Hi, A new security fix [1],[2] and [3] merged to qemu. After updating the packages we started to get "qemu-system-x86_64: Virtqueue size exceeded", when resuming the guest. Our environment is OpenStack master and we have Mellanox CI that test SR-IOV functionality. Ubuntu 14.04 with Qemu 2.0.0+dfsg-2ubuntu1.26 that contains the fixes see [2] ii qemu-kvm 2.0.0+dfsg-2ubuntu1.26 amd64 QEMU Full virtualization ii qemu-system-x86 2.0.0+dfsg-2ubuntu1.26 amd64 QEMU full system emulation binaries (x86) ii qemu-utils 2.0.0+dfsg-2ubuntu1.26 amd64 QEMU utilities Our CI started to fail last week when this security packages released. The scenarios is as follows (sorry for the OpenStack commands :)) : 1. nova boot guest 2. nova suspend guest 3. nova resume guest The result is that the guest is in poweroff state and when I power it on everything is working fine. I tested in direct port (SR-IOV) and normal port (virtual port) and it happens in both cases. According to the [3] it prevent from malicious guest to submit more requests than the virtqueuesize permits. Our CI uses proprietary Cirros image with mlnx4_en driver. (http://13.69.151.247/images/mellanox_eth.img) I started to test it with other images to see if the problem with our image. I also tested with Ubuntu image - https://cloud-images.ubuntu.com/wily/current/wily-server-cloudimg-amd64-d... And OpenStack Cirros image http://download.cirros-cloud.net/0.3.4/cirros-0.3.4-x86_64-disk.img The Ubuntu image had the same failure, but the Cirros worked. I wonder if there is a problem with the patch or with the images? What in these images can make them malicious guest? [1] - https://access.redhat.com/security/cve/cve-2016-5403 [2] - http://www.ubuntu.com/usn/usn-3047-1/ [3] - https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg06257.html