Re: [PATCH for-8.1] hw/arm/smmu: Handle big-endian hosts correctly

[Thomas Huth <thuth@redhat.com>]

On 17/07/2023 15.26, Peter Maydell wrote:
> The implementation of the SMMUv3 has multiple places where it reads a
> data structure from the guest and directly operates on it without
> doing a guest-to-host endianness conversion.  Since all SMMU data
> structures are little-endian, this means that the SMMU doesn't work
> on a big-endian host.  In particular, this causes the Avocado test
>    machine_aarch64_virt.py:Aarch64VirtMachine.test_alpine_virt_tcg_gic_max
> to fail on an s390x host.
> 
> Add appropriate byte-swapping on reads and writes of guest in-memory
> data structures so that the device works correctly on big-endian
> hosts.
> 
> As part of this we constrain queue_read() to operate only on Cmd
> structs and queue_write() on Evt structs, because in practice these
> are the only data structures the two functions are used with, and we
> need to know what the data structure is to be able to byte-swap its
> parts correctly.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> Cc: qemu-stable@nongnu.org
> ---
>   hw/arm/smmu-common.c |  3 +--
>   hw/arm/smmuv3.c      | 39 +++++++++++++++++++++++++++++++--------
>   2 files changed, 32 insertions(+), 10 deletions(-)

Thanks, this fixes the alpine test for me:

Tested-by: Thomas Huth <thuth@redhat.com>