Messages in this thread | | | Subject | Re: [PATCH 0/3] Fix virtio-blk issue with SWIOTLB | From | Jason Wang <> | Date | Mon, 14 Jan 2019 20:41:37 +0800 |
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On 2019/1/14 下午5:50, Christoph Hellwig wrote: > On Mon, Jan 14, 2019 at 05:41:56PM +0800, Jason Wang wrote: >> On 2019/1/11 下午5:15, Joerg Roedel wrote: >>> On Fri, Jan 11, 2019 at 11:29:31AM +0800, Jason Wang wrote: >>>> Just wonder if my understanding is correct IOMMU_PLATFORM must be set for >>>> all virtio devices under AMD-SEV guests? >>> Yes, that is correct. Emulated DMA can only happen on the SWIOTLB >>> aperture, because that memory is not encrypted. The guest bounces the >>> data then to its encrypted memory. >>> >>> Regards, >>> >>> Joerg >> >> Thanks, have you tested vhost-net in this case. I suspect it may not work > Which brings me back to my pet pevee that we need to take actions > that virtio uses the proper dma mapping API by default with quirks > for legacy cases. The magic bypass it uses is just causing problems > over problems.
Yes, I fully agree with you. This is probably an exact example of such problem.
Thanks
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