On Tue, Nov 23, 2021 at 09:41:34AM +0100, Paolo Bonzini wrote:

On 11/19/21 14:47, Chao Peng wrote:

quoted

For fd-based memslot store the file references for shared fd and the
private fd (if any) in the memslot structure. Since there is no 'hva'
concept we cannot call hva_to_pfn() to get a pfn, instead kvm_memfd_ops
is added to get_pfn/put_pfn from the memory backing stores that provide
these fds.

Signed-off-by: Yu Zhang<redacted>
Signed-off-by: Chao Peng<redacted>
---

What about kvm_read/write_guest? 

Hmm, that would be another area KVM needs to change. Not totally
undoable.

Maybe the proposal which kept
userspace_addr for the shared fd is more doable (it would be great to
ultimately remove the mandatory userspace mapping for the shared fd, but I
think KVM is not quite ready for that).

Agree for short term keeping shared part unchanged would be making work
easy:) Let me try that to see if any blocker.

Paolo