1. 02 9月, 2020 1 次提交
  2. 18 3月, 2020 1 次提交
  3. 15 1月, 2020 2 次提交
    • K
      ICX: perf/x86: Disable extended registers for non-supported PMUs · 43ccd37f
      Kan Liang 提交于
      commit e321d02db87af7840da29ef833a2a71fc0eab198 upstream.
      
      The perf fuzzer caused Skylake machine to crash:
      
      [ 9680.085831] Call Trace:
      [ 9680.088301]  <IRQ>
      [ 9680.090363]  perf_output_sample_regs+0x43/0xa0
      [ 9680.094928]  perf_output_sample+0x3aa/0x7a0
      [ 9680.099181]  perf_event_output_forward+0x53/0x80
      [ 9680.103917]  __perf_event_overflow+0x52/0xf0
      [ 9680.108266]  ? perf_trace_run_bpf_submit+0xc0/0xc0
      [ 9680.113108]  perf_swevent_hrtimer+0xe2/0x150
      [ 9680.117475]  ? check_preempt_wakeup+0x181/0x230
      [ 9680.122091]  ? check_preempt_curr+0x62/0x90
      [ 9680.126361]  ? ttwu_do_wakeup+0x19/0x140
      [ 9680.130355]  ? try_to_wake_up+0x54/0x460
      [ 9680.134366]  ? reweight_entity+0x15b/0x1a0
      [ 9680.138559]  ? __queue_work+0x103/0x3f0
      [ 9680.142472]  ? update_dl_rq_load_avg+0x1cd/0x270
      [ 9680.147194]  ? timerqueue_del+0x1e/0x40
      [ 9680.151092]  ? __remove_hrtimer+0x35/0x70
      [ 9680.155191]  __hrtimer_run_queues+0x100/0x280
      [ 9680.159658]  hrtimer_interrupt+0x100/0x220
      [ 9680.163835]  smp_apic_timer_interrupt+0x6a/0x140
      [ 9680.168555]  apic_timer_interrupt+0xf/0x20
      [ 9680.172756]  </IRQ>
      
      The XMM registers can only be collected by PEBS hardware events on the
      platforms with PEBS baseline support, e.g. Icelake, not software/probe
      events.
      
      Add capabilities flag PERF_PMU_CAP_EXTENDED_REGS to indicate the PMU
      which support extended registers. For X86, the extended registers are
      XMM registers.
      
      Add has_extended_regs() to check if extended registers are applied.
      
      The generic code define the mask of extended registers as 0 if arch
      headers haven't overridden it.
      Originally-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Reported-by: NVince Weaver <vincent.weaver@maine.edu>
      Signed-off-by: NKan Liang <kan.liang@linux.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>
      Fixes: 878068ea270e ("perf/x86: Support outputting XMM registers")
      Link: https://lkml.kernel.org/r/1559081314-9714-1-git-send-email-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NShen, Xiaochen <xiaochen.shen@intel.com>
      Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
      Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
      43ccd37f
    • K
      ICX: perf/x86: Support outputting XMM registers · 88cad76a
      Kan Liang 提交于
      commit 878068ea270ea82767ff1d26c91583263c81fba0 upstream.
      
      Starting from Icelake, XMM registers can be collected in PEBS record.
      But current code only output the pt_regs.
      
      Add a new struct x86_perf_regs for both pt_regs and xmm_regs. The
      xmm_regs will be used later to keep a pointer to PEBS record which has
      XMM information.
      
      XMM registers are 128 bit. To simplify the code, they are handled like
      two different registers, which means setting two bits in the register
      bitmap. This also allows only sampling the lower 64bit bits in XMM.
      
      The index of XMM registers starts from 32. There are 16 XMM registers.
      So all reserved space for regs are used. Remove REG_RESERVED.
      
      Add PERF_REG_X86_XMM_MAX, which stands for the max number of all x86
      regs including both GPRs and XMM.
      
      Add REG_NOSUPPORT for 32bit to exclude unsupported registers.
      
      Previous platforms can not collect XMM information in PEBS record.
      Adding pebs_no_xmm_regs to indicate the unsupported platforms.
      
      The common code still validates the supported registers. However, it
      cannot check model specific registers, e.g. XMM. Add extra check in
      x86_pmu_hw_config() to reject invalid config of regs_user and regs_intr.
      The regs_user never supports XMM collection.
      The regs_intr only supports XMM collection when sampling PEBS event on
      icelake and later platforms.
      Originally-by: NAndi Kleen <ak@linux.intel.com>
      Suggested-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: NKan Liang <kan.liang@linux.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: acme@kernel.org
      Cc: jolsa@kernel.org
      Link: https://lkml.kernel.org/r/20190402194509.2832-3-kan.liang@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NShen, Xiaochen <xiaochen.shen@intel.com>
      Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
      Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
      88cad76a
  4. 05 5月, 2019 1 次提交
  5. 20 9月, 2018 1 次提交
    • V
      x86/kvm/lapic: always disable MMIO interface in x2APIC mode · d1766202
      Vitaly Kuznetsov 提交于
      When VMX is used with flexpriority disabled (because of no support or
      if disabled with module parameter) MMIO interface to lAPIC is still
      available in x2APIC mode while it shouldn't be (kvm-unit-tests):
      
      PASS: apic_disable: Local apic enabled in x2APIC mode
      PASS: apic_disable: CPUID.1H:EDX.APIC[bit 9] is set
      FAIL: apic_disable: *0xfee00030: 50014
      
      The issue appears because we basically do nothing while switching to
      x2APIC mode when APIC access page is not used. apic_mmio_{read,write}
      only check if lAPIC is disabled before proceeding to actual write.
      
      When APIC access is virtualized we correctly manipulate with VMX controls
      in vmx_set_virtual_apic_mode() and we don't get vmexits from memory writes
      in x2APIC mode so there's no issue.
      
      Disabling MMIO interface seems to be easy. The question is: what do we
      do with these reads and writes? If we add apic_x2apic_mode() check to
      apic_mmio_in_range() and return -EOPNOTSUPP these reads and writes will
      go to userspace. When lAPIC is in kernel, Qemu uses this interface to
      inject MSIs only (see kvm_apic_mem_write() in hw/i386/kvm/apic.c). This
      somehow works with disabled lAPIC but when we're in xAPIC mode we will
      get a real injected MSI from every write to lAPIC. Not good.
      
      The simplest solution seems to be to just ignore writes to the region
      and return ~0 for all reads when we're in x2APIC mode. This is what this
      patch does. However, this approach is inconsistent with what currently
      happens when flexpriority is enabled: we allocate APIC access page and
      create KVM memory region so in x2APIC modes all reads and writes go to
      this pre-allocated page which is, btw, the same for all vCPUs.
      Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      d1766202
  6. 06 8月, 2018 2 次提交
    • W
      KVM: X86: Implement PV IPIs in linux guest · aaffcfd1
      Wanpeng Li 提交于
      Implement paravirtual apic hooks to enable PV IPIs for KVM if the "send IPI"
      hypercall is available.  The hypercall lets a guest send IPIs, with
      at most 128 destinations per hypercall in 64-bit mode and 64 vCPUs per
      hypercall in 32-bit mode.
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
      Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      aaffcfd1
    • J
      kvm: nVMX: Introduce KVM_CAP_NESTED_STATE · 8fcc4b59
      Jim Mattson 提交于
      For nested virtualization L0 KVM is managing a bit of state for L2 guests,
      this state can not be captured through the currently available IOCTLs. In
      fact the state captured through all of these IOCTLs is usually a mix of L1
      and L2 state. It is also dependent on whether the L2 guest was running at
      the moment when the process was interrupted to save its state.
      
      With this capability, there are two new vcpu ioctls: KVM_GET_NESTED_STATE
      and KVM_SET_NESTED_STATE. These can be used for saving and restoring a VM
      that is in VMX operation.
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: x86@kernel.org
      Cc: kvm@vger.kernel.org
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NJim Mattson <jmattson@google.com>
      [karahmed@ - rename structs and functions and make them ready for AMD and
                   address previous comments.
                 - handle nested.smm state.
                 - rebase & a bit of refactoring.
                 - Merge 7/8 and 8/8 into one patch. ]
      Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      8fcc4b59
  7. 18 5月, 2018 1 次提交
    • M
      kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME · 633711e8
      Michael S. Tsirkin 提交于
      KVM_HINTS_DEDICATED seems to be somewhat confusing:
      
      Guest doesn't really care whether it's the only task running on a host
      CPU as long as it's not preempted.
      
      And there are more reasons for Guest to be preempted than host CPU
      sharing, for example, with memory overcommit it can get preempted on a
      memory access, post copy migration can cause preemption, etc.
      
      Let's call it KVM_HINTS_REALTIME which seems to better
      match what guests expect.
      
      Also, the flag most be set on all vCPUs - current guests assume this.
      Note so in the documentation.
      Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      633711e8
  8. 27 4月, 2018 1 次提交
    • A
      x86/ipc: Fix x32 version of shmid64_ds and msqid64_ds · 1a512c08
      Arnd Bergmann 提交于
      A bugfix broke the x32 shmid64_ds and msqid64_ds data structure layout
      (as seen from user space)  a few years ago: Originally, __BITS_PER_LONG
      was defined as 64 on x32, so we did not have padding after the 64-bit
      __kernel_time_t fields, After __BITS_PER_LONG got changed to 32,
      applications would observe extra padding.
      
      In other parts of the uapi headers we seem to have a mix of those
      expecting either 32 or 64 on x32 applications, so we can't easily revert
      the path that broke these two structures.
      
      Instead, this patch decouples x32 from the other architectures and moves
      it back into arch specific headers, partially reverting the even older
      commit 73a2d096 ("x86: remove all now-duplicate header files").
      
      It's not clear whether this ever made any difference, since at least
      glibc carries its own (correct) copy of both of these header files,
      so possibly no application has ever observed the definitions here.
      
      Based on a suggestion from H.J. Lu, I tried out the tool from
      https://github.com/hjl-tools/linux-header to find other such
      bugs, which pointed out the same bug in statfs(), which also has
      a separate (correct) copy in glibc.
      
      Fixes: f4b4aae1 ("x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds")
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: "H . J . Lu" <hjl.tools@gmail.com>
      Cc: Jeffrey Walton <noloader@gmail.com>
      Cc: stable@vger.kernel.org
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Link: https://lkml.kernel.org/r/20180424212013.3967461-1-arnd@arndb.de
      1a512c08
  9. 20 4月, 2018 1 次提交
    • A
      y2038: x86: Extend sysvipc data structures · c039dbd5
      Arnd Bergmann 提交于
      This extends the x86 copy of the sysvipc data structures to deal with
      32-bit user space that has 64-bit time_t and wants to see timestamps
      beyond 2038.
      
      Fortunately, x86 has padding for this purpose in all the data structures,
      so we can just add extra fields. With msgid64_ds and shmid64_ds, the
      data structure is identical to the asm-generic version, which we have
      already extended.
      
      For some reason however, the 64-bit version of semid64_ds ended up with
      extra padding, so I'm implementing the same approach as the asm-generic
      version here, by using separate fields for the upper and lower halves
      of the two timestamps.
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      c039dbd5
  10. 05 4月, 2018 1 次提交
    • D
      x86/uapi: Fix asm/bootparam.h userspace compilation errors · 9820e1c3
      Dmitry V. Levin 提交于
      Consistently use types provided by <linux/types.h> to fix the following
      asm/bootparam.h userspace compilation errors:
      
      	/usr/include/asm/bootparam.h:140:2: error: unknown type name 'u16'
      	  u16 version;
      	/usr/include/asm/bootparam.h:141:2: error: unknown type name 'u16'
      	  u16 compatible_version;
      	/usr/include/asm/bootparam.h:142:2: error: unknown type name 'u16'
      	  u16 pm_timer_address;
      	/usr/include/asm/bootparam.h:143:2: error: unknown type name 'u16'
      	  u16 num_cpus;
      	/usr/include/asm/bootparam.h:144:2: error: unknown type name 'u64'
      	  u64 pci_mmconfig_base;
      	/usr/include/asm/bootparam.h:145:2: error: unknown type name 'u32'
      	  u32 tsc_khz;
      	/usr/include/asm/bootparam.h:146:2: error: unknown type name 'u32'
      	  u32 apic_khz;
      	/usr/include/asm/bootparam.h:147:2: error: unknown type name 'u8'
      	  u8 standard_ioapic;
      	/usr/include/asm/bootparam.h:148:2: error: unknown type name 'u8'
      	  u8 cpu_ids[255];
      Signed-off-by: NDmitry V. Levin <ldv@altlinux.org>
      Acked-by: NJan Kiszka <jan.kiszka@siemens.com>
      Cc: <stable@vger.kernel.org> # v4.16
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Fixes: 4a362601 ("x86/jailhouse: Add infrastructure for running in non-root cell")
      Link: http://lkml.kernel.org/r/20180405043210.GA13254@altlinux.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9820e1c3
  11. 29 3月, 2018 1 次提交
  12. 17 3月, 2018 1 次提交
  13. 08 3月, 2018 2 次提交
  14. 07 3月, 2018 4 次提交
    • M
      Drivers: hv: vmbus: Implement Direct Mode for stimer0 · 248e742a
      Michael Kelley 提交于
      The 2016 version of Hyper-V offers the option to operate the guest VM
      per-vcpu stimer's in Direct Mode, which means the timer interupts on its
      own vector rather than queueing a VMbus message. Direct Mode reduces
      timer processing overhead in both the hypervisor and the guest, and
      avoids having timer interrupts pollute the VMbus interrupt stream for
      the synthetic NIC and storage.  This patch enables Direct Mode by
      default on stimer0 when running on a version of Hyper-V that supports
      it.
      
      In prep for coming support of Hyper-V on ARM64, the arch independent
      portion of the code contains calls to routines that will be populated
      on ARM64 but are not needed and do nothing on x86.
      Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
      Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      248e742a
    • W
      KVM: Introduce paravirtualization hints and KVM_HINTS_DEDICATED · a4429e53
      Wanpeng Li 提交于
      This patch introduces kvm_para_has_hint() to query for hints about
      the configuration of the guests.  The first hint KVM_HINTS_DEDICATED,
      is set if the guest has dedicated physical CPUs for each vCPU (i.e.
      pinning and no over-commitment).  This allows optimizing spinlocks
      and tells the guest to avoid PV TLB flush.
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Eduardo Habkost <ehabkost@redhat.com>
      Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      a4429e53
    • K
      KVM: x86: KVM_CAP_SYNC_REGS · 01643c51
      Ken Hofsass 提交于
      This commit implements an enhanced x86 version of S390
      KVM_CAP_SYNC_REGS functionality. KVM_CAP_SYNC_REGS "allow[s]
      userspace to access certain guest registers without having
      to call SET/GET_*REGS”. This reduces ioctl overhead which
      is particularly important when userspace is making synchronous
      guest state modifications (e.g. when emulating and/or intercepting
      instructions).
      
      Originally implemented upstream for the S390, the x86 differences
      follow:
      - userspace can select the register sets to be synchronized with kvm_run
      using bit-flags in the kvm_valid_registers and kvm_dirty_registers
      fields.
      - vcpu_events is available in addition to the regs and sregs register
      sets.
      Signed-off-by: NKen Hofsass <hofsass@google.com>
      Reviewed-by: NDavid Hildenbrand <david@redhat.com>
      [Removed wrapper around check for reserved kvm_valid_regs. - Radim]
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      01643c51
    • R
      kvm: x86: hyperv: guest->host event signaling via eventfd · faeb7833
      Roman Kagan 提交于
      In Hyper-V, the fast guest->host notification mechanism is the
      SIGNAL_EVENT hypercall, with a single parameter of the connection ID to
      signal.
      
      Currently this hypercall incurs a user exit and requires the userspace
      to decode the parameters and trigger the notification of the potentially
      different I/O context.
      
      To avoid the costly user exit, process this hypercall and signal the
      corresponding eventfd in KVM, similar to ioeventfd.  The association
      between the connection id and the eventfd is established via the newly
      introduced KVM_HYPERV_EVENTFD ioctl, and maintained in an
      (srcu-protected) IDR.
      Signed-off-by: NRoman Kagan <rkagan@virtuozzo.com>
      Reviewed-by: NDavid Hildenbrand <david@redhat.com>
      [asm/hyperv.h changes approved by KY Srinivasan. - Radim]
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      faeb7833
  15. 24 2月, 2018 1 次提交
  16. 20 2月, 2018 1 次提交
  17. 31 1月, 2018 1 次提交
    • V
      x86/hyperv: Reenlightenment notifications support · 93286261
      Vitaly Kuznetsov 提交于
      Hyper-V supports Live Migration notification. This is supposed to be used
      in conjunction with TSC emulation: when a VM is migrated to a host with
      different TSC frequency for some short period the host emulates the
      accesses to TSC and sends an interrupt to notify about the event. When the
      guest is done updating everything it can disable TSC emulation and
      everything will start working fast again.
      
      These notifications weren't required until now as Hyper-V guests are not
      supposed to use TSC as a clocksource: in Linux the TSC is even marked as
      unstable on boot. Guests normally use 'tsc page' clocksource and host
      updates its values on migrations automatically.
      
      Things change when with nested virtualization: even when the PV
      clocksources (kvm-clock or tsc page) are passed through to the nested
      guests the TSC frequency and frequency changes need to be know..
      
      Hyper-V Top Level Functional Specification (as of v5.0b) wrongly specifies
      EAX:BIT(12) of CPUID:0x40000009 as the feature identification bit. The
      right one to check is EAX:BIT(13) of CPUID:0x40000003. I was assured that
      the fix in on the way.
      Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Stephen Hemminger <sthemmin@microsoft.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Haiyang Zhang <haiyangz@microsoft.com>
      Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>
      Cc: Roman Kagan <rkagan@virtuozzo.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: devel@linuxdriverproject.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Cathy Avery <cavery@redhat.com>
      Cc: Mohammed Gamal <mmorsy@redhat.com>
      Link: https://lkml.kernel.org/r/20180124132337.30138-4-vkuznets@redhat.com
      93286261
  18. 16 1月, 2018 2 次提交
    • W
      KVM: X86: use paravirtualized TLB Shootdown · 858a43aa
      Wanpeng Li 提交于
      Remote TLB flush does a busy wait which is fine in bare-metal
      scenario. But with-in the guest, the vcpus might have been pre-empted or
      blocked. In this scenario, the initator vcpu would end up busy-waiting
      for a long amount of time; it also consumes CPU unnecessarily to wake
      up the target of the shootdown.
      
      This patch set adds support for KVM's new paravirtualized TLB flush;
      remote TLB flush does not wait for vcpus that are sleeping, instead
      KVM will flush the TLB as soon as the vCPU starts running again.
      
      The improvement is clearly visible when the host is overcommitted; in this
      case, the PV TLB flush (in addition to avoiding the wait on the main CPU)
      prevents preempted vCPUs from stealing precious execution time from the
      running ones.
      
      Testing on a Xeon Gold 6142 2.6GHz 2 sockets, 32 cores, 64 threads,
      so 64 pCPUs, and each VM is 64 vCPUs.
      
      ebizzy -M
                    vanilla    optimized     boost
      1VM            46799       48670         4%
      2VM            23962       42691        78%
      3VM            16152       37539       132%
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      858a43aa
    • W
      KVM: X86: Add KVM_VCPU_PREEMPTED · fa55eedd
      Wanpeng Li 提交于
      The next patch will add another bit to the preempted field in
      kvm_steal_time.  Define a constant for bit 0 (the only one that is
      currently used).
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
      fa55eedd
  19. 15 1月, 2018 1 次提交
  20. 24 12月, 2017 1 次提交
    • P
      x86/mm: Use/Fix PCID to optimize user/kernel switches · 6fd166aa
      Peter Zijlstra 提交于
      We can use PCID to retain the TLBs across CR3 switches; including those now
      part of the user/kernel switch. This increases performance of kernel
      entry/exit at the cost of more expensive/complicated TLB flushing.
      
      Now that we have two address spaces, one for kernel and one for user space,
      we need two PCIDs per mm. We use the top PCID bit to indicate a user PCID
      (just like we use the PFN LSB for the PGD). Since we do TLB invalidation
      from kernel space, the existing code will only invalidate the kernel PCID,
      we augment that by marking the corresponding user PCID invalid, and upon
      switching back to userspace, use a flushing CR3 write for the switch.
      
      In order to access the user_pcid_flush_mask we use PER_CPU storage, which
      means the previously established SWAPGS vs CR3 ordering is now mandatory
      and required.
      
      Having to do this memory access does require additional registers, most
      sites have a functioning stack and we can spill one (RAX), sites without
      functional stack need to otherwise provide the second scratch register.
      
      Note: PCID is generally available on Intel Sandybridge and later CPUs.
      Note: Up until this point TLB flushing was broken in this series.
      
      Based-on-code-from: Dave Hansen <dave.hansen@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      6fd166aa
  21. 05 12月, 2017 1 次提交
    • H
      bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type · c895f6f7
      Hendrik Brueckner 提交于
      Commit 0515e599 ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT
      program type") introduced the bpf_perf_event_data structure which
      exports the pt_regs structure.  This is OK for multiple architectures
      but fail for s390 and arm64 which do not export pt_regs.  Programs
      using them, for example, the bpf selftest fail to compile on these
      architectures.
      
      For s390, exporting the pt_regs is not an option because s390 wants
      to allow changes to it.  For arm64, there is a user_pt_regs structure
      that covers parts of the pt_regs structure for use by user space.
      
      To solve the broken uapi for s390 and arm64, introduce an abstract
      type for pt_regs and add an asm/bpf_perf_event.h file that concretes
      the type.  An asm-generic header file covers the architectures that
      export pt_regs today.
      
      The arch-specific enablement for s390 and arm64 follows in separate
      commits.
      Reported-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
      Fixes: 0515e599 ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type")
      Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Reviewed-and-tested-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      c895f6f7
  22. 28 11月, 2017 1 次提交
  23. 08 11月, 2017 1 次提交
    • R
      x86/cpufeature: Add User-Mode Instruction Prevention definitions · 3522c2a6
      Ricardo Neri 提交于
      User-Mode Instruction Prevention is a security feature present in new
      Intel processors that, when set, prevents the execution of a subset of
      instructions if such instructions are executed in user mode (CPL > 0).
      Attempting to execute such instructions causes a general protection
      exception.
      
      The subset of instructions comprises:
      
       * SGDT - Store Global Descriptor Table
       * SIDT - Store Interrupt Descriptor Table
       * SLDT - Store Local Descriptor Table
       * SMSW - Store Machine Status Word
       * STR  - Store Task Register
      
      This feature is also added to the list of disabled-features to allow
      a cleaner handling of build-time configuration.
      Signed-off-by: NRicardo Neri <ricardo.neri-calderon@linux.intel.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Chen Yucong <slaoub@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Huang Rui <ray.huang@amd.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: ricardo.neri@intel.com
      Link: http://lkml.kernel.org/r/1509935277-22138-7-git-send-email-ricardo.neri-calderon@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3522c2a6
  24. 07 11月, 2017 1 次提交
    • T
      x86/boot: Add early boot support when running with SEV active · 1958b5fc
      Tom Lendacky 提交于
      Early in the boot process, add checks to determine if the kernel is
      running with Secure Encrypted Virtualization (SEV) active.
      
      Checking for SEV requires checking that the kernel is running under a
      hypervisor (CPUID 0x00000001, bit 31), that the SEV feature is available
      (CPUID 0x8000001f, bit 1) and then checking a non-interceptable SEV MSR
      (0xc0010131, bit 0).
      
      This check is required so that during early compressed kernel booting the
      pagetables (both the boot pagetables and KASLR pagetables (if enabled) are
      updated to include the encryption mask so that when the kernel is
      decompressed into encrypted memory, it can boot properly.
      
      After the kernel is decompressed and continues booting the same logic is
      used to check if SEV is active and set a flag indicating so.  This allows
      to distinguish between SME and SEV, each of which have unique differences
      in how certain things are handled: e.g. DMA (always bounce buffered with
      SEV) or EFI tables (always access decrypted with SME).
      Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
      Signed-off-by: NBrijesh Singh <brijesh.singh@amd.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Tested-by: NBorislav Petkov <bp@suse.de>
      Cc: Laura Abbott <labbott@redhat.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: kvm@vger.kernel.org
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Link: https://lkml.kernel.org/r/20171020143059.3291-13-brijesh.singh@amd.com
      1958b5fc
  25. 02 11月, 2017 4 次提交
    • G
      License cleanup: add SPDX license identifier to uapi header files with a license · e2be04c7
      Greg Kroah-Hartman 提交于
      Many user space API headers have licensing information, which is either
      incomplete, badly formatted or just a shorthand for referring to the
      license under which the file is supposed to be.  This makes it hard for
      compliance tools to determine the correct license.
      
      Update these files with an SPDX license identifier.  The identifier was
      chosen based on the license information in the file.
      
      GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
      identifier with the added 'WITH Linux-syscall-note' exception, which is
      the officially assigned exception identifier for the kernel syscall
      exception:
      
         NOTE! This copyright does *not* cover user programs that use kernel
         services by normal system calls - this is merely considered normal use
         of the kernel, and does *not* fall under the heading of "derived work".
      
      This exception makes it possible to include GPL headers into non GPL
      code, without confusing license compliance tools.
      
      Headers which have either explicit dual licensing or are just licensed
      under a non GPL license are updated with the corresponding SPDX
      identifier and the GPLv2 with syscall exception identifier.  The format
      is:
              ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
      
      SPDX license identifiers are a legally binding shorthand, which can be
      used instead of the full boiler plate text.  The update does not remove
      existing license information as this has to be done on a case by case
      basis and the copyright holders might have to be consulted. This will
      happen in a separate step.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.  See the previous patch in this series for the
      methodology of how this patch was researched.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e2be04c7
    • G
      License cleanup: add SPDX license identifier to uapi header files with no license · 6f52b16c
      Greg Kroah-Hartman 提交于
      Many user space API headers are missing licensing information, which
      makes it hard for compliance tools to determine the correct license.
      
      By default are files without license information under the default
      license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
      them from being included in non GPLV2 code, which is obviously not
      intended. The user space API headers fall under the syscall exception
      which is in the kernels COPYING file:
      
         NOTE! This copyright does *not* cover user programs that use kernel
         services by normal system calls - this is merely considered normal use
         of the kernel, and does *not* fall under the heading of "derived work".
      
      otherwise syscall usage would not be possible.
      
      Update the files which contain no license information with an SPDX
      license identifier.  The chosen identifier is 'GPL-2.0 WITH
      Linux-syscall-note' which is the officially assigned identifier for the
      Linux syscall exception.  SPDX license identifiers are a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.  See the previous patch in this series for the
      methodology of how this patch was researched.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6f52b16c
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
    • R
      x86/boot: Relocate definition of the initial state of CR0 · b0ce5b8c
      Ricardo Neri 提交于
      Both head_32.S and head_64.S utilize the same value to initialize the
      control register CR0. Also, other parts of the kernel might want to access
      this initial definition (e.g., emulation code for User-Mode Instruction
      Prevention uses this state to provide a sane dummy value for CR0 when
      emulating the smsw instruction). Thus, relocate this definition to a
      header file from which it can be conveniently accessed.
      Suggested-by: NBorislav Petkov <bp@alien8.de>
      Signed-off-by: NRicardo Neri <ricardo.neri-calderon@linux.intel.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Reviewed-by: NAndy Lutomirski <luto@kernel.org>
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: ricardo.neri@intel.com
      Cc: linux-mm@kvack.org
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Huang Rui <ray.huang@amd.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: linux-arch@vger.kernel.org
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Chen Yucong <slaoub@gmail.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Link: https://lkml.kernel.org/r/1509135945-13762-3-git-send-email-ricardo.neri-calderon@linux.intel.com
      b0ce5b8c
  26. 13 9月, 2017 1 次提交
  27. 07 9月, 2017 1 次提交
  28. 31 8月, 2017 1 次提交
  29. 24 8月, 2017 1 次提交
  30. 11 8月, 2017 1 次提交
    • V
      x86/hyper-v: Use hypercall for remote TLB flush · 2ffd9e33
      Vitaly Kuznetsov 提交于
      Hyper-V host can suggest us to use hypercall for doing remote TLB flush,
      this is supposed to work faster than IPIs.
      
      Implementation details: to do HvFlushVirtualAddress{Space,List} hypercalls
      we need to put the input somewhere in memory and we don't really want to
      have memory allocation on each call so we pre-allocate per cpu memory areas
      on boot.
      
      pv_ops patching is happening very early so we need to separate
      hyperv_setup_mmu_ops() and hyper_alloc_mmu().
      
      It is possible and easy to implement local TLB flushing too and there is
      even a hint for that. However, I don't see a room for optimization on the
      host side as both hypercall and native tlb flush will result in vmexit. The
      hint is also not set on modern Hyper-V versions.
      Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
      Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
      Reviewed-by: NStephen Hemminger <sthemmin@microsoft.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Haiyang Zhang <haiyangz@microsoft.com>
      Cc: Jork Loeser <Jork.Loeser@microsoft.com>
      Cc: K. Y. Srinivasan <kys@microsoft.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Simon Xiao <sixiao@microsoft.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: devel@linuxdriverproject.org
      Link: http://lkml.kernel.org/r/20170802160921.21791-8-vkuznets@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2ffd9e33