Re: [PATCH 2/2] virtio: let virtio use DMA API when guest RAM is protected

From: Halil Pasic
Date: Fri Feb 21 2020 - 08:32:52 EST


On Fri, 21 Feb 2020 11:41:57 +0800
Jason Wang <jasowang@xxxxxxxxxx> wrote:

> > I *think* what you are suggesting here is that virtio devices that
> > have !F_IOMMU_PLATFORM should have their dma_ops set up so that the
> > DMA API treats IOVA==PA, which will satisfy what the device expects.
>
>
> Can this work for swiotlb?

It works on s390. I guess it would be the responsibility of however
provides the dma ops for the virtio device to ensure that if
!F_IOMMU_PLATFORM the addresses are GPA like *mandated* by the VIRTIO
specification.

Regards,
Halil