Re: [PATCH] vhost: introduce vDPA based backend

From: Jason Wang
Date: Tue Feb 04 2020 - 22:12:42 EST



On 2020/2/5 äå10:05, Tiwei Bie wrote:
On Tue, Feb 04, 2020 at 02:46:16PM +0800, Jason Wang wrote:
On 2020/2/4 äå2:01, Michael S. Tsirkin wrote:
On Tue, Feb 04, 2020 at 11:30:11AM +0800, Jason Wang wrote:
5) generate diffs of memory table and using IOMMU API to setup the dma
mapping in this method
Frankly I think that's a bunch of work. Why not a MAP/UNMAP interface?

Sure, so that basically VHOST_IOTLB_UPDATE/INVALIDATE I think?
Do you mean we let userspace to only use VHOST_IOTLB_UPDATE/INVALIDATE
to do the DMA mapping in vhost-vdpa case? When vIOMMU isn't available,
userspace will set msg->iova to GPA, otherwise userspace will set
msg->iova to GIOVA, and vhost-vdpa module will get HPA from msg->uaddr?

Thanks,
Tiwei


I think so. Michael, do you think this makes sense?

Thanks



Thanks