[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH RFC v4 19/20] intel_iommu: unmap existing pages
Re: [Qemu-devel] [PATCH RFC v4 19/20] intel_iommu: unmap existing pages before replay
Mon, 23 Jan 2017 15:30:20 +0800
On Mon, Jan 23, 2017 at 09:57:23AM +0800, Jason Wang wrote:
> On 2017年01月22日 17:09, Peter Xu wrote:
> >On Sun, Jan 22, 2017 at 04:13:32PM +0800, Jason Wang wrote:
> >>On 2017年01月20日 21:08, Peter Xu wrote:
> >>>Previous replay works for domain switch only if the original domain does
> >>>not have mapped pages. For example, if we switch domain from A to B, it
> >>>will only work if A has no existing mapping. If there is, then there's
> >>>problem - current replay didn't make sure the old mappings are cleared
> >>>before replaying the new one.
> >>I'm not quite sure this is needed. I thought the only thing we need to do is
> >>stop DMA of device during the moving? Or is there an example that will cause
> >I think this patch is essential.
> >- device D1 moved to domain A, domain A has no mapping
> >- map page P1 in domain A, so D1 will have a mapping of page P1
> >- create domain B with mapping P2
> >- move D1 from domain A to domain B
> >Here if we don't unmap existing pages in domain A (P1),
> I thought driver should do this work instead of device, because only driver
> knows whether or not iova is still needed?
Do you mean "device driver" above?
I don't know whether I understood the question above, but the problem
should be there no matter which one is managing iova?
[Qemu-devel] [PATCH RFC v4 17/20] intel_iommu: allow dynamic switch of IOMMU region, Peter Xu, 2017/01/20
[Qemu-devel] [PATCH RFC v4 19/20] intel_iommu: unmap existing pages before replay, Peter Xu, 2017/01/20
Re: [Qemu-devel] [PATCH RFC v4 19/20] intel_iommu: unmap existing pages before replay, Jason Wang, 2017/01/23
[Qemu-devel] [PATCH RFC v4 18/20] intel_iommu: enable vfio devices, Peter Xu, 2017/01/20