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Date: Thu, 14 Oct 2021 10:42:32 +0200
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: devel@edk2.groups.io, James Bottomley <jejb@linux.ibm.com>,
	Min Xu <min.m.xu@intel.com>, Jiewen Yao <jiewen.yao@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
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	Ard Biesheuvel <ardb+tianocore@kernel.org>,
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	Michael Roth <Michael.Roth@amd.com>, Ray Ni <ray.ni@intel.com>,
	Rahul Kumar <rahul1.kumar@intel.com>,
	Eric Dong <eric.dong@intel.com>
Subject: Re: [PATCH v9 23/32] UefiCpuPkg: add PcdGhcbHypervisorFeatures
Message-ID: <20211014084232.vil7n2ae7te5wr43@sirius.home.kraxel.org>
References: <20211013165713.727815-1-brijesh.singh@amd.com>
 <20211013165713.727815-24-brijesh.singh@amd.com>
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On Wed, Oct 13, 2021 at 11:57:04AM -0500, Brijesh Singh wrote:
> 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.

Acked-by: Gerd Hoffmann <kraxel@redhat.com>

take care,
  Gerd