Commit:

  3cded417 ("x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()")

introduced a paravirt op with bool return type [*]

It turns out that the PVOP_CALL*() macros miscompile when rettype is
bool. Code that looked like:

   83 ef 01                sub    $0x1,%edi
   ff 15 32 a0 d8 00       callq  *0xd8a032(%rip)        # ffffffff81e28120 <pv_lock_ops+0x20>
   84 c0                   test   %al,%al

ended up looking like so after PVOP_CALL1() was applied:

   83 ef 01                sub    $0x1,%edi
   48 63 ff                movslq %edi,%rdi
   ff 14 25 20 81 e2 81    callq  *0xffffffff81e28120
   48 85 c0                test   %rax,%rax

Note how it tests the whole of %rax, even though a typical bool return
function only sets %al, like:

  0f 95 c0                setne  %al
  c3                      retq

This is because ____PVOP_CALL() does:

		__ret = (rettype)__eax;

and while regular integer type casts truncate the result, a cast to
bool tests for any !0 value. Fix this by explicitly truncating to
sizeof(rettype) before casting.

[*] The actual bug should've been exposed in commit:
      446f3dc8 ("locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests")
    but that didn't properly implement the paravirt call.
Reported-by: Nkernel test robot <xiaolong.ye@intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 3cded417 ("x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()")
Link: http://lkml.kernel.org/r/20161208154349.346057680@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

While chasing a regression I noticed we potentially patch the wrong
code in native_patch().

If we do not select the native code sequence, we must use the default
patcher, not fall-through the switch case.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel test robot <xiaolong.ye@intel.com>
Fixes: 3cded417 ("x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()")
Link: http://lkml.kernel.org/r/20161208154349.270616999@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

An earlier patch allowed enabling PT and LBR at the same
time on Goldmont. However it also allowed enabling BTS and LBR
at the same time, which is still not supported. Fix this by
bypassing the check only for PT.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: alexander.shishkin@intel.com
Cc: kan.liang@intel.com
Cc: <stable@vger.kernel.org>
Fixes: ccbebba4 ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it")
Link: http://lkml.kernel.org/r/20161209001417.4713-1-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

ldt->size can never be negative. The helper functions take 'unsigned int'
arguments which are assigned from ldt->size. The related user space
user_desc struct member entry_number is unsigned as well.

But ldt->size itself and a few local variables which are related to
ldt->size are type 'int' which makes no sense whatsoever and results in
typecasts which make the eyes bleed.

Clean it up and convert everything which is related to ldt->size to
unsigned it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>

My static checker complains that we put an upper bound on the "size"
argument but not a lower bound.  The checker is not smart enough to know
the possible ranges of "old_mm->context.ldt->size" from
init_new_context_ldt() so it thinks maybe it could be negative.

Let's make it unsigned to silence the warning and future proof the code
a bit.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NAndy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: kernel-janitors@vger.kernel.org
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20161208105602.GA11382@elgon.mountainSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

One include less is always a good thing(tm). Good riddance.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-6-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Reorganize the E400 detection now that we have everything in place:
switch the CPUs to broadcast mode after the LAPIC has been initialized
and remove the facilities that were used previously on the idle path.

Unfortunately static_cpu_has_bug() cannpt be used in the E400 idle routine
because alternatives have been applied when the actual detection happens,
so the static switching does not take effect and the test will stay
false. Use boot_cpu_has_bug() instead which is definitely an improvement
over the RDMSR and the cpumask handling.
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-5-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

AMD CPUs affected by the E400 erratum suffer from the issue that the
local APIC timer stops when the CPU goes into C1E. Unfortunately there
is no way to detect the affected CPUs on early boot. It's only possible
to determine the range of possibly affected CPUs from the family/model
range.

The actual decision whether to enter C1E and thus cause the bug is done
by the firmware and we need to detect that case late, after ACPI has
been initialized.

The current solution is to check in the idle routine whether the CPU is
affected by reading the MSR_K8_INT_PENDING_MSG MSR and checking for the
K8_INTP_C1E_ACTIVE_MASK bits. If one of the bits is set then the CPU is
affected and the system is switched into forced broadcast mode.

This is ineffective and on non-affected CPUs every entry to idle does
the extra RDMSR.

After doing some research it turns out that the bits are visible on the
boot CPU right after the ACPI subsystem is initialized in the early
boot process. So instead of polling for the bits in the idle loop, add
a detection function after acpi_subsystem_init() and check for the MSR
bits. If set, then the X86_BUG_AMD_APIC_C1E is set on the boot CPU and
the TSC is marked unstable when X86_FEATURE_NONSTOP_TSC is not set as it
will stop in C1E state as well.

The switch to broadcast mode cannot be done at this point because the
boot CPU still uses HPET as a clockevent device and the local APIC timer
is not yet calibrated and installed. The switch to broadcast mode on the
affected CPUs needs to be done when the local APIC timer is actually set
up.

This allows to cleanup the amd_e400_idle() function in the next step.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-4-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The workaround for the AMD Erratum E400 (Local APIC timer stops in C1E
state) is a two step process:

 - Selection of the E400 aware idle routine

 - Detection whether the platform is affected

The idle routine selection happens for possibly affected CPUs depending on
family/model/stepping information. These range of CPUs is not necessarily
affected as the decision whether to enable the C1E feature is made by the
firmware. Unfortunately there is no way to query this at early boot.

The current implementation polls a MSR in the E400 aware idle routine to
detect whether the CPU is affected. This is inefficient on non affected
CPUs because every idle entry has to do the MSR read.

There is a better way to detect this before going idle for the first time
which requires to seperate the bug flags:

  X86_BUG_AMD_E400 	- Selects the E400 aware idle routine and
  			  enables the detection
			  
  X86_BUG_AMD_APIC_C1E  - Set when the platform is affected by E400

Replace the current X86_BUG_AMD_APIC_C1E usage by the new X86_BUG_AMD_E400
bug bit to select the idle routine which currently does an unconditional
detection poll. X86_BUG_AMD_APIC_C1E is going to be used in later patches
to remove the MSR polling and simplify the handling of this misfeature.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-3-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Will be used in a later patch to set bug bits for bugs which need late
detection.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-2-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch allows XDP prog to extend/remove the packet
data at the head (like adding or removing header).  It is
done by adding a new XDP helper bpf_xdp_adjust_head().

It also renames bpf_helper_changes_skb_data() to
bpf_helper_changes_pkt_data() to better reflect
that XDP prog does not work on skb.

This patch adds one "xdp_adjust_head" bit to bpf_prog for the
XDP-capable driver to check if the XDP prog requires
bpf_xdp_adjust_head() support.  The driver can then decide
to error out during XDP_SETUP_PROG.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I recently encountered wreckage because access_ok() was used where it
should not be, add an explicit WARN when access_ok() is used wrongly.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Lukasz reported that perf stat counters overflow handling is broken on KNL/SLM.

Both these parts have full_width_write set, and that does indeed have
a problem. In order to deal with counter wrap, we must sample the
counter at at least half the counter period (see also the sampling
theorem) such that we can unambiguously reconstruct the count.

However commit:

  069e0c3c ("perf/x86/intel: Support full width counting")

sets the sampling interval to the full period, not half.

Fixing that exposes another issue, in that we must not sign extend the
delta value when we shift it right; the counter cannot have
decremented after all.

With both these issues fixed, counter overflow functions correctly
again.
Reported-by: NLukasz Odzioba <lukasz.odzioba@intel.com>
Tested-by: NLiang, Kan <kan.liang@intel.com>
Tested-by: NOdzioba, Lukasz <lukasz.odzioba@intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org
Fixes: 069e0c3c ("perf/x86/intel: Support full width counting")
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The Knights Mill is enough close to Knights Landing so the path reuses
C-state residency support of the latter.
Signed-off-by: NPiotr Luc <piotr.luc@intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20161201000853.18260-1-piotr.luc@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Right now CONFIG_SCHED_MC_PRIO has X86_INTEL_PSTATE as a dependency,
which is not enabled by default and which hides the CONFIG_SCHED_MC_PRIO
hardware-enabling feature.

Select X86_INTEL_PSTATE instead, plus its dependency (CPU_FREQ), if the
user enables CONFIG_SCHED_MC_PRIO=y.

(Also align the CONFIG_SCHED_MC_PRIO Kconfig help text in standard style.)

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: bp@suse.de
Cc: jolsa@redhat.com
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Rename CONFIG_SCHED_ITMT for Intel Turbo Boost Max Technology 3.0
to CONFIG_SCHED_MC_PRIO.  This makes the configuration extensible
in future to other architectures that wish to similarly establish
CPU core priorities support in the scheduler.

The description in Kconfig is updated to reflect this change with
added details for better clarity.  The configuration is explicitly
default-y, to enable the feature on CPUs that have this feature.

It has no effect on non-TBM3 CPUs.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Cc: jolsa@redhat.com
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/2b2ee29d93e3f162922d72d0165a1405864fbb23.1480444902.git.tim.c.chen@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

asm/mutex.h is gone from the locking tree, which makes sched/core break the build.

Use linux/mutex.h instead, which is the canonical method.

Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: bp@suse.de
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

In x86's include/asm/Kbuild three entries are appended to the genhdr-y make
variable:

    genhdr-y += unistd_32.h
    genhdr-y += unistd_64.h
    genhdr-y += unistd_x32.h

The same entries are also appended to that variable in
include/uapi/asm/Kbuild. So commit:

  10b63956 ("UAPI: Plumb the UAPI Kbuilds into the user header installation and checking")

... removed these three entries from include/asm/Kbuild. But, apparently, some
merge conflict resolution re-added them.

The net effect is, in short, that the genhdr-y make variable contains these
file names twice and, as a consequence, that the corresponding headers get
installed twice. And so the build prints:

  INSTALL usr/include/asm/ (65 files)

... while in reality only 62 files are installed in that directory.

Nothing breaks because of all that, but it's a good idea to finally remove
these unneeded entries nevertheless.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1480077707-2837-1-git-send-email-pebolle@tiscali.nlSigned-off-by: NIngo Molnar <mingo@kernel.org>

The make variable KBUILD_CFLAGS contains $(LINUXINCLUDE). But the build
already picks up $(LINUXINCLUDE) from scripts/Makefile.lib. The net effect
is that the (long) list of include directories is used twice.

This is harmless but pointless. So stop using $(LINUXINCLUDE) twice.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1480077514-2586-1-git-send-email-pebolle@tiscali.nlSigned-off-by: NIngo Molnar <mingo@kernel.org>

My attempt at fixing some KASAN false positive warnings was rather brain
dead, and it broke the guess unwinder.  With frame pointers disabled,
/proc/<pid>/stack is broken:

  # cat /proc/1/stack
  [<ffffffffffffffff>] 0xffffffffffffffff

Restore the code flow to more closely resemble its previous state, while
still using READ_ONCE_NOCHECK() macros to silence KASAN false positives.
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c2d75e03 ("x86/unwind: Prevent KASAN false positive warnings in guess unwinder")
Link: http://lkml.kernel.org/r/b824f92c2c22eca5ec95ac56bd2a7c84cf0b9df9.1480309971.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Fixes below warning with clang:

  In file included from ../arch/x86/tools/relocs_64.c:17:
  ../arch/x86/tools/relocs.c:977:6: warning: variable 'do_reloc' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
Signed-off-by: NPeter Foley <pefoley2@pefoley.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161126222229.673-1-pefoley2@pefoley.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Fix:

  arch/x86/platform/olpc/olpc-xo15-sci.c:199:12: warning: ‘xo15_sci_resume’
  defined but not used [-Wunused-function]
   static int xo15_sci_resume(struct device *dev)
              ^

which I see in randconfig builds here.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161126142706.13602-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Single-stepping through head_64.S made me look at the fixmap page PTEs
fixup loop:

So we're going through the whole level2_fixmap_pgt 4K page, looking at
whether PAGE_PRESENT is set in those PTEs and add the delta between
where we're compiled to run and where we actually end up running.

However, if that delta is 0 (most cases) we go through all those 512
PTEs for no reason at all. Oh well, we add 0 but that's no reason to me.

Skipping that useless fixup gives us a boot speedup of 0.004 seconds in
my guest. Not a lot but considering how cheap it is, I'll take it. Here
is the printk time difference:

before:
  ...
  [    0.000000] tsc: Marking TSC unstable due to TSCs unsynchronized
  [    0.013590] Calibrating delay loop (skipped), value calculated using timer frequency..
		8027.17 BogoMIPS (lpj=16054348)
  [    0.017094] pid_max: default: 32768 minimum: 301
  ...

after:
  ...
  [    0.000000] tsc: Marking TSC unstable due to TSCs unsynchronized
  [    0.009587] Calibrating delay loop (skipped), value calculated using timer frequency..
		8026.86 BogoMIPS (lpj=16053724)
  [    0.013090] pid_max: default: 32768 minimum: 301
  ...

For the other two changes converting naked numbers to defines:

  # arch/x86/kernel/head_64.o:

   text    data     bss     dec     hex filename
   1124  290864    4096  296084   48494 head_64.o.before
   1124  290864    4096  296084   48494 head_64.o.after

md5:
   87086e202588939296f66e892414ffe2  head_64.o.before.asm
   87086e202588939296f66e892414ffe2  head_64.o.after.asm
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161125111448.23623-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

... instead of naked numbers like the rest of the asm does in this file.

No code changed:

  # arch/x86/kernel/head_64.o:

   text    data     bss     dec     hex filename
   1124  290864    4096  296084   48494 head_64.o.before
   1124  290864    4096  296084   48494 head_64.o.after

md5:
   87086e202588939296f66e892414ffe2  head_64.o.before.asm
   87086e202588939296f66e892414ffe2  head_64.o.after.asm
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161124210550.15025-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some Intel cores in a package can be boosted to a higher turbo frequency
with ITMT 3.0 technology. The scheduler can use the asymmetric packing
feature to move tasks to the more capable cores.

If ITMT is enabled, add SD_ASYM_PACKING flag to the thread and core
sched domains to enable asymmetric packing.
Co-developed-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: linux-pm@vger.kernel.org
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/9bbb885bedbef4eb50e197305eb16b160cff0831.1479844244.git.tim.c.chen@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Intel Turbo Boost Max Technology 3.0 (ITMT) feature
allows some cores to be boosted to higher turbo
frequency than others.

Add /proc/sys/kernel/sched_itmt_enabled so operator
can enable/disable scheduling of tasks that favor cores
with higher turbo boost frequency potential.

By default, system that is ITMT capable and single
socket has this feature turned on.  It is more likely
to be lightly loaded and operates in Turbo range.

When there is a change in the ITMT scheduling operation
desired, a rebuild of the sched domain is initiated
so the scheduler can set up sched domains with appropriate
flag to enable/disable ITMT scheduling operations.
Co-developed-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: linux-pm@vger.kernel.org
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/07cc62426a28bad57b01ab16bb903a9c84fa5421.1479844244.git.tim.c.chen@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum
turbo frequencies of some cores in a CPU package may be higher than for
the other cores in the same package.  In that case, better performance
(and possibly lower energy consumption as well) can be achieved by
making the scheduler prefer to run tasks on the CPUs with higher max
turbo frequencies.

To that end, set up a core priority metric to abstract the core
preferences based on the maximum turbo frequency.  In that metric,
the cores with higher maximum turbo frequencies are higher-priority
than the other cores in the same package and that causes the scheduler
to favor them when making load-balancing decisions using the asymmertic
packing approach.  At the same time, the priority of SMT threads with a
higher CPU number is reduced so as to avoid scheduling tasks on all of
the threads that belong to a favored core before all of the other cores
have been given a task to run.

The priority metric will be initialized by the P-state driver with the
help of the sched_set_itmt_core_prio() function.  The P-state driver
will also determine whether or not ITMT is supported by the platform
and will call sched_set_itmt_support() to indicate that.
Co-developed-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: linux-pm@vger.kernel.org
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The scheduler calls arch_update_cpu_topology() to check whether the
scheduler domains have to be rebuilt.

So far x86 has no requirement for this, but the upcoming ITMT support
makes this necessary.

Request the rebuild when the x86 internal update flag is set.
Suggested-by: NMorten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: linux-pm@vger.kernel.org
Cc: peterz@infradead.org
Cc: jolsa@redhat.com
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/bfbf5591276ec60b2af2da798adc1060df1e2a5f.1479844244.git.tim.c.chen@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Split irqchip allows pic and ioapic routes to be used without them being
created, which results in NULL access.  Check for NULL and avoid it.
(The setup is too racy for a nicer solutions.)

Found by syzkaller:

  general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 3 PID: 11923 Comm: kworker/3:2 Not tainted 4.9.0-rc5+ #27
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Workqueue: events irqfd_inject
  task: ffff88006a06c7c0 task.stack: ffff880068638000
  RIP: 0010:[...]  [...] __lock_acquire+0xb35/0x3380 kernel/locking/lockdep.c:3221
  RSP: 0000:ffff88006863ea20  EFLAGS: 00010006
  RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
  RDX: 0000000000000039 RSI: 0000000000000000 RDI: 1ffff1000d0c7d9e
  RBP: ffff88006863ef58 R08: 0000000000000001 R09: 0000000000000000
  R10: 00000000000001c8 R11: 0000000000000000 R12: ffff88006a06c7c0
  R13: 0000000000000001 R14: ffffffff8baab1a0 R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff88006d100000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000004abdd0 CR3: 000000003e2f2000 CR4: 00000000000026e0
  Stack:
   ffffffff894d0098 1ffff1000d0c7d56 ffff88006863ecd0 dffffc0000000000
   ffff88006a06c7c0 0000000000000000 ffff88006863ecf8 0000000000000082
   0000000000000000 ffffffff815dd7c1 ffffffff00000000 ffffffff00000000
  Call Trace:
   [...] lock_acquire+0x2a2/0x790 kernel/locking/lockdep.c:3746
   [...] __raw_spin_lock include/linux/spinlock_api_smp.h:144
   [...] _raw_spin_lock+0x38/0x50 kernel/locking/spinlock.c:151
   [...] spin_lock include/linux/spinlock.h:302
   [...] kvm_ioapic_set_irq+0x4c/0x100 arch/x86/kvm/ioapic.c:379
   [...] kvm_set_ioapic_irq+0x8f/0xc0 arch/x86/kvm/irq_comm.c:52
   [...] kvm_set_irq+0x239/0x640 arch/x86/kvm/../../../virt/kvm/irqchip.c:101
   [...] irqfd_inject+0xb4/0x150 arch/x86/kvm/../../../virt/kvm/eventfd.c:60
   [...] process_one_work+0xb40/0x1ba0 kernel/workqueue.c:2096
   [...] worker_thread+0x214/0x18a0 kernel/workqueue.c:2230
   [...] kthread+0x328/0x3e0 kernel/kthread.c:209
   [...] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Fixes: 49df6397 ("KVM: x86: Split the APIC from the rest of IRQCHIP.")
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

KVM was using arrays of size KVM_MAX_VCPUS with vcpu_id, but ID can be
bigger that the maximal number of VCPUs, resulting in out-of-bounds
access.

Found by syzkaller:

  BUG: KASAN: slab-out-of-bounds in __apic_accept_irq+0xb33/0xb50 at addr [...]
  Write of size 1 by task a.out/27101
  CPU: 1 PID: 27101 Comm: a.out Not tainted 4.9.0-rc5+ #49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __apic_accept_irq+0xb33/0xb50 arch/x86/kvm/lapic.c:905
   [...] kvm_apic_set_irq+0x10e/0x180 arch/x86/kvm/lapic.c:495
   [...] kvm_irq_delivery_to_apic+0x732/0xc10 arch/x86/kvm/irq_comm.c:86
   [...] ioapic_service+0x41d/0x760 arch/x86/kvm/ioapic.c:360
   [...] ioapic_set_irq+0x275/0x6c0 arch/x86/kvm/ioapic.c:222
   [...] kvm_ioapic_inject_all arch/x86/kvm/ioapic.c:235
   [...] kvm_set_ioapic+0x223/0x310 arch/x86/kvm/ioapic.c:670
   [...] kvm_vm_ioctl_set_irqchip arch/x86/kvm/x86.c:3668
   [...] kvm_arch_vm_ioctl+0x1a08/0x23c0 arch/x86/kvm/x86.c:3999
   [...] kvm_vm_ioctl+0x1fa/0x1a70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3099
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Fixes: af1bae54 ("KVM: x86: bump KVM_MAX_VCPU_ID to 1023")
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

em_jmp_far and em_ret_far assumed that setting IP can only fail in 64
bit mode, but syzkaller proved otherwise (and SDM agrees).
Code segment was restored upon failure, but it was left uninitialized
outside of long mode, which could lead to a leak of host kernel stack.
We could have fixed that by always saving and restoring the CS, but we
take a simpler approach and just break any guest that manages to fail
as the error recovery is error-prone and modern CPUs don't need emulator
for this.

Found by syzkaller:

  WARNING: CPU: 2 PID: 3668 at arch/x86/kvm/emulate.c:2217 em_ret_far+0x428/0x480
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 2 PID: 3668 Comm: syz-executor Not tainted 4.9.0-rc4+ #49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __dump_stack lib/dump_stack.c:15
   [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51
   [...] panic+0x1b7/0x3a3 kernel/panic.c:179
   [...] __warn+0x1c4/0x1e0 kernel/panic.c:542
   [...] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585
   [...] em_ret_far+0x428/0x480 arch/x86/kvm/emulate.c:2217
   [...] em_ret_far_imm+0x17/0x70 arch/x86/kvm/emulate.c:2227
   [...] x86_emulate_insn+0x87a/0x3730 arch/x86/kvm/emulate.c:5294
   [...] x86_emulate_instruction+0x520/0x1ba0 arch/x86/kvm/x86.c:5545
   [...] emulate_instruction arch/x86/include/asm/kvm_host.h:1116
   [...] complete_emulated_io arch/x86/kvm/x86.c:6870
   [...] complete_emulated_mmio+0x4e9/0x710 arch/x86/kvm/x86.c:6934
   [...] kvm_arch_vcpu_ioctl_run+0x3b7a/0x5a90 arch/x86/kvm/x86.c:6978
   [...] kvm_vcpu_ioctl+0x61e/0xdd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2557
   [...] vfs_ioctl fs/ioctl.c:43
   [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
   [...] SYSC_ioctl fs/ioctl.c:694
   [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
   [...] entry_SYSCALL_64_fastpath+0x1f/0xc2
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Fixes: d1442d85 ("KVM: x86: Handle errors when RIP is set during far jumps")
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Cluster xAPIC delivery incorrectly assumed that dest_id <= 0xff.
With enabled KVM_X2APIC_API_USE_32BIT_IDS in KVM_CAP_X2APIC_API, a
userspace can send an interrupt with dest_id that results in
out-of-bounds access.

Found by syzkaller:

  BUG: KASAN: slab-out-of-bounds in kvm_irq_delivery_to_apic_fast+0x11fa/0x1210 at addr ffff88003d9ca750
  Read of size 8 by task syz-executor/22923
  CPU: 0 PID: 22923 Comm: syz-executor Not tainted 4.9.0-rc4+ #49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __dump_stack lib/dump_stack.c:15
   [...] dump_stack+0xb3/0x118 lib/dump_stack.c:51
   [...] kasan_object_err+0x1c/0x70 mm/kasan/report.c:156
   [...] print_address_description mm/kasan/report.c:194
   [...] kasan_report_error mm/kasan/report.c:283
   [...] kasan_report+0x231/0x500 mm/kasan/report.c:303
   [...] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:329
   [...] kvm_irq_delivery_to_apic_fast+0x11fa/0x1210 arch/x86/kvm/lapic.c:824
   [...] kvm_irq_delivery_to_apic+0x132/0x9a0 arch/x86/kvm/irq_comm.c:72
   [...] kvm_set_msi+0x111/0x160 arch/x86/kvm/irq_comm.c:157
   [...] kvm_send_userspace_msi+0x201/0x280 arch/x86/kvm/../../../virt/kvm/irqchip.c:74
   [...] kvm_vm_ioctl+0xba5/0x1670 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3015
   [...] vfs_ioctl fs/ioctl.c:43
   [...] do_vfs_ioctl+0x18c/0x1040 fs/ioctl.c:679
   [...] SYSC_ioctl fs/ioctl.c:694
   [...] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
   [...] entry_SYSCALL_64_fastpath+0x1f/0xc2
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Fixes: e45115b6 ("KVM: x86: use physical LAPIC array for logical x2APIC")
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

'm_io' is stored in 6 bits so it's a number in the 0-63 range.  Static
analysis tools complain that 1 << 63 will wrap so I have changed it to
1ULL << m_io.

This code is over three years old so presumably the bug doesn't happen
very frequently in real life or someone would have complained by now.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Fixes: b15cc4a1 ("x86, uv, uv3: Update x2apic Support for SGI UV3")
Link: http://lkml.kernel.org/r/20161123221908.GA23997@mwandaSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit:

  90954e7b ("x86/coredump: Use pr_reg size, rather that TIF_IA32 flag")

changed the coredumping code to construct the elf coredump file according
to register set size - and that's good: if binary crashes with 32-bit code
selector, generate 32-bit ELF core, otherwise - 64-bit core.

That was made for restoring 32-bit applications on x86_64: we want
32-bit application after restore to generate 32-bit ELF dump on crash.

All was quite good and recently I started reworking 32-bit applications
dumping part of CRIU: now it has two parasites (32 and 64) for seizing
compat/native tasks, after rework it'll have one parasite, working in
64-bit mode, to which 32-bit prologue long-jumps during infection.

And while it has worked for my work machine, in VM with
!CONFIG_X86_X32_ABI during reworking I faced that segfault in 32-bit
binary, that has long-jumped to 64-bit mode results in dereference
of garbage:

 32-victim[19266]: segfault at f775ef65 ip 00000000f775ef65 sp 00000000f776aa50 error 14
 BUG: unable to handle kernel paging request at ffffffffffffffff
 IP: [<ffffffff81332ce0>] strlen+0x0/0x20
 [...]
 Call Trace:
  [] elf_core_dump+0x11a9/0x1480
  [] do_coredump+0xa6b/0xe60
  [] get_signal+0x1a8/0x5c0
  [] do_signal+0x23/0x660
  [] exit_to_usermode_loop+0x34/0x65
  [] prepare_exit_to_usermode+0x2f/0x40
  [] retint_user+0x8/0x10

That's because we have 64-bit registers set (with according total size)
and we're writing it to elf_thread_core_info which has smaller size
on !CONFIG_X86_X32_ABI. That lead to overwriting ELF notes part.

Tested on 32-, 64-bit ELF crashes and on 32-bit binaries that have
jumped with 64-bit code selector - all is readable with gdb.
Signed-off-by: NDmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Fixes: 90954e7b ("x86/coredump: Use pr_reg size, rather that TIF_IA32 flag")
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Intel Xeons from Ivy Bridge onwards support a processor identification
number set in the factory. To the user this is a handy unique number to
identify a particular CPU. Intel can decode this to the fab/production
run to track errors. On systems that have it, include it in the machine
check record. I'm told that this would be helpful for users that run
large data centers with multi-socket servers to keep track of which CPUs
are seeing errors.

Boris:
* Add some clarifying comments and spacing.
* Mask out [63:2] in the disabled-but-not-locked case
* Call the MSR variable "val" for more readability.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20161123114855.njguoaygp3qnbkia@pd.tnicSigned-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Avoid the pointless function call to pv_lock_ops.vcpu_is_preempted()
when a paravirt spinlock enabled kernel is ran on native hardware.

Do this by patching out the CALL instruction with "XOR %RAX,%RAX"
which has the same effect (0 return value).
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: jgross@suse.com
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Support the vcpu_is_preempted() functionality under Xen. This will
enhance lock performance on overcommitted hosts (more runnable vCPUs
than physical CPUs in the system) as doing busy waits for preempted
vCPUs will hurt system performance far worse than early yielding.

A quick test (4 vCPUs on 1 physical CPU doing a parallel build job
with "make -j 8") reduced system time by about 5% with this patch.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NPan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: xen-devel-request@lists.xenproject.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1478077718-37424-11-git-send-email-xinhui.pan@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Support the vcpu_is_preempted() functionality under KVM. This will
enhance lock performance on overcommitted hosts (more runnable vCPUs
than physical CPUs in the system) as doing busy waits for preempted
vCPUs will hurt system performance far worse than early yielding.

struct kvm_steal_time::preempted indicates that if one vCPU is running or
not after commit "x86, kvm/x86.c: support vCPU preempted check".

 unix benchmark result:
 host:  kernel 4.8.1, i5-4570, 4 cpus
 guest: kernel 4.8.1, 8 vcpus

         test-case                       after-patch       before-patch
 Execl Throughput                       |    18307.9 lps  |    11701.6 lps
 File Copy 1024 bufsize 2000 maxblocks  |  1352407.3 KBps |   790418.9 KBps
 File Copy 256 bufsize 500 maxblocks    |   367555.6 KBps |   222867.7 KBps
 File Copy 4096 bufsize 8000 maxblocks  |  3675649.7 KBps |  1780614.4 KBps
 Pipe Throughput                        | 11872208.7 lps  | 11855628.9 lps
 Pipe-based Context Switching           |  1495126.5 lps  |  1490533.9 lps
 Process Creation                       |    29881.2 lps  |    28572.8 lps
 Shell Scripts (1 concurrent)           |    23224.3 lpm  |    22607.4 lpm
 Shell Scripts (8 concurrent)           |     3531.4 lpm  |     3211.9 lpm
 System Call Overhead                   | 10385653.0 lps  | 10419979.0 lps
Signed-off-by: NPan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: jgross@suse.com
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: rkrcmar@redhat.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: xen-devel-request@lists.xenproject.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1478077718-37424-10-git-send-email-xinhui.pan@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Support the vcpu_is_preempted() functionality under KVM. This will
enhance lock performance on overcommitted hosts (more runnable vCPUs
than physical CPUs in the system) as doing busy waits for preempted
vCPUs will hurt system performance far worse than early yielding.

Use struct kvm_steal_time::preempted to indicate that if a vCPU
is running or not.
Signed-off-by: NPan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: jgross@suse.com
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: rkrcmar@redhat.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: xen-devel-request@lists.xenproject.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1478077718-37424-9-git-send-email-xinhui.pan@linux.vnet.ibm.com
[ Typo fixes. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Optimize spinlock and mutex busy-loops by providing a vcpu_is_preempted(cpu)
function on KVM and Xen platforms.

Extend the pv_lock_ops interface accordingly and implement the callbacks
on KVM and Xen.
Signed-off-by: NPan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
[ Translated to English. ]
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: jgross@suse.com
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: rkrcmar@redhat.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: xen-devel-request@lists.xenproject.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1478077718-37424-7-git-send-email-xinhui.pan@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>