audk/UefiCpuPkg/CpuDxe
Tom Lendacky 0d7601e546 UefiCpuPkg: Add a 16-bit protected mode code segment descriptor
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

A hypervisor is not allowed to update an SEV-ES guests 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
transition from 64-bit long mode to 16-bit real mode in response to an
INIT-SIPI-SIPI sequence. This requires a 16-bit code segment descriptor.
For PEI, create this descriptor in the reset vector GDT table. For DXE,
create this descriptor from the newly reserved entry at location 0x28.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-17 02:46:39 +00:00
..
Ia32 UefiCpuPkg/CpuDxe: clean up PAGE_TABLE_LIB_PAGING_CONTEXT usage. 2019-09-25 14:29:24 +08:00
X64 UefiCpuPkg/CpuDxe: clean up PAGE_TABLE_LIB_PAGING_CONTEXT usage. 2019-09-25 14:29:24 +08:00
CpuDxe.c UefiCpuPkg: Add New Memory Attributes 2020-07-15 14:58:25 +00:00
CpuDxe.h UefiCpuPkg: Add New Memory Attributes 2020-07-15 14:58:25 +00:00
CpuDxe.inf UefiCpuPkg/CpuDxe: clean up PAGE_TABLE_LIB_PAGING_CONTEXT usage. 2019-09-25 14:29:24 +08:00
CpuDxe.uni UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
CpuDxeExtra.uni UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
CpuGdt.c UefiCpuPkg: Add a 16-bit protected mode code segment descriptor 2020-08-17 02:46:39 +00:00
CpuGdt.h UefiCpuPkg: Add a 16-bit protected mode code segment descriptor 2020-08-17 02:46:39 +00:00
CpuMp.c UefiCpuPkg/CpuDxe: Fix few typos 2020-02-10 22:30:07 +00:00
CpuMp.h UefiCpuPkg/CpuDxe: Fix few typos 2020-02-10 22:30:07 +00:00
CpuPageTable.c UefiCpuPkg: Add New Memory Attributes 2020-07-15 14:58:25 +00:00
CpuPageTable.h UefiCpuPkg/CpuDxe: Fix few typos 2020-02-10 22:30:07 +00:00