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Subject: Re: [edk2-devel] [RFC PATCH v2 04/44] OvmfPkg/ResetVector: Add support for a 32-bit SEV check
From: "Laszlo Ersek" <lersek@redhat.com>
To: devel@edk2.groups.io, thomas.lendacky@amd.com
Cc: Jordan Justen <jordan.l.justen@intel.com>,
 Ard Biesheuvel <ard.biesheuvel@linaro.org>,
 Michael D Kinney <michael.d.kinney@intel.com>,
 Liming Gao <liming.gao@intel.com>, Eric Dong <eric.dong@intel.com>,
 Ray Ni <ray.ni@intel.com>, "Singh, Brijesh" <brijesh.singh@amd.com>
References: <cover.1568922728.git.thomas.lendacky@amd.com>
 <54ebf48fe05c20a1181a3dc90496e4835912ebf2.1568922728.git.thomas.lendacky@amd.com>
 <dbce9d65-5144-7a06-2f0b-9f6dad6eaeea@redhat.com>
Message-ID: <ffbc9b50-0649-6830-e821-2146763851e1@redhat.com>
Date: Tue, 24 Sep 2019 15:50:35 +0200
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On 09/24/19 15:42, Laszlo Ersek wrote:
> On 09/19/19 21:52, Lendacky, Thomas wrote:

>> +    mov       esp, SEV_TOP_OF_STACK

> (3) Do we have an estimate how much stack we need? This would be a
> constraint on PcdOvmfSecPeiTempRamSize. The limit would be nice to
> document (perhaps in a comment somewhere).

Ah I've just been reminded by [RFC PATCH v2 06/44]:

we could use "%if" + "%error" to catch (at compile time) if the stack is
too small.

(Not sure if this is overly useful; it might not be, if the stack demand
is negligible.)

Thanks
Laszlo