Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted

Michael S. Tsirkin
2019-08-11T08:55:37Z

On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote:
> So we need a flag on the virtio device, exposed by the
> hypervisor (or hardware for hw virtio devices) that says: hey, I'm real,
> don't take a shortcut.

The point here is that it's actually still not real. So we would still
use a physical address. However Linux decides that it wants extra
security by moving all data through the bounce buffer. The distinction
made is that one can actually give device a physical address of the
bounce buffer.

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MST