audk/OvmfPkg/Include
Tom Lendacky 5667dc43d8 OvmfPkg/VmgExitLib: Support nested #VCs
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3108

In order to be able to issue messages or make interface calls that cause
another #VC (e.g. GetLocalApicBaseAddress () issues RDMSR), add support
for nested #VCs.

In order to support nested #VCs, GHCB backup pages are required. If a #VC
is received while currently processing a #VC, a backup of the current GHCB
content is made. This allows the #VC handler to continue processing the
new #VC. Upon completion of the new #VC, the GHCB is restored from the
backup page. The #VC recursion level is tracked in the per-vCPU variable
area.

Support is added to handle up to one nested #VC (or two #VCs total). If
a second nested #VC is encountered, an ASSERT will be issued and the vCPU
will enter CpuDeadLoop ().

For SEC, the GHCB backup pages are reserved in the OvmfPkgX64.fdf memory
layout, with two new fixed PCDs to provide the address and size of the
backup area.

For PEI/DXE, the GHCB backup pages are allocated as boot services pages
using the memory allocation library.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <ac2e8203fc41a351b43f60d68bdad6b57c4fb106.1610045305.git.thomas.lendacky@amd.com>
2021-01-07 19:34:39 +00:00
..
Guid OvmfPkg/AmdSev/SecretDxe: make secret location naming generic 2020-12-18 10:45:52 +00:00
IndustryStandard OvmfPkg/VirtioFsDxe: add helper for determining file mode bits update 2020-12-21 17:16:23 +00:00
Library OvmfPkg/VmgExitLib: Support nested #VCs 2021-01-07 19:34:39 +00:00
Protocol OvmfPkg: Fix spelling mistake for occurred 2020-08-19 00:54:23 +00:00
Register OvmfPkg: strip trailing whitespace 2019-10-04 11:18:32 +01:00
OvmfPlatforms.h OvmfPkg: Add bhyve support into AcpiTimerLib 2020-04-30 13:46:11 +00:00