[PATCH v6 03/16] KVM: Define a new interface kvm_intr_is_single_vcpu()

From: Feng Wu
Date: Tue Aug 11 2015 - 02:16:50 EST


This patch defines a new interface kvm_intr_is_single_vcpu(),
which can returns whether the interrupt is for single-CPU or not.

It is used by VT-d PI, since now we only support single-CPU
interrupts, For lowest-priority interrupts, if user configures
it via /proc/irq or uses irqbalance to make it single-CPU, we
can use PI to deliver the interrupts to it. Full functionality
of lowest-priority support will be added later.

Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/kvm/irq_comm.c | 24 ++++++++++++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 49ec903..af11bca 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1204,4 +1204,7 @@ int __x86_set_memory_region(struct kvm *kvm,
int x86_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem);

+bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
+ struct kvm_vcpu **dest_vcpu);
+
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
index 9efff9e..a9572a13 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -297,6 +297,30 @@ out:
return r;
}

+bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq,
+ struct kvm_vcpu **dest_vcpu)
+{
+ int i, r = 0;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (!kvm_apic_present(vcpu))
+ continue;
+
+ if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand,
+ irq->dest_id, irq->dest_mode))
+ continue;
+
+ r++;
+ *dest_vcpu = vcpu;
+ }
+
+ if (r == 1)
+ return true;
+ else
+ return false;
+}
+
#define IOAPIC_ROUTING_ENTRY(irq) \
{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
.u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
--
2.1.0

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