Re: [virtio-comment] [PATCH v1 1/2] virtio-mem: introduce VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE

On 17.08.21 11:23, Cornelia Huck wrote:

On Tue, Aug 17 2021, David Hildenbrand [off-list ref] wrote:

quoted

On 17.08.21 10:50, Cornelia Huck wrote:

quoted

On Thu, Aug 12 2021, David Hildenbrand [off-list ref] wrote:

quoted

+With VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE, the device MAY allow the CPU to

"If VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE has been negotiated, ..."

ack

quoted

quoted

+read memory of unplugged memory blocks inside \field{usable_region_size}.

A compliant driver would not read that memory, would it?

Indeed. The device could decide to allow for reading, but it's pretty
much undefined behavior.

Maybe make it "SHOULD NOT"? Less strong than "MUST NOT", but still makes
clear that a driver reading it is pretty much doing the wrong thing.

I was also wondering to just drop it completely, because it's actually 
undefined behavior. What do you think?

-- 
Thanks,

David / dhildenb