Merge tag 'kvm-x86-pmu-6.9' of https://github.com/kvm-x86/linux into HEAD

KVM x86 PMU changes for 6.9:

 - Fix several bugs where KVM speciously prevents the guest from utilizing
   fixed counters and architectural event encodings based on whether or not
   guest CPUID reports support for the _architectural_ encoding.

 - Fix a variety of bugs in KVM's emulation of RDPMC, e.g. for "fast" reads,
   priority of VMX interception vs #GP, PMC types in architectural PMUs, etc.

 - Add a selftest to verify KVM correctly emulates RDMPC, counter availability,
   and a variety of other PMC-related behaviors that depend on guest CPUID,
   i.e. are difficult to validate via KVM-Unit-Tests.

 - Zero out PMU metadata on AMD if the virtual PMU is disabled to avoid wasting
   cycles, e.g. when checking if a PMC event needs to be synthesized when
   skipping an instruction.

 - Optimize triggering of emulated events, e.g. for "count instructions" events
   when skipping an instruction, which yields a ~10% performance improvement in
   VM-Exit microbenchmarks when a vPMU is exposed to the guest.

 - Tighten the check for "PMI in guest" to reduce false positives if an NMI
   arrives in the host while KVM is handling an IRQ VM-Exit.

1 files changed, 12 insertions, 3 deletions

diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index c3bb2eb38cff..74a4c736c9ae 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -781,12 +781,21 @@ void vcpu_init_cpuid(struct kvm_vcpu *vcpu, const struct kvm_cpuid2 *cpuid)
 	vcpu_set_cpuid(vcpu);
 }
 
-void vcpu_set_cpuid_maxphyaddr(struct kvm_vcpu *vcpu, uint8_t maxphyaddr)
+void vcpu_set_cpuid_property(struct kvm_vcpu *vcpu,
+			     struct kvm_x86_cpu_property property,
+			     uint32_t value)
 {
-	struct kvm_cpuid_entry2 *entry = vcpu_get_cpuid_entry(vcpu, 0x80000008);
+	struct kvm_cpuid_entry2 *entry;
+
+	entry = __vcpu_get_cpuid_entry(vcpu, property.function, property.index);
+
+	(&entry->eax)[property.reg] &= ~GENMASK(property.hi_bit, property.lo_bit);
+	(&entry->eax)[property.reg] |= value << property.lo_bit;
 
-	entry->eax = (entry->eax & ~0xff) | maxphyaddr;
 	vcpu_set_cpuid(vcpu);
+
+	/* Sanity check that @value doesn't exceed the bounds in any way. */
+	TEST_ASSERT_EQ(kvm_cpuid_property(vcpu->cpuid, property), value);
 }
 
 void vcpu_clear_cpuid_entry(struct kvm_vcpu *vcpu, uint32_t function)