OVMF's SecMain is unique in the sense that it links against the following
two libraries *in combination*:
- IntelFrameworkModulePkg/Library/LzmaCustomDecompressLib/
LzmaCustomDecompressLib.inf
- MdePkg/Library/BaseExtractGuidedSectionLib/
BaseExtractGuidedSectionLib.inf
The ExtractGuidedSectionLib library class allows decompressor modules to
register themselves (keyed by GUID) with it, and it allows clients to
decompress file sections with a registered decompressor module that
matches the section's GUID.
BaseExtractGuidedSectionLib is a library instance (of type BASE) for this
library class. It has no constructor function.
LzmaCustomDecompressLib is a compatible decompressor module (of type
BASE). Its section type GUID is
gLzmaCustomDecompressGuid == EE4E5898-3914-4259-9D6E-DC7BD79403CF
When OVMF's SecMain module starts, the LzmaCustomDecompressLib constructor
function is executed, which registers its LZMA decompressor with the above
GUID, by calling into BaseExtractGuidedSectionLib:
LzmaDecompressLibConstructor() [GuidedSectionExtraction.c]
ExtractGuidedSectionRegisterHandlers() [BaseExtractGuidedSectionLib.c]
GetExtractGuidedSectionHandlerInfo()
PcdGet64 (PcdGuidedExtractHandlerTableAddress) -- NOTE THIS
Later, during a normal (non-S3) boot, SecMain utilizes this decompressor
to get information about, and to decompress, sections of the OVMF firmware
image:
SecCoreStartupWithStack() [OvmfPkg/Sec/SecMain.c]
SecStartupPhase2()
FindAndReportEntryPoints()
FindPeiCoreImageBase()
DecompressMemFvs()
ExtractGuidedSectionGetInfo() [BaseExtractGuidedSectionLib.c]
ExtractGuidedSectionDecode() [BaseExtractGuidedSectionLib.c]
Notably, only the extraction depends on full-config-boot; the registration
of LzmaCustomDecompressLib occurs unconditionally in the SecMain EFI
binary, triggered by the library constructor function.
This is where the bug happens. BaseExtractGuidedSectionLib maintains the
table of GUIDed decompressors (section handlers) at a fixed memory
location; selected by PcdGuidedExtractHandlerTableAddress (declared in
MdePkg.dec). The default value of this PCD is 0x1000000 (16 MB).
This causes SecMain to corrupt guest OS memory during S3, leading to
random crashes. Compare the following two memory dumps, the first taken
right before suspending, the second taken right after resuming a RHEL-7
guest:
crash> rd -8 -p 1000000 0x50
1000000: c0 00 08 00 02 00 00 00 00 00 00 00 00 00 00 00 ................
1000010: d0 33 0c 00 00 c9 ff ff c0 10 00 01 00 88 ff ff .3..............
1000020: 0a 6d 57 32 0f 00 00 00 38 00 00 01 00 88 ff ff .mW2....8.......
1000030: 00 00 00 00 00 00 00 00 73 69 67 6e 61 6c 6d 6f ........signalmo
1000040: 64 75 6c 65 2e 73 6f 00 00 00 00 00 00 00 00 00 dule.so.........
vs.
crash> rd -8 -p 1000000 0x50
1000000: 45 47 53 49 01 00 00 00 20 00 00 01 00 00 00 00 EGSI.... .......
1000010: 20 01 00 01 00 00 00 00 a0 01 00 01 00 00 00 00 ...............
1000020: 98 58 4e ee 14 39 59 42 9d 6e dc 7b d7 94 03 cf .XN..9YB.n.{....
1000030: 00 00 00 00 00 00 00 00 73 69 67 6e 61 6c 6d 6f ........signalmo
1000040: 64 75 6c 65 2e 73 6f 00 00 00 00 00 00 00 00 00 dule.so.........
The "EGSI" signature corresponds to EXTRACT_HANDLER_INFO_SIGNATURE
declared in
MdePkg/Library/BaseExtractGuidedSectionLib/BaseExtractGuidedSectionLib.c.
Additionally, the gLzmaCustomDecompressGuid (quoted above) is visible at
guest-phys offset 0x1000020.
Fix the problem as follows:
- Carve out 4KB from the 36KB gap that we currently have between
PcdOvmfLockBoxStorageBase + PcdOvmfLockBoxStorageSize == 8220 KB
and
PcdOvmfSecPeiTempRamBase == 8256 KB.
- Point PcdGuidedExtractHandlerTableAddress to 8220 KB (0x00807000).
- Cover the area with an EfiACPIMemoryNVS type memalloc HOB, if S3 is
supported and we're not currently resuming.
The 4KB size that we pick is an upper estimate for
BaseExtractGuidedSectionLib's internal storage size. The latter is
calculated as follows (see GetExtractGuidedSectionHandlerInfo()):
sizeof(EXTRACT_GUIDED_SECTION_HANDLER_INFO) + // 32
PcdMaximumGuidedExtractHandler * (
sizeof(GUID) + // 16
sizeof(EXTRACT_GUIDED_SECTION_DECODE_HANDLER) + // 8
sizeof(EXTRACT_GUIDED_SECTION_GET_INFO_HANDLER) // 8
)
OVMF sets PcdMaximumGuidedExtractHandler to 16 decimal (which is the
MdePkg default too), yielding 32 + 16 * (16 + 8 + 8) == 544 bytes.
Regarding the lifecycle of the new area:
(a) when and how it is initialized after first boot of the VM
The library linked into SecMain finds that the area lacks the signature.
It initializes the signature, plus the rest of the structure. This is
independent of S3 support.
Consumption of the area is also limited to SEC (but consumption does
depend on full-config-boot).
(b) how it is protected from memory allocations during DXE
It is not, in the general case; and we don't need to. Nothing else links
against BaseExtractGuidedSectionLib; it's OK if DXE overwrites the area.
(c) how it is protected from the OS
When S3 is enabled, we cover it with AcpiNVS in InitializeRamRegions().
When S3 is not supported, the range is not protected.
(d) how it is accessed on the S3 resume path
Examined by the library linked into SecMain. Registrations update the
table in-place (based on GUID matches).
(e) how it is accessed on the warm reset path
If S3 is enabled, then the OS won't damage the table (due to (c)), hence
see (d).
If S3 is unsupported, then the OS may or may not overwrite the
signature. (It likely will.) This is identical to the pre-patch status.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15433 6f19259b-4bc3-4df7-8a09-765794883524
If (mBootMode == BOOT_ON_S3_RESUME) -- that is, we are resuming --, then
the patch has no observable effect.
If (mBootMode != BOOT_ON_S3_RESUME && mS3Supported) -- that is, we are
booting or rebooting, and S3 is supported), then the patch has no
observable effect either.
If (mBootMode != BOOT_ON_S3_RESUME && !mS3Supported) -- that is, we are
booting or rebooting, and S3 is unsupported), then the patch effects the
following two fixes:
- The LockBox storage is reserved from DXE (but not the OS). Drivers in
DXE may save data in the LockBox regardless of S3 support, potentially
corrupting any overlapping allocations. Make sure there's no overlap.
- The LockBox storage is cleared. A LockBox inherited across a non-resume
reboot, populated with well-known GUIDs, breaks drivers that want to
save entries with those GUIDs.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15418 6f19259b-4bc3-4df7-8a09-765794883524
The S3 suspend/resume infrastructure depends on the LockBox library class.
The edk2 tree currently contains Null and SMM instances. The Null instance
is useless, and the SMM instance would require SMM emulation by including
the SMM core and adding several new drivers, which is deemed too complex.
Hence add a simple LockBoxLib instance for OVMF.
jordan.l.justen@intel.com:
* use PCDs instead of EmuNvramLib
- clear memory in PlatformPei on non S3 boots
* allocate NVS memory and store a pointer to that memory
- reduces memory use at fixed locations
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15301 6f19259b-4bc3-4df7-8a09-765794883524
On X64, the reset vector code in
"OvmfPkg/ResetVector/Ia32/PageTables64.asm" identity maps the first 4GB of
RAM for PEI, consuming six frames starting at 8MB.
This range is declared by the PcdOvmfSecPageTablesBase/Size PCDs.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
[jordan.l.justen@intel.com: Move to MemDetect.c; use PCDs]
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15298 6f19259b-4bc3-4df7-8a09-765794883524
We will not be running DXE on S3 resume, so we don't
need to do these initialization items:
* Reserve EMU Variable memory range
* Declare Firmware volumes
* Add memory HOBs
v5:
* Move MiscInitialization back to running on S3 resume
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15295 6f19259b-4bc3-4df7-8a09-765794883524
This 32k section of RAM will be declared to the PEI Core on
S3 resume to allow memory allocations during S3 resume PEI.
If the boot mode is BOOT_ON_S3_RESUME, then we publish
the pre-reserved PcdS3AcpiReservedMemory range to PEI.
If the boot mode is not BOOT_ON_S3_RESUME, then we reserve
this range as ACPI NVS so the OS will not use it.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15294 6f19259b-4bc3-4df7-8a09-765794883524
This duplicate message was intended to be removed from r15207
before it was committed. (It was pointed out by Wei Liu.)
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15213 6f19259b-4bc3-4df7-8a09-765794883524
In the next commit we will update the Xen boot path
to also use this function.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15206 6f19259b-4bc3-4df7-8a09-765794883524
The Xen and QEMU/KVM paths were calling this at nearly
the same time in the boot flow anyhow, so just make
the call in one spot.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15195 6f19259b-4bc3-4df7-8a09-765794883524
By splitting the PEI and DXE phases into separate FVs,
we can only reserve the PEI FV for ACPI S3 support.
This should save about 7MB.
Unfortunately, this all has to happen in a single commit.
DEC:
* Remove PcdOvmfMemFv(Base|Size)
* Add PcdOvmfPeiMemFv(Base|Size)
* Add PcdOvmfDxeMemFv(Base|Size)
FDF:
* Add new PEIFV. Move PEI modules here.
* Remove MAINFV
* Add PEIFV and DXEFV into FVMAIN_COMPACT
- They are added as 2 sections of a file, and compressed
together so they should retain good compression
* PcdOvmf(Pei|Dxe)MemFv(Base|Size) are set
SEC:
* Find both the PEI and DXE FVs after decompression.
- Copy them separately to their memory locations.
Platform PEI driver:
* Fv.c: Publish both FVs as appropriate
* MemDetect.c: PcdOvmfMemFv(Base|Size) =>
PcdOvmfDxeMemFv(Base|Size)
OVMF.fd before:
Non-volatile data storage
FVMAIN_COMPACT uncompressed
FV FFS file LZMA compressed
MAINFV uncompressed
individual PEI modules uncompressed
FV FFS file compressed with PI_NONE
DXEFV uncompressed
individual DXE modules uncompressed
SECFV uncompressed
OVMF.fd after:
Non-volatile data storage
FVMAIN_COMPACT uncompressed
FV FFS file LZMA compressed
PEIFV uncompressed
individual PEI modules uncompressed
DXEFV uncompressed
individual DXE modules uncompressed
SECFV uncompressed
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15151 6f19259b-4bc3-4df7-8a09-765794883524
Although SVN r14944 ("OvmfPkg: introduce PublishPeiMemory") copied a big
chunk of code from MemDetect(), calling the new PublishPeiMemory()
function in MemDetect() could not have replaced the original code in the
latter. However, with the help of the previous patch, we can do it now.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15023 6f19259b-4bc3-4df7-8a09-765794883524
MemDetect actully does too many things, the underlying platform might
want to have more control over memory layout.
Extract the functionality of publishing PEI memory to a dedicated
function.
Also fixed wrong comment while I was there.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14944 6f19259b-4bc3-4df7-8a09-765794883524
QEMU doesn't support MTRR emulation in some cases,
and therefore the MtrrLib calls may return an error.
In that case, we should silently ignore the error.
Signed-off-by: jljusten
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12618 6f19259b-4bc3-4df7-8a09-765794883524
* Only SEC is uncompressed now
* The MAIN FV with PEI & DXE can easily shrink and grow as needed
* The final output will now be OVMF.Fv rather than OVMF.fd
* The final output size will be a multiple of 64kb
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9672 6f19259b-4bc3-4df7-8a09-765794883524
Laszlo Ersek
Jordan Justen
Wei Liu
jljusten
vanjeff
hhtian