Re: [PATCH 1/3] Make kvm_cpu_(has|get)_interrupt() work for userspace irqchip too.

[Sheng Yang <sheng@linux.intel.com>]

On Tuesday 07 April 2009 17:08:12 Gleb Natapov wrote:
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> ---
>
>  arch/x86/kvm/irq.c |   39 +++++++++++++++++++++++----------------
>  arch/x86/kvm/svm.c |   11 +++++++----
>  arch/x86/kvm/vmx.c |   18 +++++++++---------
>  arch/x86/kvm/x86.c |    4 ++--
>  4 files changed, 41 insertions(+), 31 deletions(-)
>
> diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
> index cf17ed5..6974e7c 100644
> --- a/arch/x86/kvm/irq.c
> +++ b/arch/x86/kvm/irq.c
> @@ -24,6 +24,7 @@
>
>  #include "irq.h"
>  #include "i8254.h"
> +#include "x86.h"
>
>  /*
>   * check if there are pending timer events
> @@ -48,14 +49,17 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
>  {
>  	struct kvm_pic *s;
>
> -	if (kvm_apic_has_interrupt(v) == -1) {	/* LAPIC */
> -		if (kvm_apic_accept_pic_intr(v)) {
> -			s = pic_irqchip(v->kvm);	/* PIC */
> -			return s->output;
> -		} else
> -			return 0;
> +	if (irqchip_in_kernel(v->kvm)) {
> +		if (kvm_apic_has_interrupt(v) == -1) {	/* LAPIC */
> +			if (kvm_apic_accept_pic_intr(v)) {
> +				s = pic_irqchip(v->kvm);	/* PIC */
> +				return s->output;
> +			} else
> +				return 0;
> +		}
> +		return 1;
>  	}
> -	return 1;
> +	return v->arch.irq_summary;
>  }

Use if (!irqchip_in_kernel(v->kvm)) for userspace seems more simple(rather 
than a series of indention...).

>  EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
>
> @@ -64,18 +68,21 @@ EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
>   */
>  int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
>  {
> -	struct kvm_pic *s;
> -	int vector;
> +	if (irqchip_in_kernel(v->kvm)) {
> +		struct kvm_pic *s;
> +		int vector;
>
> -	vector = kvm_get_apic_interrupt(v);	/* APIC */
> -	if (vector == -1) {
> -		if (kvm_apic_accept_pic_intr(v)) {
> -			s = pic_irqchip(v->kvm);
> -			s->output = 0;		/* PIC */
> -			vector = kvm_pic_read_irq(v->kvm);
> +		vector = kvm_get_apic_interrupt(v);	/* APIC */
> +		if (vector == -1) {
> +			if (kvm_apic_accept_pic_intr(v)) {
> +				s = pic_irqchip(v->kvm);
> +				s->output = 0;		/* PIC */
> +				vector = kvm_pic_read_irq(v->kvm);
> +			}
>  		}
> +		return vector;
>  	}
> -	return vector;
> +	return kvm_pop_irq(v);
>  }
>  EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 053f3c5..1903c27 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -2089,8 +2089,9 @@ static int interrupt_window_interception(struct
> vcpu_svm *svm, * If the user space waits to inject interrupts, exit as soon
> as * possible
>  	 */
> -	if (kvm_run->request_interrupt_window &&
> -	    !svm->vcpu.arch.irq_summary) {
> +	if (!irqchip_in_kernel(svm->vcpu.kvm) &&
> +	    kvm_run->request_interrupt_window &&
> +	    !kvm_cpu_has_interrupt(&svm->vcpu)) {
>  		++svm->vcpu.stat.irq_window_exits;
>  		kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
>  		return 0;
> @@ -2371,7 +2372,8 @@ static void do_interrupt_requests(struct kvm_vcpu
> *vcpu, (svm->vmcb->save.rflags & X86_EFLAGS_IF) &&
>  		 (svm->vcpu.arch.hflags & HF_GIF_MASK));
>
> -	if (svm->vcpu.arch.interrupt_window_open && svm->vcpu.arch.irq_summary)
> +	if (svm->vcpu.arch.interrupt_window_open &&
> +	    kvm_cpu_has_interrupt(&svm->vcpu))
>  		/*
>  		 * If interrupts enabled, and not blocked by sti or mov ss. Good.
>  		 */
> @@ -2381,7 +2383,8 @@ static void do_interrupt_requests(struct kvm_vcpu
> *vcpu, * Interrupts blocked.  Wait for unblock.
>  	 */
>  	if (!svm->vcpu.arch.interrupt_window_open &&
> -	    (svm->vcpu.arch.irq_summary || kvm_run->request_interrupt_window))
> +	    (kvm_cpu_has_interrupt(&svm->vcpu) ||
> +	     kvm_run->request_interrupt_window))
>  		svm_set_vintr(svm);
>  	else
>  		svm_clear_vintr(svm);
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index c6997c0..b3292c1 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -2535,21 +2535,20 @@ static void do_interrupt_requests(struct kvm_vcpu
> *vcpu, vmx_inject_nmi(vcpu);
>  		if (vcpu->arch.nmi_pending)
>  			enable_nmi_window(vcpu);
> -		else if (vcpu->arch.irq_summary
> -			 || kvm_run->request_interrupt_window)
> +		else if (kvm_cpu_has_interrupt(vcpu) ||
> +			 kvm_run->request_interrupt_window)
>  			enable_irq_window(vcpu);
>  		return;
>  	}
>
>  	if (vcpu->arch.interrupt_window_open) {
> -		if (vcpu->arch.irq_summary && !vcpu->arch.interrupt.pending)
> -			kvm_queue_interrupt(vcpu, kvm_pop_irq(vcpu));
> +		if (kvm_cpu_has_interrupt(vcpu) && !vcpu->arch.interrupt.pending)
> +			kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
>
>  		if (vcpu->arch.interrupt.pending)
>  			vmx_inject_irq(vcpu, vcpu->arch.interrupt.nr);
> -	}
> -	if (!vcpu->arch.interrupt_window_open &&
> -	    (vcpu->arch.irq_summary || kvm_run->request_interrupt_window))
> +	} else if(kvm_cpu_has_interrupt(vcpu) ||
> +		  kvm_run->request_interrupt_window)
>  		enable_irq_window(vcpu);
>  }
>
> @@ -2976,8 +2975,9 @@ static int handle_interrupt_window(struct kvm_vcpu
> *vcpu, * If the user space waits to inject interrupts, exit as soon as *
> possible
>  	 */
> -	if (kvm_run->request_interrupt_window &&
> -	    !vcpu->arch.irq_summary) {
> +	if (!irqchip_in_kernel(vcpu->kvm) &&
> +	    kvm_run->request_interrupt_window &&

I think kvm_run->request_interrupt_window can indicate it's userspace irqchip?

> +	    !kvm_cpu_has_interrupt(vcpu)) {
>  		kvm_run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
>  		return 0;
>  	}
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 52c7a29..6e30cef 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3064,7 +3064,7 @@ EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
>  static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu,
>  					  struct kvm_run *kvm_run)
>  {
> -	return (!vcpu->arch.irq_summary &&
> +	return (!irqchip_in_kernel(vcpu->kvm) && !kvm_cpu_has_interrupt(vcpu) &&
>  		kvm_run->request_interrupt_window &&

ditto.

-- 
regards
Yang, Sheng

>  		vcpu->arch.interrupt_window_open &&
>  		(kvm_x86_ops->get_rflags(vcpu) & X86_EFLAGS_IF));
> @@ -3081,7 +3081,7 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu,
>  	else
>  		kvm_run->ready_for_interrupt_injection =
>  					(vcpu->arch.interrupt_window_open &&
> -					 vcpu->arch.irq_summary == 0);
> +					 !kvm_cpu_has_interrupt(vcpu));
>  }
>
>  static void vapic_enter(struct kvm_vcpu *vcpu)
>
> --
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