On 05/31/2016 10:09 AM, Greg Kurz wrote:
> Paolo's recent cpu.h cleanups broke legacy virtio for ppc64 LE guests (and
> arm BE guests as well, even if I have not verified that). Especially, commit
> "33c11879fd42 qemu-common: push cpu.h inclusion out of qemu-common.h" has
> the side-effect of silently hiding the TARGET_IS_BIENDIAN macro from the
> virtio memory accessors, and thus fully disabling support of endian changing
> targets.
>
> To be sure this cannot happen again, let's gather all the bi-endian bits
> where they belong in include/hw/virtio/virtio-access.h.
>
> The changes in hw/virtio/vhost.c are safe because vhost_needs_vring_endian()
> is not called on a hot path and non bi-endian targets will return false
> anyway.
>
> While here, also rename TARGET_IS_BIENDIAN to be more precise: it is only for
> legacy virtio and bi-endian guests.
>
> Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com>
biendian-ness being only used by virtio devices, I think this is a good place
where to put it.
Acked-by: Cédric Le Goater <c...@kaod.org>
> ---
> hw/virtio/vhost.c | 4 ----
> include/hw/virtio/virtio-access.h | 6 +++++-
> target-arm/cpu.h | 2 --
> target-ppc/cpu.h | 2 --
> 4 files changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 440071815408..81cc5b0ae35c 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -767,15 +767,11 @@ static inline bool
> vhost_needs_vring_endian(VirtIODevice *vdev)
> if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
> return false;
> }
> -#ifdef TARGET_IS_BIENDIAN
> #ifdef HOST_WORDS_BIGENDIAN
> return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_LITTLE;
> #else
> return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG;
> #endif
> -#else
> - return false;
> -#endif
> }
>
> static int vhost_virtqueue_set_vring_endian_legacy(struct vhost_dev *dev,
> diff --git a/include/hw/virtio/virtio-access.h
> b/include/hw/virtio/virtio-access.h
> index 8dc84f520316..4b2803814642 100644
> --- a/include/hw/virtio/virtio-access.h
> +++ b/include/hw/virtio/virtio-access.h
> @@ -17,9 +17,13 @@
> #include "hw/virtio/virtio.h"
> #include "exec/address-spaces.h"
>
> +#if defined(TARGET_PPC64) || defined(TARGET_ARM)
> +#define LEGACY_VIRTIO_IS_BIENDIAN 1
> +#endif
> +
> static inline bool virtio_access_is_big_endian(VirtIODevice *vdev)
> {
> -#if defined(TARGET_IS_BIENDIAN)
> +#if defined(LEGACY_VIRTIO_IS_BIENDIAN)
> return virtio_is_big_endian(vdev);
> #elif defined(TARGET_WORDS_BIGENDIAN)
> if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index c741b53ad45f..60971e16f7a4 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -29,8 +29,6 @@
> # define TARGET_LONG_BITS 32
> #endif
>
> -#define TARGET_IS_BIENDIAN 1
> -
> #define CPUArchState struct CPUARMState
>
> #include "qemu-common.h"
> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
> index cd33539d1ce9..556d66c39d11 100644
> --- a/target-ppc/cpu.h
> +++ b/target-ppc/cpu.h
> @@ -28,8 +28,6 @@
> #define TARGET_LONG_BITS 64
> #define TARGET_PAGE_BITS 12
>
> -#define TARGET_IS_BIENDIAN 1
> -
> /* Note that the official physical address space bits is 62-M where M
> is implementation dependent. I've not looked up M for the set of
> cpus we emulate at the system level. */
>
>
