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[Qemu-devel] [PATCH RFC v6 06/20] virtio: endianness checks for virtio 1
From: |
Cornelia Huck |
Subject: |
[Qemu-devel] [PATCH RFC v6 06/20] virtio: endianness checks for virtio 1.0 devices |
Date: |
Thu, 11 Dec 2014 14:25:08 +0100 |
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 <address@hidden>
---
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
- [Qemu-devel] [PATCH RFC v6 00/20] qemu: towards virtio-1 host support, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 02/20] virtio: cull virtio_bus_set_vdev_features, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 03/20] virtio: feature bit manipulation helpers, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 06/20] virtio: endianness checks for virtio 1.0 devices,
Cornelia Huck <=
- [Qemu-devel] [PATCH RFC v6 05/20] virtio: support more feature bits, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 08/20] dataplane: allow virtio-1 devices, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 10/20] s390x/virtio-ccw: add virtio set-revision call, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 09/20] s390x/css: Add a callback for when subchannel gets disabled, Cornelia Huck, 2014/12/11
- [Qemu-devel] [PATCH RFC v6 12/20] virtio: disallow late feature changes for virtio-1, Cornelia Huck, 2014/12/11