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[Qemu-devel] [PULL 02/42] virtio: endianness checks for virtio 1.0 devic
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 02/42] virtio: endianness checks for virtio 1.0 devices |
Date: |
Thu, 11 Jun 2015 13:58:09 +0200 |
From: Cornelia Huck <address@hidden>
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>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
---
include/hw/virtio/virtio-access.h | 4 ++++
include/hw/virtio/virtio.h | 8 ++++++--
hw/virtio/virtio.c | 6 +++++-
3 files changed, 15 insertions(+), 3 deletions(-)
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 2bb7c1a..13e8549 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -252,7 +252,11 @@ 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
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 8ac6156..d37d27b 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -903,7 +903,11 @@ 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 bool virtio_64bit_features_needed(void *opaque)
--
MST
- [Qemu-devel] [PULL 00/42] pc, acpi, virtio, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 01/42] vhost: put log correctly in vhost_dev_start(), Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 02/42] virtio: endianness checks for virtio 1.0 devices,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 03/42] virtio: allow virtio-1 queue layout, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 05/42] virtio: disallow late feature changes for virtio-1, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 04/42] dataplane: allow virtio-1 devices, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 06/42] virtio: allow to fail setting status, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 07/42] virtio-net: no writeable mac for virtio-1, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 08/42] virtio-net: support longer header, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 10/42] vhost_net: add version_1 feature, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 09/42] virtio-net: enable virtio 1.0, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 12/42] linux-headers: add virtio_pci, Michael S. Tsirkin, 2015/06/11
- [Qemu-devel] [PULL 14/42] virtio: generation counter support, Michael S. Tsirkin, 2015/06/11