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Date: Wed, 15 Dec 2021 09:19:43 +0100
From: "Gerd Hoffmann" <kraxel@redhat.com>
To: Min Xu <min.m.xu@intel.com>
Cc: devel@edk2.groups.io, Ard Biesheuvel <ardb+tianocore@kernel.org>,
	Jordan Justen <jordan.l.justen@intel.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	Erdem Aktas <erdemaktas@google.com>,
	James Bottomley <jejb@linux.ibm.com>,
	Jiewen Yao <jiewen.yao@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>
Subject: Re: [PATCH V4 18/31] OvmfPkg: Check Tdx in QemuFwCfgPei to avoid DMA operation
Message-ID: <20211215081943.jo7ticsbtttvd5pg@sirius.home.kraxel.org>
References: <cover.1639399598.git.min.m.xu@intel.com>
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On Mon, Dec 13, 2021 at 08:56:49PM +0800, Min Xu wrote:
> RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429
> 
> If TDX is enabled then we do not support DMA operation in PEI phase.
> This is mainly because DMA in TDX guest requires using bounce buffer
> (which need to allocate dynamic memory and allocating a PAGE size'd
> buffer can be challenge in PEI phase).
> 
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Brijesh Singh <brijesh.singh@amd.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Signed-off-by: Min Xu <min.m.xu@intel.com>

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