On 5/3/21 8:05 AM, Erdem Aktas wrote:
> Hi Brijesh,
> I have few naive questions inlined:
>
> On Fri, Apr 30, 2021 at 4:52 AM Brijesh Singh wrote:
>> +; Use PVALIDATE instruction to invalidate the page
>> +mov eax, GHCB_BASE
>> +mov ecx, 0
>> +mov edx, 0
>> +DB
Hi Brijesh,
I have few naive questions inlined:
On Fri, Apr 30, 2021 at 4:52 AM Brijesh Singh wrote:
> +; Use PVALIDATE instruction to invalidate the page
> +mov eax, GHCB_BASE
> +mov ecx, 0
> +mov edx, 0
> +DB 0xF2, 0x0F, 0x01, 0xFF
> +cmp eax, 0
> +
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
When SEV-SNP is active, the GHCB page is mapped un-encrypted in the
initial page table built by the reset vector code. Just clearing the
encryption attribute from the page table is not enough. The page also
needs to be added as shared in the
