f5af8eda.1450218353.git.v.maffi...@gmail.com> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > hw/virtio/virtio.c | 25 +++++++++++++++++++++---- > 1 file changed, 21 insertions(+), 4 deletions(-) Reviewed-by: Cornelia Huck <cornelia.h...@de.ibm.com>
