KVM: nVMX: Check HOST_IA32_PERF_GLOBAL_CTRL on VM-Entry

Add a consistency check on nested vm-entry for host's
IA32_PERF_GLOBAL_CTRL from vmcs12. Per Intel's SDM Vol 3 26.2.2:

  If the "load IA32_PERF_GLOBAL_CTRL"
  VM-exit control is 1, bits reserved in the IA32_PERF_GLOBAL_CTRL
  MSR must be 0 in the field for that register"

Suggested-by: Jim Mattson <[email protected]>
Co-developed-by: Krish Sadhukhan <[email protected]>
Signed-off-by: Krish Sadhukhan <[email protected]>
Signed-off-by: Oliver Upton <[email protected]>
Reviewed-by: Jim Mattson <[email protected]>
Reviewed-by: Peter Shier <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

Author: oupton

arch/x86/kvm/vmx/nested.c

@@ -2676,6 +2676,11 @@ static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu,
 	    CC(!kvm_pat_valid(vmcs12->host_ia32_pat)))
 		return -EINVAL;
 
+	if ((vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL) &&
+	    CC(!kvm_valid_perf_global_ctrl(vcpu_to_pmu(vcpu),
+					   vmcs12->host_ia32_perf_global_ctrl)))
+		return -EINVAL;
+
 #ifdef CONFIG_X86_64
 	ia32e = !!(vcpu->arch.efer & EFER_LMA);
 #else