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Message-Id: <1442393409-2623-4-git-send-email-feng.wu@intel.com>
Date: Wed, 16 Sep 2015 16:49:59 +0800
From: Feng Wu <feng.wu@...el.com>
To: pbonzini@...hat.com, alex.williamson@...hat.com, joro@...tes.org,
mtosatti@...hat.com
Cc: eric.auger@...aro.org, kvm@...r.kernel.org,
iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
Feng Wu <feng.wu@...el.com>
Subject: [PATCH v8 03/13] KVM: Define a new interface kvm_intr_is_single_vcpu()
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@...el.com>
---
v8:
- Some optimizations in kvm_intr_is_single_vcpu().
- Expose kvm_intr_is_single_vcpu() so we can use it in vmx code.
- Add kvm_intr_is_single_vcpu_fast() as the fast path to find
the target vCPU for the single-destination interrupt
arch/x86/include/asm/kvm_host.h | 3 ++
arch/x86/kvm/irq_comm.c | 94 +++++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/lapic.c | 5 +--
arch/x86/kvm/lapic.h | 2 +
4 files changed, 101 insertions(+), 3 deletions(-)
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..97ba1d6 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -297,6 +297,100 @@ out:
return r;
}
+static bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm,
+ struct kvm_lapic_irq *irq,
+ struct kvm_vcpu **dest_vcpu)
+{
+ struct kvm_apic_map *map;
+ bool ret = false;
+ struct kvm_lapic *dst = NULL;
+
+ if (irq->shorthand)
+ return false;
+
+ rcu_read_lock();
+ map = rcu_dereference(kvm->arch.apic_map);
+
+ if (!map)
+ goto out;
+
+ if (irq->dest_mode == APIC_DEST_PHYSICAL) {
+ if (irq->dest_id == 0xFF)
+ goto out;
+
+ if (irq->dest_id >= ARRAY_SIZE(map->phys_map)) {
+ WARN_ON_ONCE(1);
+ goto out;
+ }
+
+ dst = map->phys_map[irq->dest_id];
+ if (dst && kvm_apic_present(dst->vcpu))
+ *dest_vcpu = dst->vcpu;
+ else
+ goto out;
+ } else {
+ u16 cid;
+ unsigned long bitmap = 1;
+ int i, r = 0;
+
+ if (!kvm_apic_logical_map_valid(map)) {
+ WARN_ON_ONCE(1);
+ goto out;
+ }
+
+ apic_logical_id(map, irq->dest_id, &cid, (u16 *)&bitmap);
+
+ if (cid >= ARRAY_SIZE(map->logical_map)) {
+ WARN_ON_ONCE(1);
+ goto out;
+ }
+
+ for_each_set_bit(i, &bitmap, 16) {
+ dst = map->logical_map[cid][i];
+ if (++r == 2)
+ goto out;
+ }
+
+ if (dst && kvm_apic_present(dst->vcpu))
+ *dest_vcpu = dst->vcpu;
+ else
+ goto out;
+ }
+
+ ret = true;
+out:
+ rcu_read_unlock();
+ return ret;
+}
+
+
+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;
+
+ if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu))
+ return true;
+
+ 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;
+
+ if (++r == 2)
+ return false;
+
+ *dest_vcpu = vcpu;
+ }
+
+ return r == 1;
+}
+EXPORT_SYMBOL_GPL(kvm_intr_is_single_vcpu);
+
#define IOAPIC_ROUTING_ENTRY(irq) \
{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
.u.irqchip = { .irqchip = KVM_IRQCHIP_IOAPIC, .pin = (irq) } }
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2a5ca97..9848cd50 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -136,13 +136,12 @@ static inline int kvm_apic_id(struct kvm_lapic *apic)
/* The logical map is definitely wrong if we have multiple
* modes at the same time. (Physical map is always right.)
*/
-static inline bool kvm_apic_logical_map_valid(struct kvm_apic_map *map)
+bool kvm_apic_logical_map_valid(struct kvm_apic_map *map)
{
return !(map->mode & (map->mode - 1));
}
-static inline void
-apic_logical_id(struct kvm_apic_map *map, u32 dest_id, u16 *cid, u16 *lid)
+void apic_logical_id(struct kvm_apic_map *map, u32 dest_id, u16 *cid, u16 *lid)
{
unsigned lid_bits;
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 7195274..6798b87 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -169,4 +169,6 @@ bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector);
void wait_lapic_expire(struct kvm_vcpu *vcpu);
+void apic_logical_id(struct kvm_apic_map *map, u32 dest_id, u16 *cid, u16 *lid);
+bool kvm_apic_logical_map_valid(struct kvm_apic_map *map);
#endif
--
2.1.0
--
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