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Re: [Qemu-devel] [PATCH] virtio-pci: replace byte swap hack
From: |
Alexander Graf |
Subject: |
Re: [Qemu-devel] [PATCH] virtio-pci: replace byte swap hack |
Date: |
Sun, 6 Jan 2013 19:50:04 +0100 |
Am 06.01.2013 um 19:26 schrieb Blue Swirl <address@hidden>:
> On Sun, Jan 6, 2013 at 1:17 PM, Alexander Graf <address@hidden> wrote:
>>
>> On 30.12.2012, at 13:55, Blue Swirl wrote:
>>
>>> Remove byte swaps by declaring the config space
>>> as native endian.
>>
>> This is wrong. Virtio-pci config space is split into 2 regions. One with
>> native endianness, the other one with little endian.
>
> True. I must say that this is poor architectural design in multiple
> ways. The endianness problem is aggravated by device being also
> instantiated by other devices, so we can't (at least easily) pass an
> endianness flag from above, or make two devices that are selected by
> the board. Another problem is that the offset changes dynamically
> depending on if MSIX is enabled or not. The design is probably also
> fixed by the guest driver assumptions and can't ever be improved.
> Paravirtual devices should have cleaner design than what for example
> original PC devices have, not more insane. :-(
I guess now you understand my wording in the comment that your patch removes a
bit better :).
Alex
Re: [Qemu-devel] [PATCH] virtio-pci: replace byte swap hack, Blue Swirl, 2013/01/06
- Re: [Qemu-devel] [PATCH] virtio-pci: replace byte swap hack,
Alexander Graf <=