[2/2] kvm: nVMX: interrupt-window exiting should wake L2 from HLT
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Message ID 20181121002458.239673-2-jmattson@google.com
State New
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  • [1/2] kvm: nVMX: NMI-window exiting should wake L2 from HLT
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Commit Message

Jim Mattson Nov. 21, 2018, 12:24 a.m. UTC
According to the SDM, "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 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>
---
 arch/x86/kvm/vmx.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

Comments

Sean Christopherson Nov. 26, 2018, 4:37 p.m. UTC | #1
On Tue, Nov 20, 2018 at 04:24:58PM -0800, Jim Mattson wrote:
> According to the SDM, "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 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>
> ---
>  arch/x86/kvm/vmx.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 5f5c79e72a49..2dfd150f83bd 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -13432,6 +13432,18 @@ static bool nested_vmx_nmi_window_exit(struct kvm_vcpu *vcpu)
>  		  (GUEST_INTR_STATE_NMI | GUEST_INTR_STATE_MOV_SS));
>  }
>  
> +static bool nested_vmx_intr_window_exit(struct kvm_vcpu *vcpu)
> +{
> +	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

Same comment about passing vmcs12 directly.

> +	return (vmcs12->cpu_based_vm_exec_control &
> +		CPU_BASED_VIRTUAL_INTR_PENDING) &&
> +		vmcs12->guest_activity_state != GUEST_ACTIVITY_WAIT_SIPI &&
> +		(vmcs12->guest_rflags & X86_EFLAGS_IF) &&
> +		!(vmcs12->guest_interruptibility_info &
> +		  (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS));
> +}
> +
>  /*
>   * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
>   * for running an L2 nested guest.
> @@ -13524,12 +13536,13 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
>  
>  	/*
>  	 * 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,
> -	 * halt the vcpu.
> +	 * 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) &&
> -	    !nested_vmx_nmi_window_exit(vcpu)) {
> +	    !nested_vmx_nmi_window_exit(vcpu) &&
> +	    !nested_vmx_intr_window_exit(vcpu)) {
>  		vmx->nested.nested_run_pending = 0;
>  		return kvm_vcpu_halt(vcpu);
>  	}
> -- 
> 2.19.1.1215.g8438c0b245-goog
>

Patch
diff mbox series

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5f5c79e72a49..2dfd150f83bd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -13432,6 +13432,18 @@  static bool nested_vmx_nmi_window_exit(struct kvm_vcpu *vcpu)
 		  (GUEST_INTR_STATE_NMI | GUEST_INTR_STATE_MOV_SS));
 }
 
+static bool nested_vmx_intr_window_exit(struct kvm_vcpu *vcpu)
+{
+	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+
+	return (vmcs12->cpu_based_vm_exec_control &
+		CPU_BASED_VIRTUAL_INTR_PENDING) &&
+		vmcs12->guest_activity_state != GUEST_ACTIVITY_WAIT_SIPI &&
+		(vmcs12->guest_rflags & X86_EFLAGS_IF) &&
+		!(vmcs12->guest_interruptibility_info &
+		  (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS));
+}
+
 /*
  * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
  * for running an L2 nested guest.
@@ -13524,12 +13536,13 @@  static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 
 	/*
 	 * 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,
-	 * halt the vcpu.
+	 * 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) &&
-	    !nested_vmx_nmi_window_exit(vcpu)) {
+	    !nested_vmx_nmi_window_exit(vcpu) &&
+	    !nested_vmx_intr_window_exit(vcpu)) {
 		vmx->nested.nested_run_pending = 0;
 		return kvm_vcpu_halt(vcpu);
 	}