[AMD Official Use Only - General] Hello Nikunj,
That is true, but there is no SEV live migration happening before GHCB pages are re-setup and the hypercalls are invoked again for GHCB pages from the guest kernel after it checks the live migration runtime environment flag setup by OVMF. Thanks, Ashish -----Original Message----- From: Dadhania, Nikunj <[email protected]> Sent: Tuesday, May 31, 2022 10:14 AM To: [email protected]; Kalra, Ashish <[email protected]> Cc: [email protected]; [email protected]; [email protected]; Lendacky, Thomas <[email protected]>; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected] Subject: Re: [edk2-devel] [PATCH v7 5/6] OvmfPkg/PlatformPei: Mark SEC GHCB page as unencrypted via hypercall Hi Ashish, On 8/19/2021 7:36 PM, Ashish Kalra via groups.io wrote: > From: Ashish Kalra <[email protected]> > > Mark the SEC GHCB page (that is mapped as unencrypted in ResetVector > code) in the hypervisor's guest page encryption state tracking. > > Cc: Jordan Justen <[email protected]> > Cc: Ard Biesheuvel <[email protected]> > Signed-off-by: Ashish Kalra <[email protected]> > --- > OvmfPkg/PlatformPei/AmdSev.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/OvmfPkg/PlatformPei/AmdSev.c > b/OvmfPkg/PlatformPei/AmdSev.c index a8bf610022..1d38056ec0 100644 > --- a/OvmfPkg/PlatformPei/AmdSev.c > +++ b/OvmfPkg/PlatformPei/AmdSev.c > @@ -52,6 +52,17 @@ AmdSevEsInitialize ( > PcdStatus = PcdSetBoolS (PcdSevEsIsEnabled, TRUE); > ASSERT_RETURN_ERROR (PcdStatus); > > + // > + // The SEC Ghcb setup during reset-vector needs to be marked as // > + decrypted in the hypervisor's guest page encryption state // > + tracking. > + // > + SetMemoryEncDecHypercall3 ( > + FixedPcdGet32 (PcdOvmfSecGhcbBase), > + EFI_SIZE_TO_PAGES(FixedPcdGet32 (PcdOvmfSecGhcbSize)), > + FALSE > + ); PcdOvmfSecGhcbSize is set to 2 pages (8192 bytes). AFAIU, only first page needs to be change to shared, second page should be kept private. > // > // Allocate GHCB and per-CPU variable pages. > // Since the pages must survive across the UEFI to OS transition > Regards Nikunj -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#90113): https://edk2.groups.io/g/devel/message/90113 Mute This Topic: https://groups.io/mt/84997535/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
