Re: [PATCH v2] KVM: x86: Use current rather than snapshotted TSC frequency if it is constant

[kernel test robot <lkp@intel.com>]

Hi Anton,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on kvm/master]
[also build test ERROR on mst-vhost/linux-next v5.18-rc3 next-20220421]
[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/intel-lab-lkp/linux/commits/Anton-Romanov/KVM-x86-Use-current-rather-than-snapshotted-TSC-frequency-if-it-is-constant/20220421-090221
base:   https://git.kernel.org/pub/scm/virt/kvm/kvm.git master
config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20220421/202204212040.klu29ce8-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.2.0-20) 11.2.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/c60b3070bd6e7e804de118dac10002e4f5f714a6
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Anton-Romanov/KVM-x86-Use-current-rather-than-snapshotted-TSC-frequency-if-it-is-constant/20220421-090221
        git checkout c60b3070bd6e7e804de118dac10002e4f5f714a6
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   arch/x86/kvm/x86.c: In function '__get_kvmclock':
>> arch/x86/kvm/x86.c:2936:17: error: expected expression before 'struct'
    2936 |                 struct timespec64 ts;
         |                 ^~~~~~
   arch/x86/kvm/x86.c:2933:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
    2933 |         if (ka->use_master_clock &&
         |         ^~
   arch/x86/kvm/x86.c:2938:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
    2938 |                 if (kvm_get_walltime_and_clockread(&ts, &data->host_tsc)) {
         |                 ^~
>> arch/x86/kvm/x86.c:2938:53: error: 'ts' undeclared (first use in this function); did you mean 'tms'?
    2938 |                 if (kvm_get_walltime_and_clockread(&ts, &data->host_tsc)) {
         |                                                     ^~
         |                                                     tms
   arch/x86/kvm/x86.c:2938:53: note: each undeclared identifier is reported only once for each function it appears in
   arch/x86/kvm/x86.c: At top level:
   arch/x86/kvm/x86.c:2952:11: error: expected identifier or '(' before 'else'
    2952 |         } else {
         |           ^~~~
   In file included from include/linux/percpu.h:6,
                    from include/linux/context_tracking_state.h:5,
                    from include/linux/hardirq.h:5,
                    from include/linux/kvm_host.h:7,
                    from arch/x86/kvm/x86.c:19:
   include/linux/preempt.h:240:1: error: expected identifier or '(' before 'do'
     240 | do { \
         | ^~
   include/linux/smp.h:268:33: note: in expansion of macro 'preempt_enable'
     268 | #define put_cpu()               preempt_enable()
         |                                 ^~~~~~~~~~~~~~
   arch/x86/kvm/x86.c:2956:9: note: in expansion of macro 'put_cpu'
    2956 |         put_cpu();
         |         ^~~~~~~
   include/linux/preempt.h:243:3: error: expected identifier or '(' before 'while'
     243 | } while (0)
         |   ^~~~~
   include/linux/smp.h:268:33: note: in expansion of macro 'preempt_enable'
     268 | #define put_cpu()               preempt_enable()
         |                                 ^~~~~~~~~~~~~~
   arch/x86/kvm/x86.c:2956:9: note: in expansion of macro 'put_cpu'
    2956 |         put_cpu();
         |         ^~~~~~~
   arch/x86/kvm/x86.c:2957:1: error: expected identifier or '(' before '}' token
    2957 | }
         | ^


vim +/struct +2936 arch/x86/kvm/x86.c

c60b3070bd6e7e Anton Romanov 2022-04-21  2922  
869b44211adc87 Paolo Bonzini 2021-09-16  2923  /* Called within read_seqcount_begin/retry for kvm->pvclock_sc.  */
869b44211adc87 Paolo Bonzini 2021-09-16  2924  static void __get_kvmclock(struct kvm *kvm, struct kvm_clock_data *data)
108b249c453dd7 Paolo Bonzini 2016-09-01  2925  {
108b249c453dd7 Paolo Bonzini 2016-09-01  2926  	struct kvm_arch *ka = &kvm->arch;
8b953440645631 Paolo Bonzini 2016-11-16  2927  	struct pvclock_vcpu_time_info hv_clock;
8b953440645631 Paolo Bonzini 2016-11-16  2928  
e2c2206a18993b Wanpeng Li    2017-05-11  2929  	/* both __this_cpu_read() and rdtsc() should be on the same cpu */
e2c2206a18993b Wanpeng Li    2017-05-11  2930  	get_cpu();
e2c2206a18993b Wanpeng Li    2017-05-11  2931  
869b44211adc87 Paolo Bonzini 2021-09-16  2932  	data->flags = 0;
c60b3070bd6e7e Anton Romanov 2022-04-21  2933  	if (ka->use_master_clock &&
c60b3070bd6e7e Anton Romanov 2022-04-21  2934  		(static_cpu_has(X86_FEATURE_CONSTANT_TSC) || __this_cpu_read(cpu_tsc_khz)))
c68dc1b577eabd Oliver Upton  2021-09-16  2935  #ifdef CONFIG_X86_64
c68dc1b577eabd Oliver Upton  2021-09-16 @2936  		struct timespec64 ts;
c68dc1b577eabd Oliver Upton  2021-09-16  2937  
c68dc1b577eabd Oliver Upton  2021-09-16 @2938  		if (kvm_get_walltime_and_clockread(&ts, &data->host_tsc)) {
c68dc1b577eabd Oliver Upton  2021-09-16  2939  			data->realtime = ts.tv_nsec + NSEC_PER_SEC * ts.tv_sec;
c68dc1b577eabd Oliver Upton  2021-09-16  2940  			data->flags |= KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC;
c68dc1b577eabd Oliver Upton  2021-09-16  2941  		} else
c68dc1b577eabd Oliver Upton  2021-09-16  2942  #endif
c68dc1b577eabd Oliver Upton  2021-09-16  2943  		data->host_tsc = rdtsc();
c68dc1b577eabd Oliver Upton  2021-09-16  2944  
869b44211adc87 Paolo Bonzini 2021-09-16  2945  		data->flags |= KVM_CLOCK_TSC_STABLE;
869b44211adc87 Paolo Bonzini 2021-09-16  2946  		hv_clock.tsc_timestamp = ka->master_cycle_now;
869b44211adc87 Paolo Bonzini 2021-09-16  2947  		hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
c60b3070bd6e7e Anton Romanov 2022-04-21  2948  		kvm_get_time_scale(NSEC_PER_SEC, get_cpu_tsc_khz() * 1000LL,
8b953440645631 Paolo Bonzini 2016-11-16  2949  				   &hv_clock.tsc_shift,
8b953440645631 Paolo Bonzini 2016-11-16  2950  				   &hv_clock.tsc_to_system_mul);
c68dc1b577eabd Oliver Upton  2021-09-16  2951  		data->clock = __pvclock_read_cycles(&hv_clock, data->host_tsc);
55c0cefbdbdaca Oliver Upton  2021-09-16  2952  	} else {
55c0cefbdbdaca Oliver Upton  2021-09-16  2953  		data->clock = get_kvmclock_base_ns() + ka->kvmclock_offset;
55c0cefbdbdaca Oliver Upton  2021-09-16  2954  	}
e2c2206a18993b Wanpeng Li    2017-05-11  2955  
e2c2206a18993b Wanpeng Li    2017-05-11  2956  	put_cpu();
55c0cefbdbdaca Oliver Upton  2021-09-16  2957  }
e2c2206a18993b Wanpeng Li    2017-05-11  2958  

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