KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest

When kernel handles the vm-exit caused by external interrupts and NMI,
it always sets kvm_intr_type to tell if it's dealing an IRQ or NMI. For
the PMI scenario, it could be IRQ or NMI.

However, intel_pt PMIs are only generated for HARDWARE perf events, and
HARDWARE events are always configured to generate NMIs.  Use
kvm_handling_nmi_from_guest() to precisely identify if the intel_pt PMI
came from the guest; this avoids false positives if an intel_pt PMI/NMI
arrives while the host is handling an unrelated IRQ VM-Exit.

Fixes: db215756 ("KVM: x86: More precisely identify NMI from guest when handling PMI")
Signed-off-by: Yanfei Xu <yanfei.xu@intel.com>
Message-Id: <20220523140821.1345605-1-yanfei.xu@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmx.c

@@ -7853,7 +7853,7 @@ static unsigned int vmx_handle_intel_pt_intr(void)
 	struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
 
 	/* '0' on failure so that the !PT case can use a RET0 static call. */
-	if (!kvm_arch_pmi_in_guest(vcpu))
+	if (!vcpu || !kvm_handling_nmi_from_guest(vcpu))
 		return 0;
 
 	kvm_make_request(KVM_REQ_PMI, vcpu);