Re: [PATCH 3/3] arm, arm64: KVM: handle potential incoherency of readonly memslots

Peter Maydell
2014-11-20T22:00:17Z

On 20 November 2014 21:13, Laszlo Ersek <lersek@redhat.com> wrote:
> On 11/20/14 21:10, Peter Maydell wrote:
>> I think in practice for a well-behaved guest we can arrange
>> that everything is fine (roughly, the guest has to treat
>> DMA-capable devices as doing coherent-dma, which we can tell
>> them to do via DT bindings or ACPI[*], plus the special
>> case handling we already have for bootup), and naughty guests
>> will only confuse themselves. But I need to think a bit more
>> about it (and we should probably write down how it works
>> somewhere :-)).

> This basically means that virtio transfers should just use normal memory
> in the guest (treating virtio transfers as "coherent DMA"), right?

Normal *cacheable*, but yes.

-- PMM