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From: Denis Plotnikov <dplotnikov@virtuozzo.com>
To: qemu-devel@nongnu.org
Cc: mst@redhat.com
Subject: [PATCH v1] virtio: stregthen virtqueue size invariants
Date: Mon, 23 Dec 2019 16:18:20 +0300	[thread overview]
Message-ID: <20191223131820.19300-1-dplotnikov@virtuozzo.com> (raw)

1. virtqueue_size is a power of 2
2. virtqueue_size > 2, since seg_max is virtqueue_size - 2

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
---
 hw/virtio/virtio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 04716b5f6c..e3ab69061e 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2166,7 +2166,8 @@ void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
      */
     if (!!num != !!vdev->vq[n].vring.num ||
         num > VIRTQUEUE_MAX_SIZE ||
-        num < 0) {
+        num < 2 ||
+        !is_power_of_2(num)) {
         return;
     }
     vdev->vq[n].vring.num = num;
-- 
2.17.0



             reply	other threads:[~2019-12-23 13:19 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-23 13:18 Denis Plotnikov [this message]
2020-01-02 14:55 ` [PATCH v1] virtio: stregthen virtqueue size invariants Stefan Hajnoczi

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