Hans de Goede [Wed, 15 Jan 2020 16:35:46 +0000 (17:35 +0100)]
efi: Add embedded peripheral firmware support
Just like with PCI options ROMs, which we save in the setup_efi_pci*
functions from arch/x86/boot/compressed/eboot.c, the EFI code / ROM itself
sometimes may contain data which is useful/necessary for peripheral drivers
to have access to.
Specifically the EFI code may contain an embedded copy of firmware which
needs to be (re)loaded into the peripheral. Normally such firmware would be
part of linux-firmware, but in some cases this is not feasible, for 2
reasons:
1) The firmware is customized for a specific use-case of the chipset / use
with a specific hardware model, so we cannot have a single firmware file
for the chipset. E.g. touchscreen controller firmwares are compiled
specifically for the hardware model they are used with, as they are
calibrated for a specific model digitizer.
2) Despite repeated attempts we have failed to get permission to
redistribute the firmware. This is especially a problem with customized
firmwares, these get created by the chip vendor for a specific ODM and the
copyright may partially belong with the ODM, so the chip vendor cannot
give a blanket permission to distribute these.
This commit adds support for finding peripheral firmware embedded in the
EFI code and makes the found firmware available through the new
efi_get_embedded_fw() function.
Support for loading these firmwares through the standard firmware loading
mechanism is added in a follow-up commit in this patch-series.
Note we check the EFI_BOOT_SERVICES_CODE for embedded firmware near the end
of start_kernel(), just before calling rest_init(), this is on purpose
because the typical EFI_BOOT_SERVICES_CODE memory-segment is too large for
early_memremap(), so the check must be done after mm_init(). This relies
on EFI_BOOT_SERVICES_CODE not being free-ed until efi_free_boot_services()
is called, which means that this will only work on x86 for now.
Reported-by: Dave Olsthoorn <dave@bewaar.me> Suggested-by: Peter Jones <pjones@redhat.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200115163554.101315-3-hdegoede@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Hans de Goede [Wed, 15 Jan 2020 16:35:45 +0000 (17:35 +0100)]
efi: Export boot-services code and data as debugfs-blobs
Sometimes it is useful to be able to dump the efi boot-services code and
data. This commit adds these as debugfs-blobs to /sys/kernel/debug/efi,
but only if efi=debug is passed on the kernel-commandline as this requires
not freeing those memory-regions, which costs 20+ MB of RAM.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20200115163554.101315-2-hdegoede@redhat.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Arvind Sankar [Wed, 26 Feb 2020 23:00:31 +0000 (18:00 -0500)]
x86/boot/compressed: Fix reloading of GDTR post-relocation
The following commit:
ef5a7b5eb13e ("efi/x86: Remove GDT setup from efi_main")
introduced GDT setup into the 32-bit kernel's startup_32, and reloads
the GDTR after relocating the kernel for paranoia's sake.
A followup commit:
32d009137a56 ("x86/boot: Reload GDTR after copying to the end of the buffer")
introduced a similar GDTR reload in the 64-bit kernel as well.
The GDTR is adjusted by (init_size-_end), however this may not be the
correct offset to apply if the kernel was loaded at a misaligned address
or below LOAD_PHYSICAL_ADDR, as in that case the decompression buffer
has an additional offset from the original load address.
This should never happen for a conformant bootloader, but we're being
paranoid anyway, so just store the new GDT address in there instead of
adding any offsets, which is simpler as well.
Fixes: ef5a7b5eb13e ("efi/x86: Remove GDT setup from efi_main") Fixes: 32d009137a56 ("x86/boot: Reload GDTR after copying to the end of the buffer") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Link: https://lore.kernel.org/r/20200226230031.3011645-2-nivedita@alum.mit.edu
Ard Biesheuvel [Fri, 28 Feb 2020 12:14:08 +0000 (13:14 +0100)]
efi: Mark all EFI runtime services as unsupported on non-EFI boot
Recent changes to the way we deal with EFI runtime services that
are marked as unsupported by the firmware resulted in a regression
for non-EFI boot. The problem is that all EFI runtime services are
marked as available by default, and any non-NULL checks on the EFI
service function pointers (which will be non-NULL even for runtime
services that are unsupported on an EFI boot) were replaced with
checks against the mask stored in efi.runtime_supported_mask.
When doing a non-EFI boot, this check against the mask will return
a false positive, given the fact that all runtime services are
marked as enabled by default. Since we dropped the non-NULL check
of the runtime service function pointer in favor of the mask check,
we will now unconditionally dereference the function pointer, even
if it is NULL, and go boom.
So let's ensure that the mask reflects reality on a non-EFI boot,
which is that all EFI runtime services are unsupported.
Reported-by: David Hildenbrand <david@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20200228121408.9075-7-ardb@kernel.org
Ard Biesheuvel [Fri, 28 Feb 2020 12:14:07 +0000 (13:14 +0100)]
efi/arm64: Clean EFI stub exit code from cache instead of avoiding it
Commit 9f9223778 ("efi/libstub/arm: Make efi_entry() an ordinary PE/COFF
entrypoint") modified the handover code written in assembler, and for
maintainability, aligned the logic with the logic used in the 32-bit ARM
version, which is to avoid cache maintenance on the remaining instructions
in the subroutine that will be executed with the MMU and caches off, and
instead, branch into the relocated copy of the kernel image.
However, this assumes that this copy is executable, and this means we
expect EFI_LOADER_DATA regions to be executable as well, which is not
a reasonable assumption to make, even if this is true for most UEFI
implementations today.
So change this back, and add a __clean_dcache_area_poc() call to cover
the remaining code in the subroutine. While at it, switch the other
call site over to __clean_dcache_area_poc() as well, and clean up the
terminology in comments to avoid using 'flush' in the context of cache
maintenance. Also, let's switch to the new style asm annotations.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Hildenbrand <david@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20200228121408.9075-6-ardb@kernel.org
Ard Biesheuvel [Fri, 28 Feb 2020 12:14:06 +0000 (13:14 +0100)]
efi/arm: Clean EFI stub exit code from cache instead of avoiding it
The following commit:
c7225494b ("efi/arm: Work around missing cache maintenance in decompressor handover")
modified the EFI handover code written in assembler to work around the
missing cache maintenance of the piece of code that is executed after the
MMU and caches are turned off.
Due to the fact that this sequence incorporates a subroutine call, cleaning
that code from the cache is not a matter of simply passing the start and end of
the currently running subroutine into cache_clean_flush(), which is why
instead, the code jumps across into the cleaned copy of the image.
However, this assumes that this copy is executable, and this means we
expect EFI_LOADER_DATA regions to be executable as well, which is not
a reasonable assumption to make, even if this is true for most UEFI
implementations today.
So change this back, and add a cache_clean_flush() call to cover the
remaining code in the subroutine, and any code it may execute in the
context of cache_off().
Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-efi@vger.kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Hildenbrand <david@redhat.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20200228121408.9075-5-ardb@kernel.org
Tom Lendacky [Fri, 28 Feb 2020 12:14:04 +0000 (13:14 +0100)]
efi/x86: Add RNG seed EFI table to unencrypted mapping check
When booting with SME active, EFI tables must be mapped unencrypted since
they were built by UEFI in unencrypted memory. Update the list of tables
to be checked during early_memremap() processing to account for the EFI
RNG seed table.
Tom Lendacky [Fri, 28 Feb 2020 12:14:03 +0000 (13:14 +0100)]
efi/x86: Add TPM related EFI tables to unencrypted mapping checks
When booting with SME active, EFI tables must be mapped unencrypted since
they were built by UEFI in unencrypted memory. Update the list of tables
to be checked during early_memremap() processing to account for the EFI
TPM tables.
This fixes a bug where an EFI TPM log table has been created by UEFI, but
it lives in memory that has been marked as usable rather than reserved.
Ingo Molnar [Wed, 26 Feb 2020 14:21:22 +0000 (15:21 +0100)]
Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core
Pull EFI updates for v5.7 from Ard Biesheuvel:
This time, the set of changes for the EFI subsystem is much larger than
usual. The main reasons are:
- Get things cleaned up before EFI support for RISC-V arrives, which will
increase the size of the validation matrix, and therefore the threshold to
making drastic changes,
- After years of defunct maintainership, the GRUB project has finally started
to consider changes from the distros regarding UEFI boot, some of which are
highly specific to the way x86 does UEFI secure boot and measured boot,
based on knowledge of both shim internals and the layout of bootparams and
the x86 setup header. Having this maintenance burden on other architectures
(which don't need shim in the first place) is hard to justify, so instead,
we are introducing a generic Linux/UEFI boot protocol.
Summary of changes:
- Boot time GDT handling changes (Arvind)
- Simplify handling of EFI properties table on arm64
- Generic EFI stub cleanups, to improve command line handling, file I/O,
memory allocation, etc.
- Introduce a generic initrd loading method based on calling back into
the firmware, instead of relying on the x86 EFI handover protocol or
device tree.
- Introduce a mixed mode boot method that does not rely on the x86 EFI
handover protocol either, and could potentially be adopted by other
architectures (if another one ever surfaces where one execution mode
is a superset of another)
- Clean up the contents of struct efi, and move out everything that
doesn't need to be stored there.
- Incorporate support for UEFI spec v2.8A changes that permit firmware
implementations to return EFI_UNSUPPORTED from UEFI runtime services at
OS runtime, and expose a mask of which ones are supported or unsupported
via a configuration table.
- Various documentation updates and minor code cleanups (Heinrich)
- Partial fix for the lack of by-VA cache maintenance in the decompressor
on 32-bit ARM. Note that these patches were deliberately put at the
beginning so they can be used as a stable branch that will be shared with
a PR containing the complete fix, which I will send to the ARM tree.
Linus Torvalds [Tue, 25 Feb 2020 18:14:39 +0000 (10:14 -0800)]
Merge tag 'riscv-for-linux-5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V fixes from Palmer Dabbelt:
"This contains a handful of RISC-V related fixes that I've collected
and would like to target for 5.6-rc4:
- A fix to set up the PMPs on boot, which allows the kernel to access
memory on systems that don't set up permissive PMPs before getting
to Linux. This only effects machine-mode kernels, which currently
means only NOMMU kernels.
- A fix to avoid enabling supervisor-mode interrupts when running in
machine-mode, also only for NOMMU kernels.
- A pair of fixes to our KASAN support to avoid corrupting memory.
- A gitignore fix.
This boots on QEMU's virt board for me"
* tag 'riscv-for-linux-5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: adjust the indent
riscv: allocate a complete page size for each page table
riscv: Fix gitignore
RISC-V: Don't enable all interrupts in trap_init()
riscv: set pmp configuration if kernel is running in M-mode
Linus Torvalds [Tue, 25 Feb 2020 18:09:41 +0000 (10:09 -0800)]
Merge branch 'mips-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS fixes from Paul Burton:
"Here are a few MIPS fixes, and a MAINTAINERS update to hand over MIPS
maintenance to Thomas Bogendoerfer - this will be my final pull
request as MIPS maintainer.
Thanks for your helpful comments, useful corrections & responsiveness
during the time I've fulfilled the role, and I'm sure I'll pop up
elsewhere in the tree somewhere down the line"
* 'mips-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MAINTAINERS: Hand MIPS over to Thomas
MIPS: ingenic: DTS: Fix watchdog nodes
MIPS: X1000: Fix clock of watchdog node.
MIPS: vdso: Wrap -mexplicit-relocs in cc-option
MIPS: VPE: Fix a double free and a memory leak in 'release_vpe()'
MIPS: cavium_octeon: Fix syncw generation.
mips: vdso: add build time check that no 'jalr t9' calls left
MIPS: Disable VDSO time functionality on microMIPS
mips: vdso: fix 'jalr t9' crash in vdso code
Paul Burton [Sat, 22 Feb 2020 17:04:17 +0000 (09:04 -0800)]
MAINTAINERS: Hand MIPS over to Thomas
My time with MIPS the company has reached its end, and so at best I'll
have little time spend on maintaining arch/mips/.
Ralf last authored a patch over 2 years ago, the last time he committed
one is even further back & activity was sporadic for a while before
that. The reality is that he isn't active.
Having a new maintainer with time to do things properly will be
beneficial all round. Thomas Bogendoerfer has been involved in MIPS
development for a long time & has offered to step up as maintainer, so
add Thomas and remove myself & Ralf from the MIPS entry.
Ralf already has an entry in CREDITS to honor his contributions, so this
just adds one for me.
Zong Li [Fri, 7 Feb 2020 09:52:44 +0000 (17:52 +0800)]
riscv: allocate a complete page size for each page table
Each page table should be created by allocating a complete page size
for it. Otherwise, the content of the page table would be corrupted
somewhere through memory allocation which allocates the memory at the
middle of the page table for other use.
Signed-off-by: Zong Li <zong.li@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Linus Torvalds [Mon, 24 Feb 2020 19:40:23 +0000 (11:40 -0800)]
Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
"This fixes a Kconfig-related build error and an integer overflow in
chacha20poly1305"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: chacha20poly1305 - prevent integer overflow on large input
tee: amdtee: amdtee depends on CRYPTO_DEV_CCP_DD
Linus Torvalds [Fri, 21 Feb 2020 20:43:35 +0000 (12:43 -0800)]
floppy: check FDC index for errors before assigning it
Jordy Zomer reported a KASAN out-of-bounds read in the floppy driver in
wait_til_ready().
Which on the face of it can't happen, since as Willy Tarreau points out,
the function does no particular memory access. Except through the FDCS
macro, which just indexes a static allocation through teh current fdc,
which is always checked against N_FDC.
Except the checking happens after we've already assigned the value.
The floppy driver is a disgrace (a lot of it going back to my original
horrd "design"), and has no real maintainer. Nobody has the hardware,
and nobody really cares. But it still gets used in virtual environment
because it's one of those things that everybody supports.
The whole thing should be re-written, or at least parts of it should be
seriously cleaned up. The 'current fdc' index, which is used by the
FDCS macro, and which is often shadowed by a local 'fdc' variable, is a
prime example of how not to write code.
But because nobody has the hardware or the motivation, let's just fix up
the immediate problem with a nasty band-aid: test the fdc index before
actually assigning it to the static 'fdc' variable.
Ard Biesheuvel [Thu, 20 Feb 2020 10:57:20 +0000 (11:57 +0100)]
efi: Bump the Linux EFI stub major version number to #1
Now that we have introduced new, generic ways for the OS loader to
interface with Linux kernels during boot, we need to record this
fact in a way that allows loaders to discover this information, and
fall back to the existing methods for older kernels.
Ard Biesheuvel [Thu, 20 Feb 2020 10:06:00 +0000 (11:06 +0100)]
efi/libstub: Introduce symbolic constants for the stub major/minor version
Now that we have added new ways to load the initrd or the mixed mode
kernel, we will also need a way to tell the loader about this. Add
symbolic constants for the PE/COFF major/minor version numbers (which
fortunately have always been 0x0 for all architectures), so that we
can bump them later to document the capabilities of the stub.
Ard Biesheuvel [Sun, 16 Feb 2020 18:46:25 +0000 (19:46 +0100)]
integrity: Check properly whether EFI GetVariable() is available
Testing the value of the efi.get_variable function pointer is not
the right way to establish whether the platform supports EFI
variables at runtime. Instead, use the newly added granular check
that can test for the presence of each EFI runtime service
individually.
Ard Biesheuvel [Thu, 23 Jan 2020 08:14:09 +0000 (09:14 +0100)]
efi: Register EFI rtc platform device only when available
Drop the separate driver that registers the EFI rtc on all EFI
systems that have runtime services available, and instead, move
the registration into the core EFI code, and make it conditional
on whether the actual time related services are available.
Ard Biesheuvel [Thu, 23 Jan 2020 08:12:00 +0000 (09:12 +0100)]
efi: Use more granular check for availability for variable services
The UEFI spec rev 2.8 permits firmware implementations to support only
a subset of EFI runtime services at OS runtime (i.e., after the call to
ExitBootServices()), so let's take this into account in the drivers that
rely specifically on the availability of the EFI variable services.
Ard Biesheuvel [Thu, 23 Jan 2020 12:10:25 +0000 (13:10 +0100)]
efi: Add support for EFI_RT_PROPERTIES table
Take the newly introduced EFI_RT_PROPERTIES_TABLE configuration table
into account, which carries a mask of which EFI runtime services are
still functional after ExitBootServices() has been called by the OS.
Ard Biesheuvel [Tue, 21 Jan 2020 10:17:47 +0000 (11:17 +0100)]
efi: Store mask of supported runtime services in struct efi
Revision 2.8 of the UEFI spec introduces provisions for firmware to
advertise lack of support for certain runtime services at OS runtime.
Let's store this mask in struct efi for easy access.
Ard Biesheuvel [Wed, 19 Feb 2020 14:29:06 +0000 (15:29 +0100)]
efi/arm: Rewrite FDT param discovery routines
The efi_get_fdt_params() routine uses the early OF device tree
traversal helpers, that iterate over each node in the DT and invoke
a caller provided callback that can inspect the node's contents and
look for the required data. This requires a special param struct to
be passed around, with pointers into param enumeration structs that
contain (and duplicate) property names and offsets into yet another
struct that carries the collected data.
Since we know the data we look for is either under /hypervisor/uefi
or under /chosen, it is much simpler to use the libfdt routines, and
just try to grab a reference to either node directly, and read each
property in sequence.
Ard Biesheuvel [Tue, 18 Feb 2020 09:19:34 +0000 (10:19 +0100)]
efi/arm: Move FDT specific definitions into fdtparams.c
Push the FDT params specific types and definition into fdtparams.c,
and instead, pass a reference to the memory map data structure and
populate it directly, and return the system table address as the
return value.
Ard Biesheuvel [Tue, 18 Feb 2020 08:54:05 +0000 (09:54 +0100)]
efi/arm: Move FDT param discovery code out of efi.c
On ARM systems, we discover the UEFI system table address and memory
map address from the /chosen node in the device tree, or in the Xen
case, from a similar node under /hypervisor.
Before making some functional changes to that code, move it into its
own file that only gets built if CONFIG_EFI_PARAMS_FROM_FDT=y.
Ard Biesheuvel [Wed, 12 Feb 2020 11:18:17 +0000 (12:18 +0100)]
efi/x86: Add true mixed mode entry point into .compat section
Currently, mixed mode is closely tied to the EFI handover protocol
and relies on intimate knowledge of the bootparams structure, setup
header etc, all of which are rather byzantine and entirely specific
to x86.
Even though no other EFI supported architectures are currently known
that could support something like mixed mode, it still makes sense to
abstract a bit from this, and make it part of a generic Linux on EFI
boot protocol.
To that end, add a .compat section to the mixed mode binary, and populate
it with the PE machine type and entry point address, allowing firmware
implementations to match it to their native machine type, and invoke
non-native binaries using a secondary entry point.
Ard Biesheuvel [Wed, 12 Feb 2020 22:20:54 +0000 (23:20 +0100)]
efi/x86: Implement mixed mode boot without the handover protocol
Add support for booting 64-bit x86 kernels from 32-bit firmware running
on 64-bit capable CPUs without requiring the bootloader to implement
the EFI handover protocol or allocate the setup block, etc etc, all of
which can be done by the stub itself, using code that already exists.
Instead, create an ordinary EFI application entrypoint but implemented
in 32-bit code [so that it can be invoked by 32-bit firmware], and stash
the address of this 32-bit entrypoint in the .compat section where the
bootloader can find it.
Note that we use the setup block embedded in the binary to go through
startup_32(), but it gets reallocated and copied in efi_pe_entry(),
using the same code that runs when the x86 kernel is booted in EFI
mode from native firmware. This requires the loaded image protocol to
be installed on the kernel image's EFI handle, and point to the kernel
image itself and not to its loader. This, in turn, requires the
bootloader to use the LoadImage() boot service to load the 64-bit
image from 32-bit firmware, which is in fact supported by firmware
based on EDK2. (Only StartImage() will fail, and instead, the newly
added entrypoint needs to be invoked)
Ard Biesheuvel [Sat, 15 Feb 2020 23:03:25 +0000 (00:03 +0100)]
efi/libstub/x86: Use Exit() boot service to exit the stub on errors
Currently, we either return with an error [from efi_pe_entry()] or
enter a deadloop [in efi_main()] if any fatal errors occur during
execution of the EFI stub. Let's switch to calling the Exit() EFI boot
service instead in both cases, so that we
a) can get rid of the deadloop, and simply return to the boot manager
if any errors occur during execution of the stub, including during
the call to ExitBootServices(),
b) can also return cleanly from efi_pe_entry() or efi_main() in mixed
mode, once we introduce support for LoadImage/StartImage based mixed
mode in the next patch.
Note that on systems running downstream GRUBs [which do not use LoadImage
or StartImage to boot the kernel, and instead, pass their own image
handle as the loaded image handle], calling Exit() will exit from GRUB
rather than from the kernel, but this is a tolerable side effect.
Ard Biesheuvel [Wed, 12 Feb 2020 10:26:10 +0000 (11:26 +0100)]
efi/x86: Drop redundant .bss section
In commit
c7fb93ec51d462ec ("x86/efi: Include a .bss section within the PE/COFF headers")
we added a separate .bss section to the PE/COFF header of the compressed
kernel describing the static memory footprint of the decompressor, to
ensure that it has enough headroom to decompress itself.
We can achieve the exact same result by increasing the virtual size of
the .text section, without changing the raw size, which, as per the
PE/COFF specification, requires the loader to zero initialize the delta.
Doing so frees up a slot in the section table, which we will use later
to describe the mixed mode entrypoint.
Ard Biesheuvel [Sat, 22 Feb 2020 14:15:50 +0000 (15:15 +0100)]
efi/x86: add headroom to decompressor BSS to account for setup block
In the bootparams struct, init_size defines the static footprint of the
bzImage, counted from the start of the kernel image, i.e., startup_32().
The PE/COFF metadata declares the same size for the entire image, but this
time, the image includes the setup block as well, and so the space reserved
by UEFI is a bit too small. This usually doesn't matter, since we normally
relocate the kernel into a memory allocation of the correct size.
But in the unlikely case that the image happens to be loaded at exactly
the preferred offset, we skip this relocation, and execute the image in
place, stepping on memory beyond the provided allocation, which may be
in use for other purposes.
Let's fix this by adding the size of the setup block to the image size as
declared in the PE/COFF header.
Ard Biesheuvel [Tue, 21 Jan 2020 09:16:32 +0000 (10:16 +0100)]
efi/x86: Drop 'systab' member from struct efi
The systab member in struct efi has outlived its usefulness, now that
we have better ways to access the only piece of information we are
interested in after init, which is the EFI runtime services table
address. So instead of instantiating a doctored copy at early boot
with lots of mangled values, and switching the pointer when switching
into virtual mode, let's grab the values we need directly, and get
rid of the systab pointer entirely.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 16:39:39 +0000 (17:39 +0100)]
efi/arm: Drop unnecessary references to efi.systab
Instead of populating efi.systab very early during efi_init() with
a mapping that is released again before the function exits, use a
local variable here. Now that we use efi.runtime to access the runtime
services table, this removes the only reference efi.systab, so there is
no need to populate it anymore, or discover its virtually remapped
address. So drop the references entirely.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Tue, 21 Jan 2020 08:44:43 +0000 (09:44 +0100)]
efi: Add 'runtime' pointer to struct efi
Instead of going through the EFI system table each time, just copy the
runtime services table pointer into struct efi directly. This is the
last use of the system table pointer in struct efi, allowing us to
drop it in a future patch, along with a fair amount of quirky handling
of the translated address.
Note that usually, the runtime services pointer changes value during
the call to SetVirtualAddressMap(), so grab the updated value as soon
as that call returns. (Mixed mode uses a 1:1 mapping, and kexec boot
enters with the updated address in the system table, so in those cases,
we don't need to do anything here)
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 16:23:21 +0000 (17:23 +0100)]
efi/x86: Make fw_vendor, config_table and runtime sysfs nodes x86 specific
There is some code that exposes physical addresses of certain parts of
the EFI firmware implementation via sysfs nodes. These nodes are only
used on x86, and are of dubious value to begin with, so let's move
their handling into the x86 arch code.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 15:15:00 +0000 (16:15 +0100)]
efi/x86: Remove runtime table address from kexec EFI setup data
Since commit 33b85447fa61946b ("efi/x86: Drop two near identical versions
of efi_runtime_init()"), we no longer map the EFI runtime services table
before calling SetVirtualAddressMap(), which means we don't need the 1:1
mapped physical address of this table, and so there is no point in passing
the address via EFI setup data on kexec boot.
Note that the kexec tools will still look for this address in sysfs, so
we still need to provide it.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Wed, 22 Jan 2020 13:40:57 +0000 (14:40 +0100)]
efi: Clean up config_parse_tables()
config_parse_tables() is a jumble of pointer arithmetic, due to the
fact that on x86, we may be dealing with firmware whose native word
size differs from the kernel's.
This is not a concern on other architectures, and doesn't quite
justify the state of the code, so let's clean it up by adding a
non-x86 code path, constifying statically allocated tables and
replacing preprocessor conditionals with IS_ENABLED() checks.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 13:58:09 +0000 (14:58 +0100)]
efi/ia64: Switch to efi_config_parse_tables()
IA64 calls efi_config_parse_tables() via efi_config_init(), which
does an explicit memremap() of the tables, which is unnecessary
on IA64. So let's call efi_config_parse_tables() directly, passing
the __va() of the config table array.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 14:48:07 +0000 (15:48 +0100)]
efi/ia64: Use local variable for EFI system table address
The IA64 code never refers to the EFI system table except from
inside the scope of efi_init(). So let's use a local variable
instead of efi.systab, which will be going away soon.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 14:45:39 +0000 (15:45 +0100)]
efi/ia64: Use existing helpers to locate ESI table
Instead of iterating over the EFI config table array manually,
declare it as an arch table so it gets picked up by the existing
config table handling code.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 20 Jan 2020 09:49:11 +0000 (10:49 +0100)]
efi: Merge EFI system table revision and vendor checks
We have three different versions of the code that checks the EFI system
table revision and copies the firmware vendor string, and they are
mostly equivalent, with the exception of the use of early_memremap_ro
vs. __va() and the lowest major revision to warn about. Let's move this
into common code and factor out the commonalities.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Wed, 22 Jan 2020 14:06:54 +0000 (15:06 +0100)]
efi: Make memreserve table handling local to efi.c
There is no need for struct efi to carry the address of the memreserve
table and share it with the world. So move it out and make it
__initdata as well.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Wed, 22 Jan 2020 14:05:12 +0000 (15:05 +0100)]
efi: Move mem_attr_table out of struct efi
The memory attributes table is only used at init time by the core EFI
code, so there is no need to carry its address in struct efi that is
shared with the world. So move it out, and make it __ro_after_init as
well, considering that the value is set during early boot.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Wed, 22 Jan 2020 13:58:15 +0000 (14:58 +0100)]
efi: Make rng_seed table handling local to efi.c
Move the rng_seed table address from struct efi into a static global
variable in efi.c, which is the only place we ever refer to it anyway.
This reduces the footprint of struct efi, which is a r/w data structure
that is shared with the world.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Sun, 19 Jan 2020 15:17:59 +0000 (16:17 +0100)]
efi: Move UGA and PROP table handling to x86 code
The UGA table is x86 specific (its handling was introduced when the
EFI support code was modified to accommodate IA32), so there is no
need to handle it in generic code.
The EFI properties table is not strictly x86 specific, but it was
deprecated almost immediately after having been introduced, due to
implementation difficulties. Only x86 takes it into account today,
and this is not going to change, so make this table x86 only as well.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Sun, 19 Jan 2020 14:29:21 +0000 (15:29 +0100)]
efi: Drop handling of 'boot_info' configuration table
Some plumbing exists to handle a UEFI configuration table of type
BOOT_INFO but since we never match it to a GUID anywhere, we never
actually register such a table, or access it, for that matter. So
simply drop all mentions of it.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64 Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Tue, 4 Feb 2020 22:01:22 +0000 (22:01 +0000)]
efi/libstub: Take noinitrd cmdline argument into account for devpath initrd
One of the advantages of using what basically amounts to a callback
interface into the bootloader for loading the initrd is that it provides
a natural place for the bootloader or firmware to measure the initrd
contents while they are being passed to the kernel.
Unfortunately, this is not a guarantee that the initrd will in fact be
loaded and its /init invoked by the kernel, since the command line may
contain the 'noinitrd' option, in which case the initrd is ignored, but
this will not be reflected in the PCR that covers the initrd measurement.
This could be addressed by measuring the command line as well, and
including that PCR in the attestation policy, but this locks down the
command line completely, which may be too restrictive.
So let's take the noinitrd argument into account in the stub, too. This
forces any PCR that covers the initrd to assume a different value when
noinitrd is passed, allowing an attestation policy to disregard the
command line if there is no need to take its measurement into account
for other reasons.
As Peter points out, this would still require the agent that takes the
measurements to measure a separator event into the PCR in question at
ExitBootServices() time, to prevent replay attacks using the known
measurement from the TPM log.
Cc: Peter Jones <pjones@redhat.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Ard Biesheuvel [Mon, 3 Feb 2020 23:45:14 +0000 (23:45 +0000)]
efi/libstub: Add support for loading the initrd from a device path
There are currently two ways to specify the initrd to be passed to the
Linux kernel when booting via the EFI stub:
- it can be passed as a initrd= command line option when doing a pure PE
boot (as opposed to the EFI handover protocol that exists for x86)
- otherwise, the bootloader or firmware can load the initrd into memory,
and pass the address and size via the bootparams struct (x86) or
device tree (ARM)
In the first case, we are limited to loading from the same file system
that the kernel was loaded from, and it is also problematic in a trusted
boot context, given that we cannot easily protect the command line from
tampering without either adding complicated white/blacklisting of boot
arguments or locking down the command line altogether.
In the second case, we force the bootloader to duplicate knowledge about
the boot protocol which is already encoded in the stub, and which may be
subject to change over time, e.g., bootparams struct definitions, memory
allocation/alignment requirements for the placement of the initrd etc etc.
In the ARM case, it also requires the bootloader to modify the hardware
description provided by the firmware, as it is passed in the same file.
On systems where the initrd is measured after loading, it creates a time
window where the initrd contents might be manipulated in memory before
handing over to the kernel.
Address these concerns by adding support for loading the initrd into
memory by invoking the EFI LoadFile2 protocol installed on a vendor
GUIDed device path that specifically designates a Linux initrd.
This addresses the above concerns, by putting the EFI stub in charge of
placement in memory and of passing the base and size to the kernel proper
(via whatever means it desires) while still leaving it up to the firmware
or bootloader to obtain the file contents, potentially from other file
systems than the one the kernel itself was loaded from. On platforms that
implement measured boot, it permits the firmware to take the measurement
right before the kernel actually consumes the contents.
Ard Biesheuvel [Mon, 10 Feb 2020 08:46:57 +0000 (08:46 +0000)]
efi/dev-path-parser: Add struct definition for vendor type device path nodes
In preparation of adding support for loading the initrd via a special
device path, add the struct definition of a vendor GUIDed device path
node to efi.h.
Since we will be producing these data structures rather than just
consumsing the ones instantiated by the firmware, refactor the various
device path node definitions so we can take the size of each node using
sizeof() rather than having to resort to opaque arithmetic in the static
initializers.
While at it, drop the #if IS_ENABLED() check for the declaration of
efi_get_device_by_path(), which is unnecessary, and constify its first
argument as well.
Ard Biesheuvel [Sun, 2 Feb 2020 10:22:41 +0000 (11:22 +0100)]
efi/x86: Replace #ifdefs with IS_ENABLED() checks
When possible, IS_ENABLED() conditionals are preferred over #ifdefs,
given that the latter hide the code from the compiler entirely, which
reduces build test coverage when the option is not enabled.
So replace an instance in the x86 efi startup code.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:48 +0000 (17:02 +0100)]
efi/libstub: Make the LoadFile EFI protocol accessible
Add the protocol definitions, GUIDs and mixed mode glue so that
the EFI loadfile protocol can be used from the stub. This will
be used in a future patch to load the initrd.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:47 +0000 (17:02 +0100)]
efi/libstub: Expose LocateDevicePath boot service
We will be adding support for loading the initrd from a GUIDed
device path in a subsequent patch, so update the prototype of
the LocateDevicePath() boot service to make it callable from
our code.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:46 +0000 (17:02 +0100)]
efi/libstub: Clean up command line parsing routine
We currently parse the command non-destructively, to avoid having to
allocate memory for a copy before passing it to the standard parsing
routines that are used by the core kernel, and which modify the input
to delineate the parsed tokens with NUL characters.
Instead, we call strstr() and strncmp() to go over the input multiple
times, and match prefixes rather than tokens, which implies that we
would match, e.g., 'nokaslrfoo' in the stub and disable KASLR, while
the kernel would disregard the option and run with KASLR enabled.
In order to avoid having to reason about whether and how this behavior
may be abused, let's clean up the parsing routines, and rebuild them
on top of the existing helpers.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:45 +0000 (17:02 +0100)]
efi/libstub: Take soft and hard memory limits into account for initrd loading
On x86, the preferred load address of the initrd is still below 4 GB,
even though in some cases, we can cope with an initrd that is loaded
above that.
To simplify the code, and to make it more straightforward to introduce
other ways to load the initrd, pass the soft and hard memory limits at
the same time, and let the code handling the initrd= command line option
deal with this.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:44 +0000 (17:02 +0100)]
efi/libstub: Rewrite file I/O routine
The file I/O routine that is used to load initrd or dtb files from
the EFI system partition suffers from a few issues:
- it converts the u8[] command line back to a UTF-16 string, which is
pointless since we only handle initrd or dtb arguments provided via
the loaded image protocol anyway, which is where we got the UTF-16[]
command line from in the first place when booting via the PE entry
point,
- in the far majority of cases, only a single initrd= option is present,
but it optimizes for multiple options, by going over the command line
twice, allocating heap buffers for dynamically sized arrays, etc.
- the coding style is hard to follow, with few comments, and all logic
including string parsing etc all combined in a single routine.
Let's fix this by rewriting most of it, based on the idea that in the
case of multiple initrds, we can just allocate a new, bigger buffer
and copy over the data before freeing the old one.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:43 +0000 (17:02 +0100)]
efi/libstub: Move file I/O support code into separate file
Split off the file I/O support code into a separate source file so
it ends up in a separate object file in the static library, allowing
the linker to omit it if the routines are not used.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:41 +0000 (17:02 +0100)]
efi/libstub: Move efi_random_alloc() into separate source file
efi_random_alloc() is only used on arm64, but as it shares a source
file with efi_random_get_seed(), the latter will pull in the former
on other architectures as well.
Let's take advantage of the fact that libstub is a static library,
and so the linker will only incorporate objects that are needed to
satisfy dependencies in other objects. This means we can move the
random alloc code to a separate source file that gets built
unconditionally, but only used when needed.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:40 +0000 (17:02 +0100)]
efi/libstub/x86: Permit cmdline data to be allocated above 4 GB
We now support cmdline data that is located in memory that is not
32-bit addressable, so relax the allocation limit on systems where
this feature is enabled.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:39 +0000 (17:02 +0100)]
efi/libstub/x86: Permit bootparams struct to be allocated above 4 GB
We now support bootparams structures that are located in memory that
is not 32-bit addressable, so relax the allocation limit on systems
where this feature is enabled.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:37 +0000 (17:02 +0100)]
efi/libstub: Use consistent type names for file I/O protocols
Align the naming of efi_file_io_interface_t and efi_file_handle_t with
the UEFI spec, and call them efi_simple_file_system_protocol_t and
efi_file_protocol_t, respectively, using the same convention we use
for all other type definitions that originate in the UEFI spec.
While at it, move the definitions to efistub.h, so they are only seen
by code that needs them.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:36 +0000 (17:02 +0100)]
efi/libstub/x86: Incorporate eboot.c into libstub
Most of the EFI stub source files of all architectures reside under
drivers/firmware/efi/libstub, where they share a Makefile with special
CFLAGS and an include file with declarations that are only relevant
for stub code.
Currently, we carry a lot of stub specific stuff in linux/efi.h only
because eboot.c in arch/x86 needs them as well. So let's move eboot.c
into libstub/, and move the contents of eboot.h that we still care
about into efistub.h
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:35 +0000 (17:02 +0100)]
efi/libstub: Simplify efi_high_alloc() and rename to efi_allocate_pages()
The implementation of efi_high_alloc() uses a complicated way of
traversing the memory map to find an available region that is located
as close as possible to the provided upper limit, and calls AllocatePages
subsequently to create the allocation at that exact address.
This is precisely what the EFI_ALLOCATE_MAX_ADDRESS allocation type
argument to AllocatePages() does, and considering that EFI_ALLOC_ALIGN
only exceeds EFI_PAGE_SIZE on arm64, let's use AllocatePages() directly
and implement the alignment using code that the compiler can remove if
it does not exceed EFI_PAGE_SIZE.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:33 +0000 (17:02 +0100)]
efi/libstub/arm: Relax FDT alignment requirement
The arm64 kernel no longer requires the FDT blob to fit inside a
naturally aligned 2 MB memory block, so remove the code that aligns
the allocation to 2 MB.
Ard Biesheuvel [Mon, 10 Feb 2020 16:02:32 +0000 (17:02 +0100)]
efi/libstub: Use hidden visibility for all source files
Instead of setting the visibility pragma for a small set of symbol
declarations that could result in absolute references that we cannot
support in the stub, declare hidden visibility for all code in the
EFI stub, which is more robust and future proof.
To ensure that the #pragma is taken into account before any other
includes are processed, put it in a header file of its own and
include it via the compiler command line using the -include option.
Linus Torvalds [Sun, 23 Feb 2020 17:43:50 +0000 (09:43 -0800)]
Merge tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"These are fixes that were found during testing with help of error
injection, plus some other stable material.
There's a fixup to patch added to rc1 causing locking in wrong context
warnings, tests found one more deadlock scenario. The patches are
tagged for stable, two of them now in the queue but we'd like all
three released at the same time.
I'm not happy about fixes to fixes in such a fast succession during
rcs, but I hope we found all the fallouts of commit 28553fa992cb
('Btrfs: fix race between shrinking truncate and fiemap')"
* tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof
Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
btrfs: fix bytes_may_use underflow in prealloc error condtition
btrfs: handle logged extent failure properly
btrfs: do not check delayed items are empty for single transaction cleanup
btrfs: reset fs_root to NULL on error in open_ctree
btrfs: destroy qgroup extent records on transaction abort
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix mount failure with quota configured as module
jbd2: fix ocfs2 corrupt when clearing block group bits
ext4: fix race between writepages and enabling EXT4_EXTENTS_FL
ext4: rename s_journal_flag_rwsem to s_writepages_rwsem
ext4: fix potential race between s_flex_groups online resizing and access
ext4: fix potential race between s_group_info online resizing and access
ext4: fix potential race between online resizing and write operations
ext4: add cond_resched() to __ext4_find_entry()
ext4: fix a data race in EXT4_I(inode)->i_disksize
Linus Torvalds [Sun, 23 Feb 2020 17:37:41 +0000 (09:37 -0800)]
Merge tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux
Pull csky updates from Guo Ren:
"Sorry, I missed 5.6-rc1 merge window, but in this pull request the
most are the fixes and the rests are between fixes and features. The
only outside modification is the MAINTAINERS file update with our
mailing list.
- cache flush implementation fixes
- ftrace modify panic fix
- CONFIG_SMP boot problem fix
- fix pt_regs saving for atomic.S
- fix fixaddr_init without highmem.
- fix stack protector support
- fix fake Tightly-Coupled Memory code compile and use
- fix some typos and coding convention"
* tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux: (23 commits)
csky: Replace <linux/clk-provider.h> by <linux/of_clk.h>
csky: Implement copy_thread_tls
csky: Add PCI support
csky: Minimize defconfig to support buildroot config.fragment
csky: Add setup_initrd check code
csky: Cleanup old Kconfig options
arch/csky: fix some Kconfig typos
csky: Fixup compile warning for three unimplemented syscalls
csky: Remove unused cache implementation
csky: Fixup ftrace modify panic
csky: Add flush_icache_mm to defer flush icache all
csky: Optimize abiv2 copy_to_user_page with VM_EXEC
csky: Enable defer flush_dcache_page for abiv2 cpus (807/810/860)
csky: Remove unnecessary flush_icache_* implementation
csky: Support icache flush without specific instructions
csky/Kconfig: Add Kconfig.platforms to support some drivers
csky/smp: Fixup boot failed when CONFIG_SMP
csky: Set regs->usp to kernel sp, when the exception is from kernel
csky/mm: Fixup export invalid_pte_table symbol
csky: Separate fixaddr_init from highmem
...
Consult the 'unconditional IO exiting' and 'use IO bitmaps' VM-execution
controls when checking instruction interception. If the 'use IO bitmaps'
VM-execution control is 1, check the instruction access against the IO
bitmaps to determine if the instruction causes a VM-exit.
Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Tue, 4 Feb 2020 23:26:29 +0000 (15:26 -0800)]
KVM: nVMX: Don't emulate instructions in guest mode
vmx_check_intercept is not yet fully implemented. To avoid emulating
instructions disallowed by the L1 hypervisor, refuse to emulate
instructions by default.
Cc: stable@vger.kernel.org
[Made commit, added commit msg - Oliver] Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver Upton [Fri, 7 Feb 2020 10:36:07 +0000 (02:36 -0800)]
KVM: nVMX: Emulate MTF when performing instruction emulation
Since commit 5f3d45e7f282 ("kvm/x86: add support for
MONITOR_TRAP_FLAG"), KVM has allowed an L1 guest to use the monitor trap
flag processor-based execution control for its L2 guest. KVM simply
forwards any MTF VM-exits to the L1 guest, which works for normal
instruction execution.
However, when KVM needs to emulate an instruction on the behalf of an L2
guest, the monitor trap flag is not emulated. Add the necessary logic to
kvm_skip_emulated_instruction() to synthesize an MTF VM-exit to L1 upon
instruction emulation for L2.
Fixes: 5f3d45e7f282 ("kvm/x86: add support for MONITOR_TRAP_FLAG") Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Li RongQing [Sun, 23 Feb 2020 08:13:12 +0000 (16:13 +0800)]
KVM: fix error handling in svm_hardware_setup
rename svm_hardware_unsetup as svm_hardware_teardown, move
it before svm_hardware_setup, and call it to free all memory
if fail to setup in svm_hardware_setup, otherwise memory will
be leaked
remove __exit attribute for it since it is called in __init
function
Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>