Commit ce7ddec4 authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
Browse files

KVM: x86: Allow marking an exception as reinjected 



This patch adds logic to kvm/x86 which allows to mark an
injected exception as reinjected. This allows to remove an
ugly hack from svm_complete_interrupts that prevented
exceptions from being reinjected at all in the nested case.
The hack was necessary because an reinjected exception into
the nested guest could cause a nested vmexit emulation. But
reinjected exceptions must not intercept. The downside of
the hack is that a exception that in injected could get
lost.
This patch fixes the problem and puts the code for it into
generic x86 files because. Nested-VMX will likely have the
same problem and could reuse the code.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent c2c63a49

arch/x86/include/asm/kvm_host.h

+5 −1
Original line number Diff line number Diff line
@@ -312,6 +312,7 @@ struct kvm_vcpu_arch { 
	struct kvm_queued_exception {

		bool pending;

		bool has_error_code;

		bool reinject;

		u8 nr;

		u32 error_code;

	} exception;
@@ -514,7 +515,8 @@ struct kvm_x86_ops { 
	void (*set_irq)(struct kvm_vcpu *vcpu);

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

	void (*queue_exception)(struct kvm_vcpu *vcpu, unsigned nr,

				bool has_error_code, u32 error_code);

				bool has_error_code, u32 error_code,

				bool reinject);

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

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

	bool (*get_nmi_mask)(struct kvm_vcpu *vcpu);
@@ -617,6 +619,8 @@ void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags); 


void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr);

void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);

void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr);

void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);

void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long cr2,

			   u32 error_code);

bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl);

arch/x86/kvm/svm.c

+6 −6
Original line number Diff line number Diff line
@@ -338,7 +338,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) 
}



static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,

				bool has_error_code, u32 error_code)

				bool has_error_code, u32 error_code,

				bool reinject)

{

	struct vcpu_svm *svm = to_svm(vcpu);
@@ -346,7 +347,8 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, 
	 * If we are within a nested VM we'd better #VMEXIT and let the guest

	 * handle the exception

	 */

	if (nested_svm_check_exception(svm, nr, has_error_code, error_code))

	if (!reinject &&

	    nested_svm_check_exception(svm, nr, has_error_code, error_code))

		return;



	if (nr == BP_VECTOR && !svm_has(SVM_FEATURE_NRIP)) {
@@ -2918,8 +2920,6 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) 
		svm->vcpu.arch.nmi_injected = true;

		break;

	case SVM_EXITINTINFO_TYPE_EXEPT:

		if (is_nested(svm))

			break;

		/*

		 * In case of software exceptions, do not reinject the vector,

		 * but re-execute the instruction instead. Rewind RIP first
@@ -2935,10 +2935,10 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) 
		}

		if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) {

			u32 err = svm->vmcb->control.exit_int_info_err;

			kvm_queue_exception_e(&svm->vcpu, vector, err);

			kvm_requeue_exception_e(&svm->vcpu, vector, err);



		} else

			kvm_queue_exception(&svm->vcpu, vector);

			kvm_requeue_exception(&svm->vcpu, vector);

		break;

	case SVM_EXITINTINFO_TYPE_INTR:

		kvm_queue_interrupt(&svm->vcpu, vector, false);

arch/x86/kvm/vmx.c

+2 −1
Original line number Diff line number Diff line
@@ -919,7 +919,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) 
}



static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,

				bool has_error_code, u32 error_code)

				bool has_error_code, u32 error_code,

				bool reinject)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	u32 intr_info = nr | INTR_INFO_VALID_MASK;

arch/x86/kvm/x86.c

+19 −4
Original line number Diff line number Diff line
@@ -265,7 +265,8 @@ static int exception_class(int vector) 
}



static void kvm_multiple_exception(struct kvm_vcpu *vcpu,

		unsigned nr, bool has_error, u32 error_code)

		unsigned nr, bool has_error, u32 error_code,

		bool reinject)

{

	u32 prev_nr;

	int class1, class2;
@@ -276,6 +277,7 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu, 
		vcpu->arch.exception.has_error_code = has_error;

		vcpu->arch.exception.nr = nr;

		vcpu->arch.exception.error_code = error_code;

		vcpu->arch.exception.reinject = true;

		return;

	}
@@ -304,10 +306,16 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu, 


void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr)

{

	kvm_multiple_exception(vcpu, nr, false, 0);

	kvm_multiple_exception(vcpu, nr, false, 0, false);

}

EXPORT_SYMBOL_GPL(kvm_queue_exception);



void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr)

{

	kvm_multiple_exception(vcpu, nr, false, 0, true);

}

EXPORT_SYMBOL_GPL(kvm_requeue_exception);



void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long addr,

			   u32 error_code)

{
@@ -324,10 +332,16 @@ EXPORT_SYMBOL_GPL(kvm_inject_nmi); 


void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)

{

	kvm_multiple_exception(vcpu, nr, true, error_code);

	kvm_multiple_exception(vcpu, nr, true, error_code, false);

}

EXPORT_SYMBOL_GPL(kvm_queue_exception_e);



void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)

{

	kvm_multiple_exception(vcpu, nr, true, error_code, true);

}

EXPORT_SYMBOL_GPL(kvm_requeue_exception_e);



/*

 * Checks if cpl <= required_cpl; if true, return true.  Otherwise queue

 * a #GP and return false.
@@ -4408,7 +4422,8 @@ static void inject_pending_event(struct kvm_vcpu *vcpu) 
					vcpu->arch.exception.error_code);

		kvm_x86_ops->queue_exception(vcpu, vcpu->arch.exception.nr,

					  vcpu->arch.exception.has_error_code,

					  vcpu->arch.exception.error_code);

					  vcpu->arch.exception.error_code,

					  vcpu->arch.exception.reinject);

		return;

	}

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