From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38238) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZaOMZ-00048y-Pz for qemu-devel@nongnu.org; Fri, 11 Sep 2015 09:27:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZaOMV-0005LY-Oi for qemu-devel@nongnu.org; Fri, 11 Sep 2015 09:27:35 -0400 Received: from e06smtp17.uk.ibm.com ([195.75.94.113]:50548) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZaOMV-0005Ki-Fc for qemu-devel@nongnu.org; Fri, 11 Sep 2015 09:27:31 -0400 Received: from /spool/local by e06smtp17.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 11 Sep 2015 14:27:30 +0100 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 6E4C71B08069 for ; Fri, 11 Sep 2015 14:18:26 +0100 (BST) Received: from d06av10.portsmouth.uk.ibm.com (d06av10.portsmouth.uk.ibm.com [9.149.37.251]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t8BDGllf33095782 for ; Fri, 11 Sep 2015 13:16:47 GMT Received: from d06av10.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av10.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t8BCGlVP004621 for ; Fri, 11 Sep 2015 06:16:47 -0600 From: Cornelia Huck Date: Fri, 11 Sep 2015 15:16:41 +0200 Message-Id: <1441977404-37841-2-git-send-email-cornelia.huck@de.ibm.com> In-Reply-To: <1441977404-37841-1-git-send-email-cornelia.huck@de.ibm.com> References: <1441977404-37841-1-git-send-email-cornelia.huck@de.ibm.com> Subject: [Qemu-devel] [PATCH v2 1/4] virtio: ring sizes vs. reset List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Cornelia Huck , borntraeger@de.ibm.com, jasowang@redhat.com, mst@redhat.com We allow guests to change the size of the virtqueue rings by supplying a number of buffers that is different from the number of buffers the device was initialized with. Current code has some problems, however, since reset does not reset the ringsizes to the default values (as this is not saved anywhere). Let's extend the core code to keep track of the default ringsizes and migrate them once the guest changed them for any of the virtqueues for a device. Reviewed-by: Jason Wang Signed-off-by: Cornelia Huck --- hw/virtio/virtio.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 0832db9..787a319 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -60,6 +60,7 @@ typedef struct VRingUsed typedef struct VRing { unsigned int num; + unsigned int num_default; unsigned int align; hwaddr desc; hwaddr avail; @@ -633,6 +634,7 @@ void virtio_reset(void *opaque) vdev->vq[i].signalled_used = 0; vdev->vq[i].signalled_used_valid = false; vdev->vq[i].notification = true; + vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; } } @@ -964,6 +966,7 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, abort(); vdev->vq[i].vring.num = queue_size; + vdev->vq[i].vring.num_default = queue_size; vdev->vq[i].vring.align = VIRTIO_PCI_VRING_ALIGN; vdev->vq[i].handle_output = handle_output; @@ -977,6 +980,7 @@ void virtio_del_queue(VirtIODevice *vdev, int n) } vdev->vq[n].vring.num = 0; + vdev->vq[n].vring.num_default = 0; } void virtio_irq(VirtQueue *vq) @@ -1056,6 +1060,19 @@ static bool virtio_virtqueue_needed(void *opaque) return virtio_host_has_feature(vdev, VIRTIO_F_VERSION_1); } +static bool virtio_ringsize_needed(void *opaque) +{ + VirtIODevice *vdev = opaque; + int i; + + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { + if (vdev->vq[i].vring.num != vdev->vq[i].vring.num_default) { + return true; + } + } + return false; +} + static void put_virtqueue_state(QEMUFile *f, void *pv, size_t size) { VirtIODevice *vdev = pv; @@ -1104,6 +1121,52 @@ static const VMStateDescription vmstate_virtio_virtqueues = { } }; +static void put_ringsize_state(QEMUFile *f, void *pv, size_t size) +{ + VirtIODevice *vdev = pv; + int i; + + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { + qemu_put_be32(f, vdev->vq[i].vring.num_default); + } +} + +static int get_ringsize_state(QEMUFile *f, void *pv, size_t size) +{ + VirtIODevice *vdev = pv; + int i; + + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) { + vdev->vq[i].vring.num_default = qemu_get_be32(f); + } + return 0; +} + +static VMStateInfo vmstate_info_ringsize = { + .name = "ringsize_state", + .get = get_ringsize_state, + .put = put_ringsize_state, +}; + +static const VMStateDescription vmstate_virtio_ringsize = { + .name = "virtio/ringsize", + .version_id = 1, + .minimum_version_id = 1, + .needed = &virtio_ringsize_needed, + .fields = (VMStateField[]) { + { + .name = "ringsize", + .version_id = 0, + .field_exists = NULL, + .size = 0, + .info = &vmstate_info_ringsize, + .flags = VMS_SINGLE, + .offset = 0, + }, + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_virtio_device_endian = { .name = "virtio/device_endian", .version_id = 1, @@ -1138,6 +1201,7 @@ static const VMStateDescription vmstate_virtio = { &vmstate_virtio_device_endian, &vmstate_virtio_64bit_features, &vmstate_virtio_virtqueues, + &vmstate_virtio_ringsize, NULL } }; -- 2.3.8