<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/tools/arch/arm64/include, branch linus/master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/tools/arch/arm64/include?h=linus%2Fmaster</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/tools/arch/arm64/include?h=linus%2Fmaster'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2022-06-19T14:23:04Z</updated>
<entry>
<title>tools headers arm64: Sync arm64's cputype.h with the kernel sources</title>
<updated>2022-06-19T14:23:04Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-04-09T14:48:15Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=37402d5d061ba914a12d16ee8dda6d6964b4819d'/>
<id>urn:sha1:37402d5d061ba914a12d16ee8dda6d6964b4819d</id>
<content type='text'>
To get the changes in:

  cae889302ebf5a9b ("KVM: arm64: vgic-v3: List M1 Pro/Max as requiring the SEIS workaround")

That addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/arm64/include/asm/cputype.h' differs from latest version at 'arch/arm64/include/asm/cputype.h'
  diff -u tools/arch/arm64/include/asm/cputype.h arch/arm64/include/asm/cputype.h

Cc: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/lkml/Yq8w7p4omYKNwOij@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf tools arm64: Copy perf_regs.h from the kernel</title>
<updated>2022-05-26T15:36:58Z</updated>
<author>
<name>James Clark</name>
<email>james.clark@arm.com</email>
</author>
<published>2022-05-25T15:41:11Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=f450f11b2d3f48e7eb0c9ca34ee5c873521e0b7b'/>
<id>urn:sha1:f450f11b2d3f48e7eb0c9ca34ee5c873521e0b7b</id>
<content type='text'>
Get the updated header for the newly added VG register.

Reviewed-by: Leo Yan &lt;leo.yan@linaro.org&gt;
Signed-off-by: James Clark &lt;james.clark@arm.com&gt;
Cc: &lt;broonie@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: German Gomez &lt;german.gomez@arm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220525154114.718321-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>tools headers arm64: Sync arm64's cputype.h with the kernel sources</title>
<updated>2022-04-09T15:34:29Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-04-09T14:48:15Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=278aaba2c555a54e62aec40e04defaa9fffcc1c9'/>
<id>urn:sha1:278aaba2c555a54e62aec40e04defaa9fffcc1c9</id>
<content type='text'>
To get the changes in:

  83bea32ac7ed37bb ("arm64: Add part number for Arm Cortex-A78AE")

That addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/arm64/include/asm/cputype.h' differs from latest version at 'arch/arm64/include/asm/cputype.h'
  diff -u tools/arch/arm64/include/asm/cputype.h arch/arm64/include/asm/cputype.h

Cc: Ali Saidi &lt;alisaidi@amazon.com&gt;
Cc: Andrew Kilroy &lt;andrew.kilroy@arm.com&gt;
Cc: Chanho Park &lt;chanho61.park@samsung.com&gt;
Cc: German Gomez &lt;german.gomez@arm.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: http://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>tools kvm headers arm64: Update KVM headers from the kernel sources</title>
<updated>2022-04-01T19:19:35Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-12-21T15:53:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=8db38afd12ef2134a033f9d266a9493b9c2cb7c8'/>
<id>urn:sha1:8db38afd12ef2134a033f9d266a9493b9c2cb7c8</id>
<content type='text'>
To pick the changes from:

  34739fd95fab3a5e ("KVM: arm64: Indicate SYSTEM_RESET2 in kvm_run::system_event flags field")
  583cda1b0e7d5d49 ("KVM: arm64: Refuse to run VCPU if the PMU doesn't match the physical CPU")

That don't causes any changes in tooling (when built on x86), only
addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm64/include/uapi/asm/kvm.h'
  diff -u tools/arch/arm64/include/uapi/asm/kvm.h arch/arm64/include/uapi/asm/kvm.h

Cc: Marc Zyngier &lt;maz@kernel.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Alexandru Elisei &lt;alexandru.elisei@arm.com&gt;
Link: https://lore.kernel.org/lkml/YkSB4Q7kWmnaqeZU@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux</title>
<updated>2022-03-27T20:42:32Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-27T20:42:32Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=7b58b82b86c8b65a2b57a4c6cb96a460654f9e09'/>
<id>urn:sha1:7b58b82b86c8b65a2b57a4c6cb96a460654f9e09</id>
<content type='text'>
Pull perf tools updates from Arnaldo Carvalho de Melo:
 "New features:

  perf ftrace:

   - Add -n/--use-nsec option to the 'latency' subcommand.

     Default: usecs:

     $ sudo perf ftrace latency -T dput -a sleep 1
     #   DURATION     |      COUNT | GRAPH                          |
          0 - 1    us |    2098375 | #############################  |
          1 - 2    us |         61 |                                |
          2 - 4    us |         33 |                                |
          4 - 8    us |         13 |                                |
          8 - 16   us |        124 |                                |
         16 - 32   us |        123 |                                |
         32 - 64   us |          1 |                                |
         64 - 128  us |          0 |                                |
        128 - 256  us |          1 |                                |
        256 - 512  us |          0 |                                |

     Better granularity with nsec:

     $ sudo perf ftrace latency -T dput -a -n sleep 1
     #   DURATION     |      COUNT | GRAPH                          |
          0 - 1    us |          0 |                                |
          1 - 2    ns |          0 |                                |
          2 - 4    ns |          0 |                                |
          4 - 8    ns |          0 |                                |
          8 - 16   ns |          0 |                                |
         16 - 32   ns |          0 |                                |
         32 - 64   ns |          0 |                                |
         64 - 128  ns |    1163434 | ##############                 |
        128 - 256  ns |     914102 | #############                  |
        256 - 512  ns |        884 |                                |
        512 - 1024 ns |        613 |                                |
          1 - 2    us |         31 |                                |
          2 - 4    us |         17 |                                |
          4 - 8    us |          7 |                                |
          8 - 16   us |        123 |                                |
         16 - 32   us |         83 |                                |

  perf lock:

   - Add -c/--combine-locks option to merge lock instances in the same
     class into a single entry.

     # perf lock report -c
                    Name acquired contended avg wait(ns) total wait(ns) max wait(ns) min wait(ns)

           rcu_read_lock   251225         0            0              0            0            0
      hrtimer_bases.lock    39450         0            0              0            0            0
     &amp;sb-&gt;s_type-&gt;i_l...    10301         1          662            662          662          662
        ptlock_ptr(page)    10173         2          701           1402          760          642
     &amp;(ei-&gt;i_block_re...     8732         0            0              0            0            0
            &amp;xa-&gt;xa_lock     8088         0            0              0            0            0
             &amp;base-&gt;lock     6705         0            0              0            0            0
             &amp;p-&gt;pi_lock     5549         0            0              0            0            0
     &amp;dentry-&gt;d_lockr...     5010         4         1274           5097         1844          789
               &amp;ep-&gt;lock     3958         0            0              0            0            0

      - Add -F/--field option to customize the list of fields to output:

     $ perf lock report -F contended,wait_max -k avg_wait
                     Name contended max wait(ns) avg wait(ns)

           slock-AF_INET6         1        23543        23543
        &amp;lruvec-&gt;lru_lock         5        18317        11254
           slock-AF_INET6         1        10379        10379
               rcu_node_1         1         2104         2104
      &amp;dentry-&gt;d_lockr...         1         1844         1844
      &amp;dentry-&gt;d_lockr...         1         1672         1672
         &amp;newf-&gt;file_lock        15         2279         1025
      &amp;dentry-&gt;d_lockr...         1          792          792

   - Add --synth=no option for record, as there is no need to symbolize,
     lock names comes from the tracepoints.

  perf record:

   - Threaded recording, opt-in, via the new --threads command line
     option.

   - Improve AMD IBS (Instruction-Based Sampling) error handling
     messages.

  perf script:

   - Add 'brstackinsnlen' field (use it with -F) for branch stacks.

   - Output branch sample type in 'perf script'.

  perf report:

   - Add "addr_from" and "addr_to" sort dimensions.

   - Print branch stack entry type in 'perf report --dump-raw-trace'

   - Fix symbolization for chrooted workloads.

  Hardware tracing:

  Intel PT:

   - Add CFE (Control Flow Event) and EVD (Event Data) packets support.

   - Add MODE.Exec IFLAG bit support.

     Explanation about these features from the "Intel® 64 and IA-32
     architectures software developer’s manual combined volumes: 1, 2A,
     2B, 2C, 2D, 3A, 3B, 3C, 3D, and 4" PDF at:

        https://cdrdv2.intel.com/v1/dl/getContent/671200

     At page 3951:
      "32.2.4

       Event Trace is a capability that exposes details about the
       asynchronous events, when they are generated, and when their
       corresponding software event handler completes execution. These
       include:

        o Interrupts, including NMI and SMI, including the interrupt
          vector when defined.

        o Faults, exceptions including the fault vector.

           - Page faults additionally include the page fault address,
             when in context.

        o Event handler returns, including IRET and RSM.

        o VM exits and VM entries.¹

           - VM exits include the values written to the “exit reason”
             and “exit qualification” VMCS fields. INIT and SIPI events.

        o TSX aborts, including the abort status returned for the RTM
          instructions.

        o Shutdown.

       Additionally, it provides indication of the status of the
       Interrupt Flag (IF), to indicate when interrupts are masked"

  ARM CoreSight:

   - Use advertised caps/min_interval as default sample_period on ARM
     spe.

   - Update deduction of TRCCONFIGR register for branch broadcast on
     ARM's CoreSight ETM.

  Vendor Events (JSON):

  Intel:

   - Update events and metrics for: Alderlake, Broadwell, Broadwell DE,
     BroadwellX, CascadelakeX, Elkhartlake, Bonnell, Goldmont,
     GoldmontPlus, Westmere EP-DP, Haswell, HaswellX, Icelake, IcelakeX,
     Ivybridge, Ivytown, Jaketown, Knights Landing, Nehalem EP,
     Sandybridge, Silvermont, Skylake, Skylake Server, SkylakeX,
     Tigerlake, TremontX, Westmere EP-SP, and Westmere EX.

  ARM:

   - Add support for HiSilicon CPA PMU aliasing.

  perf stat:

   - Fix forked applications enablement of counters.

   - The 'slots' should only be printed on a different order than the
     one specified on the command line when 'topdown' events are
     present, fix it.

  Miscellaneous:

   - Sync msr-index, cpufeatures header files with the kernel sources.

   - Stop using some deprecated libbpf APIs in 'perf trace'.

   - Fix some spelling mistakes.

   - Refactor the maps pointers usage to pave the way for using refcount
     debugging.

   - Only offer the --tui option on perf top, report and annotate when
     perf was built with libslang.

   - Don't mention --to-ctf in 'perf data --help' when not linking with
     the required library, libbabeltrace.

   - Use ARRAY_SIZE() instead of ad hoc equivalent, spotted by
     array_size.cocci.

   - Enhance the matching of sub-commands abbreviations:
	'perf c2c rec' -&gt; 'perf c2c record'
	'perf c2c recport -&gt; error

   - Set build-id using build-id header on new mmap records.

   - Fix generation of 'perf --version' string.

  perf test:

   - Add test for the arm_spe event.

   - Add test to check unwinding using fame-pointer (fp) mode on arm64.

   - Make metric testing more robust in 'perf test'.

   - Add error message for unsupported branch stack cases.

  libperf:

   - Add API for allocating new thread map array.

   - Fix typo in perf_evlist__open() failure error messages in libperf
     tests.

  perf c2c:

   - Replace bitmap_weight() with bitmap_empty() where appropriate"

* tag 'perf-tools-for-v5.18-2022-03-26' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (143 commits)
  perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages
  perf python: Add perf_env stubs that will be needed in evsel__open_strerror()
  perf tools: Enhance the matching of sub-commands abbreviations
  libperf tests: Fix typo in perf_evlist__open() failure error messages
  tools arm64: Import cputype.h
  perf lock: Add -F/--field option to control output
  perf lock: Extend struct lock_key to have print function
  perf lock: Add --synth=no option for record
  tools headers cpufeatures: Sync with the kernel sources
  tools headers cpufeatures: Sync with the kernel sources
  perf stat: Fix forked applications enablement of counters
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  perf evsel: Make evsel__env() always return a valid env
  perf build-id: Fix spelling mistake "Cant" -&gt; "Can't"
  perf header: Fix spelling mistake "could't" -&gt; "couldn't"
  perf script: Add 'brstackinsnlen' for branch stacks
  perf parse-events: Move slots only with topdown
  perf ftrace latency: Update documentation
  perf ftrace latency: Add -n/--use-nsec option
  perf tools: Fix version kernel tag
  ...
</content>
</entry>
<entry>
<title>tools arm64: Import cputype.h</title>
<updated>2022-03-26T13:53:45Z</updated>
<author>
<name>Ali Saidi</name>
<email>alisaidi@amazon.com</email>
</author>
<published>2022-03-24T18:33:20Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=1314376d495f2d79cc58753ff3034ccc503c43c9'/>
<id>urn:sha1:1314376d495f2d79cc58753ff3034ccc503c43c9</id>
<content type='text'>
Bring-in the kernel's arch/arm64/include/asm/cputype.h into tools/
for arm64 to make use of all the core-type definitions in perf.

Replace sysreg.h with the version already imported into tools/.

Committer notes:

Added an entry to tools/perf/check-headers.sh, so that we get notified
when the original file in the kernel sources gets modified.

Tester notes:

LGTM. I did the testing on both my x86 and Arm64 platforms, thanks for
the fixing up.

Signed-off-by: Ali Saidi &lt;alisaidi@amazon.com&gt;
Tested-by: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andrew Kilroy &lt;andrew.kilroy@arm.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: German Gomez &lt;german.gomez@arm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Garry &lt;john.garry@huawei.com&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Li Huafei &lt;lihuafei1@huawei.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nick.Forrington@arm.com
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220324183323.31414-2-alisaidi@amazon.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2022-03-24T18:58:57Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-03-24T18:58:57Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=1ebdbeb03efe89f01f15df038a589077df3d21f5'/>
<id>urn:sha1:1ebdbeb03efe89f01f15df038a589077df3d21f5</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Proper emulation of the OSLock feature of the debug architecture

   - Scalibility improvements for the MMU lock when dirty logging is on

   - New VMID allocator, which will eventually help with SVA in VMs

   - Better support for PMUs in heterogenous systems

   - PSCI 1.1 support, enabling support for SYSTEM_RESET2

   - Implement CONFIG_DEBUG_LIST at EL2

   - Make CONFIG_ARM64_ERRATUM_2077057 default y

   - Reduce the overhead of VM exit when no interrupt is pending

   - Remove traces of 32bit ARM host support from the documentation

   - Updated vgic selftests

   - Various cleanups, doc updates and spelling fixes

  RISC-V:
   - Prevent KVM_COMPAT from being selected

   - Optimize __kvm_riscv_switch_to() implementation

   - RISC-V SBI v0.3 support

  s390:
   - memop selftest

   - fix SCK locking

   - adapter interruptions virtualization for secure guests

   - add Claudio Imbrenda as maintainer

   - first step to do proper storage key checking

  x86:
   - Continue switching kvm_x86_ops to static_call(); introduce
     static_call_cond() and __static_call_ret0 when applicable.

   - Cleanup unused arguments in several functions

   - Synthesize AMD 0x80000021 leaf

   - Fixes and optimization for Hyper-V sparse-bank hypercalls

   - Implement Hyper-V's enlightened MSR bitmap for nested SVM

   - Remove MMU auditing

   - Eager splitting of page tables (new aka "TDP" MMU only) when dirty
     page tracking is enabled

   - Cleanup the implementation of the guest PGD cache

   - Preparation for the implementation of Intel IPI virtualization

   - Fix some segment descriptor checks in the emulator

   - Allow AMD AVIC support on systems with physical APIC ID above 255

   - Better API to disable virtualization quirks

   - Fixes and optimizations for the zapping of page tables:

      - Zap roots in two passes, avoiding RCU read-side critical
        sections that last too long for very large guests backed by 4
        KiB SPTEs.

      - Zap invalid and defunct roots asynchronously via
        concurrency-managed work queue.

      - Allowing yielding when zapping TDP MMU roots in response to the
        root's last reference being put.

      - Batch more TLB flushes with an RCU trick. Whoever frees the
        paging structure now holds RCU as a proxy for all vCPUs running
        in the guest, i.e. to prolongs the grace period on their behalf.
        It then kicks the the vCPUs out of guest mode before doing
        rcu_read_unlock().

  Generic:
   - Introduce __vcalloc and use it for very large allocations that need
     memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
  KVM: use kvcalloc for array allocations
  KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2
  kvm: x86: Require const tsc for RT
  KVM: x86: synthesize CPUID leaf 0x80000021h if useful
  KVM: x86: add support for CPUID leaf 0x80000021
  KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask
  Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
  kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU
  KVM: arm64: fix typos in comments
  KVM: arm64: Generalise VM features into a set of flags
  KVM: s390: selftests: Add error memop tests
  KVM: s390: selftests: Add more copy memop tests
  KVM: s390: selftests: Add named stages for memop test
  KVM: s390: selftests: Add macro as abstraction for MEM_OP
  KVM: s390: selftests: Split memop tests
  KVM: s390x: fix SCK locking
  RISC-V: KVM: Implement SBI HSM suspend call
  RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
  RISC-V: Add SBI HSM suspend related defines
  RISC-V: KVM: Implement SBI v0.3 SRST extension
  ...
</content>
</entry>
<entry>
<title>tools kvm headers arm64: Update KVM headers from the kernel sources</title>
<updated>2022-03-12T13:33:13Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-12-21T15:53:44Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=3ec94eeaff9ad58a76be2232068b4a2546b2f6bb'/>
<id>urn:sha1:3ec94eeaff9ad58a76be2232068b4a2546b2f6bb</id>
<content type='text'>
To pick the changes from:

  a5905d6af492ee6a ("KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated")

That don't causes any changes in tooling (when built on x86), only
addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/kvm.h' differs from latest version at 'arch/arm64/include/uapi/asm/kvm.h'
  diff -u tools/arch/arm64/include/uapi/asm/kvm.h arch/arm64/include/uapi/asm/kvm.h

Cc: James Morse &lt;james.morse@arm.com&gt;
Link: https://lore.kernel.org/lkml/YiyhAK6sVPc83FaI@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>KVM: arm64: Add KVM_ARM_VCPU_PMU_V3_SET_PMU attribute</title>
<updated>2022-02-08T17:51:21Z</updated>
<author>
<name>Alexandru Elisei</name>
<email>alexandru.elisei@arm.com</email>
</author>
<published>2022-01-27T16:17:58Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=6ee7fca2a4a023b14aa1f1f3c4f6c833116116ef'/>
<id>urn:sha1:6ee7fca2a4a023b14aa1f1f3c4f6c833116116ef</id>
<content type='text'>
When KVM creates an event and there are more than one PMUs present on the
system, perf_init_event() will go through the list of available PMUs and
will choose the first one that can create the event. The order of the PMUs
in this list depends on the probe order, which can change under various
circumstances, for example if the order of the PMU nodes change in the DTB
or if asynchronous driver probing is enabled on the kernel command line
(with the driver_async_probe=armv8-pmu option).

Another consequence of this approach is that on heteregeneous systems all
virtual machines that KVM creates will use the same PMU. This might cause
unexpected behaviour for userspace: when a VCPU is executing on the
physical CPU that uses this default PMU, PMU events in the guest work
correctly; but when the same VCPU executes on another CPU, PMU events in
the guest will suddenly stop counting.

Fortunately, perf core allows user to specify on which PMU to create an
event by using the perf_event_attr-&gt;type field, which is used by
perf_init_event() as an index in the radix tree of available PMUs.

Add the KVM_ARM_VCPU_PMU_V3_CTRL(KVM_ARM_VCPU_PMU_V3_SET_PMU) VCPU
attribute to allow userspace to specify the arm_pmu that KVM will use when
creating events for that VCPU. KVM will make no attempt to run the VCPU on
the physical CPUs that share the PMU, leaving it up to userspace to manage
the VCPU threads' affinity accordingly.

To ensure that KVM doesn't expose an asymmetric system to the guest, the
PMU set for one VCPU will be used by all other VCPUs. Once a VCPU has run,
the PMU cannot be changed in order to avoid changing the list of available
events for a VCPU, or to change the semantics of existing events.

Signed-off-by: Alexandru Elisei &lt;alexandru.elisei@arm.com&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20220127161759.53553-6-alexandru.elisei@arm.com
</content>
</entry>
<entry>
<title>tools: arm64: Import sysreg.h</title>
<updated>2021-10-17T10:15:51Z</updated>
<author>
<name>Raghavendra Rao Ananta</name>
<email>rananta@google.com</email>
</author>
<published>2021-10-07T23:34:26Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=272a067df3c89f6f2176a350f88661625a2c8b3b'/>
<id>urn:sha1:272a067df3c89f6f2176a350f88661625a2c8b3b</id>
<content type='text'>
Bring-in the kernel's arch/arm64/include/asm/sysreg.h
into tools/ for arm64 to make use of all the standard
register definitions in consistence with the kernel.

Make use of the register read/write definitions from
sysreg.h, instead of the existing definitions. A syntax
correction is needed for the files that use write_sysreg()
to make it compliant with the new (kernel's) syntax.

Reviewed-by: Andrew Jones &lt;drjones@redhat.com&gt;
Reviewed-by: Oliver Upton &lt;oupton@google.com&gt;
Signed-off-by: Raghavendra Rao Ananta &lt;rananta@google.com&gt;
[maz: squashed two commits in order to keep the series bisectable]
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20211007233439.1826892-3-rananta@google.com
Link: https://lore.kernel.org/r/20211007233439.1826892-4-rananta@google.com
</content>
</entry>
</feed>
