Commit Graph

28349 Commits

Author SHA1 Message Date
Tom Lendacky 43c3df7846 OvmfPkg: Reserve a page in memory for the SEV-ES usage
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 After SEC, this field is no longer
     valid and the standard way of determine if SEV-ES is active should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.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky 88a363009a UefiCpuPkg: Create an SEV-ES workarea PCD
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Create an SEV-ES workarea PCD. This PCD will be used for BSP communication
during SEC and for AP startup during PEI and DXE phases, the latter is the
reason for creating it in the UefiCpuPkg.

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
Tom Lendacky 13ed9e5fc0 OvmfPkg/PlatformPei: Move early GDT into ram when SEV-ES is enabled
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

The SEV support will clear the C-bit from non-RAM areas.  The early GDT
lives in a non-RAM area, so when an exception occurs (like a #VC) the GDT
will be read as un-encrypted even though it is encrypted. This will result
in a failure to be able to handle the exception.

Move the GDT into RAM so it can be accessed without error when running as
an SEV-ES guest.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky 449a6e4934 OvmfPkg: Create GHCB pages for use during Pei and Dxe phase
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Allocate memory for the GHCB pages and the per-CPU variable pages during
SEV initialization for use during Pei and Dxe phases. The GHCB page(s)
must be shared pages, so clear the encryption mask from the current page
table entries. Upon successful allocation, set the GHCB PCDs (PcdGhcbBase
and PcdGhcbSize).

The per-CPU variable page needs to be unique per AP. Using the page after
the GHCB ensures that it is unique per AP. Only the GHCB page is marked as
shared, keeping the per-CPU variable page encyrpted. The same logic is
used in DXE using CreateIdentityMappingPageTables() before switching to
the DXE pagetables.

The GHCB pages (one per vCPU) will be used by the PEI and DXE #VC
exception handlers. The #VC exception handler will fill in the necessary
fields of the GHCB and exit to the hypervisor using the VMGEXIT
instruction. The hypervisor then accesses the GHCB associated with the
vCPU in order to perform the requested function.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky 0bbed0664f OvmfPkg/PlatformPei: Reserve GHCB-related areas if S3 is supported
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Protect the memory used by an SEV-ES guest when S3 is supported. This
includes the page table used to break down the 2MB page that contains
the GHCB so that it can be marked un-encrypted, as well as the GHCB
area.

Regarding the lifecycle of the GHCB-related memory areas:
  PcdOvmfSecGhcbPageTableBase
  PcdOvmfSecGhcbBase

(a) when and how it is initialized after first boot of the VM

  If SEV-ES is enabled, the GHCB-related areas are initialized during
  the SEC phase [OvmfPkg/ResetVector/Ia32/PageTables64.asm].

(b) how it is protected from memory allocations during DXE

  If S3 and SEV-ES are enabled, then InitializeRamRegions()
  [OvmfPkg/PlatformPei/MemDetect.c] protects the ranges with an AcpiNVS
  memory allocation HOB, in PEI.

  If S3 is disabled, then these ranges are not protected. DXE's own page
  tables are first built while still in PEI (see HandOffToDxeCore()
  [MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c]). Those tables are
  located in permanent PEI memory. After CR3 is switched over to them
  (which occurs before jumping to the DXE core entry point), we don't have
  to preserve PcdOvmfSecGhcbPageTableBase. PEI switches to GHCB pages in
  permanent PEI memory and DXE will use these PEI GHCB pages, so we don't
  have to preserve PcdOvmfSecGhcbBase.

(c) how it is protected from the OS

  If S3 is enabled, then (b) reserves it from the OS too.

  If S3 is disabled, then the range needs no protection.

(d) how it is accessed on the S3 resume path

  It is rewritten same as in (a), which is fine because (b) reserved it.

(e) how it is accessed on the warm reset path

  It is rewritten same as in (a).

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien@xen.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky 6995a1b79b OvmfPkg: Create a GHCB page for use during Sec phase
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

A GHCB page is needed during the Sec phase, so this new page must be
created. Since the #VC exception handler routines assume that a per-CPU
variable area is immediately after the GHCB, this per-CPU variable area
must also be created. Since the GHCB must be marked as an un-encrypted,
or shared, page, an additional pagetable page is required to break down
the 2MB region where the GHCB page lives into 4K pagetable entries.

Create a new entry in the OVMF memory layout for the new page table
page and for the SEC GHCB and per-CPU variable pages. After breaking down
the 2MB page, update the GHCB page table entry to remove the encryption
mask.

The GHCB page will be used by the SEC #VC exception handler. The #VC
exception handler will fill in the necessary fields of the GHCB and exit
to the hypervisor using the VMGEXIT instruction. The hypervisor then
accesses the GHCB in order to perform the requested function.

Four new fixed PCDs are needed to support the SEC GHCB page:
  - PcdOvmfSecGhcbBase  UINT32 value that is the base address of the
                        GHCB used during the SEC phase.
  - PcdOvmfSecGhcbSize  UINT32 value that is the size, in bytes, of the
                        GHCB area used during the SEC phase.

  - PcdOvmfSecGhcbPageTableBase  UINT32 value that is address of a page
                        table page used to break down the 2MB page into
                        512 4K pages.
  - PcdOvmfSecGhcbPageTableSize  UINT32 value that is the size, in bytes,
                        of the page table page.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky cf845a749a OvmfPkg: Add support to perform SEV-ES initialization
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

When SEV-ES is enabled, then SEV is also enabled. Add support to the SEV
initialization function to also check for SEV-ES being enabled, and if
enabled, set the SEV-ES enabled PCD (PcdSevEsIsEnabled).

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky 0afa1d08f1 OvmfPkg/MemEncryptSevLib: Add an SEV-ES guest indicator function
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Create a function that can be used to determine if the VM is running
as an SEV-ES guest.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.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
Tom Lendacky fefcf90c33 OvmfPkg/VmgExitLib: Add support for DR7 Read/Write NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a DR7 read or write intercept generates a #VC exception.
The #VC handler must provide special support to the guest for this. On
a DR7 write, the #VC handler must cache the value and issue a VMGEXIT
to notify the hypervisor of the write. However, the #VC handler must
not actually set the value of the DR7 register. On a DR7 read, the #VC
handler must return the cached value of the DR7 register to the guest.
VMGEXIT is not invoked for a DR7 register read.

The caching of the DR7 values will make use of the per-CPU data pages
that are allocated along with the GHCB pages. The per-CPU page for a
vCPU is the page that immediately follows the vCPU's GHCB page. Since
each GHCB page is unique for a vCPU, the page that follows becomes
unique for that vCPU. The SEC phase will reserves an area of memory for
a single GHCB and per-CPU page for use by the BSP. After transitioning
to the PEI phase, new GHCB and per-CPU pages are allocated for the BSP
and all APs.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 9f7e0d0ade OvmfPkg/VmgExitLib: Add support for MWAIT/MWAITX NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a MWAIT/MWAITX intercept generates a #VC exception.
VMGEXIT must be used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 3ef8bfc2b3 OvmfPkg/VmgExitLib: Add support for MONITOR/MONITORX NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a MONITOR/MONITORX intercept generates a #VC exception.
VMGEXIT must be used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky f4571f24d1 OvmfPkg/VmgExitLib: Add support for RDTSCP NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a RDTSCP intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky e4bb269a85 OvmfPkg/VmgExitLib: Add support for VMMCALL NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a VMMCALL intercept generates a #VC exception. VMGEXIT must
be used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 3caf1e2e22 OvmfPkg/VmgExitLib: Add support for INVD NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a INVD intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 5894fb1fa2 OvmfPkg/VmgExitLib: Add support for RDPMC NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a RDPMC intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 68d18bef41 OvmfPkg/VmgExitLib: Add support for RDTSC NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a RDTSC intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 4de7047976 OvmfPkg/VmgExitLib: Add support for WBINVD NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a WBINVD intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky c45f678a1e OvmfPkg/VmgExitLib: Add support for NPF NAE events (MMIO)
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a NPF intercept for an NPT entry with a reserved bit set
generates a #VC exception. This condition is assumed to be an MMIO access.
VMGEXIT must be used to allow the hypervisor to handle this intercept.

Add support to construct the required GHCB values to support a NPF NAE
event for MMIO.  Parse the instruction that generated the #VC exception,
setting the required register values in the GHCB and creating the proper
SW_EXIT_INFO1, SW_EXITINFO2 and SW_SCRATCH values in the GHCB.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 9711c9230b OvmfPkg/VmgExitLib: Add support for MSR_PROT NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a MSR_PROT intercept generates a #VC exception. VMGEXIT must
be used to allow the hypervisor to handle this intercept.

Add support to construct the required GHCB values to support an MSR_PROT
NAE event. Parse the instruction that generated the #VC exception to
determine whether it is RDMSR or WRMSR, setting the required register
register values in the GHCB and creating the proper SW_EXIT_INFO1 value in
the GHCB.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 6587e08d3a OvmfPkg/VmgExitLib: Add support for CPUID NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a CPUID intercept generates a #VC exception. VMGEXIT must be
used to allow the hypervisor to handle this intercept.

Add support to construct the required GHCB values to support a CPUID NAE
event. Additionally, CPUID 0x0000_000d (CPUID_EXTENDED_STATE) requires
XCR0 to be supplied in the GHCB, so add support to issue the XGETBV
instruction.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 0020157a98 OvmfPkg/VmgExitLib: Support string IO for IOIO_PROT NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Add support to the #VC exception handler to handle string IO. This
requires expanding the IO instruction parsing to recognize string based
IO instructions as well as preparing an un-encrypted buffer to be used
to transfer (either to or from the guest) the string contents for the IO
operation. The SW_EXITINFO2 and SW_SCRATCH fields of the GHCB are set
appropriately for the operation. Multiple VMGEXIT invocations may be
needed to complete the string IO operation.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky fb040cced3 OvmfPkg/VmgExitLib: Add support for IOIO_PROT NAE events
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a IOIO_PROT intercept generates a #VC exception. VMGEXIT
must be used to allow the hypervisor to handle this intercept.

Add support to construct the required GHCB values to support a IOIO_PROT
NAE event.  Parse the instruction that generated the #VC exception,
setting the required register values in the GHCB and creating the proper
SW_EXITINFO1 value in the GHCB.

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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 61bacc0fa1 OvmfPkg/VmgExitLib: Implement library support for VmgExitLib in OVMF
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>
2020-08-17 02:46:39 +00:00
Tom Lendacky 5277540e37 UefiCpuPkg/CpuExceptionHandler: Add base support for the #VC exception
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Add base support to handle #VC exceptions. Update the common exception
handlers to invoke the VmgExitHandleVc () function of the VmgExitLib
library when a #VC is encountered. A non-zero return code will propagate
to the targeted exception handler.

Under SEV-ES, a DR7 read or write intercept generates a #VC exception.
To avoid exception recursion, a #VC exception will not try to read and
push the actual debug registers into the EFI_SYSTEM_CONTEXT_X64 struct
and instead push zeroes. The #VC exception handler does not make use of
the debug registers from the saved context and the exception processing
exit code does not attempt to restore the debug register values.

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
Tom Lendacky 3a4a6ead32 UefiPayloadPkg: Prepare UefiPayloadPkg to use the VmgExitLib library
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Various CpuExceptionHandlerLib libraries will updated to use the new
VmgExitLib library. To prevent any build breakage, update the
UefiPayloadPkg DSC files that use a form of the CpuExceptionHandlerLib
library to include the VmgExitLib library.

Cc: Maurice Ma <maurice.ma@intel.com>
Cc: Guo Dong <guo.dong@intel.com>
Cc: Benjamin You <benjamin.you@intel.com>
Reviewed-by: Guo Dong <guo.dong@intel.com>
Reviewed-by: Maurice Ma <maurice.ma@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky 19c50eb61c OvmfPkg: Prepare OvmfPkg to use the VmgExitLib library
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Various CpuExceptionHandlerLib libraries will updated to use the new
VmgExitLib library. To prevent any build breakage, update the OvmfPkg
DSC files that use a form of the CpuExceptionHandlerLib library to
include the VmgExitLib library.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien@xen.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky 8714978781 UefiCpuPkg: Implement library support for VMGEXIT
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

To support handling #VC exceptions and issuing VMGEXIT instructions,
create a library with functions that can be used to perform these
#VC/VMGEXIT related operations. This includes functions for:
  - Handling #VC exceptions
  - Preparing for and issuing a VMGEXIT
  - Performing MMIO-related write operations to support flash emulation
  - Performing AP related boot opeations

The base functions in this driver will not do anything and will return
an error if a return value is required. It is expected that other packages
(like OvmfPkg) will create a version of the library to fully support an
SEV-ES guest.

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>
2020-08-16 16:45:42 +00:00
Tom Lendacky f8422f1e0b MdePkg/BaseLib: Add support for the VMGEXIT instruction
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

VMGEXIT is a new instruction used for Hypervisor/Guest communication when
running as an SEV-ES guest. A VMGEXIT will cause an automatic exit (AE)
to occur, resulting in a #VMEXIT with an exit code value of 0x403.

Since SEV-ES is only supported in X64, provide the necessary X64 support
to execute the VMGEXIT instruction, which is coded as "rep vmmcall". For
IA32, since "vmmcall" is not supported in NASM 32-bit mode and VMGEXIT
should never be called, provide a stub implementation that is identical
to CpuBreakpoint().

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky 9b3ca509ab MdePkg/BaseLib: Add support for the XGETBV instruction
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Under SEV-ES, a CPUID instruction requires the current value of the XCR0
register. In order to retrieve that value, the XGETBV instruction needs
to be executed.

Provide the necessary support to execute the XGETBV instruction.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky b098f5e9e9 MdeModulePkg/DxeIplPeim: Support GHCB pages when creating page tables
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

GHCB pages must be mapped as shared pages, so modify the process of
creating identity mapped pagetable entries so that GHCB entries are
created without the encryption bit set. The GHCB range consists of
two pages per CPU, the first being the GHCB and the second being a
per-CPU variable page. Only the GHCB page is mapped as shared.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Acked-by: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky 1c0eb91503 MdePkg: Add a structure definition for the GHCB
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

The GHCB is used by an SEV-ES guest for communicating between the guest
and the hypervisor. Create the GHCB definition as defined by the GHCB
protocol definition.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky a80e887819 MdePkg: Add the MSR definition for the GHCB register
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

For SEV-ES, the GHCB page address is stored in the GHCB MSR register
(0xc0010130). Define the register and the format used for register
during GHCB protocol negotiation.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Tom Lendacky c9db7bf10a UefiCpuPkg: Create PCD to be used in support of SEV-ES
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

A new dynamic UefiCpuPkg PCD is needed to support SEV-ES under OVMF:
  - PcdSevEsIsEnabled: BOOLEAN value used to indicate if SEV-ES is enabled

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>
2020-08-16 16:45:42 +00:00
Tom Lendacky 39936d3393 MdeModulePkg: Create PCDs to be used in support of SEV-ES
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

Two new dynamic MdeModulePkg PCDs are needed to support SEV-ES under OVMF:
  - PcdGhcbBase:       UINT64 value that is the base address of the GHCB
                       allocation.
  - PcdGhcbSize:       UINT64 value that is the size, in bytes, of the
                       GHCB allocation (size is dependent on the number of
                       APs).

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
2020-08-16 16:45:42 +00:00
Liming Gao 7f7f511c5a BaseTools: Fix the issue in VS2017/VS2019 setting
edksetup.bat VS2017 should set VS2017 only. But now,
it will set VS2017/VS2019 both. This patch corrects it.

Signed-off-by: Liming Gao <liming.gao@intel.com>
Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
2020-08-14 03:07:59 +00:00
Liming Gao 24758e993a BaseTools: Fix the issue in VS prefix setting for VS2017/VS2019
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2896

When VS2017/VS2019 are both installed. VS prefix setting will
wrongly be set. VS2017_PREFIX is set to the same value of VS2019.

This patch clears VSINSTALLDIR and VCToolsVersion env, then
the different vcvars32 can set the correct VS env.

Signed-off-by: Liming Gao <liming.gao@intel.com>
Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
2020-08-14 03:07:59 +00:00
Liming Gao a5110b8955 BaseTools: Move VS2019 env setting after VS2017 env setting
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2896

Keep the latest VS version as the last one

Signed-off-by: Liming Gao <liming.gao@intel.com>
Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
2020-08-14 03:07:59 +00:00
Cole Robinson 43bec9ea3d BaseTools: Work around array.array.tostring() removal in python 3.9
In python3, array.array.tostring() was a compat alias for tobytes().
tostring() was removed in python 3.9.

Convert this to use tolist() which should be valid for all python
versions.

This fixes this build error on python3.9:

(Python 3.9.0b5 on linux) Traceback (most recent call last):
  File "/root/edk2/edk2-edk2-stable202002/BaseTools/BinWrappers/PosixLike/../../Source/Python/Trim/Trim.py", line 593, in Main
    GenerateVfrBinSec(CommandOptions.ModuleName, CommandOptions.DebugDir, CommandOptions.OutputFile)
  File "/root/edk2/edk2-edk2-stable202002/BaseTools/BinWrappers/PosixLike/../../Source/Python/Trim/Trim.py", line 449, in GenerateVfrBinSec
    VfrUniOffsetList = GetVariableOffset(MapFileName, EfiFileName, VfrNameList)
  File "/root/edk2/edk2-edk2-stable202002/BaseTools/Source/Python/Common/Misc.py", line 88, in GetVariableOffset
    return _parseForGCC(lines, efifilepath, varnames)
  File "/root/edk2/edk2-edk2-stable202002/BaseTools/Source/Python/Common/Misc.py", line 151, in _parseForGCC
    efisecs = PeImageClass(efifilepath).SectionHeaderList
  File "/root/edk2/edk2-edk2-stable202002/BaseTools/Source/Python/Common/Misc.py", line 1638, in __init__
    if ByteArray.tostring() != b'PE\0\0':
AttributeError: 'array.array' object has no attribute 'tostring'

Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
2020-08-14 02:21:18 +00:00
Cole Robinson 5d8648345c BaseTools: fix ucs-2 lookup on python 3.9
python3.9 changed/fixed codec.register behavior to always replace
hyphen with underscore for passed in codec names:

  https://bugs.python.org/issue37751

So the custom Ucs2Search needs to be adapted to handle 'ucs_2' in
addition to existing 'ucs-2' for back compat.

This fixes test failures on python3.9, example:

======================================================================
FAIL: testUtf16InUniFile (CheckUnicodeSourceFiles.Tests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/edk2-edk2-stable202002/BaseTools/Source/Python/AutoGen/UniClassObject.py", line 375, in PreProcess
    FileIn = UniFileClassObject.OpenUniFile(LongFilePath(File.Path))
  File "/builddir/build/BUILD/edk2-edk2-stable202002/BaseTools/Source/Python/AutoGen/UniClassObject.py", line 303, in OpenUniFile
    UniFileClassObject.VerifyUcs2Data(FileIn, FileName, Encoding)
  File "/builddir/build/BUILD/edk2-edk2-stable202002/BaseTools/Source/Python/AutoGen/UniClassObject.py", line 312, in VerifyUcs2Data
    Ucs2Info = codecs.lookup('ucs-2')
LookupError: unknown encoding: ucs-2

Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
2020-08-14 02:21:18 +00:00
Bob Feng 5dc2699d10 BaseTools: Move CreateAsBuiltInf into AutoGenWorker for parallel
AsBuiltInf can be created during AutoGen phase. Move CreateAsBuiltInf
into AutoGenWorker to make this step run in parallel.

Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
2020-08-14 01:43:32 +00:00
Pierre Gondois 313d2ec991 DynamicTablesPkg: Add SSDT Serial port for DBG2
The SSDT Serial port fixup library provides
interfaces to generate a SSDT Serial port table
based on the serial port information.

Update the DBG2 Generator to use the SSDT serial
port fixup library to build a serial port definition
block for the DBG2 serial port and install the
SSDT table.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois c76028a6ff DynamicTablesPkg: Add SSDT Serial port for SPCR
According to Arm Server Base Boot Requirements,
Platform Design Document version 1.2 revision D,
September 2, 2019, section '4.2.1.8 SPCR'; the
SPCR console device must be included in the DSDT.

The SSDT Serial port fixup library provides
interfaces to generate a SSDT Serial port table
based on the serial port information.

Update the SPCR Generator to use the SSDT serial
port fixup library to build a serial port definition
block corresponding to the SPCR serial port and
install the SSDT table.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois 5b035defa8 DynamicTablesPkg: SSDT Serial Port generator
Most platforms have several serial ports. These serial ports
are described to an operating system using definition block
tables.

The SSDT Serial Port Table Generator uses the Configuration
Manager protocol to obtain information for the Serial Ports
on the platform. The serial ports are described using the
CM_ARM_SERIAL_PORT_INFO structure. The EArmObjSerialPortInfo
ID is used to represent a standard serial port.

The SSDT Serial port fixup library provides interfaces to
generate a SSDT Serial port table based on the serial port
information. The SSDT Serial Port Table Generator uses the
SSDT serial port fixup library to build serial port
definition blocks and installs the SSDT tables.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois bade7f423b DynamicTablesPkg: SSDT Serial Port Fixup library
According to Arm Server Base Boot Requirements,
Platform Design Document version 1.2 revision D,
September 2, 2019, section '4.2.1.8 SPCR'; The
SPCR console device must be included in the DSDT.

Additionally, it is often desirable to describe the
serial ports available on a platform so that they
are available for use by a rich OS.

To facilitate the description of serial ports on a
platform a common SSDT Serial Port Fixup library is
introduced. It provides interfaces to build a SSDT
serial port definition block table based on the
serial port information.

The SSDT Serial Port Fixup library is used by the
SPCR, DBG2 and SSDT Serial Port generator to describe
the serial port information in a definition block.

  +------------+   +------------+   +------------+
  |  SPCR Gen  |   |  DBG2 Gen  |   | SERIAL Gen |
  +------------+   +------------+   +------------+
        +----------------------------------+
        |  SSDT Serial Port Fixup library  |
        +----------------------------------+

The SSDT Serial Port Fixup library:
  - Parses the SSDT Serial Port template using the
    AmlLib library to generate an AML tree.
  - Updates the _UID, _HID and _CID values.
  - Fixes up the Serial port base address, length
    and the interrupt number in the _CRS descriptor.
  - Fixes up the serial-port name.
  - Serialises the AML Tree to a buffer containing
    the definition block data.
  The definition block data is then installed by the
  corresponding table generator.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Sami Mujawar f2bd39fb60 DynamicTablesPkg: Add AsciiFromHex helper function
AsciiFromHex is a function converts a hex number to an
ASCII character. This function is used across multiple
generators, so add it to the TableHelperLib.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois 095db69d4c DynamicTablesPkg: Dynamic AML: Add AmlLib library
ACPI Definition blocks are implemented using AML which has
a complex grammar making run-time generation of definition
blocks difficult. Dynamic AML is a feature of Dynamic Tables
framework that provides a solution for dynamic generation of
ACPI Definition block tables.

Since, AML bytecode represents complex AML grammar, an AmlLib
library is introduced to assist parsing and traversing of the
AML bytecode at run-time.

The AmlLib library parses a definition block and represents it
as an AML tree. The AML objects, methods and data are represented
as tree nodes. Since the AML data is represented as tree nodes,
it is possible to traverse the tree, locate a node and modify the
node data. The tree can then be serialized to a buffer (that
represents the definition block). This definition block containing
the fixed-up AML code can then be installed as an ACPI Definition
Block table.

Dynamic AML introduces the following techniques:
* AML Fixup
* AML Codegen
* AML Fixup + Codegen

AML Fixup is a technique that involves compiling an ASL template
file to generate AML bytecode. This template AML bytecode can be
parsed at run-time and a fixup code can update the required fields
in the AML template.

AML Codegen employs generating small segments of AML code.

AmlLib provides a rich set of APIs to operate on AML data for AML
Fixup and Codegen.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois c85ac5245c DynamicTablesPkg: AmlLib APIs
AmlLib library implements an AML parser, AML tree interface,
serialiser, code generator and other interfaces to generate
Definition Block tables.

The AmlLib APIs are a collection of interfaces that enable
parsing, iterating, modifying, adding, and serialising AML
data to generate a Definition Block table.

The AmlLib APIs are declared in Include\AmlLib\AmlLib.h

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois 3196253710 DynamicTablesPkg: AML Core interface
AML Core interface APIs are internal APIs of the
AmlLib library. These APIs can be used to:
 - Create/Delete/Clone an AML tree/node
 - Get/update Fixed and Variable arguments
 - Serialize an AML tree.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois 01ea2ad59c DynamicTablesPkg: AML Resource Data Codegen
AML Codegen is a Dynamic AML technique that facilitates
generation of small segments of AML code. The AML code
generated using AML Codegen is represented as nodes in
the AML Tree.

AML Resource Data Codegen implements interfaces required
for generating Resource Data elements that can be attached
to an AML tree.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00
Pierre Gondois 3a68156778 DynamicTablesPkg: AML Codegen
AML Codegen is a Dynamic AML technique that facilitates
generation of small segments of AML code. The AML code
generated using AML Codegen is represented as nodes in
the AML Tree.

Some examples where AML Codegen can be used are:
 - AML Codegen APIs can be used to generate a simple
   AML tree.
 - An AML template can be parsed to create an AML
   tree. This AML Tree can be searched to locate a
   node that needs updating. The AML Codegen APIs
   can be used to attach new AML nodes.
 - A combination of AML Fixup and AML Codegen can
   be used to generate an AML tree.

   The AML tree can then be serialised as a Definition
   Block table.

Following AML Codegen APIs are implemented:
 - AmlCodeGenDefinitionBlock()
 - AmlCodeGenScope()
 - AmlCodeGenNameString()
 - AmlCodeGenNameInteger()
 - AmlCodeGenDevice()

These AML Codegen APIs in combination with AML Resource
Data Codegen APIs can be used to generate a simple AML
tree.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-13 18:00:06 +00:00