From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34689) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2EF6-0006zI-Ml for qemu-devel@nongnu.org; Thu, 25 Jul 2013 01:37:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V2EF4-0006ta-6J for qemu-devel@nongnu.org; Thu, 25 Jul 2013 01:37:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2940) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V2EF3-0006tR-Tx for qemu-devel@nongnu.org; Thu, 25 Jul 2013 01:37:34 -0400 Date: Thu, 25 Jul 2013 08:38:41 +0300 From: "Michael S. Tsirkin" Message-ID: <20130725053841.GA15500@redhat.com> References: <1373661422-23606-1-git-send-email-peter.maydell@linaro.org> <1373661422-23606-4-git-send-email-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1373661422-23606-4-git-send-email-peter.maydell@linaro.org> Subject: Re: [Qemu-devel] [PATCH v2 3/8] virtio: Add support for guest setting of queue size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Anthony Liguori , patches@linaro.org, Alexander Graf , qemu-devel@nongnu.org, kvmarm@lists.cs.columbia.edu, David Gibson On Fri, Jul 12, 2013 at 09:36:57PM +0100, Peter Maydell wrote: > The MMIO virtio transport spec allows the guest to tell the host how > large the queue size is. Add virtio_queue_set_num() function which > implements this in the QEMU common virtio support code. > > Signed-off-by: Peter Maydell Probably needs to go back to default value on reset? Need to migrate? Is the default value a max legal value? If yes probably a good idea to enforce this. > --- > hw/virtio/virtio.c | 8 ++++++++ > include/hw/virtio/virtio.h | 1 + > 2 files changed, 9 insertions(+) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 8176c14..01b05f3 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -667,6 +667,14 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) > return vdev->vq[n].pa; > } > > +void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) > +{ > + if (num <= VIRTQUEUE_MAX_SIZE) { > + vdev->vq[n].vring.num = num; > + virtqueue_init(&vdev->vq[n]); > + } > +} > + > int virtio_queue_get_num(VirtIODevice *vdev, int n) > { > return vdev->vq[n].vring.num; > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index a6c5c53..95c4772 100644 > --- a/include/hw/virtio/virtio.h > +++ b/include/hw/virtio/virtio.h > @@ -198,6 +198,7 @@ void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data); > void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data); > 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_notify(VirtIODevice *vdev, int n); > uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); > -- > 1.7.9.5 >