On Wed, 18 Jan 2023 at 16:41, Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > On 1/18/23 07:09, Ard Biesheuvel wrote: > > However, I guess we're at a point where SEV and TDX really want > > different solutions, so I think divergence might be the way to > > proceed. > > I don't think they want different things really. > > TDX doesn't need this protocol. It sounds like SEV does need it, > though. That doesn't mean they really diverge. They're *both* going to > have to poke at this protocol knob to get the firmware to not accept the > memory. > No, on TDX, the firmware would never accept all memory. On SEV, it would only do so if the protocol has not been called prior to the call to ExitBootServices(). > This does slightly change the motivation for doing explicit unaccepted > memory support in the kernel. > Not on TDX. > I also don't know _quite_ how this will look to a guest. For instance, > will they see different memory maps based on which protocol they are > using? I assume so, but didn't see any of that explicitly mentioned in > this patch. The EFI memory map will not contain ranges of type EFI_UNACCEPTED_MEMORY if the memory was accepted on behalf of the OS by the firmware. That is the point, really, as non-enlightened OSes will ignore those.
