From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: [PATCH RFC v5 06/19] virtio: endianness checks for virtio 1.0 devices Date: Tue, 2 Dec 2014 14:00:14 +0100 Message-ID: <1417525227-14051-7-git-send-email-cornelia.huck__24666.8078158566$1417525305$gmane$org@de.ibm.com> References: <1417525227-14051-1-git-send-email-cornelia.huck@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1417525227-14051-1-git-send-email-cornelia.huck@de.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org, kvm@vger.kernel.org Cc: thuth@linux.vnet.ibm.com, mst@redhat.com List-Id: virtualization@lists.linuxfoundation.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 --- 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 -- 1.7.9.5