Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752990AbaKJV6P (ORCPT ); Mon, 10 Nov 2014 16:58:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59015 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbaKJV6K (ORCPT ); Mon, 10 Nov 2014 16:58:10 -0500 Message-ID: <1415656655.16601.292.camel@ul30vt.home> Subject: Re: [PATCH 05/13] KVM: Update IRTE according to guest interrupt configuration changes From: Alex Williamson To: Feng Wu Cc: gleb@kernel.org, pbonzini@redhat.com, dwmw2@infradead.org, joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, kvm@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Date: Mon, 10 Nov 2014 14:57:35 -0700 In-Reply-To: <1415600812-27773-6-git-send-email-feng.wu@intel.com> References: <1415600812-27773-1-git-send-email-feng.wu@intel.com> <1415600812-27773-6-git-send-email-feng.wu@intel.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-11-10 at 14:26 +0800, Feng Wu wrote: > When guest changes its interrupt configuration (such as, vector, etc.) > for direct-assigned devices, we need to update the associated IRTE > with the new guest vector, so external interrupts from the assigned > devices can be injected to guests without VM-Exit. > > The current method of handling guest lowest priority interrtups > is to use a counter 'apic_arb_prio' for each VCPU, we choose the > VCPU with smallest 'apic_arb_prio' and then increase it by 1. > However, for VT-d PI, we cannot re-use this, since we no longer > have control to 'apic_arb_prio' with posted interrupt direct > delivery by Hardware. > > Here, we introduce a similiar way with 'apic_arb_prio' to handle > guest lowest priority interrtups when VT-d PI is used. Here is the > ideas: > - Each VCPU has a counter 'round_robin_counter'. > - When guests sets an interrupts to lowest priority, we choose > the VCPU with smallest 'round_robin_counter' as the destination, > then increase it. > > Signed-off-by: Feng Wu > --- > arch/x86/include/asm/irq_remapping.h | 6 ++ > arch/x86/include/asm/kvm_host.h | 2 + > arch/x86/kvm/vmx.c | 12 +++ > arch/x86/kvm/x86.c | 11 +++ > drivers/iommu/amd_iommu.c | 6 ++ > drivers/iommu/intel_irq_remapping.c | 28 +++++++ > drivers/iommu/irq_remapping.c | 9 ++ > drivers/iommu/irq_remapping.h | 3 + > include/linux/dmar.h | 26 ++++++ > include/linux/kvm_host.h | 22 +++++ > include/uapi/linux/kvm.h | 1 + > virt/kvm/assigned-dev.c | 141 ++++++++++++++++++++++++++++++++++ > virt/kvm/irq_comm.c | 4 +- > virt/kvm/irqchip.c | 11 --- > 14 files changed, 269 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h > index a3cc437..32d6cc4 100644 > --- a/arch/x86/include/asm/irq_remapping.h > +++ b/arch/x86/include/asm/irq_remapping.h > @@ -51,6 +51,7 @@ extern void compose_remapped_msi_msg(struct pci_dev *pdev, > unsigned int irq, unsigned int dest, > struct msi_msg *msg, u8 hpet_id); > extern int setup_hpet_msi_remapped(unsigned int irq, unsigned int id); > +extern int update_pi_irte(unsigned int irq, u64 pi_desc_addr, u32 vector); > extern void panic_if_irq_remap(const char *msg); > extern bool setup_remapped_irq(int irq, > struct irq_cfg *cfg, > @@ -88,6 +89,11 @@ static inline int setup_hpet_msi_remapped(unsigned int irq, unsigned int id) > return -ENODEV; > } > > +static inline int update_pi_irte(unsigned int irq, u64 pi_desc_addr, u32 vector) > +{ > + return -ENODEV; > +} > + > static inline void panic_if_irq_remap(const char *msg) > { > } > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 6ed0c30..0630161 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -358,6 +358,7 @@ struct kvm_vcpu_arch { > struct kvm_lapic *apic; /* kernel irqchip context */ > unsigned long apic_attention; > int32_t apic_arb_prio; > + int32_t round_robin_counter; > int mp_state; > u64 ia32_misc_enable_msr; > bool tpr_access_reporting; > @@ -771,6 +772,7 @@ struct kvm_x86_ops { > int (*check_nested_events)(struct kvm_vcpu *vcpu, bool external_intr); > > void (*sched_in)(struct kvm_vcpu *kvm, int cpu); > + u64 (*get_pi_desc_addr)(struct kvm_vcpu *vcpu); > }; > > struct kvm_arch_async_pf { > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index a4670d3..ae91b72 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -544,6 +544,11 @@ static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu) > return container_of(vcpu, struct vcpu_vmx, vcpu); > } > > +struct pi_desc *vcpu_to_pi_desc(struct kvm_vcpu *vcpu) > +{ > + return &(to_vmx(vcpu)->pi_desc); > +} > + > #define VMCS12_OFFSET(x) offsetof(struct vmcs12, x) > #define FIELD(number, name) [number] = VMCS12_OFFSET(name) > #define FIELD64(number, name) [number] = VMCS12_OFFSET(name), \ > @@ -4280,6 +4285,11 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu) > return; > } > > +static u64 vmx_get_pi_desc_addr(struct kvm_vcpu *vcpu) > +{ > + return __pa((u64)vcpu_to_pi_desc(vcpu)); > +} > + > /* > * Set up the vmcs's constant host-state fields, i.e., host-state fields that > * will not change in the lifetime of the guest. > @@ -9232,6 +9242,8 @@ static struct kvm_x86_ops vmx_x86_ops = { > .check_nested_events = vmx_check_nested_events, > > .sched_in = vmx_sched_in, > + > + .get_pi_desc_addr = vmx_get_pi_desc_addr, > }; > > static int __init vmx_init(void) > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index b447a98..0c19d15 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -7735,6 +7735,17 @@ bool kvm_arch_has_noncoherent_dma(struct kvm *kvm) > } > EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma); > > +int kvm_update_pi_irte_common(struct kvm *kvm, struct kvm_vcpu *vcpu, > + u32 guest_vector, int host_irq) > +{ > + u64 pi_desc_addr = kvm_x86_ops->get_pi_desc_addr(vcpu); > + > + if (update_pi_irte(host_irq, pi_desc_addr, guest_vector)) > + return -1; > + > + return 0; > +} > + > EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit); > EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq); > EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault); > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c > index 505a9ad..a36fdc7 100644 > --- a/drivers/iommu/amd_iommu.c > +++ b/drivers/iommu/amd_iommu.c > @@ -4280,6 +4280,11 @@ static int alloc_hpet_msi(unsigned int irq, unsigned int id) > return 0; > } > > +static int dummy_update_pi_irte(int irq, u64 pi_desc_addr, u32 vector) > +{ > + return -EINVAL; > +} > + > struct irq_remap_ops amd_iommu_irq_ops = { > .supported = amd_iommu_supported, > .prepare = amd_iommu_prepare, > @@ -4294,5 +4299,6 @@ struct irq_remap_ops amd_iommu_irq_ops = { > .msi_alloc_irq = msi_alloc_irq, > .msi_setup_irq = msi_setup_irq, > .alloc_hpet_msi = alloc_hpet_msi, > + .update_pi_irte = dummy_update_pi_irte, > }; > #endif > diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c > index 776da10..87c02fe 100644 > --- a/drivers/iommu/intel_irq_remapping.c > +++ b/drivers/iommu/intel_irq_remapping.c > @@ -1172,6 +1172,33 @@ static int intel_alloc_hpet_msi(unsigned int irq, unsigned int id) > return ret; > } > > +static int intel_update_pi_irte(int irq, u64 pi_desc_addr, u32 vector) > +{ > + struct irte irte; > + > + if (get_irte(irq, &irte)) > + return -1; > + > + irte.irq_post_low.urg = 0; > + irte.irq_post_low.vector = vector; > + irte.irq_post_low.pda_l = (pi_desc_addr >> (32 - PDA_LOW_BIT)) & > + ~(-1UL << PDA_LOW_BIT); > + irte.irq_post_high.pda_h = (pi_desc_addr >> 32) & > + ~(-1UL << PDA_HIGH_BIT); > + > + irte.irq_post_low.__reserved_1 = 0; > + irte.irq_post_low.__reserved_2 = 0; > + irte.irq_post_low.__reserved_3 = 0; > + irte.irq_post_high.__reserved_4 = 0; > + > + irte.irq_post_low.pst = 1; > + > + if (modify_irte(irq, &irte)) > + return -1; > + > + return 0; > +} > + > struct irq_remap_ops intel_irq_remap_ops = { > .supported = intel_irq_remapping_supported, > .prepare = dmar_table_init, > @@ -1186,4 +1213,5 @@ struct irq_remap_ops intel_irq_remap_ops = { > .msi_alloc_irq = intel_msi_alloc_irq, > .msi_setup_irq = intel_msi_setup_irq, > .alloc_hpet_msi = intel_alloc_hpet_msi, > + .update_pi_irte = intel_update_pi_irte, Extending irq_remap_ops should really be a separate patch from it's use by KVM. > }; > diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c > index 2f8ee00..0e36860 100644 > --- a/drivers/iommu/irq_remapping.c > +++ b/drivers/iommu/irq_remapping.c > @@ -362,6 +362,15 @@ int setup_hpet_msi_remapped(unsigned int irq, unsigned int id) > return default_setup_hpet_msi(irq, id); > } > > +int update_pi_irte(unsigned int irq, u64 pi_desc_addr, u32 vector) > +{ > + if (!remap_ops || !remap_ops->update_pi_irte) > + return -ENODEV; > + > + return remap_ops->update_pi_irte(irq, pi_desc_addr, vector); > +} > +EXPORT_SYMBOL_GPL(update_pi_irte); > + > void panic_if_irq_remap(const char *msg) > { > if (irq_remapping_enabled) > diff --git a/drivers/iommu/irq_remapping.h b/drivers/iommu/irq_remapping.h > index 7bb5913..2d8f740 100644 > --- a/drivers/iommu/irq_remapping.h > +++ b/drivers/iommu/irq_remapping.h > @@ -84,6 +84,9 @@ struct irq_remap_ops { > > /* Setup interrupt remapping for an HPET MSI */ > int (*alloc_hpet_msi)(unsigned int, unsigned int); > + > + /* Update IRTE for posted-interrupt */ > + int (*update_pi_irte)(int irq, u64 pi_desc_addr, u32 vector); > }; > > extern struct irq_remap_ops intel_irq_remap_ops; > diff --git a/include/linux/dmar.h b/include/linux/dmar.h > index 8be5d42..e1ff4f7 100644 > --- a/include/linux/dmar.h > +++ b/include/linux/dmar.h > @@ -160,6 +160,20 @@ struct irte { > __reserved_2 : 8, > dest_id : 32; > } irq_remap_low; > + > + struct { > + __u64 present : 1, > + fpd : 1, > + __reserved_1 : 6, > + avail : 4, > + __reserved_2 : 2, > + urg : 1, > + pst : 1, > + vector : 8, > + __reserved_3 : 14, > + pda_l : 26; > + } irq_post_low; > + > __u64 low; > }; > > @@ -170,10 +184,22 @@ struct irte { > svt : 2, > __reserved_3 : 44; > } irq_remap_high; > + > + struct { > + __u64 sid: 16, > + sq: 2, > + svt: 2, > + __reserved_4: 12, > + pda_h: 32; > + } irq_post_high; > + > __u64 high; > }; > }; > > +#define PDA_LOW_BIT 26 > +#define PDA_HIGH_BIT 32 > + > enum { > IRQ_REMAP_XAPIC_MODE, > IRQ_REMAP_X2APIC_MODE, > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index ea53b04..6bb8287 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -335,6 +335,25 @@ struct kvm_kernel_irq_routing_entry { > struct hlist_node link; > }; > > +#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING > + > +struct kvm_irq_routing_table { > + int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS]; > + struct kvm_kernel_irq_routing_entry *rt_entries; > + u32 nr_rt_entries; > + /* > + * Array indexed by gsi. Each entry contains list of irq chips > + * the gsi is connected to. > + */ > + struct hlist_head map[0]; > +}; > + > +#else > + > +struct kvm_irq_routing_table {}; > + > +#endif > + > #ifndef KVM_PRIVATE_MEM_SLOTS > #define KVM_PRIVATE_MEM_SLOTS 0 > #endif > @@ -766,6 +785,9 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm, > struct kvm_irq_ack_notifier *kian); > int kvm_request_irq_source_id(struct kvm *kvm); > void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id); > +void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e, > + struct kvm_lapic_irq *irq); > +bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq); > > #ifdef CONFIG_KVM_DEVICE_ASSIGNMENT > int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot); > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 7593c52..509223a 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -1027,6 +1027,7 @@ struct kvm_s390_ucas_mapping { > #define KVM_XEN_HVM_CONFIG _IOW(KVMIO, 0x7a, struct kvm_xen_hvm_config) > #define KVM_SET_CLOCK _IOW(KVMIO, 0x7b, struct kvm_clock_data) > #define KVM_GET_CLOCK _IOR(KVMIO, 0x7c, struct kvm_clock_data) > +#define KVM_ASSIGN_DEV_PI_UPDATE _IOR(KVMIO, 0x7d, __u32) > /* Available with KVM_CAP_PIT_STATE2 */ > #define KVM_GET_PIT2 _IOR(KVMIO, 0x9f, struct kvm_pit_state2) > #define KVM_SET_PIT2 _IOW(KVMIO, 0xa0, struct kvm_pit_state2) Needs an accompanying Documentation/virtual/kvm/api.txt update. > diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c > index e05000e..e154009 100644 > --- a/virt/kvm/assigned-dev.c > +++ b/virt/kvm/assigned-dev.c Since legacy KVM device assignment is effectively deprecated, have you considered how we might do this with VFIO? Thanks, Alex > @@ -326,6 +326,135 @@ void kvm_free_all_assigned_devices(struct kvm *kvm) > } > } > > +int __weak kvm_update_pi_irte_common(struct kvm *kvm, struct kvm_vcpu *vcpu, > + u32 guest_vector, int host_irq) > +{ > + return 0; > +} > + > +int kvm_compare_rr_counter(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2) > +{ > + return vcpu1->arch.round_robin_counter - > + vcpu2->arch.round_robin_counter; > +} > + > +bool kvm_pi_find_dest_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq, > + struct kvm_vcpu **dest_vcpu) > +{ > + int i, r = 0; > + struct kvm_vcpu *vcpu, *dest = NULL; > + > + 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 (!kvm_is_dm_lowest_prio(irq)) { > + r++; > + *dest_vcpu = vcpu; > + } else if (kvm_lapic_enabled(vcpu)) { > + if (!dest) > + dest = vcpu; > + else if (kvm_compare_rr_counter(vcpu, dest) < 0) > + dest = vcpu; > + } > + } > + > + if (dest) { > + dest->arch.round_robin_counter++; > + *dest_vcpu = dest; > + return true; > + } else if (r == 1) > + return true; > + > + return false; > +} > + > +static int __kvm_update_pi_irte(struct kvm *kvm, int host_irq, int guest_irq) > +{ > + struct kvm_kernel_irq_routing_entry *e; > + struct kvm_irq_routing_table *irq_rt; > + struct kvm_lapic_irq irq; > + struct kvm_vcpu *vcpu; > + int idx, ret = -EINVAL; > + > + idx = srcu_read_lock(&kvm->irq_srcu); > + irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); > + ASSERT(guest_irq < irq_rt->nr_rt_entries); > + > + hlist_for_each_entry(e, &irq_rt->map[guest_irq], link) { > + if (e->type != KVM_IRQ_ROUTING_MSI) > + continue; > + /* > + * VT-d posted-interrupt has the following > + * limitations: > + * - No support for posting multicast/broadcast > + * interrupts to a VCPU > + * Still use interrupt remapping for these > + * kind of interrupts > + */ > + > + kvm_set_msi_irq(e, &irq); > + if (!kvm_pi_find_dest_vcpu(kvm, &irq, &vcpu)) { > + printk(KERN_INFO "%s: can not find the target VCPU\n", > + __func__); > + ret = -EINVAL; > + goto out; > + } > + > + if (kvm_update_pi_irte_common(kvm, vcpu, irq.vector, > + host_irq)) { > + printk(KERN_INFO "%s: failed to update PI IRTE\n", > + __func__); > + ret = -EINVAL; > + goto out; > + } > + } > + > + ret = 0; > +out: > + srcu_read_unlock(&kvm->irq_srcu, idx); > + return ret; > +} > + > +int kvm_update_pi_irte(struct kvm *kvm, u32 dev_id) > +{ > + int i, rc = -1; > + struct kvm_assigned_dev_kernel *dev; > + > + mutex_lock(&kvm->lock); > + dev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, dev_id); > + if (!dev) { > + printk(KERN_INFO "%s: cannot find the assigned dev.\n", > + __func__); > + rc = -1; > + goto out; > + } > + > + BUG_ON(dev->irq_requested_type == 0); > + > + if ((dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI) && > + (dev->dev->msi_enabled == 1)) { > + __kvm_update_pi_irte(kvm, > + dev->host_irq, dev->guest_irq); > + } else if ((dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) && > + (dev->dev->msix_enabled == 1)) { > + for (i = 0; i < dev->entries_nr; i++) { > + __kvm_update_pi_irte(kvm, > + dev->host_msix_entries[i].vector, > + dev->guest_msix_entries[i].vector); > + } > + } > + > +out: > + rc = 0; > + mutex_unlock(&kvm->lock); > + return rc; > +} > + > static int assigned_device_enable_host_intx(struct kvm *kvm, > struct kvm_assigned_dev_kernel *dev) > { > @@ -1017,6 +1146,18 @@ long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl, > r = kvm_vm_ioctl_set_pci_irq_mask(kvm, &assigned_dev); > break; > } > + case KVM_ASSIGN_DEV_PI_UPDATE: { > + u32 dev_id; > + > + r = -EFAULT; > + if (copy_from_user(&dev_id, argp, sizeof(dev_id))) > + goto out; > + r = kvm_update_pi_irte(kvm, dev_id); > + if (r) > + goto out; > + break; > + > + } > default: > r = -ENOTTY; > break; > diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c > index 963b899..f51aed3 100644 > --- a/virt/kvm/irq_comm.c > +++ b/virt/kvm/irq_comm.c > @@ -55,7 +55,7 @@ static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e, > line_status); > } > > -inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq) > +bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq) > { > #ifdef CONFIG_IA64 > return irq->delivery_mode == > @@ -106,7 +106,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, > return r; > } > > -static inline void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e, > +void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e, > struct kvm_lapic_irq *irq) > { > trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data); > diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c > index 7f256f3..cdf29a6 100644 > --- a/virt/kvm/irqchip.c > +++ b/virt/kvm/irqchip.c > @@ -31,17 +31,6 @@ > #include > #include "irq.h" > > -struct kvm_irq_routing_table { > - int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS]; > - struct kvm_kernel_irq_routing_entry *rt_entries; > - u32 nr_rt_entries; > - /* > - * Array indexed by gsi. Each entry contains list of irq chips > - * the gsi is connected to. > - */ > - struct hlist_head map[0]; > -}; > - > int kvm_irq_map_gsi(struct kvm *kvm, > struct kvm_kernel_irq_routing_entry *entries, int gsi) > { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/