Re: [kvm-unit-tests PATCH v2 3/3] x86: Skip perf related tests when pmu is disabled

[Sean Christopherson <seanjc@google.com>]

On Wed, Jun 15, 2022, Yang Weijiang wrote:
> When pmu is disabled in KVM, reading MSR_CORE_PERF_GLOBAL_CTRL
> or executing rdpmc leads to #GP, so skip related tests in this case.
> 
> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
> ---
>  x86/vmx_tests.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index 4d581e7..dd6fc13 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -944,6 +944,16 @@ static void insn_intercept_main(void)
>  			continue;
>  		}
>  
> +		if (insn_table[cur_insn].flag == CPU_RDPMC) {
> +			struct cpuid id = cpuid(10);
> +
> +			if (!(id.a & 0xff)) {

Please add helpers to query (a) the PMU version and (b) whether or not PERF_GLOBAL_CTRL
is supported.

> +				printf("\tFeature required for %s is not supported.\n",
> +				       insn_table[cur_insn].name);
> +				continue;
> +			}
> +		}
> +
>  		if (insn_table[cur_insn].disabled) {
>  			printf("\tFeature required for %s is not supported.\n",
>  			       insn_table[cur_insn].name);
> @@ -7490,6 +7500,13 @@ static void test_perf_global_ctrl(u32 nr, const char *name, u32 ctrl_nr,
>  
>  static void test_load_host_perf_global_ctrl(void)
>  {
> +	struct cpuid id = cpuid(10);
> +
> +	if (!(id.a & 0xff)) {
> +		report_skip("test_load_host_perf_global_ctrl");
> +		return;
> +	}
> +
>  	if (!(ctrl_exit_rev.clr & EXI_LOAD_PERF)) {
>  		printf("\"load IA32_PERF_GLOBAL_CTRL\" exit control not supported\n");
>  		return;
> @@ -7502,6 +7519,13 @@ static void test_load_host_perf_global_ctrl(void)
>  
>  static void test_load_guest_perf_global_ctrl(void)
>  {
> +	struct cpuid id = cpuid(10);
> +
> +	if (!(id.a & 0xff)) {
> +		report_skip("test_load_guest_perf_global_ctrl");
> +		return;
> +	}
> +
>  	if (!(ctrl_enter_rev.clr & ENT_LOAD_PERF)) {
>  		printf("\"load IA32_PERF_GLOBAL_CTRL\" entry control not supported\n");
>  		return;
> -- 
> 2.31.1
>