Re: [PATCH v7 02/17] OvmfPkg/ResetVector: Set C-bit when building initial page table

[Laszlo Ersek <lersek@redhat.com>]

On 06/22/17 22:37, Brijesh Singh wrote:
> SEV guest VMs have the concept of private and shared memory. Private
> memory is encrypted with the guest-specific key, while shared memory
> may be encrypted with hypervisor key. Certain types of memory (namely
> instruction pages and guest page tables) are always treated as private
> memory by the hardware. The C-bit in PTE indicate whether the page is
> private or shared. The C-bit position for the PTE can be obtained from
> CPUID Fn8000_001F[EBX].
> 
> When SEV is active, the BIOS is encrypted by the Qemu launch sequence,
> we must set the C-bit when building the page table.
> 
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Tom Lendacky <Thomas.Lendacky@amd.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> ---
>  OvmfPkg/ResetVector/Ia32/PageTables64.asm | 62 +++++++++++++++++++-
>  1 file changed, 61 insertions(+), 1 deletion(-)

My R-b stands; your modifications relative to v6 patch match the
discussion under the v6 patch.

Thanks
Laszlo