Commit 33f089ca authored by Jan Kiszka's avatar Jan Kiszka Committed by Avi Kivity
Browse files

KVM: VMX: refactor/fix IRQ and NMI injectability determination 



There are currently two ways in VMX to check if an IRQ or NMI can be
injected:
 - vmx_{nmi|irq}_enabled and
 - vcpu.arch.{nmi|interrupt}_window_open.
Even worse, one test (at the end of vmx_vcpu_run) uses an inconsistent,
likely incorrect logic.

This patch consolidates and unifies the tests over
{nmi|interrupt}_window_open as cache + vmx_update_window_states
for updating the cache content.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 448fa4a9

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -327,6 +327,7 @@ struct kvm_vcpu_arch { 


	bool nmi_pending;

	bool nmi_injected;

	bool nmi_window_open;



	u64 mtrr[0x100];

};

arch/x86/kvm/vmx.c

+21 −25
Original line number Diff line number Diff line
@@ -2362,6 +2362,21 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu) 
			INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR);

}



static void vmx_update_window_states(struct kvm_vcpu *vcpu)

{

	u32 guest_intr = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);



	vcpu->arch.nmi_window_open =

		!(guest_intr & (GUEST_INTR_STATE_STI |

				GUEST_INTR_STATE_MOV_SS |

				GUEST_INTR_STATE_NMI));



	vcpu->arch.interrupt_window_open =

		((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) &&

		 !(guest_intr & (GUEST_INTR_STATE_STI |

				 GUEST_INTR_STATE_MOV_SS)));

}



static void kvm_do_inject_irq(struct kvm_vcpu *vcpu)

{

	int word_index = __ffs(vcpu->arch.irq_summary);
@@ -2374,15 +2389,12 @@ static void kvm_do_inject_irq(struct kvm_vcpu *vcpu) 
	kvm_queue_interrupt(vcpu, irq);

}





static void do_interrupt_requests(struct kvm_vcpu *vcpu,

				       struct kvm_run *kvm_run)

{

	u32 cpu_based_vm_exec_control;



	vcpu->arch.interrupt_window_open =

		((vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) &&

		 (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & 3) == 0);

	vmx_update_window_states(vcpu);



	if (vcpu->arch.interrupt_window_open &&

	    vcpu->arch.irq_summary && !vcpu->arch.interrupt.pending)
@@ -3075,22 +3087,6 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu) 
	vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);

}



static int vmx_nmi_enabled(struct kvm_vcpu *vcpu)

{

	u32 guest_intr = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);

	return !(guest_intr & (GUEST_INTR_STATE_NMI |

			       GUEST_INTR_STATE_MOV_SS |

			       GUEST_INTR_STATE_STI));

}



static int vmx_irq_enabled(struct kvm_vcpu *vcpu)

{

	u32 guest_intr = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);

	return (!(guest_intr & (GUEST_INTR_STATE_MOV_SS |

			       GUEST_INTR_STATE_STI)) &&

		(vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF));

}



static void enable_intr_window(struct kvm_vcpu *vcpu)

{

	if (vcpu->arch.nmi_pending)
@@ -3159,11 +3155,13 @@ static void vmx_intr_assist(struct kvm_vcpu *vcpu) 
{

	update_tpr_threshold(vcpu);



	vmx_update_window_states(vcpu);



	if (cpu_has_virtual_nmis()) {

		if (vcpu->arch.nmi_pending && !vcpu->arch.nmi_injected) {

			if (vcpu->arch.interrupt.pending) {

				enable_nmi_window(vcpu);

			} else if (vmx_nmi_enabled(vcpu)) {

			} else if (vcpu->arch.nmi_window_open) {

				vcpu->arch.nmi_pending = false;

				vcpu->arch.nmi_injected = true;

			} else {
@@ -3178,7 +3176,7 @@ static void vmx_intr_assist(struct kvm_vcpu *vcpu) 
		}

	}

	if (!vcpu->arch.interrupt.pending && kvm_cpu_has_interrupt(vcpu)) {

		if (vmx_irq_enabled(vcpu))

		if (vcpu->arch.interrupt_window_open)

			kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));

		else

			enable_irq_window(vcpu);
@@ -3339,9 +3337,7 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (vmx->rmode.irq.pending)

		fixup_rmode_irq(vmx);



	vcpu->arch.interrupt_window_open =

		(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &

		 (GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS)) == 0;

	vmx_update_window_states(vcpu);



	asm("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));

	vmx->launched = 1;

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