[PATCH v3 2/3] x86: Skip perf related tests when platform cannot support

[Yang Weijiang <weijiang.yang@intel.com>]

Add helpers to check whether MSR_CORE_PERF_GLOBAL_CTRL and rdpmc
are supported in KVM. When pmu is disabled with enable_pmu=0,
reading MSR_CORE_PERF_GLOBAL_CTRL or executing rdpmc leads to #GP,
so skip related tests in this case to avoid test failure.

Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 lib/x86/processor.h | 10 ++++++++++
 x86/vmx_tests.c     | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index 9a0dad6..70b9193 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -690,4 +690,14 @@ static inline bool cpuid_osxsave(void)
 	return cpuid(1).c & (1 << (X86_FEATURE_OSXSAVE % 32));
 }
 
+static inline u8 pmu_version(void)
+{
+	return cpuid(10).a & 0xff;
+}
+
+static inline bool has_perf_global_ctrl(void)
+{
+	return pmu_version() > 1;
+}
+
 #endif
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 4d581e7..3cf0776 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -944,6 +944,14 @@ static void insn_intercept_main(void)
 			continue;
 		}
 
+		if (insn_table[cur_insn].flag == CPU_RDPMC) {
+			if (!!pmu_version()) {
+				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 +7498,11 @@ static void test_perf_global_ctrl(u32 nr, const char *name, u32 ctrl_nr,
 
 static void test_load_host_perf_global_ctrl(void)
 {
+	if (!has_perf_global_ctrl()) {
+		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 +7515,11 @@ static void test_load_host_perf_global_ctrl(void)
 
 static void test_load_guest_perf_global_ctrl(void)
 {
+	if (!has_perf_global_ctrl()) {
+		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;
-- 
2.27.0