Re: [Qemu-devel] [PATCH] virtio: move bi-endian target support to a single location

[Paolo Bonzini <pbonzini@redhat.com>]

On 31/05/2016 10:09, Greg Kurz wrote:
> 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

This should be okay.

>  }
>  
>  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

These will only be correct if something else includes cpu.h.  Instead of
defining this, you should add

#include "cpu.h"

at the top of include/hw/virtio-access.h and leave the definitions in
target-*/cpu.h.

Thanks,

Paolo

>  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.  */
>