2022-02-21 15:18:52

by Like Xu

[permalink] [raw]
Subject: [PATCH 09/11] KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config()

From: Like Xu <[email protected]>

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 <[email protected]>
---
arch/x86/kvm/pmu.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

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)
--
2.35.0


2022-02-22 04:37:59

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH 09/11] KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config()

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/[email protected]/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 <[email protected]>

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/[email protected]

2022-02-28 09:58:02

by kernel test robot

[permalink] [raw]
Subject: [KVM] 29bdfb8b85: kvm-unit-tests.pmu_emulation.fail



Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: 29bdfb8b85a85f36e3fca739146845d7050a372d ("[PATCH 09/11] KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config()")
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/cgit/virt/kvm/kvm.git master
patch link: https://lore.kernel.org/kvm/[email protected]

in testcase: kvm-unit-tests
version: kvm-unit-tests-x86_64-882825e-1_20220215
with following parameters:

ucode: 0x28



on test machine: 8 threads 1 sockets Intel(R) Core(TM) i7-4790 v3 @ 3.60GHz with 6G memory

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):




If you fix the issue, kindly add following tag
Reported-by: kernel test robot <[email protected]>



PASS pmu (142 tests) <--- we noticed there are failures on parent commit
PASS pmu_lbr (3 tests)
FAIL pmu_emulation (4 tests, 2 unexpected failures) <--- paerent can pass



To reproduce:

git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
sudo bin/lkp install job.yaml # job file is attached in this email
bin/lkp split-job --compatible job.yaml # generate the yaml file for lkp run
sudo bin/lkp run generated-yaml-file

# if come across any failure that blocks the test,
# please remove ~/.lkp and /lkp dir to run from a clean state.



---
0DAY/LKP+ Test Infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/[email protected] Intel Corporation

Thanks,
Oliver Sang


Attachments:
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config-5.17.0-rc3-00034-g29bdfb8b85a8 (168.87 kB)
job-script (5.56 kB)
dmesg.xz (19.10 kB)
kvm-unit-tests (2.81 kB)
job.yaml (4.58 kB)
reproduce (16.00 B)
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