From f3200d00ea42e485772ff92d6d649aa8eeb640c0 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Mon, 10 Dec 2012 14:05:55 +0200 Subject: [PATCH] KVM: inject ExtINT interrupt before APIC interrupts According to Intel SDM Volume 3 Section 10.8.1 "Interrupt Handling with the Pentium 4 and Intel Xeon Processors" and Section 10.8.2 "Interrupt Handling with the P6 Family and Pentium Processors" ExtINT interrupts are sent directly to the processor core for handling. Currently KVM checks APIC before it considers ExtINT interrupts for injection which is backwards from the spec. Make code behave according to the SDM. Signed-off-by: Gleb Natapov Acked-by: "Zhang, Yang Z" Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/i8259.c | 2 ++ arch/x86/kvm/irq.c | 26 ++++++++------------------ 2 files changed, 10 insertions(+), 18 deletions(-) diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index 848206df0967..cc31f7c06d3d 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -241,6 +241,8 @@ int kvm_pic_read_irq(struct kvm *kvm) int irq, irq2, intno; struct kvm_pic *s = pic_irqchip(kvm); + s->output = 0; + pic_lock(s); irq = pic_get_irq(&s->pics[0]); if (irq >= 0) { diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index 7e06ba1618bd..ebd98d0c4f6e 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -48,14 +48,10 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v) if (!irqchip_in_kernel(v->kvm)) return v->arch.interrupt.pending; - 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; + if (kvm_apic_accept_pic_intr(v) && pic_irqchip(v->kvm)->output) + return pic_irqchip(v->kvm)->output; /* PIC */ + + return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ } EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); @@ -65,20 +61,14 @@ 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)) return v->arch.interrupt.nr; - 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; + if (kvm_apic_accept_pic_intr(v) && pic_irqchip(v->kvm)->output) + return kvm_pic_read_irq(v->kvm); /* PIC */ + + return kvm_get_apic_interrupt(v); /* APIC */ } EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); -- 2.34.1