From: yuchenlin Date: Fri, 12 Oct 2018 09:07:52 +0000 (+0800) Subject: vhost-scsi: prevent using uninitialized vqs X-Git-Tag: qemu-xen-4.13.0-rc1~575^2 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e6cc11d64fc998c11a4dfcde8fda3fc33a74d844;p=qemu-xen.git vhost-scsi: prevent using uninitialized vqs There are 3 virtqueues (ctrl, event and cmd) for virtio scsi device, but seabios will only set the physical address for the 3rd one (cmd). Then in vhost_virtqueue_start(), virtio_queue_get_desc_addr() will be 0 for ctrl and event vq. In this case, ctrl and event vq are not initialized. vhost_verify_ring_mappings may use uninitialized vhost_virtqueue such that vhost_verify_ring_part_mapping returns ENOMEM. When encountered this problem, we got the following logs: qemu-system-x86_64: Unable to map available ring for ring 0 qemu-system-x86_64: Verify ring failure on region 0 Signed-off-by: Forrest Liu Signed-off-by: yuchenlin Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c index becf550085..7f21b4f9d6 100644 --- a/hw/scsi/vhost-scsi.c +++ b/hw/scsi/vhost-scsi.c @@ -183,7 +183,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) } vsc->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; - vsc->dev.vqs = g_new(struct vhost_virtqueue, vsc->dev.nvqs); + vsc->dev.vqs = g_new0(struct vhost_virtqueue, vsc->dev.nvqs); vsc->dev.vq_index = 0; vsc->dev.backend_features = 0;