Merge tag 'kvm-x86-pmu-6.4' of https://github.com/kvm-x86/linux into HEAD

KVM x86 PMU changes for 6.4:

 - Disallow virtualizing legacy LBRs if architectural LBRs are available,
   the two are mutually exclusive in hardware

 - Disallow writes to immutable feature MSRs (notably PERF_CAPABILITIES)
   after KVM_RUN, and overhaul the vmx_pmu_caps selftest to better
   validate PERF_CAPABILITIES

 - Apply PMU filters to emulated events and add test coverage to the
   pmu_event_filter selftest

 - Misc cleanups and fixes

1 files changed, 38 insertions, 7 deletions

diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 90387ddcb2a9..e1d65d933310 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -928,14 +928,45 @@ static inline void vcpu_clear_cpuid_feature(struct kvm_vcpu *vcpu,
 uint64_t vcpu_get_msr(struct kvm_vcpu *vcpu, uint64_t msr_index);
 int _vcpu_set_msr(struct kvm_vcpu *vcpu, uint64_t msr_index, uint64_t msr_value);
 
-static inline void vcpu_set_msr(struct kvm_vcpu *vcpu, uint64_t msr_index,
-				uint64_t msr_value)
-{
-	int r = _vcpu_set_msr(vcpu, msr_index, msr_value);
-
-	TEST_ASSERT(r == 1, KVM_IOCTL_ERROR(KVM_SET_MSRS, r));
-}
+/*
+ * Assert on an MSR access(es) and pretty print the MSR name when possible.
+ * Note, the caller provides the stringified name so that the name of macro is
+ * printed, not the value the macro resolves to (due to macro expansion).
+ */
+#define TEST_ASSERT_MSR(cond, fmt, msr, str, args...)				\
+do {										\
+	if (__builtin_constant_p(msr)) {					\
+		TEST_ASSERT(cond, fmt, str, args);				\
+	} else if (!(cond)) {							\
+		char buf[16];							\
+										\
+		snprintf(buf, sizeof(buf), "MSR 0x%x", msr);			\
+		TEST_ASSERT(cond, fmt, buf, args);				\
+	}									\
+} while (0)
 
+/*
+ * Returns true if KVM should return the last written value when reading an MSR
+ * from userspace, e.g. the MSR isn't a command MSR, doesn't emulate state that
+ * is changing, etc.  This is NOT an exhaustive list!  The intent is to filter
+ * out MSRs that are not durable _and_ that a selftest wants to write.
+ */
+static inline bool is_durable_msr(uint32_t msr)
+{
+	return msr != MSR_IA32_TSC;
+}
+
+#define vcpu_set_msr(vcpu, msr, val)							\
+do {											\
+	uint64_t r, v = val;								\
+											\
+	TEST_ASSERT_MSR(_vcpu_set_msr(vcpu, msr, v) == 1,				\
+			"KVM_SET_MSRS failed on %s, value = 0x%lx", msr, #msr, v);	\
+	if (!is_durable_msr(msr))							\
+		break;									\
+	r = vcpu_get_msr(vcpu, msr);							\
+	TEST_ASSERT_MSR(r == v, "Set %s to '0x%lx', got back '0x%lx'", msr, #msr, v, r);\
+} while (0)
 
 void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits);
 bool vm_is_unrestricted_guest(struct kvm_vm *vm);