<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/x86/include/uapi, branch v5.18</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-03-27T17:17:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-27T17:17:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7001052160d172f6de06adeffde24dde9935ece8'/>
<id>7001052160d172f6de06adeffde24dde9935ece8</id>
<content type='text'>
Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld &gt;= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang &gt;= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld &gt;= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang &gt;= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86</title>
<updated>2022-03-25T19:14:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-25T19:14:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1464677662943738741500a6f16b85d36bbde2be'/>
<id>1464677662943738741500a6f16b85d36bbde2be</id>
<content type='text'>
Pull x86 platform driver updates from Hans de Goede:
  "New drivers:
    - AMD Host System Management Port (HSMP)
    - Intel Software Defined Silicon

  Removed drivers (functionality folded into other drivers):
    - intel_cht_int33fe_microb
    - surface3_button

  amd-pmc:
    - s2idle bug-fixes
    - Support for AMD Spill to DRAM STB feature

  hp-wmi:
    - Fix SW_TABLET_MODE detection method (and other fixes)
    - Support omen thermal profile policy v1

  serial-multi-instantiate:
    - Add SPI device support
    - Add support for CS35L41 amplifiers used in new laptops

  think-lmi:
    - syfs-class-firmware-attributes Certificate authentication support

  thinkpad_acpi:
    - Fixes + quirks
    - Add platform_profile support on AMD based ThinkPads

  x86-android-tablets:
    - Improve Asus ME176C / TF103C support
    - Support Nextbook Ares 8, Lenovo Tab 2 830 and 1050 tablets

  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (60 commits)
  platform/x86: think-lmi: Certificate authentication support
  Documentation: syfs-class-firmware-attributes: Lenovo Certificate support
  platform/x86: amd-pmc: Only report STB errors when STB enabled
  platform/x86: amd-pmc: Drop CPU QoS workaround
  platform/x86: amd-pmc: Output error codes in messages
  platform/x86: amd-pmc: Move to later in the suspend process
  ACPI / x86: Add support for LPS0 callback handler
  platform/x86: thinkpad_acpi: consistently check fan_get_status return.
  platform/x86: hp-wmi: support omen thermal profile policy v1
  platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated
  platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls
  platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method
  platform/x86: hp-wmi: Fix hp_wmi_read_int() reporting error (0x05)
  platform/x86: amd-pmc: Validate entry into the deepest state on resume
  platform/x86: thinkpad_acpi: Don't use test_bit on an integer
  platform/x86: thinkpad_acpi: Fix compiler warning about uninitialized err variable
  platform/x86: thinkpad_acpi: clean up dytc profile convert
  platform/x86: x86-android-tablets: Depend on EFI and SPI
  platform/x86: amd-pmc: uninitialized variable in amd_pmc_s2d_init()
  platform/x86: intel-uncore-freq: fix uncore_freq_common_init() error codes
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 platform driver updates from Hans de Goede:
  "New drivers:
    - AMD Host System Management Port (HSMP)
    - Intel Software Defined Silicon

  Removed drivers (functionality folded into other drivers):
    - intel_cht_int33fe_microb
    - surface3_button

  amd-pmc:
    - s2idle bug-fixes
    - Support for AMD Spill to DRAM STB feature

  hp-wmi:
    - Fix SW_TABLET_MODE detection method (and other fixes)
    - Support omen thermal profile policy v1

  serial-multi-instantiate:
    - Add SPI device support
    - Add support for CS35L41 amplifiers used in new laptops

  think-lmi:
    - syfs-class-firmware-attributes Certificate authentication support

  thinkpad_acpi:
    - Fixes + quirks
    - Add platform_profile support on AMD based ThinkPads

  x86-android-tablets:
    - Improve Asus ME176C / TF103C support
    - Support Nextbook Ares 8, Lenovo Tab 2 830 and 1050 tablets

  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (60 commits)
  platform/x86: think-lmi: Certificate authentication support
  Documentation: syfs-class-firmware-attributes: Lenovo Certificate support
  platform/x86: amd-pmc: Only report STB errors when STB enabled
  platform/x86: amd-pmc: Drop CPU QoS workaround
  platform/x86: amd-pmc: Output error codes in messages
  platform/x86: amd-pmc: Move to later in the suspend process
  ACPI / x86: Add support for LPS0 callback handler
  platform/x86: thinkpad_acpi: consistently check fan_get_status return.
  platform/x86: hp-wmi: support omen thermal profile policy v1
  platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated
  platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls
  platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method
  platform/x86: hp-wmi: Fix hp_wmi_read_int() reporting error (0x05)
  platform/x86: amd-pmc: Validate entry into the deepest state on resume
  platform/x86: thinkpad_acpi: Don't use test_bit on an integer
  platform/x86: thinkpad_acpi: Fix compiler warning about uninitialized err variable
  platform/x86: thinkpad_acpi: clean up dytc profile convert
  platform/x86: x86-android-tablets: Depend on EFI and SPI
  platform/x86: amd-pmc: uninitialized variable in amd_pmc_s2d_init()
  platform/x86: intel-uncore-freq: fix uncore_freq_common_init() error codes
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/ibt: Add IBT feature, MSR and #CP handling</title>
<updated>2022-03-15T09:32:39+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-03-08T15:30:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=991625f3dd2cbc4b787deb0213e2bcf8fa264b21'/>
<id>991625f3dd2cbc4b787deb0213e2bcf8fa264b21</id>
<content type='text'>
The bits required to make the hardware go.. Of note is that, provided
the syscall entry points are covered with ENDBR, #CP doesn't need to
be an IST because we'll never hit the syscall gap.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Link: https://lore.kernel.org/r/20220308154318.582331711@infradead.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The bits required to make the hardware go.. Of note is that, provided
the syscall entry points are covered with ENDBR, #CP doesn't need to
be an IST because we'll never hit the syscall gap.

Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Link: https://lore.kernel.org/r/20220308154318.582331711@infradead.org
</pre>
</div>
</content>
</entry>
<entry>
<title>platform/x86: Add AMD system management interface</title>
<updated>2022-03-02T10:42:36+00:00</updated>
<author>
<name>Suma Hegde</name>
<email>suma.hegde@amd.com</email>
</author>
<published>2022-02-22T05:05:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=91f410aa679a035e7abdff47daca4418c384c770'/>
<id>91f410aa679a035e7abdff47daca4418c384c770</id>
<content type='text'>
Recent Fam19h EPYC server line of processors from AMD support system
management functionality via HSMP (Host System Management Port) interface.

The Host System Management Port (HSMP) is an interface to provide
OS-level software with access to system management functions via a
set of mailbox registers.

More details on the interface can be found in chapter
"7 Host System Management Port (HSMP)" of the following PPR
https://www.amd.com/system/files/TechDocs/55898_B1_pub_0.50.zip

This patch adds new amd_hsmp module under the drivers/platforms/x86/
which creates miscdevice with an IOCTL interface to the user space.
/dev/hsmp is for running the hsmp mailbox commands.

Signed-off-by: Suma Hegde &lt;suma.hegde@amd.com&gt;
Signed-off-by: Naveen Krishna Chatradhi &lt;nchatrad@amd.com&gt;
Reviewed-by: Carlos Bilbao &lt;carlos.bilbao@amd.com&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Reviewed-by: Nathan Fontenot &lt;nathan.fontenot@amd.com&gt;
Link: https://lore.kernel.org/r/20220222050501.18789-1-nchatrad@amd.com
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Recent Fam19h EPYC server line of processors from AMD support system
management functionality via HSMP (Host System Management Port) interface.

The Host System Management Port (HSMP) is an interface to provide
OS-level software with access to system management functions via a
set of mailbox registers.

More details on the interface can be found in chapter
"7 Host System Management Port (HSMP)" of the following PPR
https://www.amd.com/system/files/TechDocs/55898_B1_pub_0.50.zip

This patch adds new amd_hsmp module under the drivers/platforms/x86/
which creates miscdevice with an IOCTL interface to the user space.
/dev/hsmp is for running the hsmp mailbox commands.

Signed-off-by: Suma Hegde &lt;suma.hegde@amd.com&gt;
Signed-off-by: Naveen Krishna Chatradhi &lt;nchatrad@amd.com&gt;
Reviewed-by: Carlos Bilbao &lt;carlos.bilbao@amd.com&gt;
Acked-by: Song Liu &lt;song@kernel.org&gt;
Reviewed-by: Nathan Fontenot &lt;nathan.fontenot@amd.com&gt;
Link: https://lore.kernel.org/r/20220222050501.18789-1-nchatrad@amd.com
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>shmbuf.h: add asm/shmbuf.h to UAPI compile-test coverage</title>
<updated>2022-02-17T08:09:37+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2022-02-10T02:11:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4a3233c1a69885aa7e71c48ff39ae11c212ac90a'/>
<id>4a3233c1a69885aa7e71c48ff39ae11c212ac90a</id>
<content type='text'>
asm/shmbuf.h is currently excluded from the UAPI compile-test because of
the errors like follows:

    HDRTEST usr/include/asm/shmbuf.h
  In file included from ./usr/include/asm/shmbuf.h:6,
                   from &lt;command-line&gt;:
  ./usr/include/asm-generic/shmbuf.h:26:33: error: field ‘shm_perm’ has incomplete type
     26 |         struct ipc64_perm       shm_perm;       /* operation perms */
        |                                 ^~~~~~~~
  ./usr/include/asm-generic/shmbuf.h:27:9: error: unknown type name ‘size_t’
     27 |         size_t                  shm_segsz;      /* size of segment (bytes) */
        |         ^~~~~~
  ./usr/include/asm-generic/shmbuf.h:40:9: error: unknown type name ‘__kernel_pid_t’
     40 |         __kernel_pid_t          shm_cpid;       /* pid of creator */
        |         ^~~~~~~~~~~~~~
  ./usr/include/asm-generic/shmbuf.h:41:9: error: unknown type name ‘__kernel_pid_t’
     41 |         __kernel_pid_t          shm_lpid;       /* pid of last operator */
        |         ^~~~~~~~~~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t and by
including proper headers.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
asm/shmbuf.h is currently excluded from the UAPI compile-test because of
the errors like follows:

    HDRTEST usr/include/asm/shmbuf.h
  In file included from ./usr/include/asm/shmbuf.h:6,
                   from &lt;command-line&gt;:
  ./usr/include/asm-generic/shmbuf.h:26:33: error: field ‘shm_perm’ has incomplete type
     26 |         struct ipc64_perm       shm_perm;       /* operation perms */
        |                                 ^~~~~~~~
  ./usr/include/asm-generic/shmbuf.h:27:9: error: unknown type name ‘size_t’
     27 |         size_t                  shm_segsz;      /* size of segment (bytes) */
        |         ^~~~~~
  ./usr/include/asm-generic/shmbuf.h:40:9: error: unknown type name ‘__kernel_pid_t’
     40 |         __kernel_pid_t          shm_cpid;       /* pid of creator */
        |         ^~~~~~~~~~~~~~
  ./usr/include/asm-generic/shmbuf.h:41:9: error: unknown type name ‘__kernel_pid_t’
     41 |         __kernel_pid_t          shm_lpid;       /* pid of last operator */
        |         ^~~~~~~~~~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t and by
including proper headers.

Then, remove the no-header-test entry from user/include/Makefile.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>signal.h: add linux/signal.h and asm/signal.h to UAPI compile-test coverage</title>
<updated>2022-02-17T08:09:36+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2022-02-10T02:11:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=72113d0a7d90d950c7c9a87ab905bffb6bc5752d'/>
<id>72113d0a7d90d950c7c9a87ab905bffb6bc5752d</id>
<content type='text'>
linux/signal.h and asm/signal.h are currently excluded from the UAPI
compile-test because of the errors like follows:

    HDRTEST usr/include/asm/signal.h
  In file included from &lt;command-line&gt;:
  ./usr/include/asm/signal.h:103:9: error: unknown type name ‘size_t’
    103 |         size_t ss_size;
        |         ^~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entries from user/include/Makefile.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
linux/signal.h and asm/signal.h are currently excluded from the UAPI
compile-test because of the errors like follows:

    HDRTEST usr/include/asm/signal.h
  In file included from &lt;command-line&gt;:
  ./usr/include/asm/signal.h:103:9: error: unknown type name ‘size_t’
    103 |         size_t ss_size;
        |         ^~~~~~

The errors can be fixed by replacing size_t with __kernel_size_t.

Then, remove the no-header-test entries from user/include/Makefile.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86: add system attribute to retrieve full set of supported xsave states</title>
<updated>2022-01-28T12:33:32+00:00</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2022-01-26T12:49:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dd6e631220181162478984d2d46dd979e04d8e75'/>
<id>dd6e631220181162478984d2d46dd979e04d8e75</id>
<content type='text'>
Because KVM_GET_SUPPORTED_CPUID is meant to be passed (by simple-minded
VMMs) to KVM_SET_CPUID2, it cannot include any dynamic xsave states that
have not been enabled.  Probing those, for example so that they can be
passed to ARCH_REQ_XCOMP_GUEST_PERM, requires a new ioctl or arch_prctl.
The latter is in fact worse, even though that is what the rest of the
API uses, because it would require supported_xcr0 to be moved from the
KVM module to the kernel just for this use.  In addition, the value
would be nonsensical (or an error would have to be returned) until
the KVM module is loaded in.

Therefore, to limit the growth of system ioctls, add a /dev/kvm
variant of KVM_{GET,HAS}_DEVICE_ATTR, and implement it in x86
with just one group (0) and attribute (KVM_X86_XCOMP_GUEST_SUPP).

Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Because KVM_GET_SUPPORTED_CPUID is meant to be passed (by simple-minded
VMMs) to KVM_SET_CPUID2, it cannot include any dynamic xsave states that
have not been enabled.  Probing those, for example so that they can be
passed to ARCH_REQ_XCOMP_GUEST_PERM, requires a new ioctl or arch_prctl.
The latter is in fact worse, even though that is what the rest of the
API uses, because it would require supported_xcr0 to be moved from the
KVM module to the kernel just for this use.  In addition, the value
would be nonsensical (or an error would have to be returned) until
the KVM module is loaded in.

Therefore, to limit the growth of system ioctls, add a /dev/kvm
variant of KVM_{GET,HAS}_DEVICE_ATTR, and implement it in x86
with just one group (0) and attribute (KVM_X86_XCOMP_GUEST_SUPP).

Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kvm: x86: Add support for getting/setting expanded xstate buffer</title>
<updated>2022-01-14T18:44:41+00:00</updated>
<author>
<name>Guang Zeng</name>
<email>guang.zeng@intel.com</email>
</author>
<published>2022-01-05T12:35:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=be50b2065dfa3d88428fdfdc340d154d96bf6848'/>
<id>be50b2065dfa3d88428fdfdc340d154d96bf6848</id>
<content type='text'>
With KVM_CAP_XSAVE, userspace uses a hardcoded 4KB buffer to get/set
xstate data from/to KVM. This doesn't work when dynamic xfeatures
(e.g. AMX) are exposed to the guest as they require a larger buffer
size.

Introduce a new capability (KVM_CAP_XSAVE2). Userspace VMM gets the
required xstate buffer size via KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2).
KVM_SET_XSAVE is extended to work with both legacy and new capabilities
by doing properly-sized memdup_user() based on the guest fpu container.
KVM_GET_XSAVE is kept for backward-compatible reason. Instead,
KVM_GET_XSAVE2 is introduced under KVM_CAP_XSAVE2 as the preferred
interface for getting xstate buffer (4KB or larger size) from KVM
(Link: https://lkml.org/lkml/2021/12/15/510)

Also, update the api doc with the new KVM_GET_XSAVE2 ioctl.

Signed-off-by: Guang Zeng &lt;guang.zeng@intel.com&gt;
Signed-off-by: Wei Wang &lt;wei.w.wang@intel.com&gt;
Signed-off-by: Jing Liu &lt;jing2.liu@intel.com&gt;
Signed-off-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Signed-off-by: Yang Zhong &lt;yang.zhong@intel.com&gt;
Message-Id: &lt;20220105123532.12586-19-yang.zhong@intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With KVM_CAP_XSAVE, userspace uses a hardcoded 4KB buffer to get/set
xstate data from/to KVM. This doesn't work when dynamic xfeatures
(e.g. AMX) are exposed to the guest as they require a larger buffer
size.

Introduce a new capability (KVM_CAP_XSAVE2). Userspace VMM gets the
required xstate buffer size via KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2).
KVM_SET_XSAVE is extended to work with both legacy and new capabilities
by doing properly-sized memdup_user() based on the guest fpu container.
KVM_GET_XSAVE is kept for backward-compatible reason. Instead,
KVM_GET_XSAVE2 is introduced under KVM_CAP_XSAVE2 as the preferred
interface for getting xstate buffer (4KB or larger size) from KVM
(Link: https://lkml.org/lkml/2021/12/15/510)

Also, update the api doc with the new KVM_GET_XSAVE2 ioctl.

Signed-off-by: Guang Zeng &lt;guang.zeng@intel.com&gt;
Signed-off-by: Wei Wang &lt;wei.w.wang@intel.com&gt;
Signed-off-by: Jing Liu &lt;jing2.liu@intel.com&gt;
Signed-off-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Signed-off-by: Yang Zhong &lt;yang.zhong@intel.com&gt;
Message-Id: &lt;20220105123532.12586-19-yang.zhong@intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/fpu: Extend fpu_xstate_prctl() with guest permissions</title>
<updated>2022-01-07T18:33:03+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2022-01-05T12:35:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=980fe2fddcff21937c93532b4597c8ea450346c1'/>
<id>980fe2fddcff21937c93532b4597c8ea450346c1</id>
<content type='text'>
KVM requires a clear separation of host user space and guest permissions
for dynamic XSTATE components.

Add a guest permissions member to struct fpu and a separate set of prctl()
arguments: ARCH_GET_XCOMP_GUEST_PERM and ARCH_REQ_XCOMP_GUEST_PERM.

The semantics are equivalent to the host user space permission control
except for the following constraints:

  1) Permissions have to be requested before the first vCPU is created

  2) Permissions are frozen when the first vCPU is created to ensure
     consistency. Any attempt to expand permissions via the prctl() after
     that point is rejected.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Jing Liu &lt;jing2.liu@intel.com&gt;
Signed-off-by: Yang Zhong &lt;yang.zhong@intel.com&gt;
Message-Id: &lt;20220105123532.12586-2-yang.zhong@intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
KVM requires a clear separation of host user space and guest permissions
for dynamic XSTATE components.

Add a guest permissions member to struct fpu and a separate set of prctl()
arguments: ARCH_GET_XCOMP_GUEST_PERM and ARCH_REQ_XCOMP_GUEST_PERM.

The semantics are equivalent to the host user space permission control
except for the following constraints:

  1) Permissions have to be requested before the first vCPU is created

  2) Permissions are frozen when the first vCPU is created to ensure
     consistency. Any attempt to expand permissions via the prctl() after
     that point is rejected.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Jing Liu &lt;jing2.liu@intel.com&gt;
Signed-off-by: Yang Zhong &lt;yang.zhong@intel.com&gt;
Message-Id: &lt;20220105123532.12586-2-yang.zhong@intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'kvm-5.16-fixes' into kvm-master</title>
<updated>2021-11-11T16:03:05+00:00</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2021-11-11T16:03:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f5396f2d826823b16de5d2cef6f46ffc66712482'/>
<id>f5396f2d826823b16de5d2cef6f46ffc66712482</id>
<content type='text'>
* Fix misuse of gfn-to-pfn cache when recording guest steal time / preempted status

* Fix selftests on APICv machines

* Fix sparse warnings

* Fix detection of KVM features in CPUID

* Cleanups for bogus writes to MSR_KVM_PV_EOI_EN

* Fixes and cleanups for MSR bitmap handling

* Cleanups for INVPCID

* Make x86 KVM_SOFT_MAX_VCPUS consistent with other architectures
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* Fix misuse of gfn-to-pfn cache when recording guest steal time / preempted status

* Fix selftests on APICv machines

* Fix sparse warnings

* Fix detection of KVM features in CPUID

* Cleanups for bogus writes to MSR_KVM_PV_EOI_EN

* Fixes and cleanups for MSR bitmap handling

* Cleanups for INVPCID

* Make x86 KVM_SOFT_MAX_VCPUS consistent with other architectures
</pre>
</div>
</content>
</entry>
</feed>
