From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36584) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XvojU-0005Cz-M7 for qemu-devel@nongnu.org; Tue, 02 Dec 2014 09:47:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XvojL-00007o-2f for qemu-devel@nongnu.org; Tue, 02 Dec 2014 09:47:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44365) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XvojK-000056-Pw for qemu-devel@nongnu.org; Tue, 02 Dec 2014 09:47:06 -0500 Date: Tue, 2 Dec 2014 16:46:28 +0200 From: "Michael S. Tsirkin" Message-ID: <20141202144628.GA2974@redhat.com> References: <1417525227-14051-1-git-send-email-cornelia.huck@de.ibm.com> <1417525227-14051-8-git-send-email-cornelia.huck@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1417525227-14051-8-git-send-email-cornelia.huck@de.ibm.com> Subject: Re: [Qemu-devel] [PATCH RFC v5 07/19] virtio: allow virtio-1 queue layout List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cornelia Huck Cc: thuth@linux.vnet.ibm.com, rusty@rustcorp.com.au, qemu-devel@nongnu.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org On Tue, Dec 02, 2014 at 02:00:15PM +0100, Cornelia Huck wrote: > For virtio-1 devices, we allow a more complex queue layout that doesn't > require descriptor table and rings on a physically-contigous memory area: > add virtio_queue_set_rings() to allow transports to set this up. > > Signed-off-by: Cornelia Huck > --- > hw/virtio/virtio.c | 16 ++++++++++++++++ > include/hw/virtio/virtio.h | 2 ++ > 2 files changed, 18 insertions(+) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 8f69ffa..508dccf 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -96,6 +96,13 @@ static void virtqueue_init(VirtQueue *vq) > { > hwaddr pa = vq->pa; > > + if (pa == -1ULL) { > + /* > + * This is a virtio-1 style vq that has already been setup > + * in virtio_queue_set. > + */ > + return; > + } > vq->vring.desc = pa; > vq->vring.avail = pa + vq->vring.num * sizeof(VRingDesc); > vq->vring.used = vring_align(vq->vring.avail + > @@ -717,6 +724,15 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) > return vdev->vq[n].pa; > } > > +void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, > + hwaddr avail, hwaddr used) > +{ > + vdev->vq[n].pa = -1ULL; > + vdev->vq[n].vring.desc = desc; > + vdev->vq[n].vring.avail = avail; > + vdev->vq[n].vring.used = used; > +} > + > void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) > { > /* Don't allow guest to flip queue between existent and pa == -1ULL tricks look quite ugly. Can't we set desc/avail/used unconditionally, and drop the pa value? > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index 68c40db..80ee313 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -224,6 +224,8 @@ void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr); > hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n); > void virtio_queue_set_num(VirtIODevice *vdev, int n, int num); > int virtio_queue_get_num(VirtIODevice *vdev, int n); > +void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, > + hwaddr avail, hwaddr used); > void virtio_queue_set_align(VirtIODevice *vdev, int n, int align); > void virtio_queue_notify(VirtIODevice *vdev, int n); > uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); > -- > 1.7.9.5