Re: [PATCH v12 23/32] UefiCpuPkg: add PcdGhcbHypervisorFeatures

["Ni, Ray" <ray.ni@intel.com>]

Acked-by: Ray Ni <ray.ni@Intel.com>

> -----Original Message-----
> From: Brijesh Singh <brijesh.singh@amd.com>
> Sent: Thursday, November 11, 2021 6:15 AM
> To: devel@edk2.groups.io
> Cc: James Bottomley <jejb@linux.ibm.com>; Xu, Min M <min.m.xu@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>;
> Tom Lendacky <thomas.lendacky@amd.com>; Justen, Jordan L <jordan.l.justen@intel.com>; Ard Biesheuvel
> <ardb+tianocore@kernel.org>; Erdem Aktas <erdemaktas@google.com>; Michael Roth <Michael.Roth@amd.com>; Gerd
> Hoffmann <kraxel@redhat.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Liming Gao
> <gaoliming@byosoft.com.cn>; Liu, Zhiguang <zhiguang.liu@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar, Rahul1
> <rahul1.kumar@intel.com>; Dong, Eric <eric.dong@intel.com>; Brijesh Singh <brijesh.singh@amd.com>; Michael Roth
> <michael.roth@amd.com>
> Subject: [PATCH v12 23/32] UefiCpuPkg: add PcdGhcbHypervisorFeatures
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
> 
> Version 2 of the GHCB specification added a new VMGEXIT that the guest
> could use for querying the hypervisor features. One of the immediate
> users for it will be an AP creation code. When SEV-SNP is enabled, the
> guest can use the newly added AP_CREATE VMGEXIT to create the APs.
> 
> The MpInitLib will check the hypervisor feature, and if AP_CREATE is
> available, it will use it.
> 
> See GHCB spec version 2 for more details on the VMGEXIT.
> 
> Cc: Michael Roth <michael.roth@amd.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Min Xu <min.m.xu@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Acked-by: Gerd Hoffmann <kraxel@redhat.com>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  UefiCpuPkg/UefiCpuPkg.dec | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
> index 62acb291f309..7de66fde674c 100644
> --- a/UefiCpuPkg/UefiCpuPkg.dec
> +++ b/UefiCpuPkg/UefiCpuPkg.dec
> @@ -396,5 +396,10 @@ [PcdsDynamic, PcdsDynamicEx]
>    # @Prompt SEV-ES Status
>    gUefiCpuPkgTokenSpaceGuid.PcdSevEsIsEnabled|FALSE|BOOLEAN|0x60000016
> 
> +  ## This dynamic PCD contains the hypervisor features value obtained through the GHCB HYPERVISOR
> +  #  features VMGEXIT defined in the version 2 of GHCB spec.
> +  # @Prompt GHCB Hypervisor Features
> +  gUefiCpuPkgTokenSpaceGuid.PcdGhcbHypervisorFeatures|0x0|UINT64|0x60000018
> +
>  [UserExtensions.TianoCore."ExtraFiles"]
>    UefiCpuPkgExtra.uni
> --
> 2.25.1