From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52327) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f87IG-0006i8-Ru for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:47:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f87IC-0003Im-QI for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:47:52 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48152 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f87IC-0003Hv-MW for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:47:48 -0400 Date: Mon, 16 Apr 2018 19:47:44 +0300 From: "Michael S. Tsirkin" Message-ID: <1523895458-475479-2-git-send-email-mst@redhat.com> References: <1523895458-475479-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1523895458-475479-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL 1/1] vhost: do not verify ring mappings when IOMMU is enabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Jason Wang , "Dr . David Alan Gilbert" , Igor Mammedov From: Jason Wang 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 f51bf57..9d5850a 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; -- MST