<feed xmlns='http://www.w3.org/2005/Atom'>
<title>wireguard-linux/arch/x86/include/asm/processor.h, branch jd/unified-crypt-queue</title>
<subtitle>WireGuard for the Linux kernel</subtitle>
<id>https://git.zx2c4.com/wireguard-linux/atom/arch/x86/include/asm/processor.h?h=jd%2Funified-crypt-queue</id>
<link rel='self' href='https://git.zx2c4.com/wireguard-linux/atom/arch/x86/include/asm/processor.h?h=jd%2Funified-crypt-queue'/>
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<updated>2020-03-31T18:04:05Z</updated>
<entry>
<title>Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2020-03-31T18:04:05Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-03-31T18:04:05Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=fdf5563a720004199324371c08071b8ea27bd994'/>
<id>urn:sha1:fdf5563a720004199324371c08071b8ea27bd994</id>
<content type='text'>
Pull x86 cleanups from Ingo Molnar:
 "This topic tree contains more commits than usual:

   - most of it are uaccess cleanups/reorganization by Al

   - there's a bunch of prototype declaration (--Wmissing-prototypes)
     cleanups

   - misc other cleanups all around the map"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/mm/set_memory: Fix -Wmissing-prototypes warnings
  x86/efi: Add a prototype for efi_arch_mem_reserve()
  x86/mm: Mark setup_emu2phys_nid() static
  x86/jump_label: Move 'inline' keyword placement
  x86/platform/uv: Add a missing prototype for uv_bau_message_interrupt()
  kill uaccess_try()
  x86: unsafe_put-style macro for sigmask
  x86: x32_setup_rt_frame(): consolidate uaccess areas
  x86: __setup_rt_frame(): consolidate uaccess areas
  x86: __setup_frame(): consolidate uaccess areas
  x86: setup_sigcontext(): list user_access_{begin,end}() into callers
  x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit)
  x86: ia32_setup_rt_frame(): consolidate uaccess areas
  x86: ia32_setup_frame(): consolidate uaccess areas
  x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers
  x86/alternatives: Mark text_poke_loc_init() static
  x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl()
  x86/mm: Drop pud_mknotpresent()
  x86: Replace setup_irq() by request_irq()
  x86/configs: Slightly reduce defconfigs
  ...
</content>
</entry>
<entry>
<title>kill uaccess_try()</title>
<updated>2020-03-26T19:02:14Z</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2020-02-16T02:10:25Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=cf122cfba5b1d9daf64009d143f51dfec4b1705a'/>
<id>urn:sha1:cf122cfba5b1d9daf64009d143f51dfec4b1705a</id>
<content type='text'>
finally

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>x86/vdso: Enable x86 to use common headers</title>
<updated>2020-03-21T14:24:02Z</updated>
<author>
<name>Vincenzo Frascino</name>
<email>vincenzo.frascino@arm.com</email>
</author>
<published>2020-03-20T14:53:48Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=abc22418db02b986fc5623c035507b6357e191ed'/>
<id>urn:sha1:abc22418db02b986fc5623c035507b6357e191ed</id>
<content type='text'>
Enable x86 to use only the common headers in the implementation
of the vDSO library.

Signed-off-by: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lkml.kernel.org/r/20200320145351.32292-24-vincenzo.frascino@arm.com

</content>
</entry>
<entry>
<title>Merge tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx</title>
<updated>2020-01-31T00:11:50Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-01-31T00:11:50Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=ccaaaf6fe5a5e1fffca5cca0f3fc4ec84d7ae752'/>
<id>urn:sha1:ccaaaf6fe5a5e1fffca5cca0f3fc4ec84d7ae752</id>
<content type='text'>
Pull x86 MPX removal from Dave Hansen:
 "MPX requires recompiling applications, which requires compiler
  support. Unfortunately, GCC 9.1 is expected to be be released without
  support for MPX. This means that there was only a relatively small
  window where folks could have ever used MPX. It failed to gain wide
  adoption in the industry, and Linux was the only mainstream OS to ever
  support it widely.

  Support for the feature may also disappear on future processors.

  This set completes the process that we started during the 5.4 merge
  window when the MPX prctl()s were removed. XSAVE support is left in
  place, which allows MPX-using KVM guests to continue to function"

* tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx:
  x86/mpx: remove MPX from arch/x86
  mm: remove arch_bprm_mm_init() hook
  x86/mpx: remove bounds exception code
  x86/mpx: remove build infrastructure
  x86/alternatives: add missing insn.h include
</content>
</entry>
<entry>
<title>x86/mpx: remove MPX from arch/x86</title>
<updated>2020-01-23T18:41:20Z</updated>
<author>
<name>Dave Hansen</name>
<email>dave.hansen@linux.intel.com</email>
</author>
<published>2020-01-23T18:41:20Z</published>
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<id>urn:sha1:45fc24e89b7cc2e227b2f03d99dda0a2204bf383</id>
<content type='text'>
From: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;

MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).

This removes all the remaining (dead at this point) MPX handling
code remaining in the tree.  The only remaining code is the XSAVE
support for MPX state which is currently needd for KVM to handle
VMs which might use MPX.

Cc: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: x86@kernel.org
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
</content>
</entry>
<entry>
<title>x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs</title>
<updated>2020-01-13T17:02:53Z</updated>
<author>
<name>Sean Christopherson</name>
<email>sean.j.christopherson@intel.com</email>
</author>
<published>2019-12-21T04:45:04Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=b47ce1fed42eeb9ac8c07fcda6c795884826723d'/>
<id>urn:sha1:b47ce1fed42eeb9ac8c07fcda6c795884826723d</id>
<content type='text'>
Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill
the capabilities during IA32_FEAT_CTL MSR initialization.

Make the VMX capabilities dependent on IA32_FEAT_CTL and
X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't
possibly support VMX, or when /proc/cpuinfo is not available.

Signed-off-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
</content>
</entry>
<entry>
<title>x86/vmx: Introduce VMX_FEATURES_*</title>
<updated>2020-01-13T16:57:26Z</updated>
<author>
<name>Sean Christopherson</name>
<email>sean.j.christopherson@intel.com</email>
</author>
<published>2019-12-21T04:45:03Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=159348784ff0654291f4c7607fc55e73da8e87e8'/>
<id>urn:sha1:159348784ff0654291f4c7607fc55e73da8e87e8</id>
<content type='text'>
Add a VMX-specific variant of X86_FEATURE_* flags, which will eventually
supplant the synthetic VMX flags defined in cpufeatures word 8.  Use the
Intel-defined layouts for the major VMX execution controls so that their
word entries can be directly populated from their respective MSRs, and
so that the VMX_FEATURE_* flags can be used to define the existing bit
definitions in asm/vmx.h, i.e. force developers to define a VMX_FEATURE
flag when adding support for a new hardware feature.

The majority of Intel's (and compatible CPU's) VMX capabilities are
enumerated via MSRs and not CPUID, i.e. querying /proc/cpuinfo doesn't
naturally provide any insight into the virtualization capabilities of
VMX enabled CPUs.  Commit

  e38e05a85828d ("x86: extended "flags" to show virtualization HW feature
		 in /proc/cpuinfo")

attempted to address the issue by synthesizing select VMX features into
a Linux-defined word in cpufeatures.

Lack of reporting of VMX capabilities via /proc/cpuinfo is problematic
because there is no sane way for a user to query the capabilities of
their platform, e.g. when trying to find a platform to test a feature or
debug an issue that has a hardware dependency.  Lack of reporting is
especially problematic when the user isn't familiar with VMX, e.g. the
format of the MSRs is non-standard, existence of some MSRs is reported
by bits in other MSRs, several "features" from KVM's point of view are
enumerated as 3+ distinct features by hardware, etc...

The synthetic cpufeatures approach has several flaws:

  - The set of synthesized VMX flags has become extremely stale with
    respect to the full set of VMX features, e.g. only one new flag
    (EPT A/D) has been added in the the decade since the introduction of
    the synthetic VMX features.  Failure to keep the VMX flags up to
    date is likely due to the lack of a mechanism that forces developers
    to consider whether or not a new feature is worth reporting.

  - The synthetic flags may incorrectly be misinterpreted as affecting
    kernel behavior, i.e. KVM, the kernel's sole consumer of VMX,
    completely ignores the synthetic flags.

  - New CPU vendors that support VMX have duplicated the hideous code
    that propagates VMX features from MSRs to cpufeatures.  Bringing the
    synthetic VMX flags up to date would exacerbate the copy+paste
    trainwreck.

Define separate VMX_FEATURE flags to set the stage for enumerating VMX
capabilities outside of the cpu_has() framework, and for adding
functional usage of VMX_FEATURE_* to help ensure the features reported
via /proc/cpuinfo is up to date with respect to kernel recognition of
VMX capabilities.

Signed-off-by: Sean Christopherson &lt;sean.j.christopherson@intel.com&gt;
Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lkml.kernel.org/r/20191221044513.21680-10-sean.j.christopherson@intel.com
</content>
</entry>
<entry>
<title>x86/bugs: Move enum taa_mitigations to bugs.c</title>
<updated>2019-12-14T15:06:33Z</updated>
<author>
<name>Borislav Petkov</name>
<email>bp@suse.de</email>
</author>
<published>2019-11-12T20:58:57Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=72c2ce9867d9e8535f8c29eb6d842d1caad281af'/>
<id>urn:sha1:72c2ce9867d9e8535f8c29eb6d842d1caad281af</id>
<content type='text'>
... because it is used only there.

No functional changes.

Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20191112221823.19677-1-bp@alien8.de
</content>
</entry>
<entry>
<title>x86/doublefault/32: Move #DF stack and TSS to cpu_entry_area</title>
<updated>2019-11-26T20:53:34Z</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2019-11-26T17:27:16Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=dc4e0021b00b5a4ecba56fae509217776592b0aa'/>
<id>urn:sha1:dc4e0021b00b5a4ecba56fae509217776592b0aa</id>
<content type='text'>
There are three problems with the current layout of the doublefault
stack and TSS.  First, the TSS is only cacheline-aligned, which is
not enough -- if the hardware portion of the TSS (struct x86_hw_tss)
crosses a page boundary, horrible things happen [0].  Second, the
stack and TSS are global, so simultaneous double faults on different
CPUs will cause massive corruption.  Third, the whole mechanism
won't work if user CR3 is loaded, resulting in a triple fault [1].

Let the doublefault stack and TSS share a page (which prevents the
TSS from spanning a page boundary), make it percpu, and move it into
cpu_entry_area.  Teach the stack dump code about the doublefault
stack.

[0] Real hardware will read past the end of the page onto the next
    *physical* page if a task switch happens.  Virtual machines may
    have any number of bugs, and I would consider it reasonable for
    a VM to summarily kill the guest if it tries to task-switch to
    a page-spanning TSS.

[1] Real hardware triple faults.  At least some VMs seem to hang.
    I'm not sure what's going on.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>x86/traps: Disentangle the 32-bit and 64-bit doublefault code</title>
<updated>2019-11-26T20:53:34Z</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@kernel.org</email>
</author>
<published>2019-11-21T06:12:38Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=93efbde2c331004d8053f04b4bf0ca3e630b474a'/>
<id>urn:sha1:93efbde2c331004d8053f04b4bf0ca3e630b474a</id>
<content type='text'>
The 64-bit doublefault handler is much nicer than the 32-bit one.
As a first step toward unifying them, make the 64-bit handler
self-contained.  This should have no effect no functional effect
except in the odd case of x86_64 with CONFIG_DOUBLEFAULT=n in which
case it will change the logging a bit.

This also gets rid of CONFIG_DOUBLEFAULT configurability on 64-bit
kernels.  It didn't do anything useful -- CONFIG_DOUBLEFAULT=n
didn't actually disable doublefault handling on x86_64.

Signed-off-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
</feed>
