diff options
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 417 |
1 files changed, 387 insertions, 30 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1e6b84b96ea6..f8157a36ab09 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -34,6 +34,8 @@ #include <linux/sched.h> #include <linux/trace_events.h> #include <linux/slab.h> +#include <linux/amd-iommu.h> +#include <linux/hashtable.h> #include <asm/apic.h> #include <asm/perf_event.h> @@ -41,6 +43,7 @@ #include <asm/desc.h> #include <asm/debugreg.h> #include <asm/kvm_para.h> +#include <asm/irq_remapping.h> #include <asm/virtext.h> #include "trace.h" @@ -96,6 +99,19 @@ MODULE_DEVICE_TABLE(x86cpu, svm_cpu_id); #define AVIC_UNACCEL_ACCESS_OFFSET_MASK 0xFF0 #define AVIC_UNACCEL_ACCESS_VECTOR_MASK 0xFFFFFFFF +/* AVIC GATAG is encoded using VM and VCPU IDs */ +#define AVIC_VCPU_ID_BITS 8 +#define AVIC_VCPU_ID_MASK ((1 << AVIC_VCPU_ID_BITS) - 1) + +#define AVIC_VM_ID_BITS 24 +#define AVIC_VM_ID_NR (1 << AVIC_VM_ID_BITS) +#define AVIC_VM_ID_MASK ((1 << AVIC_VM_ID_BITS) - 1) + +#define AVIC_GATAG(x, y) (((x & AVIC_VM_ID_MASK) << AVIC_VCPU_ID_BITS) | \ + (y & AVIC_VCPU_ID_MASK)) +#define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VCPU_ID_BITS) & AVIC_VM_ID_MASK) +#define AVIC_GATAG_TO_VCPUID(x) (x & AVIC_VCPU_ID_MASK) + static bool erratum_383_found __read_mostly; static const u32 host_save_user_msrs[] = { @@ -185,6 +201,23 @@ struct vcpu_svm { struct page *avic_backing_page; u64 *avic_physical_id_cache; bool avic_is_running; + + /* + * Per-vcpu list of struct amd_svm_iommu_ir: + * This is used mainly to store interrupt remapping information used + * when update the vcpu affinity. This avoids the need to scan for + * IRTE and try to match ga_tag in the IOMMU driver. + */ + struct list_head ir_list; + spinlock_t ir_list_lock; +}; + +/* + * This is a wrapper of struct amd_iommu_ir_data. + */ +struct amd_svm_iommu_ir { + struct list_head node; /* Used by SVM for per-vcpu ir_list */ + void *data; /* Storing pointer to struct amd_ir_data */ }; #define AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK (0xFF) @@ -242,6 +275,10 @@ static int avic; module_param(avic, int, S_IRUGO); #endif +/* AVIC VM ID bit masks and lock */ +static DECLARE_BITMAP(avic_vm_id_bitmap, AVIC_VM_ID_NR); +static DEFINE_SPINLOCK(avic_vm_id_lock); + static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0); static void svm_flush_tlb(struct kvm_vcpu *vcpu); static void svm_complete_interrupts(struct vcpu_svm *svm); @@ -928,6 +965,55 @@ static void svm_disable_lbrv(struct vcpu_svm *svm) set_msr_interception(msrpm, MSR_IA32_LASTINTTOIP, 0, 0); } +/* Note: + * This hash table is used to map VM_ID to a struct kvm_arch, + * when handling AMD IOMMU GALOG notification to schedule in + * a particular vCPU. + */ +#define SVM_VM_DATA_HASH_BITS 8 +DECLARE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS); +static spinlock_t svm_vm_data_hash_lock; + +/* Note: + * This function is called from IOMMU driver to notify + * SVM to schedule in a particular vCPU of a particular VM. + */ +static int avic_ga_log_notifier(u32 ga_tag) +{ + unsigned long flags; + struct kvm_arch *ka = NULL; + struct kvm_vcpu *vcpu = NULL; + u32 vm_id = AVIC_GATAG_TO_VMID(ga_tag); + u32 vcpu_id = AVIC_GATAG_TO_VCPUID(ga_tag); + + pr_debug("SVM: %s: vm_id=%#x, vcpu_id=%#x\n", __func__, vm_id, vcpu_id); + + spin_lock_irqsave(&svm_vm_data_hash_lock, flags); + hash_for_each_possible(svm_vm_data_hash, ka, hnode, vm_id) { + struct kvm *kvm = container_of(ka, struct kvm, arch); + struct kvm_arch *vm_data = &kvm->arch; + + if (vm_data->avic_vm_id != vm_id) + continue; + vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id); + break; + } + spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags); + + if (!vcpu) + return 0; + + /* Note: + * At this point, the IOMMU should have already set the pending + * bit in the vAPIC backing page. So, we just need to schedule + * in the vcpu. + */ + if (vcpu->mode == OUTSIDE_GUEST_MODE) + kvm_vcpu_wake_up(vcpu); + + return 0; +} + static __init int svm_hardware_setup(void) { int cpu; @@ -986,10 +1072,15 @@ static __init int svm_hardware_setup(void) if (avic) { if (!npt_enabled || !boot_cpu_has(X86_FEATURE_AVIC) || - !IS_ENABLED(CONFIG_X86_LOCAL_APIC)) + !IS_ENABLED(CONFIG_X86_LOCAL_APIC)) { avic = false; - else + } else { pr_info("AVIC enabled\n"); + + hash_init(svm_vm_data_hash); + spin_lock_init(&svm_vm_data_hash_lock); + amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier); + } } return 0; @@ -1028,13 +1119,6 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type) seg->base = 0; } -static u64 svm_read_tsc_offset(struct kvm_vcpu *vcpu) -{ - struct vcpu_svm *svm = to_svm(vcpu); - - return svm->vmcb->control.tsc_offset; -} - static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { struct vcpu_svm *svm = to_svm(vcpu); @@ -1280,19 +1364,55 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu) return 0; } +static inline int avic_get_next_vm_id(void) +{ + int id; + + spin_lock(&avic_vm_id_lock); + + /* AVIC VM ID is one-based. */ + id = find_next_zero_bit(avic_vm_id_bitmap, AVIC_VM_ID_NR, 1); + if (id <= AVIC_VM_ID_MASK) + __set_bit(id, avic_vm_id_bitmap); + else + id = -EAGAIN; + + spin_unlock(&avic_vm_id_lock); + return id; +} + +static inline int avic_free_vm_id(int id) +{ + if (id <= 0 || id > AVIC_VM_ID_MASK) + return -EINVAL; + + spin_lock(&avic_vm_id_lock); + __clear_bit(id, avic_vm_id_bitmap); + spin_unlock(&avic_vm_id_lock); + return 0; +} + static void avic_vm_destroy(struct kvm *kvm) { + unsigned long flags; struct kvm_arch *vm_data = &kvm->arch; + avic_free_vm_id(vm_data->avic_vm_id); + if (vm_data->avic_logical_id_table_page) __free_page(vm_data->avic_logical_id_table_page); if (vm_data->avic_physical_id_table_page) __free_page(vm_data->avic_physical_id_table_page); + + spin_lock_irqsave(&svm_vm_data_hash_lock, flags); + hash_del(&vm_data->hnode); + spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags); } static int avic_vm_init(struct kvm *kvm) { - int err = -ENOMEM; + unsigned long flags; + int vm_id, err = -ENOMEM; struct kvm_arch *vm_data = &kvm->arch; struct page *p_page; struct page *l_page; @@ -1300,6 +1420,11 @@ static int avic_vm_init(struct kvm *kvm) if (!avic) return 0; + vm_id = avic_get_next_vm_id(); + if (vm_id < 0) + return vm_id; + vm_data->avic_vm_id = (u32)vm_id; + /* Allocating physical APIC ID table (4KB) */ p_page = alloc_page(GFP_KERNEL); if (!p_page) @@ -1316,6 +1441,10 @@ static int avic_vm_init(struct kvm *kvm) vm_data->avic_logical_id_table_page = l_page; clear_page(page_address(l_page)); + spin_lock_irqsave(&svm_vm_data_hash_lock, flags); + hash_add(svm_vm_data_hash, &vm_data->hnode, vm_data->avic_vm_id); + spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags); + return 0; free_avic: @@ -1323,31 +1452,34 @@ free_avic: return err; } -/** - * This function is called during VCPU halt/unhalt. - */ -static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run) +static inline int +avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu, int cpu, bool r) { - u64 entry; - int h_physical_id = kvm_cpu_get_apicid(vcpu->cpu); + int ret = 0; + unsigned long flags; + struct amd_svm_iommu_ir *ir; struct vcpu_svm *svm = to_svm(vcpu); - if (!kvm_vcpu_apicv_active(vcpu)) - return; - - svm->avic_is_running = is_run; + if (!kvm_arch_has_assigned_device(vcpu->kvm)) + return 0; - /* ID = 0xff (broadcast), ID > 0xff (reserved) */ - if (WARN_ON(h_physical_id >= AVIC_MAX_PHYSICAL_ID_COUNT)) - return; + /* + * Here, we go through the per-vcpu ir_list to update all existing + * interrupt remapping table entry targeting this vcpu. + */ + spin_lock_irqsave(&svm->ir_list_lock, flags); - entry = READ_ONCE(*(svm->avic_physical_id_cache)); - WARN_ON(is_run == !!(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK)); + if (list_empty(&svm->ir_list)) + goto out; - entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; - if (is_run) - entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; - WRITE_ONCE(*(svm->avic_physical_id_cache), entry); + list_for_each_entry(ir, &svm->ir_list, node) { + ret = amd_iommu_update_ga(cpu, r, ir->data); + if (ret) + break; + } +out: + spin_unlock_irqrestore(&svm->ir_list_lock, flags); + return ret; } static void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) @@ -1374,6 +1506,8 @@ static void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; WRITE_ONCE(*(svm->avic_physical_id_cache), entry); + avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, + svm->avic_is_running); } static void avic_vcpu_put(struct kvm_vcpu *vcpu) @@ -1385,10 +1519,27 @@ static void avic_vcpu_put(struct kvm_vcpu *vcpu) return; entry = READ_ONCE(*(svm->avic_physical_id_cache)); + if (entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK) + avic_update_iommu_vcpu_affinity(vcpu, -1, 0); + entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; WRITE_ONCE(*(svm->avic_physical_id_cache), entry); } +/** + * This function is called during VCPU halt/unhalt. + */ +static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + svm->avic_is_running = is_run; + if (is_run) + avic_vcpu_load(vcpu, vcpu->cpu); + else + avic_vcpu_put(vcpu); +} + static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) { struct vcpu_svm *svm = to_svm(vcpu); @@ -1450,6 +1601,9 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) err = avic_init_backing_page(&svm->vcpu); if (err) goto free_page4; + + INIT_LIST_HEAD(&svm->ir_list); + spin_lock_init(&svm->ir_list_lock); } /* We initialize this flag to true to make sure that the is_running @@ -4246,6 +4400,209 @@ static void svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec) kvm_vcpu_wake_up(vcpu); } +static void svm_ir_list_del(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi) +{ + unsigned long flags; + struct amd_svm_iommu_ir *cur; + + spin_lock_irqsave(&svm->ir_list_lock, flags); + list_for_each_entry(cur, &svm->ir_list, node) { + if (cur->data != pi->ir_data) + continue; + list_del(&cur->node); + kfree(cur); + break; + } + spin_unlock_irqrestore(&svm->ir_list_lock, flags); +} + +static int svm_ir_list_add(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi) +{ + int ret = 0; + unsigned long flags; + struct amd_svm_iommu_ir *ir; + + /** + * In some cases, the existing irte is updaed and re-set, + * so we need to check here if it's already been * added + * to the ir_list. + */ + if (pi->ir_data && (pi->prev_ga_tag != 0)) { + struct kvm *kvm = svm->vcpu.kvm; + u32 vcpu_id = AVIC_GATAG_TO_VCPUID(pi->prev_ga_tag); + struct kvm_vcpu *prev_vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id); + struct vcpu_svm *prev_svm; + + if (!prev_vcpu) { + ret = -EINVAL; + goto out; + } + + prev_svm = to_svm(prev_vcpu); + svm_ir_list_del(prev_svm, pi); + } + + /** + * Allocating new amd_iommu_pi_data, which will get + * add to the per-vcpu ir_list. + */ + ir = kzalloc(sizeof(struct amd_svm_iommu_ir), GFP_KERNEL); + if (!ir) { + ret = -ENOMEM; + goto out; + } + ir->data = pi->ir_data; + + spin_lock_irqsave(&svm->ir_list_lock, flags); + list_add(&ir->node, &svm->ir_list); + spin_unlock_irqrestore(&svm->ir_list_lock, flags); +out: + return ret; +} + +/** + * Note: + * The HW cannot support posting multicast/broadcast + * interrupts to a vCPU. So, we still use legacy interrupt + * remapping for these kind of interrupts. + * + * For lowest-priority interrupts, we only support + * those with single CPU as the destination, e.g. user + * configures the interrupts via /proc/irq or uses + * irqbalance to make the interrupts single-CPU. + */ +static int +get_pi_vcpu_info(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e, + struct vcpu_data *vcpu_info, struct vcpu_svm **svm) +{ + struct kvm_lapic_irq irq; + struct kvm_vcpu *vcpu = NULL; + + kvm_set_msi_irq(kvm, e, &irq); + + if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu)) { + pr_debug("SVM: %s: use legacy intr remap mode for irq %u\n", + __func__, irq.vector); + return -1; + } + + pr_debug("SVM: %s: use GA mode for irq %u\n", __func__, + irq.vector); + *svm = to_svm(vcpu); + vcpu_info->pi_desc_addr = page_to_phys((*svm)->avic_backing_page); + vcpu_info->vector = irq.vector; + + return 0; +} + +/* + * svm_update_pi_irte - set IRTE for Posted-Interrupts + * + * @kvm: kvm + * @host_irq: host irq of the interrupt + * @guest_irq: gsi of the interrupt + * @set: set or unset PI + * returns 0 on success, < 0 on failure + */ +static int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq, + uint32_t guest_irq, bool set) +{ + struct kvm_kernel_irq_routing_entry *e; + struct kvm_irq_routing_table *irq_rt; + int idx, ret = -EINVAL; + + if (!kvm_arch_has_assigned_device(kvm) || + !irq_remapping_cap(IRQ_POSTING_CAP)) + return 0; + + pr_debug("SVM: %s: host_irq=%#x, guest_irq=%#x, set=%#x\n", + __func__, host_irq, guest_irq, set); + + idx = srcu_read_lock(&kvm->irq_srcu); + irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); + WARN_ON(guest_irq >= irq_rt->nr_rt_entries); + + hlist_for_each_entry(e, &irq_rt->map[guest_irq], link) { + struct vcpu_data vcpu_info; + struct vcpu_svm *svm = NULL; + + if (e->type != KVM_IRQ_ROUTING_MSI) + continue; + + /** + * Here, we setup with legacy mode in the following cases: + * 1. When cannot target interrupt to a specific vcpu. + * 2. Unsetting posted interrupt. + * 3. APIC virtialization is disabled for the vcpu. + */ + if (!get_pi_vcpu_info(kvm, e, &vcpu_info, &svm) && set && + kvm_vcpu_apicv_active(&svm->vcpu)) { + struct amd_iommu_pi_data pi; + + /* Try to enable guest_mode in IRTE */ + pi.base = page_to_phys(svm->avic_backing_page) & AVIC_HPA_MASK; + pi.ga_tag = AVIC_GATAG(kvm->arch.avic_vm_id, + svm->vcpu.vcpu_id); + pi.is_guest_mode = true; + pi.vcpu_data = &vcpu_info; + ret = irq_set_vcpu_affinity(host_irq, &pi); + + /** + * Here, we successfully setting up vcpu affinity in + * IOMMU guest mode. Now, we need to store the posted + * interrupt information in a per-vcpu ir_list so that + * we can reference to them directly when we update vcpu + * scheduling information in IOMMU irte. + */ + if (!ret && pi.is_guest_mode) + svm_ir_list_add(svm, &pi); + } else { + /* Use legacy mode in IRTE */ + struct amd_iommu_pi_data pi; + + /** + * Here, pi is used to: + * - Tell IOMMU to use legacy mode for this interrupt. + * - Retrieve ga_tag of prior interrupt remapping data. + */ + pi.is_guest_mode = false; + ret = irq_set_vcpu_affinity(host_irq, &pi); + + /** + * Check if the posted interrupt was previously + * setup with the guest_mode by checking if the ga_tag + * was cached. If so, we need to clean up the per-vcpu + * ir_list. + */ + if (!ret && pi.prev_ga_tag) { + int id = AVIC_GATAG_TO_VCPUID(pi.prev_ga_tag); + struct kvm_vcpu *vcpu; + + vcpu = kvm_get_vcpu_by_id(kvm, id); + if (vcpu) + svm_ir_list_del(to_svm(vcpu), &pi); + } + } + + if (!ret && svm) { + trace_kvm_pi_irte_update(svm->vcpu.vcpu_id, + host_irq, e->gsi, + vcpu_info.vector, + vcpu_info.pi_desc_addr, set); + } + + if (ret < 0) { + pr_err("%s: failed to update PI IRTE\n", __func__); + goto out; + } + } + + ret = 0; +out: + srcu_read_unlock(&kvm->irq_srcu, idx); + return ret; +} + static int svm_nmi_allowed(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -5064,7 +5421,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .has_wbinvd_exit = svm_has_wbinvd_exit, - .read_tsc_offset = svm_read_tsc_offset, .write_tsc_offset = svm_write_tsc_offset, .adjust_tsc_offset_guest = svm_adjust_tsc_offset_guest, .read_l1_tsc = svm_read_l1_tsc, @@ -5078,6 +5434,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .pmu_ops = &amd_pmu_ops, .deliver_posted_interrupt = svm_deliver_avic_intr, + .update_pi_irte = svm_update_pi_irte, }; static int __init svm_init(void) |
