> -----Original Message----- > From: Paolo Bonzini [mailto:pbonzini@xxxxxxxxxx] > Sent: Wednesday, September 16, 2015 5:23 PM > To: Wu, Feng; alex.williamson@xxxxxxxxxx; joro@xxxxxxxxxx; > mtosatti@xxxxxxxxxx > Cc: eric.auger@xxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v8 03/13] KVM: Define a new interface > kvm_intr_is_single_vcpu() > > > > On 16/09/2015 10:49, Feng Wu wrote: > > 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> > > --- > > 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) > > Please put this in lapic.c, similar to kvm_irq_delivery_to_apic_fast, so > that you do not have to export other functions. > > > +{ > > + 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)) { > > Warning here is wrong, the guest can trigger it. Could you please share more information about how the guest triggers these conditions (including the following two), Thanks a lot! Thanks, Feng > > > + 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); > > Same here. > > > + goto out; > > + } > > + > > + apic_logical_id(map, irq->dest_id, &cid, (u16 *)&bitmap); > > + > > + if (cid >= ARRAY_SIZE(map->logical_map)) { > > + WARN_ON_ONCE(1); > > Same here. > > Otherwise looks good. > > Paolo > > > + 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 > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
