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[09/11] KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config()

Message ID 20220221115201.22208-10-likexu@tencent.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86/pmu: Get rid of PERF_TYPE_HARDWAR and other minor fixes | expand

Commit Message

Like Xu Feb. 21, 2022, 11:51 a.m. UTC 
From: Like Xu <likexu@tencent.com>

With the help of perf_get_hw_event_config(), KVM could query the correct
EVENTSEL_{EVENT, UMASK} pair of a kernel-generic hw event directly from
the different *_perfmon_event_map[] by the kernel's pre-defined perf_hw_id.

Also extend the bit range of the comparison field to
AMD64_RAW_EVENT_MASK_NB to prevent AMD from
defining EventSelect[11:8] into perfmon_event_map[] one day.

Signed-off-by: Like Xu <likexu@tencent.com>
---
 arch/x86/kvm/pmu.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

Comments

kernel test robot Feb. 21, 2022, 8:57 p.m. UTC | #1 
Hi Like,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on kvm/master]
[also build test WARNING on linus/master v5.17-rc5 next-20220217]
[cannot apply to tip/perf/core mst-vhost/linux-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Like-Xu/KVM-x86-pmu-Get-rid-of-PERF_TYPE_HARDWAR-and-other-minor-fixes/20220221-195359
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git master
config: x86_64-randconfig-c007-20220221 (https://download.01.org/0day-ci/archive/20220222/202202220414.dzxjtMiF-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/29bdfb8b85a85f36e3fca739146845d7050a372d
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Like-Xu/KVM-x86-pmu-Get-rid-of-PERF_TYPE_HARDWAR-and-other-minor-fixes/20220221-195359
        git checkout 29bdfb8b85a85f36e3fca739146845d7050a372d
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/kvm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> arch/x86/kvm/pmu.c:471:66: warning: use of logical '&&' with constant operand [-Wconstant-logical-operand]
           return !((pmc->eventsel ^ perf_get_hw_event_config(perf_hw_id)) &&
                                                                           ^
   arch/x86/kvm/pmu.c:471:66: note: use '&' for a bitwise operation
           return !((pmc->eventsel ^ perf_get_hw_event_config(perf_hw_id)) &&
                                                                           ^~
                                                                           &
   arch/x86/kvm/pmu.c:471:66: note: remove constant to silence this warning
           return !((pmc->eventsel ^ perf_get_hw_event_config(perf_hw_id)) &&
                                                                          ~^~
   1 warning generated.


vim +471 arch/x86/kvm/pmu.c

   467	
   468	static inline bool eventsel_match_perf_hw_id(struct kvm_pmc *pmc,
   469		unsigned int perf_hw_id)
   470	{
 > 471		return !((pmc->eventsel ^ perf_get_hw_event_config(perf_hw_id)) &&
   472			AMD64_RAW_EVENT_MASK_NB);
   473	}
   474	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index edd51ec7711d..a6bfcbd3412d 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -468,13 +468,8 @@  static void kvm_pmu_incr_counter(struct kvm_pmc *pmc)
 static inline bool eventsel_match_perf_hw_id(struct kvm_pmc *pmc,
 	unsigned int perf_hw_id)
 {
-	u64 old_eventsel = pmc->eventsel;
-	unsigned int config;
-
-	pmc->eventsel &= (ARCH_PERFMON_EVENTSEL_EVENT | ARCH_PERFMON_EVENTSEL_UMASK);
-	config = kvm_x86_ops.pmu_ops->pmc_perf_hw_id(pmc);
-	pmc->eventsel = old_eventsel;
-	return config == perf_hw_id;
+	return !((pmc->eventsel ^ perf_get_hw_event_config(perf_hw_id)) &&
+		AMD64_RAW_EVENT_MASK_NB);
 }
 
 static inline bool cpl_is_matched(struct kvm_pmc *pmc)