From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47475) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f6oye-0006Vp-UJ for qemu-devel@nongnu.org; Thu, 12 Apr 2018 23:02:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f6oyY-0003tx-FW for qemu-devel@nongnu.org; Thu, 12 Apr 2018 23:02:16 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43862 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 1f6oyY-0003tU-Aa for qemu-devel@nongnu.org; Thu, 12 Apr 2018 23:02:10 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3B1208185338 for ; Fri, 13 Apr 2018 03:01:59 +0000 (UTC) From: Jason Wang Date: Fri, 13 Apr 2018 11:01:49 +0800 Message-Id: <1523588509-4868-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH] vhost: do not verify ring mappings when IOMMU is enabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com Cc: qemu-devel@nongnu.org, Jason Wang , "Dr . David Alan Gilbert" , Igor Mammedov 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 --- 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; -- 2.7.4