Commit c9a7953f authored by Jan Kiszka's avatar Jan Kiszka Committed by Paolo Bonzini
Browse files

KVM: x86: Remove return code from enable_irq/nmi_window 



It's no longer possible to enter enable_irq_window in guest mode when
L1 intercepts external interrupts and we are entering L2. This is now
caught in vcpu_enter_guest. So we can remove the check from the VMX
version of enable_irq_window, thus the need to return an error code from
both enable_irq_window and enable_nmi_window.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 220c5672

arch/x86/include/asm/kvm_host.h

+2 −2
Original line number Diff line number Diff line
@@ -729,8 +729,8 @@ struct kvm_x86_ops { 
	int (*nmi_allowed)(struct kvm_vcpu *vcpu);

	bool (*get_nmi_mask)(struct kvm_vcpu *vcpu);

	void (*set_nmi_mask)(struct kvm_vcpu *vcpu, bool masked);

	int (*enable_nmi_window)(struct kvm_vcpu *vcpu);

	int (*enable_irq_window)(struct kvm_vcpu *vcpu);

	void (*enable_nmi_window)(struct kvm_vcpu *vcpu);

	void (*enable_irq_window)(struct kvm_vcpu *vcpu);

	void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr);

	int (*vm_has_apicv)(struct kvm *kvm);

	void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);

arch/x86/kvm/svm.c

+3 −5
Original line number Diff line number Diff line
@@ -3650,7 +3650,7 @@ static int svm_interrupt_allowed(struct kvm_vcpu *vcpu) 
	return ret;

}



static int enable_irq_window(struct kvm_vcpu *vcpu)

static void enable_irq_window(struct kvm_vcpu *vcpu)

{

	struct vcpu_svm *svm = to_svm(vcpu);
@@ -3664,16 +3664,15 @@ static int enable_irq_window(struct kvm_vcpu *vcpu) 
		svm_set_vintr(svm);

		svm_inject_irq(svm, 0x0);

	}

	return 0;

}



static int enable_nmi_window(struct kvm_vcpu *vcpu)

static void enable_nmi_window(struct kvm_vcpu *vcpu)

{

	struct vcpu_svm *svm = to_svm(vcpu);



	if ((svm->vcpu.arch.hflags & (HF_NMI_MASK | HF_IRET_MASK))

	    == HF_NMI_MASK)

		return 0; /* IRET will cause a vm exit */

		return; /* IRET will cause a vm exit */



	/*

	 * Something prevents NMI from been injected. Single step over possible
@@ -3682,7 +3681,6 @@ static int enable_nmi_window(struct kvm_vcpu *vcpu) 
	svm->nmi_singlestep = true;

	svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);

	update_db_bp_intercept(vcpu);

	return 0;

}



static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)

arch/x86/kvm/vmx.c

+7 −18
Original line number Diff line number Diff line
@@ -4514,39 +4514,28 @@ static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu) 
		PIN_BASED_NMI_EXITING;

}



static int enable_irq_window(struct kvm_vcpu *vcpu)

static void enable_irq_window(struct kvm_vcpu *vcpu)

{

	u32 cpu_based_vm_exec_control;



	if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu))

		/*

		 * We get here if vmx_interrupt_allowed() said we can't

		 * inject to L1 now because L2 must run. The caller will have

		 * to make L2 exit right after entry, so we can inject to L1

		 * more promptly.

		 */

		return -EBUSY;



	cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);

	cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING;

	vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);

	return 0;

}



static int enable_nmi_window(struct kvm_vcpu *vcpu)

static void enable_nmi_window(struct kvm_vcpu *vcpu)

{

	u32 cpu_based_vm_exec_control;



	if (!cpu_has_virtual_nmis())

		return enable_irq_window(vcpu);



	if (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI)

		return enable_irq_window(vcpu);

	if (!cpu_has_virtual_nmis() ||

	    vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI) {

		enable_irq_window(vcpu);

		return;

	}



	cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL);

	cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_NMI_PENDING;

	vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);

	return 0;

}



static void vmx_inject_irq(struct kvm_vcpu *vcpu)

arch/x86/kvm/x86.c

+2 −4
Original line number Diff line number Diff line
@@ -5976,11 +5976,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) 
			req_immediate_exit = true;

		/* enable NMI/IRQ window open exits if needed */

		else if (vcpu->arch.nmi_pending)

			req_immediate_exit =

				kvm_x86_ops->enable_nmi_window(vcpu) != 0;

			kvm_x86_ops->enable_nmi_window(vcpu);

		else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win)

			req_immediate_exit =

				kvm_x86_ops->enable_irq_window(vcpu) != 0;

			kvm_x86_ops->enable_irq_window(vcpu);



		if (kvm_lapic_enabled(vcpu)) {

			/*

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