Re: [PATCH 05/15] Coalesce userspace/kernel irqchip interrupt injection logic.

[Jan Kiszka <jan.kiszka@web.de>]

[-- Attachment #1: Type: text/plain, Size: 3164 bytes --]

Gleb Natapov wrote:
> Start to use interrupt/exception queues like VMX does.
> This also fix the bug that if exit was caused by a guest
> internal exception access to IDT the exception was not
> reinjected.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> ---
>  arch/x86/kvm/svm.c |  176 ++++++++++++++++++++++------------------------------
>  1 files changed, 75 insertions(+), 101 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 52c41aa..053370d 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -70,7 +70,6 @@ module_param(npt, int, S_IRUGO);
>  static int nested = 0;
>  module_param(nested, int, S_IRUGO);
>  
> -static void kvm_reput_irq(struct vcpu_svm *svm);
>  static void svm_flush_tlb(struct kvm_vcpu *vcpu);
>  
>  static int nested_svm_exit_handled(struct vcpu_svm *svm, bool kvm_override);
> @@ -199,9 +198,7 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
>  
>  static bool svm_exception_injected(struct kvm_vcpu *vcpu)
>  {
> -	struct vcpu_svm *svm = to_svm(vcpu);
> -
> -	return !(svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_VALID);
> +	return false;
>  }
>  
>  static int is_external_interrupt(u32 info)
> @@ -976,12 +973,9 @@ static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
>  
>  static int svm_get_irq(struct kvm_vcpu *vcpu)
>  {
> -	struct vcpu_svm *svm = to_svm(vcpu);
> -	u32 exit_int_info = svm->vmcb->control.exit_int_info;
> -
> -	if (is_external_interrupt(exit_int_info))
> -		return exit_int_info & SVM_EVTINJ_VEC_MASK;
> -	return -1;
> +	if (!vcpu->arch.interrupt.pending)
> +		return -1;
> +	return vcpu->arch.interrupt.nr;
>  }
>  
>  static void load_host_msrs(struct kvm_vcpu *vcpu)
> @@ -1088,17 +1082,8 @@ static void svm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long value,
>  
>  static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
>  {
> -	u32 exit_int_info = svm->vmcb->control.exit_int_info;
> -	struct kvm *kvm = svm->vcpu.kvm;
>  	u64 fault_address;
>  	u32 error_code;
> -	bool event_injection = false;
> -
> -	if (!irqchip_in_kernel(kvm) &&
> -	    is_external_interrupt(exit_int_info)) {
> -		event_injection = true;
> -		kvm_push_irq(&svm->vcpu, exit_int_info & SVM_EVTINJ_VEC_MASK);
> -	}
>  
>  	fault_address  = svm->vmcb->control.exit_info_2;
>  	error_code = svm->vmcb->control.exit_info_1;
> @@ -1118,9 +1103,11 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
>  	 */
>  	if (npt_enabled)
>  		svm_flush_tlb(&svm->vcpu);
> -
> -	if (!npt_enabled && event_injection)
> -		kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
> +	else {
> +		if (svm->vcpu.arch.interrupt.pending ||
> +				svm->vcpu.arch.exception.pending)
> +			kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
> +	}

Without understanding yet why kvm_mmu_unprotect_page_virt is required
here, this looks like it is lacking '|| svm->vcpu.arch.nmi_injected'.
Interrupts and exceptions are re-queued on fault-during-injection,
therefore they are now pending again, right?

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 257 bytes --]