[kvm-unit-tests PATCH 3/4] 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.

Opportunistically hoist mwait support check function as helper and
change related code.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
---
 lib/x86/processor.h | 15 +++++++++++++++
 x86/vmx_tests.c     | 21 +++++++++++++--------
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index d071aba..b772cf3 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -744,4 +744,19 @@ static inline u8 pmu_fixed_counter_width(void)
 	else
 		return 0;
 }
+
+static inline bool cpu_has_perf_global_ctrl(void)
+{
+	return pmu_version() > 1;
+}
+
+static inline bool cpu_has_pmu(void)
+{
+	return !!pmu_version();
+}
+
+static inline bool cpu_has_mwait(void)
+{
+	return this_cpu_has(X86_FEATURE_MWAIT);
+}
 #endif
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index d5868a3..3afc8b8 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -847,11 +847,6 @@ u64 cr3;
 
 typedef bool (*supported_fn)(void);
 
-static bool monitor_supported(void)
-{
-	return this_cpu_has(X86_FEATURE_MWAIT);
-}
-
 struct insn_table {
 	const char *name;
 	u32 flag;
@@ -880,8 +875,8 @@ static struct insn_table insn_table[] = {
 	{"HLT",  CPU_HLT, insn_hlt, INSN_CPU0, 12, 0, 0, 0},
 	{"INVLPG", CPU_INVLPG, insn_invlpg, INSN_CPU0, 14,
 		0x12345678, 0, FIELD_EXIT_QUAL},
-	{"MWAIT", CPU_MWAIT, insn_mwait, INSN_CPU0, 36, 0, 0, 0, &monitor_supported},
-	{"RDPMC", CPU_RDPMC, insn_rdpmc, INSN_CPU0, 15, 0, 0, 0},
+	{"MWAIT", CPU_MWAIT, insn_mwait, INSN_CPU0, 36, 0, 0, 0, &cpu_has_mwait},
+	{"RDPMC", CPU_RDPMC, insn_rdpmc, INSN_CPU0, 15, 0, 0, 0, &cpu_has_pmu},
 	{"RDTSC", CPU_RDTSC, insn_rdtsc, INSN_CPU0, 16, 0, 0, 0},
 	{"CR3 load", CPU_CR3_LOAD, insn_cr3_load, INSN_CPU0, 28, 0x3, 0,
 		FIELD_EXIT_QUAL},
@@ -891,7 +886,7 @@ static struct insn_table insn_table[] = {
 		FIELD_EXIT_QUAL},
 	{"CR8 store", CPU_CR8_STORE, insn_cr8_store, INSN_CPU0, 28, 0x18, 0,
 		FIELD_EXIT_QUAL},
-	{"MONITOR", CPU_MONITOR, insn_monitor, INSN_CPU0, 39, 0, 0, 0, &monitor_supported},
+	{"MONITOR", CPU_MONITOR, insn_monitor, INSN_CPU0, 39, 0, 0, 0, &cpu_has_mwait},
 	{"PAUSE", CPU_PAUSE, insn_pause, INSN_CPU0, 40, 0, 0, 0},
 	// Flags for Secondary Processor-Based VM-Execution Controls
 	{"WBINVD", CPU_WBINVD, insn_wbinvd, INSN_CPU1, 54, 0, 0, 0},
@@ -7490,6 +7485,11 @@ static void test_perf_global_ctrl(u32 nr, const char *name, u32 ctrl_nr,
 
 static void test_load_host_perf_global_ctrl(void)
 {
+	if (!cpu_has_perf_global_ctrl()) {
+		report_skip("%s :IA32_PERF_GLOBAL_CTRL MSR not supported", __func__);
+		return;
+	}
+
 	if (!(ctrl_exit_rev.clr & EXI_LOAD_PERF)) {
 		report_skip("%s :\"Load IA32_PERF_GLOBAL_CTRL\" exit control not supported", __func__);
 		return;
@@ -7502,6 +7502,11 @@ static void test_load_host_perf_global_ctrl(void)
 
 static void test_load_guest_perf_global_ctrl(void)
 {
+	if (!cpu_has_perf_global_ctrl()) {
+		report_skip("%s :IA32_PERF_GLOBAL_CTRL MSR not supported", __func__);
+		return;
+	}
+
 	if (!(ctrl_enter_rev.clr & ENT_LOAD_PERF)) {
 		report_skip("%s :\"Load IA32_PERF_GLOBAL_CTRL\" entry control not supported", __func__);
 		return;
-- 
2.31.1