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>
The base VmgExitLib library provides a default limited interface. As it
does not provide full support, create an OVMF version of this library to
begin the process of providing full support of SEV-ES within OVMF.
SEV-ES support is only provided for X64 builds, so only OvmfPkgX64.dsc is
updated to make use of the OvmfPkg version of the library.
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
