From aebbdbee559389a9f0d0e56670b9332534b6bb9b Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Fri, 13 Apr 2018 11:01:49 +0800 Subject: vhost: do not verify ring mappings when IOMMU is enabled When IOMMU is enabled, we store virtqueue metadata as iova (though it may has _phys suffix) and access them through dma helpers. Any translation failures could be reported by IOMMU. In this case, trying to validate iova against gpa won't work and will cause a false error reporting. So this patch bypasses the ring verification if IOMMU is enabled which is similar to the behavior before 0ca1fd2d6878 that calls vhost_memory_map() which is a nop when IOMMU is enabled. Fixes: 0ca1fd2d6878 ("vhost: Simplify ring verification checks") Cc: Dr. David Alan Gilbert Cc: Igor Mammedov Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Reviewed-by: Igor Mammedov Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/vhost.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index f51bf573d5..9d5850a7d7 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -342,6 +342,10 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev, "used ring" }; + if (vhost_dev_has_iommu(dev)) { + return 0; + } + for (i = 0; i < dev->nvqs; ++i) { struct vhost_virtqueue *vq = dev->vqs + i; -- cgit v1.2.1