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[Qemu-devel] [PATCH RFC v2 05/12] virtio: introduce legacy virtio device
From: |
Cornelia Huck |
Subject: |
[Qemu-devel] [PATCH RFC v2 05/12] virtio: introduce legacy virtio devices |
Date: |
Tue, 25 Nov 2014 14:24:16 +0100 |
Introduce a helper function to indicate whether a virtio device is
operating in legacy or virtio standard mode.
It may be used to make decisions about the endianess of virtio accesses
and other virtio-1 specific changes, enabling us to support transitional
devices.
Reviewed-by: Thomas Huth <address@hidden>
Signed-off-by: Cornelia Huck <address@hidden>
---
hw/virtio/virtio.c | 6 +++++-
include/hw/virtio/virtio-access.h | 4 ++++
include/hw/virtio/virtio.h | 13 +++++++++++--
3 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 2eb5d3c..4149f45 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -883,7 +883,11 @@ 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_device_is_legacy(vdev)) {
+ 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..c123ee0 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_device_is_legacy(vdev)) {
+ /* 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 b408166..40e567c 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -275,9 +275,18 @@ void virtio_queue_set_host_notifier_fd_handler(VirtQueue
*vq, bool assign,
void virtio_queue_notify_vq(VirtQueue *vq);
void virtio_irq(VirtQueue *vq);
+static inline bool virtio_device_is_legacy(VirtIODevice *vdev)
+{
+ return !(vdev->guest_features[1] & (1 << (VIRTIO_F_VERSION_1 - 32)));
+}
+
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_device_is_legacy(vdev)) {
+ 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 v2 00/12] qemu: towards virtio-1 host support, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 01/12] linux-headers/virtio_config: Update with VIRTIO_F_VERSION_1, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 02/12] virtio: cull virtio_bus_set_vdev_features, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 04/12] s390x/virtio-ccw: fix check for WRITE_FEAT, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 06/12] virtio: allow virtio-1 queue layout, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 09/12] s390x/virtio-ccw: add virtio set-revision call, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 03/12] virtio: support more feature bits, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 05/12] virtio: introduce legacy virtio devices,
Cornelia Huck <=
- [Qemu-devel] [PATCH RFC v2 11/12] virtio-net/virtio-blk: enable virtio 1.0, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 07/12] dataplane: allow virtio-1 devices, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 08/12] s390x/css: Add a callback for when subchannel gets disabled, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 12/12] s390x/virtio-ccw: enable virtio 1.0, Cornelia Huck, 2014/11/25
- [Qemu-devel] [PATCH RFC v2 10/12] s390x/virtio-ccw: support virtio-1 set_vq format, Cornelia Huck, 2014/11/25
- Re: [Qemu-devel] [PATCH RFC v2 00/12] qemu: towards virtio-1 host support, Michael S. Tsirkin, 2014/11/25