From patchwork Thu Dec 11 13:25:08 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 420119 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id F18A81400A0 for ; Fri, 12 Dec 2014 00:36:28 +1100 (AEDT) Received: from localhost ([::1]:51253 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xz3ut-0004OH-4O for incoming@patchwork.ozlabs.org; Thu, 11 Dec 2014 08:36:27 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37793) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xz3kU-0006n0-Hk for qemu-devel@nongnu.org; Thu, 11 Dec 2014 08:25:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xz3kL-00082H-Bp for qemu-devel@nongnu.org; Thu, 11 Dec 2014 08:25:42 -0500 Received: from e06smtp17.uk.ibm.com ([195.75.94.113]:46195) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xz3kL-00081t-46 for qemu-devel@nongnu.org; Thu, 11 Dec 2014 08:25:33 -0500 Received: from /spool/local by e06smtp17.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 11 Dec 2014 13:25:31 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 42A9817D8056 for ; Thu, 11 Dec 2014 13:25:53 +0000 (GMT) Received: from d06av11.portsmouth.uk.ibm.com (d06av11.portsmouth.uk.ibm.com [9.149.37.252]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id sBBDPUre40697940 for ; Thu, 11 Dec 2014 13:25:30 GMT Received: from d06av11.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id sBBDPTK7006582 for ; Thu, 11 Dec 2014 06:25:30 -0700 Received: from gondolin.boeblingen.de.ibm.com (dyn-9-152-224-210.boeblingen.de.ibm.com [9.152.224.210]) by d06av11.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id sBBDPPEO006366; Thu, 11 Dec 2014 06:25:29 -0700 From: Cornelia Huck To: virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org Date: Thu, 11 Dec 2014 14:25:08 +0100 Message-Id: <1418304322-7546-7-git-send-email-cornelia.huck@de.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1418304322-7546-1-git-send-email-cornelia.huck@de.ibm.com> References: <1418304322-7546-1-git-send-email-cornelia.huck@de.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14121113-0029-0000-0000-0000022673CB X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 195.75.94.113 Cc: Cornelia Huck , rusty@rustcorp.com.au, thuth@linux.vnet.ibm.com, mst@redhat.com Subject: [Qemu-devel] [PATCH RFC v6 06/20] virtio: endianness checks for virtio 1.0 devices X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Add code that checks for the VERSION_1 feature bit in order to make decisions about the device's endianness. This allows us to support transitional devices. Signed-off-by: Cornelia Huck Reviewed-by: Stefan Hajnoczi --- hw/virtio/virtio.c | 6 +++++- include/hw/virtio/virtio-access.h | 4 ++++ include/hw/virtio/virtio.h | 8 ++++++-- 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 7f74ae5..8f69ffa 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -881,7 +881,11 @@ static bool virtio_device_endian_needed(void *opaque) VirtIODevice *vdev = opaque; assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); - return vdev->device_endian != virtio_default_endian(); + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + return vdev->device_endian != virtio_default_endian(); + } + /* Devices conforming to VIRTIO 1.0 or later are always LE. */ + return vdev->device_endian != VIRTIO_DEVICE_ENDIAN_LITTLE; } static const VMStateDescription vmstate_virtio_device_endian = { diff --git a/include/hw/virtio/virtio-access.h b/include/hw/virtio/virtio-access.h index 46456fd..ee28c21 100644 --- a/include/hw/virtio/virtio-access.h +++ b/include/hw/virtio/virtio-access.h @@ -19,6 +19,10 @@ static inline bool virtio_access_is_big_endian(VirtIODevice *vdev) { + if (virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + /* Devices conforming to VIRTIO 1.0 or later are always LE. */ + return false; + } #if defined(TARGET_IS_BIENDIAN) return virtio_is_big_endian(vdev); #elif defined(TARGET_WORDS_BIGENDIAN) diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 08141c7..68c40db 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -297,7 +297,11 @@ static inline bool virtio_has_feature(VirtIODevice *vdev, unsigned int fbit) static inline bool virtio_is_big_endian(VirtIODevice *vdev) { - assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); - return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) { + assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); + return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; + } + /* Devices conforming to VIRTIO 1.0 or later are always LE. */ + return false; } #endif