Commit Graph

604 Commits

Author SHA1 Message Date
Min M Xu 70d1481b55 OvmfPkg/PeilessStartupLib: Find NCCFV in non-td guest
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4152

As described in BZ#4152, NCCFV includes the DXE phase drivers for non-cc
guest. PeilessStartupLib is updated to find NCCFV for non-cc guest.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2023-01-18 03:04:27 +00:00
Gerd Hoffmann 015a001b03 OvmfPkg/PlatformInitLib: reorder PlatformQemuUc32BaseInitialization
First handle the cases which do not need know the value of
PlatformInfoHob->LowMemory (microvm and cloudhv).  Then call
PlatformGetSystemMemorySizeBelow4gb() to get LowMemory.  Finally handle
the cases (q35 and pc) which need to look at LowMemory,

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2023-01-17 16:36:59 +00:00
Gerd Hoffmann c0a0b9bc35 OvmfPkg/PlatformInitLib: Add PlatformReservationConflictCB
Add PlatformReservationConflictCB() callback function for use with
PlatformScanE820().  It checks whenever the 64bit PCI MMIO window
overlaps with a reservation from qemu.  If so move down the MMIO window
to resolve the conflict.

Write any actions done (moving mmio window) to the firmware log with
INFO loglevel.

This happens on (virtual) AMD machines with 1TB address space,
because the AMD IOMMU uses an address window just below 1TB.

Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=4251
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2023-01-17 16:36:59 +00:00
Gerd Hoffmann 328076cfdf OvmfPkg/PlatformInitLib: Add PlatformAddHobCB
Add PlatformAddHobCB() callback function for use with
PlatformScanE820().  It adds HOBs for high memory and reservations (low
memory is handled elsewhere because there are some special cases to
consider).  This replaces calls to PlatformScanOrAdd64BitE820Ram() with
AddHighHobs = TRUE.

Write any actions done (adding HOBs, skip unknown types) to the firmware
log with INFO loglevel.

Also remove PlatformScanOrAdd64BitE820Ram() which is not used any more.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2023-01-17 16:36:59 +00:00
Gerd Hoffmann 124b765051 OvmfPkg/PlatformInitLib: Add PlatformGetLowMemoryCB
Add PlatformGetLowMemoryCB() callback function for use with
PlatformScanE820().  It stores the low memory size in
PlatformInfoHob->LowMemory.  This replaces calls to
PlatformScanOrAdd64BitE820Ram() with non-NULL LowMemory.

Write any actions done (setting LowMemory) to the firmware log
with INFO loglevel.

Also change PlatformGetSystemMemorySizeBelow4gb() to likewise set
PlatformInfoHob->LowMemory instead of returning the value.  Update
all Callers to the new convention.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2023-01-17 16:36:59 +00:00
Gerd Hoffmann e037530468 OvmfPkg/PlatformInitLib: Add PlatformScanE820 and GetFirstNonAddressCB
First step replacing the PlatformScanOrAdd64BitE820Ram() function.

Add a PlatformScanE820() function which loops over the e280 entries
from FwCfg and calls a callback for each of them.

Add a GetFirstNonAddressCB() function which will store the first free
address (right after the last RAM block) in
PlatformInfoHob->FirstNonAddress.  This replaces calls to
PlatformScanOrAdd64BitE820Ram() with non-NULL MaxAddress.

Write any actions done (setting FirstNonAddress) to the firmware log
with INFO loglevel.

Also drop local FirstNonAddress variables and use
PlatformInfoHob->FirstNonAddress instead everywhere.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2023-01-17 16:36:59 +00:00
Sophia Wolf 59aa48bb7d OvmfPkg: Realize EfiMemoryAcceptProtocol in AmdSevDxe
When a guest OS does not support unaccepted memory, the unaccepted
memory must be accepted before returning a memory map to the caller.

EfiMemoryAcceptProtocol is defined in MdePkg and is implemented /
Installed in AmdSevDxe for AMD SEV-SNP memory acceptance.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
Message-Id: <20221108164616.3251967-2-dionnaglaze@google.com>
2023-01-12 16:03:30 +00:00
Laszlo Ersek 85fd05ab97 OvmfPkg/PlatformInitLib: fix comment about uncacheable MTRRs
In commit 49edde1523 ("OvmfPkg/PlatformPei: set 32-bit UC area at
PciBase / PciExBarBase (pc/q35)", 2019-06-03), I forgot to update the
comment. Do it now.

Fixes: 49edde1523
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-12 10:37:16 +00:00
Laszlo Ersek 9ce09870e7 OvmfPkg/SmmCpuFeaturesLib: drop obsolete API implementation
Commit 0426115b67 ("UefiCpuPkg: Remove unused API in
SmmCpuFeaturesLib.h", 2022-12-21) removed the declaration of the function
SmmCpuFeaturesAllocatePageTableMemory() from the "SmmCpuFeaturesLib.h"
library class header.

Remove the API's (null-)implementation from OvmfPkg/SmmCpuFeaturesLib as
well.

Testing: OVMF builds, boots, and suspends/resumes (see earlier in this
series).

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Bugzilla: https://bugzilla.tianocore.org/show_bug.cgi?id=4235
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2023-01-04 09:45:06 +00:00
Michael Brown a24fbd6061 OvmfPkg: Add library to handle TPL from within nested interrupt handlers
UEFI requires us to support nested interrupts, but provides no way for
an interrupt handler to call RestoreTPL() without implicitly
re-enabling interrupts.  In a virtual machine, it is possible for a
large burst of interrupts to arrive.  We must prevent such a burst
from leading to stack underrun, while continuing to allow nested
interrupts to occur.

This can be achieved by allowing, when provably safe to do so, an
inner interrupt handler to return from the interrupt without restoring
the TPL and with interrupts remaining disabled after IRET, with the
deferred call to RestoreTPL() then being issued from the outer
interrupt handler.  This is necessarily messy and involves direct
manipulation of the interrupt stack frame, and so should not be
implemented as open-coded logic within each interrupt handler.

Add the Nested Interrupt TPL Library (NestedInterruptTplLib) to
provide helper functions that can be used by nested interrupt handlers
in place of RaiseTPL()/RestoreTPL().

Example call tree for a timer interrupt occurring at TPL_APPLICATION
with a nested timer interrupt that makes its own call to RestoreTPL():

  outer TimerInterruptHandler()
    InterruptedTPL == TPL_APPLICATION
    ...
    IsrState->InProgressRestoreTPL = TPL_APPLICATION;
    gBS->RestoreTPL (TPL_APPLICATION);
      EnableInterrupts();
      dispatch a TPL_CALLBACK event
        gEfiCurrentTpl = TPL_CALLBACK;
        nested timer interrupt occurs
        inner TimerInterruptHandler()
          InterruptedTPL == TPL_CALLBACK
          ...
          IsrState->InProgressRestoreTPL = TPL_CALLBACK;
          gBS->RestoreTPL (TPL_CALLBACK);
            EnableInterrupts();
          DisableInterrupts();
          IsrState->InProgressRestoreTPL = TPL_APPLICATION;
          IRET re-enables interrupts
      ... finish dispatching TPL_CALLBACK events ...
      gEfiCurrentTpl = TPL_APPLICATION;
    DisableInterrupts();
    IsrState->InProgressRestoreTPL = 0;
    sees IsrState->DeferredRestoreTPL == FALSE and returns
    IRET re-enables interrupts

Example call tree for a timer interrupt occurring at TPL_APPLICATION
with a nested timer interrupt that defers its call to RestoreTPL() to
the outer instance of the interrupt handler:

  outer TimerInterruptHandler()
    InterruptedTPL == TPL_APPLICATION
    ...
    IsrState->InProgressRestoreTPL = TPL_APPLICATION;
    gBS->RestoreTPL (TPL_APPLICATION);
      EnableInterrupts();
      dispatch a TPL_CALLBACK event
      ... finish dispatching TPL_CALLBACK events ...
      gEfiCurrentTpl = TPL_APPLICATION;
      nested timer interrupt occurs
      inner TimerInterruptHandler()
        InterruptedTPL == TPL_APPLICATION;
        ...
        sees InterruptedTPL == IsrState->InProgressRestoreTPL
        IsrState->DeferredRestoreTPL = TRUE;
        DisableInterruptsOnIret();
        IRET returns without re-enabling interrupts
    DisableInterrupts();
    IsrState->InProgressRestoreTPL = 0;
    sees IsrState->DeferredRestoreTPL == TRUE and loops
    IsrState->InProgressRestoreTPL = TPL_APPLICATION;
    gBS->RestoreTPL (TPL_APPLICATION);  <-- deferred call
      EnableInterrupts();
    DisableInterrupts();
    IsrState->InProgressRestoreTPL = 0;
    sees IsrState->DeferredRestoreTPL == FALSE and returns
    IRET re-enables interrupts

Cc: Paolo Bonzini <pbonzini@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4162
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2022-12-23 14:44:48 +00:00
Gerd Hoffmann bf65d7ee88 OvmfPkg/PlatformInitLib: pass through reservations from qemu
qemu uses the etc/e820 fw_cfg file not only for memory, but
also for reservations.  Handle reservations by adding resource
descriptor hobs for them.

A typical qemu configuration has a small reservation between
lapic and flash:

  # sudo cat /proc/iomem
  [ ... ]
  fee00000-fee00fff : Local APIC
  feffc000-feffffff : Reserved          <= HERE
  ffc00000-ffffffff : Reserved
  [ ... ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2022-12-23 11:53:40 +00:00
Min M Xu 451521ccbc OvmfPkg/PlatformInitLib: Implement multi-core accept memory for TDVF
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4172

TDVF once accepts memory only by BSP. To improve the boot performance
this patch introduce the multi-core accpet memory. Multi-core means
BSP and APs work together to accept memory.

TDVF leverages mailbox to wake up APs. It is not enabled in MpInitLib
(Which requires SIPI). So multi-core accept memory cannot leverages
MpInitLib to coordinate BSP and APs to work together.

So TDVF split the accept memory into 2 phases.
- AcceptMemoryForAPsStack:
  BSP accepts a small piece of memory which is then used by APs to setup
  stack. We assign a 16KB stack for each AP. So a td-guest with 256 vCPU
  requires 255*16KB = 4080KB.
- AcceptMemory:
  After above small piece of memory is accepted, BSP commands APs to
  accept memory by sending AcceptPages command in td-mailbox. Together
  with the command and accpet-function, the APsStack address is send
  as well. APs then set the stack and jump to accept-function to accept
  memory.

AcceptMemoryForAPsStack accepts as small memory as possible and then jump
to AcceptMemory. It fully takes advantage of BSP/APs to work together.
After accept memory is done, the memory region for APsStack is not used
anymore. It can be used as other private memory. Because accept-memory
is in the very beginning of boot process and it will not impact other
phases.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-21 07:06:17 +00:00
Min M Xu b21fe5a8a6 OvmfPkg/TdxMailboxLib: Add NULL instance of TdxMailboxLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4172

TdxMailboxLib is designed only for TDX guest which arch is X64. This
patch set the VALID_ARCHITECTURES of TdxMailboxLib as X64.

Because in the following patches TdxMailboxLib will be included in
PlatformInitLib. While PlatformInitLib is imported by some X64 platforms
(for example AmdSevX64.dsc). So we need a NULL instance of TdxMailboxLib
which VALID_ARCHITECTURES is X64 as well. Based on this consideration
we design TdxMailboxLibNull.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-21 07:06:17 +00:00
Min M Xu a00b71b009 OvmfPkg/TdxMailboxLib: Delete global variables
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4172

TdxMailboxLib once was designed to be used in DXE phase. But now it is
going to be used in SEC/PEI phase (in the following patches). Global
variables are not allowed. The library is refactored after those global
variables are deleted.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-21 07:06:17 +00:00
Chun-Yi Lee ceb52713b0 OvmfPkg/PlatformInitLib: Fix integrity checking failed of NvVarStore
In the commit 4f173db8b4 "OvmfPkg/PlatformInitLib: Add functions for
EmuVariableNvStore", it introduced a PlatformValidateNvVarStore() function
for checking the integrity of NvVarStore.

In some cases when the VariableHeader->StartId is VARIABLE_DATA, the
VariableHeader->State is not just one of the four primary states:
VAR_IN_DELETED_TRANSITION, VAR_DELETED, VAR_HEADER_VALID_ONLY, VAR_ADDED.
The state may combined two or three states, e.g.

    0x3C = (VAR_IN_DELETED_TRANSITION & VAR_ADDED) & VAR_DELETED
or
    0x3D = VAR_ADDED & VAR_DELETED

When the variable store has those variables, system booting/rebooting will
hangs in a ASSERT:

NvVarStore Variable header State was invalid.
ASSERT
/mnt/working/source_code-git/edk2/OvmfPkg/Library/PlatformInitLib/Platform.c(819):
((BOOLEAN)(0==1))

Adding more log to UpdateVariable() and PlatformValidateNvVarStore(), we
saw some variables which have 0x3C or 0x3D state in store.
e.g.

UpdateVariable(), VariableName=BootOrder
L1871, State=0000003F        <-- VAR_ADDED
State &= VAR_DELETED=0000003D
FlushHobVariableToFlash(), VariableName=BootOrder
...
UpdateVariable(), VariableName=InitialAttemptOrder
L1977, State=0000003F
State &= VAR_IN_DELETED_TRANSITION=0000003E
L2376, State=0000003E
State &= VAR_DELETED=0000003C
FlushHobVariableToFlash(), VariableName=InitialAttemptOrder
...
UpdateVariable(), VariableName=ConIn
L1977, State=0000003F
State &= VAR_IN_DELETED_TRANSITION=0000003E
L2376, State=0000003E
State &= VAR_DELETED=0000003C
FlushHobVariableToFlash(), VariableName=ConIn
...

So, only allowing the four primary states is not enough. This patch changes
the falid states list (Follow Jiewen Yao's suggestion):

1. VAR_HEADER_VALID_ONLY (0x7F)
    - Header added (*)
2. VAR_ADDED (0x3F)
    - Header + data added
3. VAR_ADDED & VAR_IN_DELETED_TRANSITION (0x3E)
    - marked as deleted, but still valid, before new data is added. (*)
4. VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED (0x3C)
    - deleted, after new data is added.
5. VAR_ADDED & VAR_DELETED (0x3D)
    - deleted directly, without new data.
(*) means to support surprise shutdown.

And removed (VAR_IN_DELETED_TRANSITION) and (VAR_DELETED) because they are
invalid states.

v2:
Follow Jiewen Yao's suggestion to add the following valid states:
    VAR_ADDED & VAR_DELETED (0x3D)
    VAR_ADDED & VAR_IN_DELETED_TRANSITION (0x3E)
    VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED (0x3C)
and removed the following invalid states:
    VAR_IN_DELETED_TRANSITION
    VAR_DELETED

Signed-off-by: Chun-Yi Lee <jlee@suse.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-20 05:11:57 +00:00
Sebastien Boeuf 57162cb62d OvmfPkg/PlatformInitLib: Transfer GUID Extension HOB
This is required for passing the ACPI tables from the VMM up to the
guest OS. They are transferred through this GUID extension.

Signed-off-by: Jiaqi Gao <jiaqi.gao@intel.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Reviewed-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-16 02:37:56 +00:00
Sebastien Boeuf e03b0d0672 OvmfPkg/PlatformInitLib: Differentiate TDX case for Cloud Hypervisor
Rely on the CcProbe() function to identify when running on TDX. This
allows the firmware to follow a different codepath for Cloud Hypervisor,
which means it doesn't rely on PVH to find out about memory below 4GiB.
instead it falls back onto the CMOS to retrieve that information.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Reviewed-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-16 02:37:56 +00:00
Gerd Hoffmann cda98df162 OvmfPkg/QemuFwCfgLib: remove mQemuFwCfgSupported + mQemuFwCfgDmaSupported
Remove global variables, store the state in PlatformInfoHob instead.
Probing for fw_cfg happens on first use, at library initialization
time the Hob might not be present yet.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-14 17:45:41 +00:00
Gerd Hoffmann 81bbc1452c OvmfPkg/QemuFwCfgLib: rewrite fw_cfg probe
Move the code to a new QemuFwCfgProbe() function.  Use direct Io*() calls
instead of indirect QemuFwCfg*() calls to make sure we don't get
recursive calls.  Also simplify CC guest detection.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-14 17:45:41 +00:00
Gerd Hoffmann e59747bd82 OvmfPkg/DebugLibIoPort: use Rom version for PEI
This variant does not use global variables.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-14 17:45:41 +00:00
Ryan Afranji 127e2c5315 OvmfPkg: Add INVD case in #VE handler
According to the Intel GHCI specification document section 2.4.1, the
goal for instructions that do not have a corresponding TDCALL is for the
handler to treat the instruction as a NOP.

INVD does not have a corresponding TDCALL. This patch makes the #VE
handler treat INVD as a NOP.

Signed-off-by: Ryan Afranji <afranji@google.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-09 07:08:50 +00:00
Min M Xu 47d988387e OvmfPkg/PlatformInitLib: Add check to NvVarStoreFV HeaderLength
There should be a check that the FV HeaderLength cannot be an odd
number. Otherwise in the following CalculateSum16 there would be an
ASSERT.

In ValidateFvHeader@QemuFlashFvbServicesRuntimeDxe/FwBlockServices.c
there a is similar check to the FwVolHeader->HeaderLength.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-12-02 01:06:01 +00:00
Min M Xu 765ba5bf05 OvmfPkg/UefiCpuPkg: Add CcExit prefix to the APIs of CcExitLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4123

APIs which are defined in CcExitLib.h are added with the CcExit prefix.
This is to make the APIs' name more meaningful.

This change impacts OvmfPkg/UefiCpuPkg.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
2022-11-14 04:55:34 +00:00
Min M Xu a89f558d3c OvmfPkg/UefiCpuPkg/UefiPayloadPkg: Rename VmgExitLib to CcExitLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4123

VmgExitLib once was designed to provide interfaces to support #VC handler
and issue VMGEXIT instruction. After TDVF (enable TDX feature in OVMF) is
introduced, this library is updated to support #VE as well. Now the name
of VmgExitLib cannot reflect what the lib does.

This patch renames VmgExitLib to CcExitLib (Cc means Confidential
Computing). This is a simple renaming and there is no logic changes.
After renaming all the VmgExitLib related codes are updated with
CcExitLib. These changes are in OvmfPkg/UefiCpuPkg/UefiPayloadPkg.

Cc: Guo Dong <guo.dong@intel.com>
Cc: Sean Rhodes <sean@starlabs.systems>
Cc: James Lu <james.lu@intel.com>
Cc: Gua Guo <gua.guo@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: James Lu <james.lu@intel.com>
Reviewed-by: Gua Guo <gua.guo@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
2022-11-14 04:55:34 +00:00
Min M Xu eff44c008d OvmfPkg/VmgExitLig: HALT on #VE when access to private memory
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4125

EPT-violation #VE should be always on shared memory, which means the
shared bit of the GuestPA should be set. But in current #VE Handler
it is not checked. When it occurs, stop TD immediately and log out
the error.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Guorui Yu <ruogui.ygr@alibaba-inc.com>
Tested-by: Guorui Yu <ruogui.ygr@alibaba-inc.com>
2022-11-04 09:41:23 +00:00
Min M Xu 720c25ab41 OvmfPkg: Call gEdkiiMemoryAcceptProtocolGuid to accept pages
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3937

After EdkiiMemoryAcceptProtocol is implemented in TdxDxe driver, we can
call it to accept pages in DXE phase.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-11-01 10:08:10 +00:00
Min M Xu d1e41c620f OvmfPkg: Introduce lazy accept in PlatformInitLib and PlatformPei
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3937

There are below major changes in PlatformInitLib/PlatformPei
1. ProcessHobList
  The unaccepted memory is accepted if it is under 4G address.
  Please be noted: in current stage, we only accept the memory under 4G.
  We will re-visit here in the future when on-demand accept memory is
  required.

2. TransferTdxHobList
  Transfer the unaccepted memory hob to EFI_RESOURCE_SYSTEM_MEMORY hob
  if it is accepted.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-11-01 10:08:10 +00:00
Min M Xu 9b648112a5 OvmfPkg: Use BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED defined in MdeModulePkg
RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3937

BZ3937_EFI_RESOURCE_MEMORY_UNACCEPTED is defined in MdeModulePkg. The
files which use the definition are updated as well.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-11-01 10:08:10 +00:00
Gerd Hoffmann 406ad0582a OvmfPkg: rename QemuBootOrderNNNN to VMMBootOrderNNNN
While the actual implementation (using qemu fw_cfg) is qemu-specific,
the idea to store the boot order as configured by the VMM in EFI
variables is not.  So lets give the variables a more neutral name while
we still can (i.e. no stable tag yet with the new feature).

While being at it also fix the NNNN format (use %x instead of %d for
consistency with BootNNNN).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-10-07 18:14:05 +00:00
Gerd Hoffmann ecb778d0ac OvmfPkg/PlatformInitLib: dynamic mmio window size
In case we have a reliable PhysMemAddressWidth use that to dynamically
size the 64bit address window.  Allocate 1/8 of the physical address
space and place the window at the upper end of the address space.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-10-07 18:14:05 +00:00
Gerd Hoffmann bbda386d25 OvmfPkg/PlatformInitLib: detect physical address space
Try detect physical address space, when successful use it.
Otherwise go continue using the current guesswork code path.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-10-07 18:14:05 +00:00
Gerd Hoffmann 8f9ef9c9a0 OvmfPkg/PlatformInitLib: qemu cpuid physbits detection
Add some qemu specific quirks to PlatformAddressWidthFromCpuid()
to figure whenever the PhysBits value returned by CPUID is
something real we can work with or not.

See the source code comment for details on the logic.

Also apply some limits to the address space we are going to use:
 * Place a hard cap at 47 PhysBits (128 TB) to avoid using addresses
   which require 5-level paging support.
 * Cap at 40 PhysBits (1 TB) in case the CPU has no support for
   gigabyte pages, to avoid excessive amounts of pages being
   used for page tables.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-10-07 18:14:05 +00:00
Gerd Hoffmann b7213bbd59 OvmfPkg/QemuBootOrderLib: skip unsupported entries in StoreQemuBootOrder
When finding an unsupported entry just skip over and continue
with the next entry instead of stop processing altogether.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-28 10:46:29 +00:00
Gerd Hoffmann d63242bd69 OvmfPkg/QemuBootOrderLib: allow slash in rom filenames
See comment for details.  Needed to avoid the parser abort,
so we can continue parsing the bootorder fw_cfg file.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-28 10:46:29 +00:00
Gerd Hoffmann 2a0bd3bffc OvmfPkg/PlatformInitLib: q35 mtrr setup fix
Traditional q35 memory layout is 2.75 GB of low memory, leaving room
for the pcie mmconfig at 0xb0000000 and the 32-bit pci mmio window at
0xc0000000.  Because of that OVMF tags the memory range above
0xb0000000 as uncachable via mtrr.

A while ago qemu started to gigabyte-align memory by default (to make
huge pages more effective) and q35 uses only 2G of low memory in that
case.  Which effectively makes the 32-bit pci mmio window start at
0x80000000.

This patch updates the mtrr setup code accordingly.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-28 10:46:29 +00:00
Min M Xu f4d539007c OvmfPkg/PeilessStartupLib: move mPageTablePool to stack
PeilessStartupLib is running in SEC phase. In this phase global variable
is not allowed to be modified. This patch moves mPageTablePool to stack
and pass it as input parameter between functions.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-28 00:31:16 +00:00
Ard Biesheuvel 477b5b7d55 OvmfPkg: Introduce alternate UefiDriverEntrypoint to inhibit driver load
Add a new library that can be incorporated into any driver built from
source, and which permits loading of the driver to be inhibited based on
the value of a QEMU fw_cfg boolean variable. This will be used in a
subsequent patch to allow dispatch of the IPv4 and IPv6 network protocol
driver to be controlled from the QEMU command line.

This approach is based on the notion that all UEFI and DXE drivers share
a single UefiDriverEntryPoint implementation, which we can easily swap
out at build time with one that will abort execution based on the value
of some QEMU fw_cfg variable.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
2022-09-10 08:23:27 +00:00
Gerd Hoffmann 5eeb088ad6 OvmfPkg/QemuBootOrderLib: add StoreQemuBootOrder()
The function reads the boot order from qemu fw_cfg, translates it into
device paths and stores them in 'QemuBootOrderNNNN' variables.  In case
there is no boot ordering configured the function will do nothing.

Use case: Allow applications loaded via 'qemu -kernel bootloader.efi'
obey the boot order.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
2022-09-06 16:55:33 +00:00
Min M Xu 70165fa6e2 OvmfPkg/NvVarsFileLib: Shortcut ConnectNvVarsToFileSystem in secure-boot
OvmfPkg/Library/NvVarsFileLib allows loading variables into emulated
varstore from a on-disk NvVars file.  We can't allow that when secure
boot is active.  So check secure-boot feature and shortcut the
ConnectNvVarsToFileSystem() function when sb is enabled.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Suggested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-06 07:21:42 +00:00
Min M Xu ee91d9ef24 OvmfPkg: Reserve and init EmuVariableNvStore in Pei-less Startup
EmuVariableNvStore is reserved and init with below 2 functions defined in
PlatformInitLib:
 - PlatformReserveEmuVariableNvStore
 - PlatformInitEmuVariableNvStore

PlatformInitEmuVariableNvStore works when secure boot feature is enabled.
This is because secure boot needs the EFI variables (PK/KEK/DB/DBX, etc)
and EmuVariableNvStore is cleared when OVMF is launched with -bios
parameter.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-06 07:21:42 +00:00
Min M Xu 4f173db8b4 OvmfPkg/PlatformInitLib: Add functions for EmuVariableNvStore
There are 3 functions added for EmuVariableNvStore:
 - PlatformReserveEmuVariableNvStore
 - PlatformInitEmuVariableNvStore
 - PlatformValidateNvVarStore

PlatformReserveEmuVariableNvStore allocate storage for NV variables early
on so it will be at a consistent address.

PlatformInitEmuVariableNvStore copies the content in
PcdOvmfFlashNvStorageVariableBase to the storage allocated by
PlatformReserveEmuVariableNvStore. This is used in the case that OVMF is
launched with -bios parameter. Because in that situation UEFI variables
will be partially emulated, and non-volatile variables may lose their
contents after a reboot. This makes the secure boot feature not working.

PlatformValidateNvVarStore is renamed from TdxValidateCfv and it is used
to validate the integrity of FlashNvVarStore
(PcdOvmfFlashNvStorageVariableBase). It should be called before
PlatformInitEmuVariableNvStore is called to copy over the content.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-06 07:21:42 +00:00
Min M Xu 0e72e8762a OvmfPkg/PeilessStartupLib: Delete TdxValidateCfv
TdxValidateCfv is used to validate the integrity of FlashNvVarStore
(PcdOvmfFlashNvStorageVariableBase) and it is not Tdx specific.
So it will be moved to PlatformInitLib and be renamed to
PlatformValidateNvVarStore in the following patch. And it will be called
before EmuVaribleNvStore is initialized with the content in
FlashNvVarStore.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-06 07:21:42 +00:00
Min M Xu 1b1c58ab32 OvmfPkg: Update CcProbeLib to DxeCcProbeLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3974

CcProbeLib once was designed to probe the Confidential Computing guest
type by checking the PcdOvmfWorkArea. But this memory is allocated with
either EfiACPIMemoryNVS or EfiBootServicesData. It cannot be accessed
after ExitBootService. Please see the detailed analysis in BZ#3974.

To fix this issue, CcProbeLib is redesigned as 2 implementation:
 - SecPeiCcProbeLib
 - DxeCcProbeLib

In SecPeiCcProbeLib we check the CC guest type by reading the
PcdOvmfWorkArea. Because it is used in SEC / PEI and we don't worry about
the issues in BZ#3974.

In DxeCcProbeLib we cache the GuestType in Ovmf work area in a variable.
After that the Guest type is returned with the cached value. So that we
don't need to worry about the access to Ovmf work area after
ExitBootService.

The reason why we probe CC guest type in 2 different ways is the global
varialbe. Global variable cannot be used in SEC/PEI and CcProbe is called
very frequently.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-06 06:03:45 +00:00
Min M Xu c4bc1a9498 OvmfPkg: Add SecPeiCcProbeLib
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3974

SecPeiCcProbeLib is designed to probe the Confidential Computing guest
type in SEC/PEI phase. The CC guest type was set by each CC guest at
the beginning of boot up and saved in PcdOvmfWorkArea.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
2022-09-06 06:03:45 +00:00
Laszlo Ersek b5d1dc94d0 OvmfPkg: increase max debug message length to 512
Increase the maximum line length for debug messages.
While log messages should be short, they can still
get quite long, for example when printing device paths
or config strings in HII routing.
512 chars is an empirically good value.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
2022-09-05 13:52:51 +00:00
Pierre Gondois e87ac5ef49 OvmfPkg: Remove duplicated words
In an effort to clean the documentation of the above
package, remove duplicated words.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
2022-09-05 13:52:51 +00:00
Anthony PERARD 0e7add1d75 OvmfPkg/XenHypercallLib: Fix naming of AArch64
Fix path to follow naming convention of "AArch64", and allow the path
in "Maintainers.txt" to work as expected.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3982
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
2022-07-28 01:22:13 +00:00
Nicolas Ojeda Leon 3f5b1b9132 OvmfPkg/PciHostBridgeUtilityLib: Initialize RootBridges apertures with spec
Consume the host-provided specification of PCI host bridges if
available. Using the DxeHardwareInfoLib, populate a list of
hardware descriptors based on the content of the "hardware-info"
fw-cfg file, if provided. In the affirmative case, use the
resources and attributes specified by the hypervisor for each
Host Bridge to create the RootBridge elements.

In Ovmf platforms, the host can provide the specification of
non-discoverable hardware resources like PCI host bridges. If the
proper fw-cfg file is found, parse the contents provided by the
host into a linked list by using the Hardware Info library. Then,
using the list of PCI host bridges' descriptions, populate the
PCI_ROOT_BRIDGES array with the resources and attributes specified
by the host. If the file is not provided or no Host Bridge is found
in it, fold back to the legacy method based on pre-defined
apertures and rules.

In some use cases, the host requires additional control over the
hardware resources' configurations in the guest for performance and
discoverability reasons. For instance, to disclose information about
the PCI hierarchy to the guest so that this can profit from
optimized accesses. In this case, the host can decide to describe
multiple PCI Host Bridges and provide a specific set of resources
(e.g. MMIO apertures) so that the guest uses the values provided.
Using the provided values may entitle the guest to added performance,
for example by using specific MMIO mappings that can enable peer-to-peer
communication across the PCI hierarchy or by allocating memory closer
to a device for faster DMA transactions.

Cc: Alexander Graf <graf@amazon.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com>
2022-06-22 15:34:16 +00:00
Nicolas Ojeda Leon 3497fd5c26 Ovmf/PlatformPei: Use host-provided GPA end if available
Read the "hardware-info" item from fw-cfg to extract specifications
of PCI host bridges and analyze the 64-bit apertures of them to
find out the highest 64-bit MMIO address required which determines
the address space required by the guest, and, consequently, the
FirstNonAddress used to calculate size of physical addresses.

Using the static PeiHardwareInfoLib, read the fw-cfg file of
hardware information to extract, one by one, all the host
bridges. Find the last 64-bit MMIO address of each host bridge,
using the HardwareInfoPciHostBridgeLib API, and compare it to an
accumulate value to discover the highest address used, which
corresponds to the highest value that must be included in the
guest's physical address space.

Given that platforms with multiple host bridges may provide the PCI
apertures' addresses, the memory detection logic must take into
account that, if the host provided the MMIO windows that can and must
be used, the guest needs to take those values. Therefore, if the
MMIO windows are found in the host-provided fw-cfg file, skip all the
logic calculating the physical address size and just use the value
provided. Since each PCI host bridge corresponds to an element in
the information provided by the host, each of these must be analyzed
looking for the highest address used.

Cc: Alexander Graf <graf@amazon.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com>
2022-06-22 15:34:16 +00:00
Nicolas Ojeda Leon a1bd79c514 Ovmf/HardwareInfoLib: Add Dxe lib to dynamically parse heterogenous data
Following the Hardware Info library, create the DxeHardwareInfoLib
which implements the whole API capable of parsing heterogeneous hardware
information. The list-like API grants callers a flexible and common
pattern to retrieve the data. Moreover, the initial source is a BLOB
which generalizes the host-to-guest transmission mechanism.

The Hardware Info library main objective is to provide a way to
describe non-discoverable hardware so that the host can share the
available resources with the guest in Ovmf platforms. This change
features and embraces the main idea behind the library by providing
an API that parses a BLOB into a linked list to retrieve hardware
data from any source. Additionally, list-like APIs are provided so
that the hardware info list can be traversed conveniently.
Similarly, the capability is provided to filter results by specific
hardware types. However, heterogeneous elements can be added to the
list, increasing the flexibility. This way, a single source, for
example a fw-cfg file, can be used to describe several instances of
multiple types of hardware.

This part of the Hardware Info library makes use of dynamic memory
and is intended for stages in which memory services are available.
A motivation example is the PciHostBridgeLib. This library, part
of the PCI driver populates the list of PCI root bridges during DXE
stage for future steps to discover the resources under them. The
hardware info library can be used to obtain the detailed description
of available host bridges, for instance in the form of a fw-cfg file,
and parse that information into a dynmaic list that allows, first to
verify consistency of the data, and second discover the resources
availabe for each root bridge.

Cc: Alexander Graf <graf@amazon.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Nicolas Ojeda Leon <ncoleon@amazon.com>
2022-06-22 15:34:16 +00:00