Re: [PATCH] swiotlb: Validate bounce size in the sync/unmap path

From: Christoph Hellwig
Date: Wed Feb 03 2021 - 07:53:03 EST


On Mon, Jan 18, 2021 at 12:44:58PM +0100, Martin Radev wrote:
> Your comment makes sense but then that would require the cooperation
> of these vendors and the cloud providers to agree on something meaningful.
> I am also not sure whether the end result would be better than hardening
> this interface to catch corruption. There is already some validation in
> unmap path anyway.

So what? If you guys want to provide a new capability you'll have to do
work. And designing a new protocol based around the fact that the
hardware/hypervisor is not trusted and a copy is always required makes
a lot of more sense than throwing in band aids all over the place.