The struct used for GHCB-based page-state change requests uses a 40-bit
bit-field for the GFN, which is shifted by PAGE_SHIFT to generate a
64-bit address. However, anything beyond 40-bits simply gets shifted off
when doing this, which will cause issues when dealing with 1TB+
addresses. Fix this by casting the 40-bit GFN values to 64-bit ones
prior to shifting it by PAGE_SHIFT.
Fixes: ade62c18f4 ("OvmfPkg/MemEncryptSevLib: add support to validate system RAM")
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-Id: <20231115175153.813213-1-michael.roth@amd.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
8259InterruptControllerDxe is not used by any platforms at this point,
remove it.
This patch removes mentions of the following CSM resources from the source
code:
- GUIDs (protocols or otherwise):
- gEfiLegacy8259ProtocolGuid
- headers:
- Protocol/Legacy8259.h
- PCDs:
- Pcd8259LegacyModeEdgeLevel
- Pcd8259LegacyModeMask
which extends the list of resources scheduled for removal to:
- GUIDs (protocols or otherwise):
- gEfiLegacy8259ProtocolGuid
- headers:
- Protocol/Legacy8259.h
- PCDs:
- Pcd8259LegacyModeEdgeLevel
- Pcd8259LegacyModeMask
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-35-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
The <FrameworkDxe.h> header is not used by any source file at this point,
remove it.
<FrameworkDxe.h> is a thin wrapper for including all header files under
the "OvmfPkg/Csm/Include/Framework" directory. Remove that directory at
the same time (nothing else references contents in that directory
directly).
Consequently, the "OvmfPkg/Csm/Include" directory becomes empty, and git
automatically deletes it; remove that include path from
"OvmfPkg/OvmfPkg.dec".
This shrinks the list of resources scheduled for removal to:
- GUIDs (protocols or otherwise):
- SYSTEM_ROM_FILE_GUID (1547B4F3-3E8A-4FEF-81C8-328ED647AB1A)
- gEfiLegacy8259ProtocolGuid
- headers:
- Protocol/Legacy8259.h
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-28-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
CsmSupportLib is not used by any platform at this point, remove it.
This patch removes mentions of the following CSM resources from the source
code [*]:
- GUIDs (protocols or otherwise):
- SYSTEM_ROM_FILE_GUID (1547B4F3-3E8A-4FEF-81C8-328ED647AB1A)
- gEfiFirmwareVolumeProtocolGuid (by cutting the
<Protocol/FirmwareVolume.h> link)
- gEfiLegacyBiosPlatformProtocolGuid
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyInterruptProtocolGuid
- headers:
- FrameworkDxe.h
- Protocol/FirmwareVolume.h
- Protocol/LegacyBiosPlatform.h
- Protocol/LegacyInterrupt.h
which extends the list of resources scheduled for removal to:
- GUIDs (protocols or otherwise):
- SYSTEM_ROM_FILE_GUID (1547B4F3-3E8A-4FEF-81C8-328ED647AB1A)
- gEfiFirmwareVolumeProtocolGuid
- gEfiLegacy8259ProtocolGuid
- gEfiLegacyBiosPlatformProtocolGuid
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyInterruptProtocolGuid
- headers:
- FrameworkDxe.h
- Protocol/FirmwareVolume.h
- Protocol/Legacy8259.h
- Protocol/LegacyBios.h
- Protocol/LegacyBiosPlatform.h
- Protocol/LegacyInterrupt.h
[*] Note that gEfiLegacyRegion2ProtocolGuid, while a CSM-related protocol,
cannot be scheduled for removal, because the protocol GUID is defined in
"MdePkg.dec", and it's not only "OvmfPkg/Csm/CsmSupportLib" that produces
it in all of edk2, but also "MdeModulePkg/Universal/LegacyRegion2Dxe" (not
used by OVMF). For the same reason, the "Protocol/LegacyRegion2.h" header
(from MdePkg) cannot be scheduled for removal.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-23-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
CsmSupportLib is effectively a hack. It produces the following protocols:
- Legacy Bios Platform,
- Legacy Interrupt,
- Legacy Region2.
(Note that the "OvmfPkg/Csm/CsmSupportLib/CsmSupportLib.inf" file contains
an error where it claims that "Legacy Bios Platform" is "consumed" -- it
is not; the lib instance produces that protocol).
At the same time, the library instance consumes
gEfiLegacyBiosProtocolGuid.
This *seemingly* creates a circular dependency with LegacyBiosDxe, because
that driver has the exact opposite protocol usage patterns. The solution
is that LegacyBiosDxe has a DEPEX on the protocols produced by
CsmSupportLib, while CsmSupportLib consumes the Legacy Bios Protocol from
LegacyBiosDxe only in the member functions of the protocols it produces.
Therefore, once BdsDxe is dispatched, and the CsmSupportLib constructor
exposes those three protocols, LegacyBiosDxe can also be started by the
DXE dispatcher, and then the protocols from CsmSupportLib become
functional.
But the main reason why CsmSupportLib is a hack is that it should be a
normal platform DXE driver (called e.g. "CsmSupportDxe"), and not a NULL
class library that's randomly hooked into BdsDxe.
Given that we have removed LegacyBiosDxe earlier (so there is no DEPEX we
need to satisfy now, conceptually), unhook CsmSupportLib from BdsDxe.
--*--
Note that in the BhyveX64 platform, the pathname
"OvmfPkg/Bhyve/Csm/CsmSupportLib/CsmSupportLib.inf" is bogus, and has
always been, since commit 656419f922 ("Add BhyvePkg, to support the
bhyve hypervisor", 2020-07-31).
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Corvin Köhne <corvink@freebsd.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Rebecca Cran <rebecca@bsdio.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-22-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
LegacyBiosDxe is not used by any platform at this point, remove it.
This patch removes mentions of the following CSM resources from the source
code [*] [**]:
- GUIDs (protocols or otherwise):
- gEfiIsaIoProtocolGuid
- gEfiLegacy8259ProtocolGuid
- gEfiLegacyBiosGuid
- gEfiLegacyBiosPlatformProtocolGuid
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyInterruptProtocolGuid
- headers:
- FrameworkDxe.h
- Guid/LegacyBios.h
- Protocol/IsaIo.h
- Protocol/Legacy8259.h
- Protocol/LegacyBios.h
- Protocol/LegacyBiosPlatform.h
- Protocol/LegacyInterrupt.h
- PCDs:
- PcdEbdaReservedMemorySize
- PcdEndOpromShadowAddress
- PcdHighPmmMemorySize
- PcdLegacyBiosCacheLegacyRegion
- PcdLowPmmMemorySize
- PcdOpromReservedMemoryBase
- PcdOpromReservedMemorySize
which extends the list of resources scheduled for removal to:
- GUIDs (protocols or otherwise):
- gEfiIsaIoProtocolGuid
- gEfiLegacy8259ProtocolGuid
- gEfiLegacyBiosGuid
- gEfiLegacyBiosPlatformProtocolGuid
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyInterruptProtocolGuid
- headers:
- FrameworkDxe.h
- Guid/LegacyBios.h
- Protocol/IsaIo.h
- Protocol/Legacy8259.h
- Protocol/LegacyBios.h
- Protocol/LegacyBiosPlatform.h
- Protocol/LegacyInterrupt.h
- PCDs:
- PcdEbdaReservedMemorySize
- PcdEndOpromShadowAddress
- PcdHighPmmMemorySize
- PcdLegacyBiosCacheLegacyRegion
- PcdLowPmmMemorySize
- PcdOpromReservedMemoryBase
- PcdOpromReservedMemorySize
[*] Note that gEfiGenericMemTestProtocolGuid, while not a CSM-related
protocol, also becomes useless in the OVMF platforms, so we'll deal with
that later in the series as well.
[**] Note that gEfiLegacyRegion2ProtocolGuid, while a CSM-related
protocol, cannot be scheduled for removal, because the protocol GUID is
defined in "MdePkg.dec", and it's not only "OvmfPkg/Csm/CsmSupportLib"
that produces it in all of edk2, but also
"MdeModulePkg/Universal/LegacyRegion2Dxe" (not used by OVMF). For the same
reason, the "Protocol/LegacyRegion2.h" header (from MdePkg) cannot be
scheduled for removal.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-16-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
The UEFI protocol database cannot contain gEfiLegacyBiosProtocolGuid any
longer, after excluding LegacyBiosDxe from the OVMF platforms. Therefore,
instruct PciBusDxe from IncompatiblePciDeviceSupportDxe to allocate 64-bit
BARs above 4 GB regardless of a CSM.
Regression test: in commit 855743f717 ("OvmfPkg: prevent 64-bit MMIO BAR
degradation if there is no CSM", 2016-05-25), where we introduced
IncompatiblePciDeviceSupportDxe, we said, "By default, the PCI Bus driver
considers an option ROM reason enough for allocating the 64-bit MMIO BARs
in 32-bit address space". Therefore it suffices to verify the 64-bit BARs
of a device for which QEMU provides an option ROM. The simplest case is
the virtio-net-pci device. And indeed, with this patch applied, the log
contains:
> PciBus: Discovered PCI @ [04|00|00] [VID = 0x1AF4, DID = 0x1041]
> BAR[1]: Type = Mem32; Alignment = 0xFFF; Length = 0x1000; Offset = 0x14
> BAR[4]: Type = PMem64; Alignment = 0x3FFF; Length = 0x4000; Offset = 0x20
This portion shows that Bus|Device|Function 04|00|00 is a (modern)
virito-net-pci device [VID = 0x1AF4, DID = 0x1041].
> PciBus: Resource Map for Bridge [00|01|03]
> Type = Mem32; Base = 0x81200000; Length = 0x200000; Alignment = 0x1FFFFF
> Base = Padding; Length = 0x200000; Alignment = 0x1FFFFF
> Base = 0x81200000; Length = 0x1000; Alignment = 0xFFF; Owner = PCI [04|00|00:14]
> Type = Mem32; Base = 0x81A43000; Length = 0x1000; Alignment = 0xFFF
> Type = PMem64; Base = 0x800200000; Length = 0x100000; Alignment = 0xFFFFF
> Base = 0x800200000; Length = 0x4000; Alignment = 0x3FFF; Owner = PCI [04|00|00:20]
This quote shows that 04|00|00 has a BAR at 0x8_0020_0000.
(It also shows that the device is behind a bridge (PCIe root port) whose
own BDF is 00|01|03.)
> [Security] 3rd party image[7CEEB418] can be loaded after EndOfDxe: PciRoot(0x0)/Pci(0x1,0x3)/Pci(0x0,0x0)/Offset(0x10E00,0x273FF).
> None of Tcg2Protocol/CcMeasurementProtocol is installed.
> InstallProtocolInterface: [EfiLoadedImageProtocol] 7D2E5140
> Loading driver at 0x0007CA9F000 EntryPoint=0x0007CAA5447 1af41000.efi
> InstallProtocolInterface: [EfiLoadedImageDevicePathProtocol] 7D5B2198
And this part finally shows that the iPXE option ROM for the device
(1af41000.efi) was detected and is loaded. (Same PCIe root port, and PCIe
root ports can only host a single device.)
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-14-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
The CSM-based VideoDxe driver is a special UEFI_DRIVER module that both
follows and doesn't follow the UEFI driver model.
Namely, in the Supported and Start members of its Driver Binding Protocol
instance, it consumes the Legacy Bios Protocol directly from the UEFI
protocol database, as opposed to (only) opening protocols on the handle
that it is supposed to bind.
Furthermore, the driver "marks" its own image handle with the
NULL-interface "Legacy Bios" (pseudo-protocol) GUID, in order to "inform
back" the provider of the Legacy Bios Protocol, i.e., LegacyBiosDxe, that
VideoDxe is a "BIOS Thunk Driver" in the system.
Quoting "OvmfPkg/Csm/Include/Guid/LegacyBios.h", such a driver follows the
UEFI Driver Model, but still uses the Int86() or FarCall() services of the
Legacy Bios Protocol as the basis for the UEFI protocol it produces.
In a sense, there is a circular dependency between VideoDxe and
LegacyBiosDxe; each knows about the other. However, VideoDxe is a
UEFI_DRIVER, while LegacyBiosDxe is a platform DXE_DRIVER with a very long
DEPEX. Therefore, for keeping dependencies conceptually intact, first
exclude VideoDxe from the OVMF platforms. Always include the
hypervisor-specific real UEFI video driver.
--*--
Note that the pathname
"IntelFrameworkModulePkg/Csm/BiosThunk/VideoDxe/VideoDxe.inf" in the bhyve
platform DSC and FDF files is bogus anyway.
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Corvin Köhne <corvink@freebsd.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Rebecca Cran <rebecca@bsdio.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-9-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
LegacyBootMaintUiLib is not used by any platform at this point, remove it.
This patch removes mentions of the following CSM resources from the source
code:
- GUIDs (protocols or otherwise):
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyDevOrderVariableGuid
- headers:
- Guid/LegacyDevOrder.h
- Protocol/LegacyBios.h
which extends the list of resources scheduled for removal to:
- GUIDs (protocols or otherwise):
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyDevOrderVariableGuid
- headers:
- Guid/LegacyDevOrder.h
- Protocol/LegacyBios.h
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-7-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
LegacyBootManagerLib is not used by any platform at this point, remove it.
This patch removes mentions of the following CSM resources from the source
code:
- GUIDs (protocols or otherwise):
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyDevOrderVariableGuid
- headers:
- Guid/LegacyDevOrder.h
- Protocol/LegacyBios.h
which extends the list of resources scheduled for removal to:
- GUIDs (protocols or otherwise):
- gEfiLegacyBiosProtocolGuid
- gEfiLegacyDevOrderVariableGuid
- headers:
- Guid/LegacyDevOrder.h
- Protocol/LegacyBios.h
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=4588
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231110235820.644381-5-lersek@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Corvin Köhne <corvink@FreeBSD.org>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
In order to allow the VMM (such as QEMU) to add a page with hashes of
kernel/initrd/cmdline for measured direct boot on SNP, add it explicitly
to the SNP metadata list report to the VMM.
In such case, VMM should fill the page with the hashes content, or
explicitly update it as a zero page (if kernel hashes are not used).
Note that for SNP, the launch secret part of the page (lower 3KB) are
not relevant and will remain zero. The last 1KB is used for the hashes.
This should have no effect on OvmfPkgX64 targets (which don't define
PcdSevLaunchSecretBase).
Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Resize the MEMFD section of AmdSevX64.fdf and reorder its pages so that
it matches the same size and order used in OvmfPkgX64.fdf.
After this change, this is the difference in the MEMFD of the two
targets:
$ diff -u \
<(sed -ne '/FD.MEMFD/,/FV.SECFV/p' OvmfPkg/OvmfPkgX64.fdf) \
<(sed -ne '/FD.MEMFD/,/FV.SECFV/p' OvmfPkg/AmdSev/AmdSevX64.fdf)
--- /dev/fd/63 2023-02-16 07:06:15.365308683 +0000
+++ /dev/fd/62 2023-02-16 07:06:15.365308683 +0000
@@ -32,6 +32,12 @@
0x00E000|0x001000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfCpuidSize
+0x00F000|0x000C00
+gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretBase|gUefiOvmfPkgTokenSpaceGuid.PcdSevLaunchSecretSize
+
+0x00FC00|0x000400
+gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableBase|gUefiOvmfPkgTokenSpaceGuid.PcdQemuHashTableSize
+
0x010000|0x010000
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamBase|gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecPeiTempRamSize
Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Adds the varpolicy EFI shell command to all DSC files that
currently include other dynamic shell commands from ShellPkg.
This command allows variable policies to be dumped in the EFI
shell for convenient auditing and debug.
Use the command in QEMU EFI shell as follows:
- `"varpolicy"` dumps platform variables
- `"varpolicy -?"` shows help text
- `"varpolicy -b"` pages output as expected
- `"varpolicy -s"` shows accurate variable statistic information
- `"varpolicy -p"` shows accurate UEFI variable policy information
- `"varpolicy-v -b"` dumps all information including variable data hex dump
Cc: Anatol Belski <anbelski@linux.microsoft.com>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jianyong Wu <jianyong.wu@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien@xen.org>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Message-Id: <20231030203112.736-4-mikuback@linux.microsoft.com>
Referring to a file relative to a regular file makes no sense (or at least
it cannot be implemented consistently with how a file is referred to
relative to a directory). VirtioFsSimpleFileOpen() has enforced this
strictly since the beginning, and a few months ago I reported USWG Mantis
ticket #2367 [1] too, for clearing up the related confusion in the UEFI
spec.
Unfortunately, the shim boot loader contains such a bug [2] [3]. I don't
believe the shim bug is ever going to be fixed. We can however relax the
check in VirtioFsSimpleFileOpen() a bit: if the pathname that's being
opened relative to a regular file is absolute, then the base file is going
to be ignored anyway, so we can let the caller's bug slide. This happens
to make shim work.
Why this matters: UEFI-bootable Linux installer ISOs tend to come with
shim and grub in the embedded (ElTorito) FAT image (ESP). Sometimes you
want to build upstream shim/grub binaries, but boot the same ISO
otherwise. The fastest way for overriding the ESP for this purpose is to
copy its original contents to a virtio filesystem, then overwrite the shim
and grub binaries from the host side. Note that this is different from
direct-booting a kernel (via fw_cfg); the point is to check whether the
just-built shim and grub are able to boot the rest of the ISO.
[1] https://mantis.uefi.org/mantis/view.php?id=2367
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1966973
[3] https://github.com/rhboot/shim/issues/382
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>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20231018172434.91280-1-lersek@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
