On 8/11/23 14:48, Dexuan Cui wrote: > TDX guest memory is private by default and the VMM may not access it. > However, in cases where the guest needs to share data with the VMM, > the guest and the VMM can coordinate to make memory shared between > them. > > The guest side of this protocol includes the "MapGPA" hypercall. This > call takes a guest physical address range. The hypercall spec (aka. > the GHCI) says that the MapGPA call is allowed to return partial > progress in mapping this range and indicate that fact with a special > error code. A guest that sees such partial progress is expected to > retry the operation for the portion of the address range that was not > completed. > > Hyper-V does this partial completion dance when set_memory_decrypted() > is called to "decrypt" swiotlb bounce buffers that can be up to 1GB > in size. It is evidently the only VMM that does this, which is why > nobody noticed this until now. > > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> > Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Is there any reason that this needs to go into the stable trees? If so, Fixes: and Cc:stable@ tags would be nice.
