Re: [Qemu-devel] [PATCH v9 16/20] memory: Single byte swap along the I/O path

From: Richard Henderson <richard.henderson@linaro.org>
To: Tony Nguyen <tony.nguyen@bt.com>, qemu-devel@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [Qemu-devel] [PATCH v9 16/20] memory: Single byte swap along the I/O path
Date: Fri, 23 Aug 2019 12:12:35 -0700	[thread overview]
Message-ID: <543522bf-2809-8277-1baf-0ee7656c04ac@linaro.org> (raw)
In-Reply-To: <911ff31af11922a9afba9b7ce128af8b8b80f316.1566466906.git.tony.nguyen@bt.com>

On 8/23/19 11:36 AM, Tony Nguyen wrote:
> Now that MemOp has been pushed down into the memory API, and
> callers are encoding endianness, we can collapse byte swaps
> along the I/O path into the accelerator and target independent
> adjust_endianness.
> 
> Collapsing byte swaps along the I/O path enables additional endian
> inversion logic, e.g. SPARC64 Invert Endian TTE bit, with redundant
> byte swaps cancelling out.
> 
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
> ---
>  accel/tcg/cputlb.c     | 42 ++--------------------------
>  exec.c                 | 17 +++---------
>  hw/virtio/virtio-pci.c | 10 +++----
>  memory.c               | 33 ++++++++--------------
>  memory_ldst.inc.c      | 63 ------------------------------------------
>  5 files changed, 23 insertions(+), 142 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~