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Message-ID: <00a1b20bdf0a0764253acca0b9fb35c0c09e6a8c.camel@redhat.com>
Subject: Re: [PATCH v4 12/24] KVM: x86: Make kvm_queued_exception a properly
 named, visible struct
From:   Maxim Levitsky <mlevitsk@redhat.com>
To:     Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jim Mattson <jmattson@google.com>,
        Oliver Upton <oupton@google.com>,
        Peter Shier <pshier@google.com>
Date:   Mon, 01 Aug 2022 19:10:56 +0300
In-Reply-To: <20220723005137.1649592-13-seanjc@google.com>
References: <20220723005137.1649592-1-seanjc@google.com>
         <20220723005137.1649592-13-seanjc@google.com>
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On Sat, 2022-07-23 at 00:51 +0000, Sean Christopherson wrote:
> Move the definition of "struct kvm_queued_exception" out of kvm_vcpu_arch
> in anticipation of adding a second instance in kvm_vcpu_arch to handle
> exceptions that occur when vectoring an injected exception and are
> morphed to VM-Exit instead of leading to #DF.
> 
> Opportunistically take advantage of the churn to rename "nr" to "vector".
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 23 +++++-----
>  arch/x86/kvm/svm/nested.c       | 47 ++++++++++---------
>  arch/x86/kvm/svm/svm.c          | 14 +++---
>  arch/x86/kvm/vmx/nested.c       | 42 +++++++++--------
>  arch/x86/kvm/vmx/vmx.c          | 20 ++++-----
>  arch/x86/kvm/x86.c              | 80 ++++++++++++++++-----------------
>  arch/x86/kvm/x86.h              |  3 +-
>  7 files changed, 113 insertions(+), 116 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index dbb9eab979d4..0a6a05e25f24 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -639,6 +639,17 @@ struct kvm_vcpu_xen {
>  	struct timer_list poll_timer;
>  };
>  
> +struct kvm_queued_exception {
> +	bool pending;
> +	bool injected;
> +	bool has_error_code;
> +	u8 vector;
> +	u32 error_code;
> +	unsigned long payload;
> +	bool has_payload;
> +	u8 nested_apf;
> +};
> +
>  struct kvm_vcpu_arch {
>  	/*
>  	 * rip and regs accesses must go through
> @@ -737,16 +748,8 @@ struct kvm_vcpu_arch {
>  
>  	u8 event_exit_inst_len;
>  
> -	struct kvm_queued_exception {
> -		bool pending;
> -		bool injected;
> -		bool has_error_code;
> -		u8 nr;
> -		u32 error_code;
> -		unsigned long payload;
> -		bool has_payload;
> -		u8 nested_apf;
> -	} exception;
> +	/* Exceptions to be injected to the guest. */
> +	struct kvm_queued_exception exception;
>  
>  	struct kvm_queued_interrupt {
>  		bool injected;
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index 76dcc8a3e849..8f991592d277 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -468,7 +468,7 @@ static void nested_save_pending_event_to_vmcb12(struct vcpu_svm *svm,
>  	unsigned int nr;
>  
>  	if (vcpu->arch.exception.injected) {
> -		nr = vcpu->arch.exception.nr;
> +		nr = vcpu->arch.exception.vector;
>  		exit_int_info = nr | SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_EXEPT;
>  
>  		if (vcpu->arch.exception.has_error_code) {
> @@ -1306,42 +1306,45 @@ int nested_svm_check_permissions(struct kvm_vcpu *vcpu)
>  
>  static bool nested_exit_on_exception(struct vcpu_svm *svm)
>  {
> -	unsigned int nr = svm->vcpu.arch.exception.nr;
> +	unsigned int vector = svm->vcpu.arch.exception.vector;
>  
> -	return (svm->nested.ctl.intercepts[INTERCEPT_EXCEPTION] & BIT(nr));
> +	return (svm->nested.ctl.intercepts[INTERCEPT_EXCEPTION] & BIT(vector));
>  }
>  
> -static void nested_svm_inject_exception_vmexit(struct vcpu_svm *svm)
> +static void nested_svm_inject_exception_vmexit(struct kvm_vcpu *vcpu)
>  {
> -	unsigned int nr = svm->vcpu.arch.exception.nr;
> +	struct kvm_queued_exception *ex = &vcpu->arch.exception;
> +	struct vcpu_svm *svm = to_svm(vcpu);
>  	struct vmcb *vmcb = svm->vmcb;
>  
> -	vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + nr;
> +	vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + ex->vector;
>  	vmcb->control.exit_code_hi = 0;
>  
> -	if (svm->vcpu.arch.exception.has_error_code)
> -		vmcb->control.exit_info_1 = svm->vcpu.arch.exception.error_code;
> +	if (ex->has_error_code)
> +		vmcb->control.exit_info_1 = ex->error_code;
>  
>  	/*
>  	 * EXITINFO2 is undefined for all exception intercepts other
>  	 * than #PF.
>  	 */
> -	if (nr == PF_VECTOR) {
> -		if (svm->vcpu.arch.exception.nested_apf)
> -			vmcb->control.exit_info_2 = svm->vcpu.arch.apf.nested_apf_token;
> -		else if (svm->vcpu.arch.exception.has_payload)
> -			vmcb->control.exit_info_2 = svm->vcpu.arch.exception.payload;
> +	if (ex->vector == PF_VECTOR) {
> +		if (ex->nested_apf)
> +			vmcb->control.exit_info_2 = vcpu->arch.apf.nested_apf_token;
> +		else if (ex->has_payload)
> +			vmcb->control.exit_info_2 = ex->payload;
>  		else
> -			vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
> -	} else if (nr == DB_VECTOR) {
> +			vmcb->control.exit_info_2 = vcpu->arch.cr2;
> +	} else if (ex->vector == DB_VECTOR) {
>  		/* See inject_pending_event.  */
> -		kvm_deliver_exception_payload(&svm->vcpu);
> -		if (svm->vcpu.arch.dr7 & DR7_GD) {
> -			svm->vcpu.arch.dr7 &= ~DR7_GD;
> -			kvm_update_dr7(&svm->vcpu);
> +		kvm_deliver_exception_payload(vcpu, ex);
> +
> +		if (vcpu->arch.dr7 & DR7_GD) {
> +			vcpu->arch.dr7 &= ~DR7_GD;
> +			kvm_update_dr7(vcpu);
>  		}
> -	} else
> -		WARN_ON(svm->vcpu.arch.exception.has_payload);
> +	} else {
> +		WARN_ON(ex->has_payload);
> +	}
>  
>  	nested_svm_vmexit(svm);
>  }
> @@ -1379,7 +1382,7 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
>                          return -EBUSY;
>  		if (!nested_exit_on_exception(svm))
>  			return 0;
> -		nested_svm_inject_exception_vmexit(svm);
> +		nested_svm_inject_exception_vmexit(vcpu);
>  		return 0;
>  	}
>  
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index e73d79ae0e45..74cbe177e0d1 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -456,22 +456,20 @@ static int svm_update_soft_interrupt_rip(struct kvm_vcpu *vcpu)
>  
>  static void svm_inject_exception(struct kvm_vcpu *vcpu)
>  {
> +	struct kvm_queued_exception *ex = &vcpu->arch.exception;
>  	struct vcpu_svm *svm = to_svm(vcpu);
> -	unsigned nr = vcpu->arch.exception.nr;
> -	bool has_error_code = vcpu->arch.exception.has_error_code;
> -	u32 error_code = vcpu->arch.exception.error_code;
>  
> -	kvm_deliver_exception_payload(vcpu);
> +	kvm_deliver_exception_payload(vcpu, ex);
>  
> -	if (kvm_exception_is_soft(nr) &&
> +	if (kvm_exception_is_soft(ex->vector) &&
>  	    svm_update_soft_interrupt_rip(vcpu))
>  		return;
>  
> -	svm->vmcb->control.event_inj = nr
> +	svm->vmcb->control.event_inj = ex->vector
>  		| SVM_EVTINJ_VALID
> -		| (has_error_code ? SVM_EVTINJ_VALID_ERR : 0)
> +		| (ex->has_error_code ? SVM_EVTINJ_VALID_ERR : 0)
>  		| SVM_EVTINJ_TYPE_EXEPT;
> -	svm->vmcb->control.event_inj_err = error_code;
> +	svm->vmcb->control.event_inj_err = ex->error_code;
>  }
>  
>  static void svm_init_erratum_383(void)
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 17df0c31f0b5..0f5a7aec82a2 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -446,29 +446,27 @@ static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12,
>   */
>  static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned long *exit_qual)
>  {
> +	struct kvm_queued_exception *ex = &vcpu->arch.exception;
>  	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
> -	unsigned int nr = vcpu->arch.exception.nr;
> -	bool has_payload = vcpu->arch.exception.has_payload;
> -	unsigned long payload = vcpu->arch.exception.payload;
>  
> -	if (nr == PF_VECTOR) {
> -		if (vcpu->arch.exception.nested_apf) {
> +	if (ex->vector == PF_VECTOR) {
> +		if (ex->nested_apf) {
>  			*exit_qual = vcpu->arch.apf.nested_apf_token;
>  			return 1;
>  		}
> -		if (nested_vmx_is_page_fault_vmexit(vmcs12,
> -						    vcpu->arch.exception.error_code)) {
> -			*exit_qual = has_payload ? payload : vcpu->arch.cr2;
> +		if (nested_vmx_is_page_fault_vmexit(vmcs12, ex->error_code)) {
> +			*exit_qual = ex->has_payload ? ex->payload : vcpu->arch.cr2;
>  			return 1;
>  		}
> -	} else if (vmcs12->exception_bitmap & (1u << nr)) {
> -		if (nr == DB_VECTOR) {
> -			if (!has_payload) {
> -				payload = vcpu->arch.dr6;
> -				payload &= ~DR6_BT;
> -				payload ^= DR6_ACTIVE_LOW;
> +	} else if (vmcs12->exception_bitmap & (1u << ex->vector)) {
> +		if (ex->vector == DB_VECTOR) {
> +			if (ex->has_payload) {
> +				*exit_qual = ex->payload;
> +			} else {
> +				*exit_qual = vcpu->arch.dr6;
> +				*exit_qual &= ~DR6_BT;
> +				*exit_qual ^= DR6_ACTIVE_LOW;
>  			}
> -			*exit_qual = payload;
>  		} else
>  			*exit_qual = 0;
>  		return 1;
> @@ -3718,7 +3716,7 @@ static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
>  	     is_double_fault(exit_intr_info))) {
>  		vmcs12->idt_vectoring_info_field = 0;
>  	} else if (vcpu->arch.exception.injected) {
> -		nr = vcpu->arch.exception.nr;
> +		nr = vcpu->arch.exception.vector;
>  		idt_vectoring = nr | VECTORING_INFO_VALID_MASK;
>  
>  		if (kvm_exception_is_soft(nr)) {
> @@ -3822,11 +3820,11 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
>  static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu,
>  					       unsigned long exit_qual)
>  {
> +	struct kvm_queued_exception *ex = &vcpu->arch.exception;
> +	u32 intr_info = ex->vector | INTR_INFO_VALID_MASK;
>  	struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
> -	unsigned int nr = vcpu->arch.exception.nr;
> -	u32 intr_info = nr | INTR_INFO_VALID_MASK;
>  
> -	if (vcpu->arch.exception.has_error_code) {
> +	if (ex->has_error_code) {
>  		/*
>  		 * Intel CPUs do not generate error codes with bits 31:16 set,
>  		 * and more importantly VMX disallows setting bits 31:16 in the
> @@ -3836,11 +3834,11 @@ static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu,
>  		 * generate "full" 32-bit error codes, so KVM allows userspace
>  		 * to inject exception error codes with bits 31:16 set.
>  		 */
> -		vmcs12->vm_exit_intr_error_code = (u16)vcpu->arch.exception.error_code;
> +		vmcs12->vm_exit_intr_error_code = (u16)ex->error_code;
>  		intr_info |= INTR_INFO_DELIVER_CODE_MASK;
>  	}
>  
> -	if (kvm_exception_is_soft(nr))
> +	if (kvm_exception_is_soft(ex->vector))
>  		intr_info |= INTR_TYPE_SOFT_EXCEPTION;
>  	else
>  		intr_info |= INTR_TYPE_HARD_EXCEPTION;
> @@ -3871,7 +3869,7 @@ static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu,
>  static inline unsigned long vmx_get_pending_dbg_trap(struct kvm_vcpu *vcpu)
>  {
>  	if (!vcpu->arch.exception.pending ||
> -	    vcpu->arch.exception.nr != DB_VECTOR)
> +	    vcpu->arch.exception.vector != DB_VECTOR)
>  		return 0;
>  
>  	/* General Detect #DBs are always fault-like. */
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 14f75e4003d3..4cfe6646476b 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -1585,7 +1585,7 @@ static void vmx_update_emulated_instruction(struct kvm_vcpu *vcpu)
>  	 */
>  	if (nested_cpu_has_mtf(vmcs12) &&
>  	    (!vcpu->arch.exception.pending ||
> -	     vcpu->arch.exception.nr == DB_VECTOR))
> +	     vcpu->arch.exception.vector == DB_VECTOR))
>  		vmx->nested.mtf_pending = true;
>  	else
>  		vmx->nested.mtf_pending = false;
> @@ -1612,15 +1612,13 @@ static void vmx_clear_hlt(struct kvm_vcpu *vcpu)
>  
>  static void vmx_inject_exception(struct kvm_vcpu *vcpu)
>  {
> +	struct kvm_queued_exception *ex = &vcpu->arch.exception;
> +	u32 intr_info = ex->vector | INTR_INFO_VALID_MASK;
>  	struct vcpu_vmx *vmx = to_vmx(vcpu);
> -	unsigned nr = vcpu->arch.exception.nr;
> -	bool has_error_code = vcpu->arch.exception.has_error_code;
> -	u32 error_code = vcpu->arch.exception.error_code;
> -	u32 intr_info = nr | INTR_INFO_VALID_MASK;
>  
> -	kvm_deliver_exception_payload(vcpu);
> +	kvm_deliver_exception_payload(vcpu, ex);
>  
> -	if (has_error_code) {
> +	if (ex->has_error_code) {
>  		/*
>  		 * Despite the error code being architecturally defined as 32
>  		 * bits, and the VMCS field being 32 bits, Intel CPUs and thus
> @@ -1631,21 +1629,21 @@ static void vmx_inject_exception(struct kvm_vcpu *vcpu)
>  		 * the upper bits to avoid VM-Fail, losing information that
>  		 * does't really exist is preferable to killing the VM.
>  		 */
> -		vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, (u16)error_code);
> +		vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, (u16)ex->error_code);
>  		intr_info |= INTR_INFO_DELIVER_CODE_MASK;
>  	}
>  
>  	if (vmx->rmode.vm86_active) {
>  		int inc_eip = 0;
> -		if (kvm_exception_is_soft(nr))
> +		if (kvm_exception_is_soft(ex->vector))
>  			inc_eip = vcpu->arch.event_exit_inst_len;
> -		kvm_inject_realmode_interrupt(vcpu, nr, inc_eip);
> +		kvm_inject_realmode_interrupt(vcpu, ex->vector, inc_eip);
>  		return;
>  	}
>  
>  	WARN_ON_ONCE(vmx->emulation_required);
>  
> -	if (kvm_exception_is_soft(nr)) {
> +	if (kvm_exception_is_soft(ex->vector)) {
>  		vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
>  			     vmx->vcpu.arch.event_exit_inst_len);
>  		intr_info |= INTR_TYPE_SOFT_EXCEPTION;
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index a61b6cbd7194..027fc518ba75 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -557,16 +557,13 @@ static int exception_type(int vector)
>  	return EXCPT_FAULT;
>  }
>  
> -void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
> +void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu,
> +				   struct kvm_queued_exception *ex)
>  {
> -	unsigned nr = vcpu->arch.exception.nr;
> -	bool has_payload = vcpu->arch.exception.has_payload;
> -	unsigned long payload = vcpu->arch.exception.payload;
> -
> -	if (!has_payload)
> +	if (!ex->has_payload)
>  		return;
>  
> -	switch (nr) {
> +	switch (ex->vector) {
>  	case DB_VECTOR:
>  		/*
>  		 * "Certain debug exceptions may clear bit 0-3.  The
> @@ -591,8 +588,8 @@ void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
>  		 * So they need to be flipped for DR6.
>  		 */
>  		vcpu->arch.dr6 |= DR6_ACTIVE_LOW;
> -		vcpu->arch.dr6 |= payload;
> -		vcpu->arch.dr6 ^= payload & DR6_ACTIVE_LOW;
> +		vcpu->arch.dr6 |= ex->payload;
> +		vcpu->arch.dr6 ^= ex->payload & DR6_ACTIVE_LOW;
>  
>  		/*
>  		 * The #DB payload is defined as compatible with the 'pending
> @@ -603,12 +600,12 @@ void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
>  		vcpu->arch.dr6 &= ~BIT(12);
>  		break;
>  	case PF_VECTOR:
> -		vcpu->arch.cr2 = payload;
> +		vcpu->arch.cr2 = ex->payload;
>  		break;
>  	}
>  
> -	vcpu->arch.exception.has_payload = false;
> -	vcpu->arch.exception.payload = 0;
> +	ex->has_payload = false;
> +	ex->payload = 0;
>  }
>  EXPORT_SYMBOL_GPL(kvm_deliver_exception_payload);
>  
> @@ -647,17 +644,18 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
>  			vcpu->arch.exception.injected = false;
>  		}
>  		vcpu->arch.exception.has_error_code = has_error;
> -		vcpu->arch.exception.nr = nr;
> +		vcpu->arch.exception.vector = nr;
>  		vcpu->arch.exception.error_code = error_code;
>  		vcpu->arch.exception.has_payload = has_payload;
>  		vcpu->arch.exception.payload = payload;
>  		if (!is_guest_mode(vcpu))
> -			kvm_deliver_exception_payload(vcpu);
> +			kvm_deliver_exception_payload(vcpu,
> +						      &vcpu->arch.exception);
>  		return;
>  	}
>  
>  	/* to check exception */
> -	prev_nr = vcpu->arch.exception.nr;
> +	prev_nr = vcpu->arch.exception.vector;
>  	if (prev_nr == DF_VECTOR) {
>  		/* triple fault -> shutdown */
>  		kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
> @@ -675,7 +673,7 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
>  		vcpu->arch.exception.pending = true;
>  		vcpu->arch.exception.injected = false;
>  		vcpu->arch.exception.has_error_code = true;
> -		vcpu->arch.exception.nr = DF_VECTOR;
> +		vcpu->arch.exception.vector = DF_VECTOR;
>  		vcpu->arch.exception.error_code = 0;
>  		vcpu->arch.exception.has_payload = false;
>  		vcpu->arch.exception.payload = 0;
> @@ -5006,25 +5004,24 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
>  static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
>  					       struct kvm_vcpu_events *events)
>  {
> +	struct kvm_queued_exception *ex = &vcpu->arch.exception;
> +
>  	process_nmi(vcpu);
>  
>  	if (kvm_check_request(KVM_REQ_SMI, vcpu))
>  		process_smi(vcpu);
>  
>  	/*
> -	 * In guest mode, payload delivery should be deferred,
> -	 * so that the L1 hypervisor can intercept #PF before
> -	 * CR2 is modified (or intercept #DB before DR6 is
> -	 * modified under nVMX). Unless the per-VM capability,
> -	 * KVM_CAP_EXCEPTION_PAYLOAD, is set, we may not defer the delivery of
> -	 * an exception payload and handle after a KVM_GET_VCPU_EVENTS. Since we
> -	 * opportunistically defer the exception payload, deliver it if the
> -	 * capability hasn't been requested before processing a
> -	 * KVM_GET_VCPU_EVENTS.
> +	 * In guest mode, payload delivery should be deferred if the exception
> +	 * will be intercepted by L1, e.g. KVM should not modifying CR2 if L1
> +	 * intercepts #PF, ditto for DR6 and #DBs.  If the per-VM capability,
> +	 * KVM_CAP_EXCEPTION_PAYLOAD, is not set, userspace may or may not
> +	 * propagate the payload and so it cannot be safely deferred.  Deliver
> +	 * the payload if the capability hasn't been requested.
>  	 */
>  	if (!vcpu->kvm->arch.exception_payload_enabled &&
> -	    vcpu->arch.exception.pending && vcpu->arch.exception.has_payload)
> -		kvm_deliver_exception_payload(vcpu);
> +	    ex->pending && ex->has_payload)
> +		kvm_deliver_exception_payload(vcpu, ex);
>  
>  	/*
>  	 * The API doesn't provide the instruction length for software
> @@ -5032,26 +5029,25 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
>  	 * isn't advanced, we should expect to encounter the exception
>  	 * again.
>  	 */
> -	if (kvm_exception_is_soft(vcpu->arch.exception.nr)) {
> +	if (kvm_exception_is_soft(ex->vector)) {
>  		events->exception.injected = 0;
>  		events->exception.pending = 0;
>  	} else {
> -		events->exception.injected = vcpu->arch.exception.injected;
> -		events->exception.pending = vcpu->arch.exception.pending;
> +		events->exception.injected = ex->injected;
> +		events->exception.pending = ex->pending;
>  		/*
>  		 * For ABI compatibility, deliberately conflate
>  		 * pending and injected exceptions when
>  		 * KVM_CAP_EXCEPTION_PAYLOAD isn't enabled.
>  		 */
>  		if (!vcpu->kvm->arch.exception_payload_enabled)
> -			events->exception.injected |=
> -				vcpu->arch.exception.pending;
> +			events->exception.injected |= ex->pending;
>  	}
> -	events->exception.nr = vcpu->arch.exception.nr;
> -	events->exception.has_error_code = vcpu->arch.exception.has_error_code;
> -	events->exception.error_code = vcpu->arch.exception.error_code;
> -	events->exception_has_payload = vcpu->arch.exception.has_payload;
> -	events->exception_payload = vcpu->arch.exception.payload;
> +	events->exception.nr = ex->vector;
> +	events->exception.has_error_code = ex->has_error_code;
> +	events->exception.error_code = ex->error_code;
> +	events->exception_has_payload = ex->has_payload;
> +	events->exception_payload = ex->payload;
>  
>  	events->interrupt.injected =
>  		vcpu->arch.interrupt.injected && !vcpu->arch.interrupt.soft;
> @@ -5123,7 +5119,7 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
>  	process_nmi(vcpu);
>  	vcpu->arch.exception.injected = events->exception.injected;
>  	vcpu->arch.exception.pending = events->exception.pending;
> -	vcpu->arch.exception.nr = events->exception.nr;
> +	vcpu->arch.exception.vector = events->exception.nr;
>  	vcpu->arch.exception.has_error_code = events->exception.has_error_code;
>  	vcpu->arch.exception.error_code = events->exception.error_code;
>  	vcpu->arch.exception.has_payload = events->exception_has_payload;
> @@ -9665,7 +9661,7 @@ int kvm_check_nested_events(struct kvm_vcpu *vcpu)
>  
>  static void kvm_inject_exception(struct kvm_vcpu *vcpu)
>  {
> -	trace_kvm_inj_exception(vcpu->arch.exception.nr,
> +	trace_kvm_inj_exception(vcpu->arch.exception.vector,
>  				vcpu->arch.exception.has_error_code,
>  				vcpu->arch.exception.error_code,
>  				vcpu->arch.exception.injected);
> @@ -9737,12 +9733,12 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit)
>  		 * describe the behavior of General Detect #DBs, which are
>  		 * fault-like.  They do _not_ set RF, a la code breakpoints.
>  		 */
> -		if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT)
> +		if (exception_type(vcpu->arch.exception.vector) == EXCPT_FAULT)
>  			__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
>  					     X86_EFLAGS_RF);
>  
> -		if (vcpu->arch.exception.nr == DB_VECTOR) {
> -			kvm_deliver_exception_payload(vcpu);
> +		if (vcpu->arch.exception.vector == DB_VECTOR) {
> +			kvm_deliver_exception_payload(vcpu, &vcpu->arch.exception);
>  			if (vcpu->arch.dr7 & DR7_GD) {
>  				vcpu->arch.dr7 &= ~DR7_GD;
>  				kvm_update_dr7(vcpu);
> diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
> index 1926d2cb8e79..4147d27f9fbc 100644
> --- a/arch/x86/kvm/x86.h
> +++ b/arch/x86/kvm/x86.h
> @@ -286,7 +286,8 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu,
>  
>  int handle_ud(struct kvm_vcpu *vcpu);
>  
> -void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu);
> +void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu,
> +				   struct kvm_queued_exception *ex);
>  
>  void kvm_vcpu_mtrr_init(struct kvm_vcpu *vcpu);
>  u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn);


To be honest, it is still a bit hard to review this patch because it does too much things
at once.

Anyway, while I can't be 100% sure I didn't miss anything, I haven't found any issues either, so:

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>

Best regards,
	Maxim Levitsky