Re: [RFC Part1 PATCH 13/13] x86/kernel: add support to validate memory when changing C-bit

Brijesh Singh
2021-04-12T14:31:50Z

On 4/12/21 8:05 AM, Borislav Petkov wrote:
> On Mon, Apr 12, 2021 at 07:55:01AM -0500, Brijesh Singh wrote:
>> The cur_entry is updated by the hypervisor. While building the psc
>> buffer the guest sets the cur_entry=0 and the end_entry point to the
>> last valid entry. The cur_entry is incremented by the hypervisor after
>> it successfully processes one 4K page. As per the spec, the hypervisor
>> could get interrupted in middle of the page state change and cur_entry
>> allows the guest to resume the page state change from the point where it
>> was interrupted.
> This is non-obvious and belongs in a comment above it. Otherwise it
> looks weird.

Sure, I will add the comment and provide reference to the GHCB section.

Thanks