kvm: nVMX: NMI-window and interrupt-window exiting should wake L2 from HLT

According to the SDM, "NMI-window exiting" VM-exits wake a logical
processor from the same inactive states as would an NMI and
"interrupt-window exiting" VM-exits wake a logical processor from the
same inactive states as would an external interrupt. Specifically, they
wake a logical processor from the shutdown state and from the states
entered using the HLT and MWAIT instructions.

Fixes: 6dfacadd5858 ("KVM: nVMX: Add support for activity state HLT")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
[Squashed comments of two Jim's patches and used the simplified code
 hunk provided by Sean. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3f019aa63341e239d512ebf5536d9ee9f4598f25..adc8493132ee4a0f7b29a1f3f86e843c25fe21d2 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3156,11 +3156,15 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
        nested_cache_shadow_vmcs12(vcpu, vmcs12);
 
        /*
-        * If we're entering a halted L2 vcpu and the L2 vcpu won't be woken
-        * by event injection, halt vcpu.
+        * If we're entering a halted L2 vcpu and the L2 vcpu won't be
+        * awakened by event injection or by an NMI-window VM-exit or
+        * by an interrupt-window VM-exit, halt the vcpu.
         */
        if ((vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) &&
-           !(vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK)) {
+           !(vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK) &&
+           !(vmcs12->cpu_based_vm_exec_control & CPU_BASED_VIRTUAL_NMI_PENDING) &&
+           !((vmcs12->cpu_based_vm_exec_control & CPU_BASED_VIRTUAL_INTR_PENDING) &&
+             (vmcs12->guest_rflags & X86_EFLAGS_IF))) {
                vmx->nested.nested_run_pending = 0;
                return kvm_vcpu_halt(vcpu);
        }