From: Tom Lendacky <thomas.lenda...@amd.com>
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198
Reserve a fixed area of memory for SEV-ES use and set a fixed PCD,
PcdSevEsWorkAreaBase, to this value.
This area will be used by SEV-ES support for two purposes:
1. Communicating the SEV-ES status during BSP boot to SEC:
Using a byte of memory from the page, the BSP reset vector code can
communicate the SEV-ES status to SEC for use before exception
handling can be enabled in SEC. After SEC, this field is no longer
valid and the standard way of determine if SEV-ES is active should
be used.
2. Establishing an area of memory for AP boot support:
A hypervisor is not allowed to update an SEV-ES guest's register
state, so when booting an SEV-ES guest AP, the hypervisor is not
allowed to set the RIP to the guest requested value. Instead an
SEV-ES AP must be re-directed from within the guest to the actual
requested staring location as specified in the INIT-SIPI-SIPI
sequence.
Use this memory for reset vector code that can be programmed to have
the AP jump to the desired RIP location after starting the AP. This
is required for only the very first AP reset.
Cc: Jordan Justen <jordan.l.jus...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Cc: Ard Biesheuvel <ard.biesheu...@arm.com>
Reviewed-by: Laszlo Ersek <ler...@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
---
OvmfPkg/OvmfPkgX64.fdf | 3 +++
1 file changed, 3 insertions(+)
diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
index edb03b5464d4..8da59037e5f0 100644
--- a/OvmfPkg/OvmfPkgX64.fdf
+++ b/OvmfPkg/OvmfPkgX64.fdf
@@ -82,6 +82,9 @@ [FD.MEMFD]
0x009000|0x002000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbSize
+0x00B000|0x001000
+gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaBase|gUefiCpuPkgTokenSpaceGuid.PcdSevEsWorkAreaSize
+
0x010000|0x010000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
--
2.28.0
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