From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752417AbbIPJXK (ORCPT ); Wed, 16 Sep 2015 05:23:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58974 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752145AbbIPJXG (ORCPT ); Wed, 16 Sep 2015 05:23:06 -0400 Subject: Re: [PATCH v8 03/13] KVM: Define a new interface kvm_intr_is_single_vcpu() To: Feng Wu , alex.williamson@redhat.com, joro@8bytes.org, mtosatti@redhat.com References: <1442393409-2623-1-git-send-email-feng.wu@intel.com> <1442393409-2623-4-git-send-email-feng.wu@intel.com> Cc: eric.auger@linaro.org, kvm@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org From: Paolo Bonzini X-Enigmail-Draft-Status: N1110 Message-ID: <55F934F5.7040605@redhat.com> Date: Wed, 16 Sep 2015 11:23:01 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1442393409-2623-4-git-send-email-feng.wu@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > --- > 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. > + 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 >