// SPDX-License-Identifier: GPL-2.0-only /* * Kernel-based Virtual Machine driver for Linux * * AMD SVM support * * Copyright (C) 2006 Qumranet, Inc. * Copyright 2010 Red Hat, Inc. and/or its affiliates. * * Authors: * Yaniv Kamay * Avi Kivity */ #define pr_fmt(fmt) "SVM: " fmt #include #include #include #include #include #include "trace.h" #include "lapic.h" #include "x86.h" #include "irq.h" #include "svm.h" /* * Encode the arbitrary VM ID and the vCPU's default APIC ID, i.e the vCPU ID, * into the GATag so that KVM can retrieve the correct vCPU from a GALog entry * if an interrupt can't be delivered, e.g. because the vCPU isn't running. * * For the vCPU ID, use however many bits are currently allowed for the max * guest physical APIC ID (limited by the size of the physical ID table), and * use whatever bits remain to assign arbitrary AVIC IDs to VMs. Note, the * size of the GATag is defined by hardware (32 bits), but is an opaque value * as far as hardware is concerned. */ #define AVIC_VCPU_ID_MASK AVIC_PHYSICAL_MAX_INDEX_MASK #define AVIC_VM_ID_SHIFT HWEIGHT32(AVIC_PHYSICAL_MAX_INDEX_MASK) #define AVIC_VM_ID_MASK (GENMASK(31, AVIC_VM_ID_SHIFT) >> AVIC_VM_ID_SHIFT) #define AVIC_GATAG(x, y) (((x & AVIC_VM_ID_MASK) << AVIC_VM_ID_SHIFT) | \ (y & AVIC_VCPU_ID_MASK)) #define AVIC_GATAG_TO_VMID(x) ((x >> AVIC_VM_ID_SHIFT) & AVIC_VM_ID_MASK) #define AVIC_GATAG_TO_VCPUID(x) (x & AVIC_VCPU_ID_MASK) static_assert(AVIC_GATAG(AVIC_VM_ID_MASK, AVIC_VCPU_ID_MASK) == -1u); static bool force_avic; module_param_unsafe(force_avic, bool, 0444); /* Note: * This hash table is used to map VM_ID to a struct kvm_svm, * when handling AMD IOMMU GALOG notification to schedule in * a particular vCPU. */ #define SVM_VM_DATA_HASH_BITS 8 static DEFINE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS); static u32 next_vm_id = 0; static bool next_vm_id_wrapped = 0; static DEFINE_SPINLOCK(svm_vm_data_hash_lock); enum avic_modes avic_mode; /* * 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 */ }; static void avic_activate_vmcb(struct vcpu_svm *svm) { struct vmcb *vmcb = svm->vmcb01.ptr; vmcb->control.int_ctl &= ~(AVIC_ENABLE_MASK | X2APIC_MODE_MASK); vmcb->control.avic_physical_id &= ~AVIC_PHYSICAL_MAX_INDEX_MASK; vmcb->control.int_ctl |= AVIC_ENABLE_MASK; /* Note: * KVM can support hybrid-AVIC mode, where KVM emulates x2APIC * MSR accesses, while interrupt injection to a running vCPU * can be achieved using AVIC doorbell. The AVIC hardware still * accelerate MMIO accesses, but this does not cause any harm * as the guest is not supposed to access xAPIC mmio when uses x2APIC. */ if (apic_x2apic_mode(svm->vcpu.arch.apic) && avic_mode == AVIC_MODE_X2) { vmcb->control.int_ctl |= X2APIC_MODE_MASK; vmcb->control.avic_physical_id |= X2AVIC_MAX_PHYSICAL_ID; /* Disabling MSR intercept for x2APIC registers */ svm_set_x2apic_msr_interception(svm, false); } else { /* * Flush the TLB, the guest may have inserted a non-APIC * mapping into the TLB while AVIC was disabled. */ kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, &svm->vcpu); /* For xAVIC and hybrid-xAVIC modes */ vmcb->control.avic_physical_id |= AVIC_MAX_PHYSICAL_ID; /* Enabling MSR intercept for x2APIC registers */ svm_set_x2apic_msr_interception(svm, true); } } static void avic_deactivate_vmcb(struct vcpu_svm *svm) { struct vmcb *vmcb = svm->vmcb01.ptr; vmcb->control.int_ctl &= ~(AVIC_ENABLE_MASK | X2APIC_MODE_MASK); vmcb->control.avic_physical_id &= ~AVIC_PHYSICAL_MAX_INDEX_MASK; /* * If running nested and the guest uses its own MSR bitmap, there * is no need to update L0's msr bitmap */ if (is_guest_mode(&svm->vcpu) && vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)) return; /* Enabling MSR intercept for x2APIC registers */ svm_set_x2apic_msr_interception(svm, true); } /* Note: * This function is called from IOMMU driver to notify * SVM to schedule in a particular vCPU of a particular VM. */ int avic_ga_log_notifier(u32 ga_tag) { unsigned long flags; struct kvm_svm *kvm_svm; 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); trace_kvm_avic_ga_log(vm_id, vcpu_id); spin_lock_irqsave(&svm_vm_data_hash_lock, flags); hash_for_each_possible(svm_vm_data_hash, kvm_svm, hnode, vm_id) { if (kvm_svm->avic_vm_id != vm_id) continue; vcpu = kvm_get_vcpu_by_id(&kvm_svm->kvm, vcpu_id); break; } spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags); /* 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) kvm_vcpu_wake_up(vcpu); return 0; } void avic_vm_destroy(struct kvm *kvm) { unsigned long flags; struct kvm_svm *kvm_svm = to_kvm_svm(kvm); if (!enable_apicv) return; if (kvm_svm->avic_logical_id_table_page) __free_page(kvm_svm->avic_logical_id_table_page); if (kvm_svm->avic_physical_id_table_page) __free_page(kvm_svm->avic_physical_id_table_page); spin_lock_irqsave(&svm_vm_data_hash_lock, flags); hash_del(&kvm_svm->hnode); spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags); } int avic_vm_init(struct kvm *kvm) { unsigned long flags; int err = -ENOMEM; struct kvm_svm *kvm_svm = to_kvm_svm(kvm); struct kvm_svm *k2; struct page *p_page; struct page *l_page; u32 vm_id; if (!enable_apicv) return 0; /* Allocating physical APIC ID table (4KB) */ p_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!p_page) goto free_avic; kvm_svm->avic_physical_id_table_page = p_page; /* Allocating logical APIC ID table (4KB) */ l_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!l_page) goto free_avic; kvm_svm->avic_logical_id_table_page = l_page; spin_lock_irqsave(&svm_vm_data_hash_lock, flags); again: vm_id = next_vm_id = (next_vm_id + 1) & AVIC_VM_ID_MASK; if (vm_id == 0) { /* id is 1-based, zero is not okay */ next_vm_id_wrapped = 1; goto again; } /* Is it still in use? Only possible if wrapped at least once */ if (next_vm_id_wrapped) { hash_for_each_possible(svm_vm_data_hash, k2, hnode, vm_id) { if (k2->avic_vm_id == vm_id) goto again; } } kvm_svm->avic_vm_id = vm_id; hash_add(svm_vm_data_hash, &kvm_svm->hnode, kvm_svm->avic_vm_id); spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags); return 0; free_avic: avic_vm_destroy(kvm); return err; } void avic_init_vmcb(struct vcpu_svm *svm, struct vmcb *vmcb) { struct kvm_svm *kvm_svm = to_kvm_svm(svm->vcpu.kvm); phys_addr_t bpa = __sme_set(page_to_phys(svm->avic_backing_page)); phys_addr_t lpa = __sme_set(page_to_phys(kvm_svm->avic_logical_id_table_page)); phys_addr_t ppa = __sme_set(page_to_phys(kvm_svm->avic_physical_id_table_page)); vmcb->control.avic_backing_page = bpa & AVIC_HPA_MASK; vmcb->control.avic_logical_id = lpa & AVIC_HPA_MASK; vmcb->control.avic_physical_id = ppa & AVIC_HPA_MASK; vmcb->control.avic_vapic_bar = APIC_DEFAULT_PHYS_BASE & VMCB_AVIC_APIC_BAR_MASK; if (kvm_apicv_activated(svm->vcpu.kvm)) avic_activate_vmcb(svm); else avic_deactivate_vmcb(svm); } static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu, unsigned int index) { u64 *avic_physical_id_table; struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm); if ((avic_mode == AVIC_MODE_X1 && index > AVIC_MAX_PHYSICAL_ID) || (avic_mode == AVIC_MODE_X2 && index > X2AVIC_MAX_PHYSICAL_ID)) return NULL; avic_physical_id_table = page_address(kvm_svm->avic_physical_id_table_page); return &avic_physical_id_table[index]; } /* * Note: * AVIC hardware walks the nested page table to check permissions, * but does not use the SPA address specified in the leaf page * table entry since it uses address in the AVIC_BACKING_PAGE pointer * field of the VMCB. Therefore, we set up the * APIC_ACCESS_PAGE_PRIVATE_MEMSLOT (4KB) here. */ static int avic_alloc_access_page(struct kvm *kvm) { void __user *ret; int r = 0; mutex_lock(&kvm->slots_lock); if (kvm->arch.apic_access_memslot_enabled) goto out; ret = __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, APIC_DEFAULT_PHYS_BASE, PAGE_SIZE); if (IS_ERR(ret)) { r = PTR_ERR(ret); goto out; } kvm->arch.apic_access_memslot_enabled = true; out: mutex_unlock(&kvm->slots_lock); return r; } static int avic_init_backing_page(struct kvm_vcpu *vcpu) { u64 *entry, new_entry; int id = vcpu->vcpu_id; struct vcpu_svm *svm = to_svm(vcpu); if ((avic_mode == AVIC_MODE_X1 && id > AVIC_MAX_PHYSICAL_ID) || (avic_mode == AVIC_MODE_X2 && id > X2AVIC_MAX_PHYSICAL_ID)) return -EINVAL; if (!vcpu->arch.apic->regs) return -EINVAL; if (kvm_apicv_activated(vcpu->kvm)) { int ret; ret = avic_alloc_access_page(vcpu->kvm); if (ret) return ret; } svm->avic_backing_page = virt_to_page(vcpu->arch.apic->regs); /* Setting AVIC backing page address in the phy APIC ID table */ entry = avic_get_physical_id_entry(vcpu, id); if (!entry) return -EINVAL; new_entry = __sme_set((page_to_phys(svm->avic_backing_page) & AVIC_PHYSICAL_ID_ENTRY_BACKING_PAGE_MASK) | AVIC_PHYSICAL_ID_ENTRY_VALID_MASK); WRITE_ONCE(*entry, new_entry); svm->avic_physical_id_cache = entry; return 0; } void avic_ring_doorbell(struct kvm_vcpu *vcpu) { /* * Note, the vCPU could get migrated to a different pCPU at any point, * which could result in signalling the wrong/previous pCPU. But if * that happens the vCPU is guaranteed to do a VMRUN (after being * migrated) and thus will process pending interrupts, i.e. a doorbell * is not needed (and the spurious one is harmless). */ int cpu = READ_ONCE(vcpu->cpu); if (cpu != get_cpu()) { wrmsrl(MSR_AMD64_SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpu)); trace_kvm_avic_doorbell(vcpu->vcpu_id, kvm_cpu_get_apicid(cpu)); } put_cpu(); } /* * A fast-path version of avic_kick_target_vcpus(), which attempts to match * destination APIC ID to vCPU without looping through all vCPUs. */ static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source, u32 icrl, u32 icrh, u32 index) { u32 l1_physical_id, dest; struct kvm_vcpu *target_vcpu; int dest_mode = icrl & APIC_DEST_MASK; int shorthand = icrl & APIC_SHORT_MASK; struct kvm_svm *kvm_svm = to_kvm_svm(kvm); if (shorthand != APIC_DEST_NOSHORT) return -EINVAL; if (apic_x2apic_mode(source)) dest = icrh; else dest = GET_XAPIC_DEST_FIELD(icrh); if (dest_mode == APIC_DEST_PHYSICAL) { /* broadcast destination, use slow path */ if (apic_x2apic_mode(source) && dest == X2APIC_BROADCAST) return -EINVAL; if (!apic_x2apic_mode(source) && dest == APIC_BROADCAST) return -EINVAL; l1_physical_id = dest; if (WARN_ON_ONCE(l1_physical_id != index)) return -EINVAL; } else { u32 bitmap, cluster; int logid_index; if (apic_x2apic_mode(source)) { /* 16 bit dest mask, 16 bit cluster id */ bitmap = dest & 0xFFFF0000; cluster = (dest >> 16) << 4; } else if (kvm_lapic_get_reg(source, APIC_DFR) == APIC_DFR_FLAT) { /* 8 bit dest mask*/ bitmap = dest; cluster = 0; } else { /* 4 bit desk mask, 4 bit cluster id */ bitmap = dest & 0xF; cluster = (dest >> 4) << 2; } if (unlikely(!bitmap)) /* guest bug: nobody to send the logical interrupt to */ return 0; if (!is_power_of_2(bitmap)) /* multiple logical destinations, use slow path */ return -EINVAL; logid_index = cluster + __ffs(bitmap); if (!apic_x2apic_mode(source)) { u32 *avic_logical_id_table = page_address(kvm_svm->avic_logical_id_table_page); u32 logid_entry = avic_logical_id_table[logid_index]; if (WARN_ON_ONCE(index != logid_index)) return -EINVAL; /* guest bug: non existing/reserved logical destination */ if (unlikely(!(logid_entry & AVIC_LOGICAL_ID_ENTRY_VALID_MASK))) return 0; l1_physical_id = logid_entry & AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK; } else { /* * For x2APIC logical mode, cannot leverage the index. * Instead, calculate physical ID from logical ID in ICRH. */ int cluster = (icrh & 0xffff0000) >> 16; int apic = ffs(icrh & 0xffff) - 1; /* * If the x2APIC logical ID sub-field (i.e. icrh[15:0]) * contains anything but a single bit, we cannot use the * fast path, because it is limited to a single vCPU. */ if (apic < 0 || icrh != (1 << apic)) return -EINVAL; l1_physical_id = (cluster << 4) + apic; } } target_vcpu = kvm_get_vcpu_by_id(kvm, l1_physical_id); if (unlikely(!target_vcpu)) /* guest bug: non existing vCPU is a target of this IPI*/ return 0; target_vcpu->arch.apic->irr_pending = true; svm_complete_interrupt_delivery(target_vcpu, icrl & APIC_MODE_MASK, icrl & APIC_INT_LEVELTRIG, icrl & APIC_VECTOR_MASK); return 0; } static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source, u32 icrl, u32 icrh, u32 index) { unsigned long i; struct kvm_vcpu *vcpu; if (!avic_kick_target_vcpus_fast(kvm, source, icrl, icrh, index)) return; trace_kvm_avic_kick_vcpu_slowpath(icrh, icrl, index); /* * Wake any target vCPUs that are blocking, i.e. waiting for a wake * event. There's no need to signal doorbells, as hardware has handled * vCPUs that were in guest at the time of the IPI, and vCPUs that have * since entered the guest will have processed pending IRQs at VMRUN. */ kvm_for_each_vcpu(i, vcpu, kvm) { u32 dest; if (apic_x2apic_mode(vcpu->arch.apic)) dest = icrh; else dest = GET_XAPIC_DEST_FIELD(icrh); if (kvm_apic_match_dest(vcpu, source, icrl & APIC_SHORT_MASK, dest, icrl & APIC_DEST_MASK)) { vcpu->arch.apic->irr_pending = true; svm_complete_interrupt_delivery(vcpu, icrl & APIC_MODE_MASK, icrl & APIC_INT_LEVELTRIG, icrl & APIC_VECTOR_MASK); } } } int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); u32 icrh = svm->vmcb->control.exit_info_1 >> 32; u32 icrl = svm->vmcb->control.exit_info_1; u32 id = svm->vmcb->control.exit_info_2 >> 32; u32 index = svm->vmcb->control.exit_info_2 & 0x1FF; struct kvm_lapic *apic = vcpu->arch.apic; trace_kvm_avic_incomplete_ipi(vcpu->vcpu_id, icrh, icrl, id, index); switch (id) { case AVIC_IPI_FAILURE_INVALID_TARGET: case AVIC_IPI_FAILURE_INVALID_INT_TYPE: /* * Emulate IPIs that are not handled by AVIC hardware, which * only virtualizes Fixed, Edge-Triggered INTRs, and falls over * if _any_ targets are invalid, e.g. if the logical mode mask * is a superset of running vCPUs. * * The exit is a trap, e.g. ICR holds the correct value and RIP * has been advanced, KVM is responsible only for emulating the * IPI. Sadly, hardware may sometimes leave the BUSY flag set, * in which case KVM needs to emulate the ICR write as well in * order to clear the BUSY flag. */ if (icrl & APIC_ICR_BUSY) kvm_apic_write_nodecode(vcpu, APIC_ICR); else kvm_apic_send_ipi(apic, icrl, icrh); break; case AVIC_IPI_FAILURE_TARGET_NOT_RUNNING: /* * At this point, we expect that the AVIC HW has already * set the appropriate IRR bits on the valid target * vcpus. So, we just need to kick the appropriate vcpu. */ avic_kick_target_vcpus(vcpu->kvm, apic, icrl, icrh, index); break; case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE: WARN_ONCE(1, "Invalid backing page\n"); break; default: pr_err("Unknown IPI interception\n"); } return 1; } unsigned long avic_vcpu_get_apicv_inhibit_reasons(struct kvm_vcpu *vcpu) { if (is_guest_mode(vcpu)) return APICV_INHIBIT_REASON_NESTED; return 0; } static u32 *avic_get_logical_id_entry(struct kvm_vcpu *vcpu, u32 ldr, bool flat) { struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm); int index; u32 *logical_apic_id_table; int dlid = GET_APIC_LOGICAL_ID(ldr); if (!dlid) return NULL; if (flat) { /* flat */ index = ffs(dlid) - 1; if (index > 7) return NULL; } else { /* cluster */ int cluster = (dlid & 0xf0) >> 4; int apic = ffs(dlid & 0x0f) - 1; if ((apic < 0) || (apic > 7) || (cluster >= 0xf)) return NULL; index = (cluster << 2) + apic; } logical_apic_id_table = (u32 *) page_address(kvm_svm->avic_logical_id_table_page); return &logical_apic_id_table[index]; } static int avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr) { bool flat; u32 *entry, new_entry; flat = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR) == APIC_DFR_FLAT; entry = avic_get_logical_id_entry(vcpu, ldr, flat); if (!entry) return -EINVAL; new_entry = READ_ONCE(*entry); new_entry &= ~AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK; new_entry |= (g_physical_id & AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK); new_entry |= AVIC_LOGICAL_ID_ENTRY_VALID_MASK; WRITE_ONCE(*entry, new_entry); return 0; } static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); bool flat = svm->dfr_reg == APIC_DFR_FLAT; u32 *entry; /* Note: x2AVIC does not use logical APIC ID table */ if (apic_x2apic_mode(vcpu->arch.apic)) return; entry = avic_get_logical_id_entry(vcpu, svm->ldr_reg, flat); if (entry) clear_bit(AVIC_LOGICAL_ID_ENTRY_VALID_BIT, (unsigned long *)entry); } static int avic_handle_ldr_update(struct kvm_vcpu *vcpu) { int ret = 0; struct vcpu_svm *svm = to_svm(vcpu); u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR); u32 id = kvm_xapic_id(vcpu->arch.apic); /* AVIC does not support LDR update for x2APIC */ if (apic_x2apic_mode(vcpu->arch.apic)) return 0; if (ldr == svm->ldr_reg) return 0; avic_invalidate_logical_id_entry(vcpu); if (ldr) ret = avic_ldr_write(vcpu, id, ldr); if (!ret) svm->ldr_reg = ldr; return ret; } static void avic_handle_dfr_update(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); u32 dfr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR); if (svm->dfr_reg == dfr) return; avic_invalidate_logical_id_entry(vcpu); svm->dfr_reg = dfr; } static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu) { u32 offset = to_svm(vcpu)->vmcb->control.exit_info_1 & AVIC_UNACCEL_ACCESS_OFFSET_MASK; switch (offset) { case APIC_LDR: if (avic_handle_ldr_update(vcpu)) return 0; break; case APIC_DFR: avic_handle_dfr_update(vcpu); break; default: break; } kvm_apic_write_nodecode(vcpu, offset); return 1; } static bool is_avic_unaccelerated_access_trap(u32 offset) { bool ret = false; switch (offset) { case APIC_ID: case APIC_EOI: case APIC_RRR: case APIC_LDR: case APIC_DFR: case APIC_SPIV: case APIC_ESR: case APIC_ICR: case APIC_LVTT: case APIC_LVTTHMR: case APIC_LVTPC: case APIC_LVT0: case APIC_LVT1: case APIC_LVTERR: case APIC_TMICT: case APIC_TDCR: ret = true; break; default: break; } return ret; } int avic_unaccelerated_access_interception(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); int ret = 0; u32 offset = svm->vmcb->control.exit_info_1 & AVIC_UNACCEL_ACCESS_OFFSET_MASK; u32 vector = svm->vmcb->control.exit_info_2 & AVIC_UNACCEL_ACCESS_VECTOR_MASK; bool write = (svm->vmcb->control.exit_info_1 >> 32) & AVIC_UNACCEL_ACCESS_WRITE_MASK; bool trap = is_avic_unaccelerated_access_trap(offset); trace_kvm_avic_unaccelerated_access(vcpu->vcpu_id, offset, trap, write, vector); if (trap) { /* Handling Trap */ WARN_ONCE(!write, "svm: Handling trap read.\n"); ret = avic_unaccel_trap_write(vcpu); } else { /* Handling Fault */ ret = kvm_emulate_instruction(vcpu, 0); } return ret; } int avic_init_vcpu(struct vcpu_svm *svm) { int ret; struct kvm_vcpu *vcpu = &svm->vcpu; if (!enable_apicv || !irqchip_in_kernel(vcpu->kvm)) return 0; ret = avic_init_backing_page(vcpu); if (ret) return ret; INIT_LIST_HEAD(&svm->ir_list); spin_lock_init(&svm->ir_list_lock); svm->dfr_reg = APIC_DFR_FLAT; return ret; } void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu) { avic_handle_dfr_update(vcpu); avic_handle_ldr_update(vcpu); } static int avic_set_pi_irte_mode(struct kvm_vcpu *vcpu, bool activate) { int ret = 0; unsigned long flags; struct amd_svm_iommu_ir *ir; struct vcpu_svm *svm = to_svm(vcpu); if (!kvm_arch_has_assigned_device(vcpu->kvm)) return 0; /* * 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); if (list_empty(&svm->ir_list)) goto out; list_for_each_entry(ir, &svm->ir_list, node) { if (activate) ret = amd_iommu_activate_guest_mode(ir->data); else ret = amd_iommu_deactivate_guest_mode(ir->data); if (ret) break; } out: spin_unlock_irqrestore(&svm->ir_list_lock, flags); return ret; } 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; u64 entry; /** * In some cases, the existing irte is updated 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_ACCOUNT); if (!ir) { ret = -ENOMEM; goto out; } ir->data = pi->ir_data; spin_lock_irqsave(&svm->ir_list_lock, flags); /* * Update the target pCPU for IOMMU doorbells if the vCPU is running. * If the vCPU is NOT running, i.e. is blocking or scheduled out, KVM * will update the pCPU info when the vCPU awkened and/or scheduled in. * See also avic_vcpu_load(). */ entry = READ_ONCE(*(svm->avic_physical_id_cache)); if (entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK) amd_iommu_update_ga(entry & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK, true, pi->ir_data); 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) || !kvm_irq_is_postable(&irq)) { 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 = __sme_set(page_to_phys((*svm)->avic_backing_page)); vcpu_info->vector = irq.vector; return 0; } /* * avic_pi_update_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 */ int avic_pi_update_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 = 0; 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); if (guest_irq >= irq_rt->nr_rt_entries || hlist_empty(&irq_rt->map[guest_irq])) { pr_warn_once("no route for guest_irq %u/%u (broken user space?)\n", guest_irq, irq_rt->nr_rt_entries); goto out; } 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 virtualization is disabled for the vcpu. * 4. IRQ has incompatible delivery mode (SMI, INIT, etc) */ 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 = __sme_set(page_to_phys(svm->avic_backing_page) & AVIC_HPA_MASK); pi.ga_tag = AVIC_GATAG(to_kvm_svm(kvm)->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.prev_ga_tag = 0; 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(host_irq, svm->vcpu.vcpu_id, 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; } bool avic_check_apicv_inhibit_reasons(enum kvm_apicv_inhibit reason) { ulong supported = BIT(APICV_INHIBIT_REASON_DISABLE) | BIT(APICV_INHIBIT_REASON_ABSENT) | BIT(APICV_INHIBIT_REASON_HYPERV) | BIT(APICV_INHIBIT_REASON_NESTED) | BIT(APICV_INHIBIT_REASON_IRQWIN) | BIT(APICV_INHIBIT_REASON_PIT_REINJ) | BIT(APICV_INHIBIT_REASON_BLOCKIRQ) | BIT(APICV_INHIBIT_REASON_SEV) | BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) | BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); return supported & BIT(reason); } static inline int avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu, int cpu, bool r) { int ret = 0; struct amd_svm_iommu_ir *ir; struct vcpu_svm *svm = to_svm(vcpu); lockdep_assert_held(&svm->ir_list_lock); if (!kvm_arch_has_assigned_device(vcpu->kvm)) return 0; /* * Here, we go through the per-vcpu ir_list to update all existing * interrupt remapping table entry targeting this vcpu. */ if (list_empty(&svm->ir_list)) return 0; list_for_each_entry(ir, &svm->ir_list, node) { ret = amd_iommu_update_ga(cpu, r, ir->data); if (ret) return ret; } return 0; } void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { u64 entry; int h_physical_id = kvm_cpu_get_apicid(cpu); struct vcpu_svm *svm = to_svm(vcpu); unsigned long flags; lockdep_assert_preemption_disabled(); if (WARN_ON(h_physical_id & ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK)) return; /* * No need to update anything if the vCPU is blocking, i.e. if the vCPU * is being scheduled in after being preempted. The CPU entries in the * Physical APIC table and IRTE are consumed iff IsRun{ning} is '1'. * If the vCPU was migrated, its new CPU value will be stuffed when the * vCPU unblocks. */ if (kvm_vcpu_is_blocking(vcpu)) return; /* * Grab the per-vCPU interrupt remapping lock even if the VM doesn't * _currently_ have assigned devices, as that can change. Holding * ir_list_lock ensures that either svm_ir_list_add() will consume * up-to-date entry information, or that this task will wait until * svm_ir_list_add() completes to set the new target pCPU. */ spin_lock_irqsave(&svm->ir_list_lock, flags); entry = READ_ONCE(*(svm->avic_physical_id_cache)); entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK; entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK); 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, true); spin_unlock_irqrestore(&svm->ir_list_lock, flags); } void avic_vcpu_put(struct kvm_vcpu *vcpu) { u64 entry; struct vcpu_svm *svm = to_svm(vcpu); unsigned long flags; lockdep_assert_preemption_disabled(); /* * Note, reading the Physical ID entry outside of ir_list_lock is safe * as only the pCPU that has loaded (or is loading) the vCPU is allowed * to modify the entry, and preemption is disabled. I.e. the vCPU * can't be scheduled out and thus avic_vcpu_{put,load}() can't run * recursively. */ entry = READ_ONCE(*(svm->avic_physical_id_cache)); /* Nothing to do if IsRunning == '0' due to vCPU blocking. */ if (!(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK)) return; /* * Take and hold the per-vCPU interrupt remapping lock while updating * the Physical ID entry even though the lock doesn't protect against * multiple writers (see above). Holding ir_list_lock ensures that * either svm_ir_list_add() will consume up-to-date entry information, * or that this task will wait until svm_ir_list_add() completes to * mark the vCPU as not running. */ spin_lock_irqsave(&svm->ir_list_lock, flags); avic_update_iommu_vcpu_affinity(vcpu, -1, 0); entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; WRITE_ONCE(*(svm->avic_physical_id_cache), entry); spin_unlock_irqrestore(&svm->ir_list_lock, flags); } void avic_refresh_virtual_apic_mode(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); struct vmcb *vmcb = svm->vmcb01.ptr; if (!lapic_in_kernel(vcpu) || avic_mode == AVIC_MODE_NONE) return; if (!enable_apicv) return; if (kvm_vcpu_apicv_active(vcpu)) { /** * During AVIC temporary deactivation, guest could update * APIC ID, DFR and LDR registers, which would not be trapped * by avic_unaccelerated_access_interception(). In this case, * we need to check and update the AVIC logical APIC ID table * accordingly before re-activating. */ avic_apicv_post_state_restore(vcpu); avic_activate_vmcb(svm); } else { avic_deactivate_vmcb(svm); } vmcb_mark_dirty(vmcb, VMCB_AVIC); } void avic_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { bool activated = kvm_vcpu_apicv_active(vcpu); if (!enable_apicv) return; avic_refresh_virtual_apic_mode(vcpu); if (activated) avic_vcpu_load(vcpu, vcpu->cpu); else avic_vcpu_put(vcpu); avic_set_pi_irte_mode(vcpu, activated); } void avic_vcpu_blocking(struct kvm_vcpu *vcpu) { if (!kvm_vcpu_apicv_active(vcpu)) return; /* * Unload the AVIC when the vCPU is about to block, _before_ * the vCPU actually blocks. * * Any IRQs that arrive before IsRunning=0 will not cause an * incomplete IPI vmexit on the source, therefore vIRR will also * be checked by kvm_vcpu_check_block() before blocking. The * memory barrier implicit in set_current_state orders writing * IsRunning=0 before reading the vIRR. The processor needs a * matching memory barrier on interrupt delivery between writing * IRR and reading IsRunning; the lack of this barrier might be * the cause of errata #1235). */ avic_vcpu_put(vcpu); } void avic_vcpu_unblocking(struct kvm_vcpu *vcpu) { if (!kvm_vcpu_apicv_active(vcpu)) return; avic_vcpu_load(vcpu, vcpu->cpu); } /* * Note: * - The module param avic enable both xAPIC and x2APIC mode. * - Hypervisor can support both xAVIC and x2AVIC in the same guest. * - The mode can be switched at run-time. */ bool avic_hardware_setup(struct kvm_x86_ops *x86_ops) { if (!npt_enabled) return false; if (boot_cpu_has(X86_FEATURE_AVIC)) { avic_mode = AVIC_MODE_X1; pr_info("AVIC enabled\n"); } else if (force_avic) { /* * Some older systems does not advertise AVIC support. * See Revision Guide for specific AMD processor for more detail. */ avic_mode = AVIC_MODE_X1; pr_warn("AVIC is not supported in CPUID but force enabled"); pr_warn("Your system might crash and burn"); } /* AVIC is a prerequisite for x2AVIC. */ if (boot_cpu_has(X86_FEATURE_X2AVIC)) { if (avic_mode == AVIC_MODE_X1) { avic_mode = AVIC_MODE_X2; pr_info("x2AVIC enabled\n"); } else { pr_warn(FW_BUG "Cannot support x2AVIC due to AVIC is disabled"); pr_warn(FW_BUG "Try enable AVIC using force_avic option"); } } if (avic_mode != AVIC_MODE_NONE) amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier); return !!avic_mode; }