From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49096) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cTJzw-0008KF-Dl for qemu-devel@nongnu.org; Mon, 16 Jan 2017 21:59:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cTJzs-00075m-HH for qemu-devel@nongnu.org; Mon, 16 Jan 2017 21:59:48 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:36695) by eggs.gnu.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1cTJzr-00074i-VP for qemu-devel@nongnu.org; Mon, 16 Jan 2017 21:59:44 -0500 From: "Longpeng(Mike)" Date: Tue, 17 Jan 2017 10:59:24 +0800 Message-ID: <1484621964-187372-1-git-send-email-longpeng2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH v2] qtest: virtio: zeroed last vring_desc after allocate List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: stefanha@redhat.com, lvivier@redhat.com, eblake@redhat.com, peter.maydell@linaro.org, groug@kaod.org Cc: arei.gonglei@huawei.com, qemu-devel@nongnu.org, "Longpeng(Mike)" As qvring_indirect_desc_setup() wouldn't initialize last vring_desc, so it's filled with dirty data, this might cause virtio backend broken. For example, the last bit of this vring_desc's flags might be 1, so virtqueue_read_next_desc() would report "Desc next is ***". Signed-off-by: Longpeng(Mike) --- Changes since v1: - use writel() for @len as it's 32 bits long. [Stefan] --- tests/libqos/virtio.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tests/libqos/virtio.c b/tests/libqos/virtio.c index ec30cb9..02e6a43 100644 --- a/tests/libqos/virtio.c +++ b/tests/libqos/virtio.c @@ -171,12 +171,20 @@ QVRingIndirectDesc *qvring_indirect_desc_setup(QVirtioDevice *d, for (i = 0; i < elem - 1; ++i) { /* indirect->desc[i].addr */ writeq(indirect->desc + (16 * i), 0); + /* indirect->desc[i].len */ + writel(indirect->desc + (16 * i) + 8, 0); /* indirect->desc[i].flags */ writew(indirect->desc + (16 * i) + 12, VRING_DESC_F_NEXT); /* indirect->desc[i].next */ writew(indirect->desc + (16 * i) + 14, i + 1); } + /* zeroed last element */ + writeq(indirect->desc + (16 * i), 0); /* addr */ + writel(indirect->desc + (16 * i) + 8, 0); /* len */ + writew(indirect->desc + (16 * i) + 12, 0); /* flags */ + writew(indirect->desc + (16 * i) + 14, 0); /* next */ + return indirect; } -- 1.8.3.1