<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux/efi.h, branch v5.5.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>efi: Fix efi_loaded_image_t::unload type</title>
<updated>2019-12-08T11:42:19+00:00</updated>
<author>
<name>Arvind Sankar</name>
<email>nivedita@alum.mit.edu</email>
</author>
<published>2019-12-06T16:55:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9fa76ca7b8bdcdf51fc8c7b7b7a7bfc4eccceb58'/>
<id>9fa76ca7b8bdcdf51fc8c7b7b7a7bfc4eccceb58</id>
<content type='text'>
The ::unload field is a function pointer, so it should be u32 for 32-bit,
u64 for 64-bit. Add a prototype for it in the native efi_loaded_image_t
type. Also change type of parent_handle and device_handle from void * to
efi_handle_t for documentation purposes.

The unload method is not used, so no functional change.

Signed-off-by: Arvind Sankar &lt;nivedita@alum.mit.edu&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Bhupesh Sharma &lt;bhsharma@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Masayoshi Mizuma &lt;m.mizuma@jp.fujitsu.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191206165542.31469-6-ardb@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ::unload field is a function pointer, so it should be u32 for 32-bit,
u64 for 64-bit. Add a prototype for it in the native efi_loaded_image_t
type. Also change type of parent_handle and device_handle from void * to
efi_handle_t for documentation purposes.

The unload method is not used, so no functional change.

Signed-off-by: Arvind Sankar &lt;nivedita@alum.mit.edu&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Bhupesh Sharma &lt;bhsharma@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Masayoshi Mizuma &lt;m.mizuma@jp.fujitsu.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191206165542.31469-6-ardb@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'acpi-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2019-11-27T03:25:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-11-27T03:25:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6e9f879684b46331f51d0c76ebee981c788417db'/>
<id>6e9f879684b46331f51d0c76ebee981c788417db</id>
<content type='text'>
Pull ACPI updates from Rafael Wysocki:
 "These update the ACPICA code in the kernel to upstream revision
  20191018, add support for EFI specific purpose memory, update the ACPI
  EC driver to make it work on systems with hardware-reduced ACPI,
  improve ACPI-based device enumeration for some platforms, rework the
  lid blacklist handling in the button driver and add more lid quirks to
  it, unify ACPI _HID/_UID matching, fix assorted issues and clean up
  the code and documentation.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20191018
     including:
      * Fixes for Clang warnings (Bob Moore)
      * Fix for possible overflow in get_tick_count() (Bob Moore)
      * Introduction of acpi_unload_table() (Bob Moore)
      * Debugger and utilities updates (Erik Schmauss)
      * Fix for unloading tables loaded via configfs (Nikolaus Voss)

   - Add support for EFI specific purpose memory to optionally allow
     either application-exclusive or core-kernel-mm managed access to
     differentiated memory (Dan Williams)

   - Fix and clean up processing of the HMAT table (Brice Goglin, Qian
     Cai, Tao Xu)

   - Update the ACPI EC driver to make it work on systems with
     hardware-reduced ACPI (Daniel Drake)

   - Always build in support for the Generic Event Device (GED) to allow
     one kernel binary to work both on systems with full hardware ACPI
     and hardware-reduced ACPI (Arjan van de Ven)

   - Fix the table unload mechanism to unregister platform devices
     created when the given table was loaded (Andy Shevchenko)

   - Rework the lid blacklist handling in the button driver and add more
     lid quirks to it (Hans de Goede)

   - Improve ACPI-based device enumeration for some platforms based on
     Intel BayTrail SoCs (Hans de Goede)

   - Add an OpRegion driver for the Cherry Trail Crystal Cove PMIC and
     prevent handlers from being registered for unhandled PMIC OpRegions
     (Hans de Goede)

   - Unify ACPI _HID/_UID matching (Andy Shevchenko)

   - Clean up documentation and comments (Cao jin, James Pack, Kacper
     Piwiński)"

* tag 'acpi-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  ACPI: OSI: Shoot duplicate word
  ACPI: HMAT: use %u instead of %d to print u32 values
  ACPI: NUMA: HMAT: fix a section mismatch
  ACPI: HMAT: don't mix pxm and nid when setting memory target processor_pxm
  ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device
  ACPI: NUMA: HMAT: Register HMAT at device_initcall level
  device-dax: Add a driver for "hmem" devices
  dax: Fix alloc_dax_region() compile warning
  lib: Uplevel the pmem "region" ida to a global allocator
  x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP
  arm/efi: EFI soft reservation to memblock
  x86/efi: EFI soft reservation to E820 enumeration
  efi: Common enable/disable infrastructure for EFI soft reservation
  x86/efi: Push EFI_MEMMAP check into leaf routines
  efi: Enumerate EFI_MEMORY_SP
  ACPI: NUMA: Establish a new drivers/acpi/numa/ directory
  ACPICA: Update version to 20191018
  ACPICA: debugger: remove leading whitespaces when converting a string to a buffer
  ACPICA: acpiexec: initialize all simple types and field units from user input
  ACPICA: debugger: add field unit support for acpi_db_get_next_token
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ACPI updates from Rafael Wysocki:
 "These update the ACPICA code in the kernel to upstream revision
  20191018, add support for EFI specific purpose memory, update the ACPI
  EC driver to make it work on systems with hardware-reduced ACPI,
  improve ACPI-based device enumeration for some platforms, rework the
  lid blacklist handling in the button driver and add more lid quirks to
  it, unify ACPI _HID/_UID matching, fix assorted issues and clean up
  the code and documentation.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20191018
     including:
      * Fixes for Clang warnings (Bob Moore)
      * Fix for possible overflow in get_tick_count() (Bob Moore)
      * Introduction of acpi_unload_table() (Bob Moore)
      * Debugger and utilities updates (Erik Schmauss)
      * Fix for unloading tables loaded via configfs (Nikolaus Voss)

   - Add support for EFI specific purpose memory to optionally allow
     either application-exclusive or core-kernel-mm managed access to
     differentiated memory (Dan Williams)

   - Fix and clean up processing of the HMAT table (Brice Goglin, Qian
     Cai, Tao Xu)

   - Update the ACPI EC driver to make it work on systems with
     hardware-reduced ACPI (Daniel Drake)

   - Always build in support for the Generic Event Device (GED) to allow
     one kernel binary to work both on systems with full hardware ACPI
     and hardware-reduced ACPI (Arjan van de Ven)

   - Fix the table unload mechanism to unregister platform devices
     created when the given table was loaded (Andy Shevchenko)

   - Rework the lid blacklist handling in the button driver and add more
     lid quirks to it (Hans de Goede)

   - Improve ACPI-based device enumeration for some platforms based on
     Intel BayTrail SoCs (Hans de Goede)

   - Add an OpRegion driver for the Cherry Trail Crystal Cove PMIC and
     prevent handlers from being registered for unhandled PMIC OpRegions
     (Hans de Goede)

   - Unify ACPI _HID/_UID matching (Andy Shevchenko)

   - Clean up documentation and comments (Cao jin, James Pack, Kacper
     Piwiński)"

* tag 'acpi-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  ACPI: OSI: Shoot duplicate word
  ACPI: HMAT: use %u instead of %d to print u32 values
  ACPI: NUMA: HMAT: fix a section mismatch
  ACPI: HMAT: don't mix pxm and nid when setting memory target processor_pxm
  ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device
  ACPI: NUMA: HMAT: Register HMAT at device_initcall level
  device-dax: Add a driver for "hmem" devices
  dax: Fix alloc_dax_region() compile warning
  lib: Uplevel the pmem "region" ida to a global allocator
  x86/efi: Add efi_fake_mem support for EFI_MEMORY_SP
  arm/efi: EFI soft reservation to memblock
  x86/efi: EFI soft reservation to E820 enumeration
  efi: Common enable/disable infrastructure for EFI soft reservation
  x86/efi: Push EFI_MEMMAP check into leaf routines
  efi: Enumerate EFI_MEMORY_SP
  ACPI: NUMA: Establish a new drivers/acpi/numa/ directory
  ACPICA: Update version to 20191018
  ACPICA: debugger: remove leading whitespaces when converting a string to a buffer
  ACPICA: acpiexec: initialize all simple types and field units from user input
  ACPICA: debugger: add field unit support for acpi_db_get_next_token
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>efi: Common enable/disable infrastructure for EFI soft reservation</title>
<updated>2019-11-07T14:44:08+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2019-11-07T01:43:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b617c5266eedbef2ccbb90931bb9175faa4ae0bc'/>
<id>b617c5266eedbef2ccbb90931bb9175faa4ae0bc</id>
<content type='text'>
UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose".

The proposed Linux behavior for specific purpose memory is that it is
reserved for direct-access (device-dax) by default and not available for
any kernel usage, not even as an OOM fallback.  Later, through udev
scripts or another init mechanism, these device-dax claimed ranges can
be reconfigured and hot-added to the available System-RAM with a unique
node identifier. This device-dax management scheme implements "soft" in
the "soft reserved" designation by allowing some or all of the
reservation to be recovered as typical memory. This policy can be
disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with
efi=nosoftreserve.

As for this patch, define the common helpers to determine if the
EFI_MEMORY_SP attribute should be honored. The determination needs to be
made early to prevent the kernel from being loaded into soft-reserved
memory, or otherwise allowing early allocations to land there. Follow-on
changes are needed per architecture to leverage these helpers in their
respective mem-init paths.

Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose".

The proposed Linux behavior for specific purpose memory is that it is
reserved for direct-access (device-dax) by default and not available for
any kernel usage, not even as an OOM fallback.  Later, through udev
scripts or another init mechanism, these device-dax claimed ranges can
be reconfigured and hot-added to the available System-RAM with a unique
node identifier. This device-dax management scheme implements "soft" in
the "soft reserved" designation by allowing some or all of the
reservation to be recovered as typical memory. This policy can be
disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with
efi=nosoftreserve.

As for this patch, define the common helpers to determine if the
EFI_MEMORY_SP attribute should be honored. The determination needs to be
made early to prevent the kernel from being loaded into soft-reserved
memory, or otherwise allowing early allocations to land there. Follow-on
changes are needed per architecture to leverage these helpers in their
respective mem-init paths.

Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/efi: Push EFI_MEMMAP check into leaf routines</title>
<updated>2019-11-07T14:44:04+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2019-11-07T01:43:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6950e31b35fdf4588cbbdec1813091bb02cf8871'/>
<id>6950e31b35fdf4588cbbdec1813091bb02cf8871</id>
<content type='text'>
In preparation for adding another EFI_MEMMAP dependent call that needs
to occur before e820__memblock_setup() fixup the existing efi calls to
check for EFI_MEMMAP internally. This ends up being cleaner than the
alternative of checking EFI_MEMMAP multiple times in setup_arch().

Reviewed-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In preparation for adding another EFI_MEMMAP dependent call that needs
to occur before e820__memblock_setup() fixup the existing efi calls to
check for EFI_MEMMAP internally. This ends up being cleaner than the
alternative of checking EFI_MEMMAP multiple times in setup_arch().

Reviewed-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>efi: Enumerate EFI_MEMORY_SP</title>
<updated>2019-11-07T14:43:54+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2019-11-07T01:43:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fe3e5e65c06edb1c56e64e567f053e243142001f'/>
<id>fe3e5e65c06edb1c56e64e567f053e243142001f</id>
<content type='text'>
UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose". The intent of this bit is to allow the OS to identify precious
or scarce memory resources and optionally manage it separately from
EfiConventionalMemory. As defined older OSes that do not know about this
attribute are permitted to ignore it and the memory will be handled
according to the OS default policy for the given memory type.

In other words, this "specific purpose" hint is deliberately weaker than
EfiReservedMemoryType in that the system continues to operate if the OS
takes no action on the attribute. The risk of taking no action is
potentially unwanted / unmovable kernel allocations from the designated
resource that prevent the full realization of the "specific purpose".
For example, consider a system with a high-bandwidth memory pool. Older
kernels are permitted to boot and consume that memory as conventional
"System-RAM" newer kernels may arrange for that memory to be set aside
(soft reserved) by the system administrator for a dedicated
high-bandwidth memory aware application to consume.

Specifically, this mechanism allows for the elimination of scenarios
where platform firmware tries to game OS policy by lying about ACPI SLIT
values, i.e. claiming that a precious memory resource has a high
distance to trigger the OS to avoid it by default. This reservation hint
allows platform-firmware to instead tell the truth about performance
characteristics by indicate to OS memory management to put immovable
allocations elsewhere.

Implement simple detection of the bit for EFI memory table dumps and
save the kernel policy for a follow-on change.

Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Reviewed-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the
interpretation of the EFI Memory Types as "reserved for a specific
purpose". The intent of this bit is to allow the OS to identify precious
or scarce memory resources and optionally manage it separately from
EfiConventionalMemory. As defined older OSes that do not know about this
attribute are permitted to ignore it and the memory will be handled
according to the OS default policy for the given memory type.

In other words, this "specific purpose" hint is deliberately weaker than
EfiReservedMemoryType in that the system continues to operate if the OS
takes no action on the attribute. The risk of taking no action is
potentially unwanted / unmovable kernel allocations from the designated
resource that prevent the full realization of the "specific purpose".
For example, consider a system with a high-bandwidth memory pool. Older
kernels are permitted to boot and consume that memory as conventional
"System-RAM" newer kernels may arrange for that memory to be set aside
(soft reserved) by the system administrator for a dedicated
high-bandwidth memory aware application to consume.

Specifically, this mechanism allows for the elimination of scenarios
where platform firmware tries to game OS policy by lying about ACPI SLIT
values, i.e. claiming that a precious memory resource has a high
distance to trigger the OS to avoid it by default. This reservation hint
allows platform-firmware to instead tell the truth about performance
characteristics by indicate to OS memory management to put immovable
allocations elsewhere.

Implement simple detection of the bit for EFI memory table dumps and
save the kernel policy for a follow-on change.

Reviewed-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Reviewed-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: efi/random: Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table</title>
<updated>2019-11-07T09:18:45+00:00</updated>
<author>
<name>Dominik Brodowski</name>
<email>linux@dominikbrodowski.net</email>
</author>
<published>2019-11-06T07:06:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0d95981438c3bdb53cc99b0fb656d24d7a80e1f3'/>
<id>0d95981438c3bdb53cc99b0fb656d24d7a80e1f3</id>
<content type='text'>
Invoke the EFI_RNG_PROTOCOL protocol in the context of the x86 EFI stub,
same as is done on arm/arm64 since commit 568bc4e87033 ("efi/arm*/libstub:
Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table"). Within the stub,
a Linux-specific RNG seed UEFI config table will be seeded. The EFI routines
in the core kernel will pick that up later, yet still early during boot,
to seed the kernel entropy pool. If CONFIG_RANDOM_TRUST_BOOTLOADER, entropy
is credited for this seed.

Signed-off-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Invoke the EFI_RNG_PROTOCOL protocol in the context of the x86 EFI stub,
same as is done on arm/arm64 since commit 568bc4e87033 ("efi/arm*/libstub:
Invoke EFI_RNG_PROTOCOL to seed the UEFI RNG table"). Within the stub,
a Linux-specific RNG seed UEFI config table will be seeded. The EFI routines
in the core kernel will pick that up later, yet still early during boot,
to seed the kernel entropy pool. If CONFIG_RANDOM_TRUST_BOOTLOADER, entropy
is credited for this seed.

Signed-off-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, efi: Never relocate kernel below lowest acceptable address</title>
<updated>2019-10-31T08:40:19+00:00</updated>
<author>
<name>Kairui Song</name>
<email>kasong@redhat.com</email>
</author>
<published>2019-10-29T17:37:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=220dd7699c46d5940115bd797b01b2ab047c87b8'/>
<id>220dd7699c46d5940115bd797b01b2ab047c87b8</id>
<content type='text'>
Currently, kernel fails to boot on some HyperV VMs when using EFI.
And it's a potential issue on all x86 platforms.

It's caused by broken kernel relocation on EFI systems, when below three
conditions are met:

1. Kernel image is not loaded to the default address (LOAD_PHYSICAL_ADDR)
   by the loader.
2. There isn't enough room to contain the kernel, starting from the
   default load address (eg. something else occupied part the region).
3. In the memmap provided by EFI firmware, there is a memory region
   starts below LOAD_PHYSICAL_ADDR, and suitable for containing the
   kernel.

EFI stub will perform a kernel relocation when condition 1 is met. But
due to condition 2, EFI stub can't relocate kernel to the preferred
address, so it fallback to ask EFI firmware to alloc lowest usable memory
region, got the low region mentioned in condition 3, and relocated
kernel there.

It's incorrect to relocate the kernel below LOAD_PHYSICAL_ADDR. This
is the lowest acceptable kernel relocation address.

The first thing goes wrong is in arch/x86/boot/compressed/head_64.S.
Kernel decompression will force use LOAD_PHYSICAL_ADDR as the output
address if kernel is located below it. Then the relocation before
decompression, which move kernel to the end of the decompression buffer,
will overwrite other memory region, as there is no enough memory there.

To fix it, just don't let EFI stub relocate the kernel to any address
lower than lowest acceptable address.

[ ardb: introduce efi_low_alloc_above() to reduce the scope of the change ]

Signed-off-by: Kairui Song &lt;kasong@redhat.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Acked-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191029173755.27149-6-ardb@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, kernel fails to boot on some HyperV VMs when using EFI.
And it's a potential issue on all x86 platforms.

It's caused by broken kernel relocation on EFI systems, when below three
conditions are met:

1. Kernel image is not loaded to the default address (LOAD_PHYSICAL_ADDR)
   by the loader.
2. There isn't enough room to contain the kernel, starting from the
   default load address (eg. something else occupied part the region).
3. In the memmap provided by EFI firmware, there is a memory region
   starts below LOAD_PHYSICAL_ADDR, and suitable for containing the
   kernel.

EFI stub will perform a kernel relocation when condition 1 is met. But
due to condition 2, EFI stub can't relocate kernel to the preferred
address, so it fallback to ask EFI firmware to alloc lowest usable memory
region, got the low region mentioned in condition 3, and relocated
kernel there.

It's incorrect to relocate the kernel below LOAD_PHYSICAL_ADDR. This
is the lowest acceptable kernel relocation address.

The first thing goes wrong is in arch/x86/boot/compressed/head_64.S.
Kernel decompression will force use LOAD_PHYSICAL_ADDR as the output
address if kernel is located below it. Then the relocation before
decompression, which move kernel to the end of the decompression buffer,
will overwrite other memory region, as there is no enough memory there.

To fix it, just don't let EFI stub relocate the kernel to any address
lower than lowest acceptable address.

[ ardb: introduce efi_low_alloc_above() to reduce the scope of the change ]

Signed-off-by: Kairui Song &lt;kasong@redhat.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Acked-by: Jarkko Sakkinen &lt;jarkko.sakkinen@linux.intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191029173755.27149-6-ardb@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>efi: Export Runtime Configuration Interface table to sysfs</title>
<updated>2019-08-08T08:10:25+00:00</updated>
<author>
<name>Narendra K</name>
<email>Narendra.K@dell.com</email>
</author>
<published>2019-07-10T18:59:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1c5fecb61255aa12a16c4c06335ab68979865914'/>
<id>1c5fecb61255aa12a16c4c06335ab68979865914</id>
<content type='text'>
System firmware advertises the address of the 'Runtime
Configuration Interface table version 2 (RCI2)' via
an EFI Configuration Table entry. This code retrieves the RCI2
table from the address and exports it to sysfs as a binary
attribute 'rci2' under /sys/firmware/efi/tables directory.
The approach adopted is similar to the attribute 'DMI' under
/sys/firmware/dmi/tables.

RCI2 table contains BIOS HII in XML format and is used to populate
BIOS setup page in Dell EMC OpenManage Server Administrator tool.
The BIOS setup page contains BIOS tokens which can be configured.

Signed-off-by: Narendra K &lt;Narendra.K@dell.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@dell.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
System firmware advertises the address of the 'Runtime
Configuration Interface table version 2 (RCI2)' via
an EFI Configuration Table entry. This code retrieves the RCI2
table from the address and exports it to sysfs as a binary
attribute 'rci2' under /sys/firmware/efi/tables directory.
The approach adopted is similar to the attribute 'DMI' under
/sys/firmware/dmi/tables.

RCI2 table contains BIOS HII in XML format and is used to populate
BIOS setup page in Dell EMC OpenManage Server Administrator tool.
The BIOS setup page contains BIOS tokens which can be configured.

Signed-off-by: Narendra K &lt;Narendra.K@dell.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@dell.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>efi: ia64: move SAL systab handling out of generic EFI code</title>
<updated>2019-08-08T08:01:48+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2019-06-25T14:28:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5828efb95bc43ad6a59f05458d3aed9649dd5a63'/>
<id>5828efb95bc43ad6a59f05458d3aed9649dd5a63</id>
<content type='text'>
The SAL systab is an Itanium specific EFI configuration table, so
move its handling into arch/ia64 where it belongs.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The SAL systab is an Itanium specific EFI configuration table, so
move its handling into arch/ia64 where it belongs.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>efi/x86: move UV_SYSTAB handling into arch/x86</title>
<updated>2019-08-08T08:01:48+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ard.biesheuvel@linaro.org</email>
</author>
<published>2019-06-25T13:48:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ec7e1605d79d1d469b25e396f2056e42386f512f'/>
<id>ec7e1605d79d1d469b25e396f2056e42386f512f</id>
<content type='text'>
The SGI UV UEFI machines are tightly coupled to the x86 architecture
so there is no need to keep any awareness of its existence in the
generic EFI layer, especially since we already have the infrastructure
to handle arch-specific configuration tables, and were even already
using it to some extent.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The SGI UV UEFI machines are tightly coupled to the x86 architecture
so there is no need to keep any awareness of its existence in the
generic EFI layer, especially since we already have the infrastructure
to handle arch-specific configuration tables, and were even already
using it to some extent.

Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
