From 44a95dae1d229a4967bbfcc56fb2116a9b4fe942 Mon Sep 17 00:00:00 2001 From: Suravee Suthikulpanit Date: Wed, 4 May 2016 14:09:46 -0500 Subject: [PATCH] KVM: x86: Detect and Initialize AVIC support This patch introduces AVIC-related data structure, and AVIC initialization code. There are three main data structures for AVIC: * Virtual APIC (vAPIC) backing page (per-VCPU) * Physical APIC ID table (per-VM) * Logical APIC ID table (per-VM) Currently, AVIC is disabled by default. Users can manually enable AVIC via kernel boot option kvm-amd.avic=1 or during kvm-amd module loading with parameter avic=1. Signed-off-by: Suravee Suthikulpanit [Avoid extra indentation (Boris). - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 4 + arch/x86/include/asm/svm.h | 3 + arch/x86/kvm/svm.c | 225 +++++++++++++++++++++++++++++++- 3 files changed, 231 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 2df5db6fb58b..337e13b0d01d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -773,6 +773,10 @@ struct kvm_arch { u8 nr_reserved_ioapic_pins; bool disabled_lapic_found; + + /* Struct members for AVIC */ + struct page *avic_logical_id_table_page; + struct page *avic_physical_id_table_page; }; struct kvm_vm_stat { diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 4711fa4457f3..d0fe23ec7e98 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -116,6 +116,9 @@ struct __attribute__ ((__packed__)) vmcb_control_area { #define V_INTR_MASKING_SHIFT 24 #define V_INTR_MASKING_MASK (1 << V_INTR_MASKING_SHIFT) +#define AVIC_ENABLE_SHIFT 31 +#define AVIC_ENABLE_MASK (1 << AVIC_ENABLE_SHIFT) + #define SVM_INTERRUPT_SHADOW_MASK 1 #define SVM_IOIO_STR_SHIFT 2 diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 31346a3f20a5..192cad25d321 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -14,6 +14,9 @@ * the COPYING file in the top-level directory. * */ + +#define pr_fmt(fmt) "SVM: " fmt + #include #include "irq.h" @@ -78,6 +81,14 @@ MODULE_DEVICE_TABLE(x86cpu, svm_cpu_id); #define TSC_RATIO_MIN 0x0000000000000001ULL #define TSC_RATIO_MAX 0x000000ffffffffffULL +#define AVIC_HPA_MASK ~((0xFFFULL << 52) || 0xFFF) + +/* + * 0xff is broadcast, so the max index allowed for physical APIC ID + * table is 0xfe. APIC IDs above 0xff are reserved. + */ +#define AVIC_MAX_PHYSICAL_ID_COUNT 255 + static bool erratum_383_found __read_mostly; static const u32 host_save_user_msrs[] = { @@ -162,8 +173,19 @@ struct vcpu_svm { /* cached guest cpuid flags for faster access */ bool nrips_enabled : 1; + + struct page *avic_backing_page; + u64 *avic_physical_id_cache; }; +#define AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK (0xFF) +#define AVIC_LOGICAL_ID_ENTRY_VALID_MASK (1 << 31) + +#define AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK (0xFFULL) +#define AVIC_PHYSICAL_ID_ENTRY_BACKING_PAGE_MASK (0xFFFFFFFFFFULL << 12) +#define AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK (1ULL << 62) +#define AVIC_PHYSICAL_ID_ENTRY_VALID_MASK (1ULL << 63) + static DEFINE_PER_CPU(u64, current_tsc_ratio); #define TSC_RATIO_DEFAULT 0x0100000000ULL @@ -205,6 +227,10 @@ module_param(npt, int, S_IRUGO); static int nested = true; module_param(nested, int, S_IRUGO); +/* enable / disable AVIC */ +static int avic; +module_param(avic, int, S_IRUGO); + 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); @@ -228,12 +254,18 @@ enum { VMCB_SEG, /* CS, DS, SS, ES, CPL */ VMCB_CR2, /* CR2 only */ VMCB_LBR, /* DBGCTL, BR_FROM, BR_TO, LAST_EX_FROM, LAST_EX_TO */ + VMCB_AVIC, /* AVIC APIC_BAR, AVIC APIC_BACKING_PAGE, + * AVIC PHYSICAL_TABLE pointer, + * AVIC LOGICAL_TABLE pointer + */ VMCB_DIRTY_MAX, }; /* TPR and CR2 are always written before VMRUN */ #define VMCB_ALWAYS_DIRTY_MASK ((1U << VMCB_INTR) | (1U << VMCB_CR2)) +#define VMCB_AVIC_APIC_BAR_MASK 0xFFFFFFFFFF000ULL + static inline void mark_all_dirty(struct vmcb *vmcb) { vmcb->control.clean = 0; @@ -255,6 +287,12 @@ static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu) return container_of(vcpu, struct vcpu_svm, vcpu); } +static inline void avic_update_vapic_bar(struct vcpu_svm *svm, u64 data) +{ + svm->vmcb->control.avic_vapic_bar = data & VMCB_AVIC_APIC_BAR_MASK; + mark_dirty(svm->vmcb, VMCB_AVIC); +} + static void recalc_intercepts(struct vcpu_svm *svm) { struct vmcb_control_area *c, *h; @@ -923,6 +961,12 @@ static __init int svm_hardware_setup(void) } else kvm_disable_tdp(); + if (avic && (!npt_enabled || !boot_cpu_has(X86_FEATURE_AVIC))) + avic = false; + + if (avic) + pr_info("AVIC enabled\n"); + return 0; err: @@ -1000,6 +1044,22 @@ static void svm_adjust_tsc_offset_guest(struct kvm_vcpu *vcpu, s64 adjustment) mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } +static void avic_init_vmcb(struct vcpu_svm *svm) +{ + struct vmcb *vmcb = svm->vmcb; + struct kvm_arch *vm_data = &svm->vcpu.kvm->arch; + phys_addr_t bpa = page_to_phys(svm->avic_backing_page); + phys_addr_t lpa = page_to_phys(vm_data->avic_logical_id_table_page); + phys_addr_t ppa = page_to_phys(vm_data->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_physical_id |= AVIC_MAX_PHYSICAL_ID_COUNT; + vmcb->control.int_ctl |= AVIC_ENABLE_MASK; + svm->vcpu.arch.apicv_active = true; +} + static void init_vmcb(struct vcpu_svm *svm) { struct vmcb_control_area *control = &svm->vmcb->control; @@ -1110,9 +1170,131 @@ static void init_vmcb(struct vcpu_svm *svm) set_intercept(svm, INTERCEPT_PAUSE); } + if (avic) + avic_init_vmcb(svm); + mark_all_dirty(svm->vmcb); enable_gif(svm); + +} + +static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu, int index) +{ + u64 *avic_physical_id_table; + struct kvm_arch *vm_data = &vcpu->kvm->arch; + + if (index >= AVIC_MAX_PHYSICAL_ID_COUNT) + return NULL; + + avic_physical_id_table = page_address(vm_data->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_init_access_page(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + int ret; + + if (kvm->arch.apic_access_page_done) + return 0; + + ret = x86_set_memory_region(kvm, + APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, + APIC_DEFAULT_PHYS_BASE, + PAGE_SIZE); + if (ret) + return ret; + + kvm->arch.apic_access_page_done = true; + return 0; +} + +static int avic_init_backing_page(struct kvm_vcpu *vcpu) +{ + int ret; + u64 *entry, new_entry; + int id = vcpu->vcpu_id; + struct vcpu_svm *svm = to_svm(vcpu); + + ret = avic_init_access_page(vcpu); + if (ret) + return ret; + + if (id >= AVIC_MAX_PHYSICAL_ID_COUNT) + return -EINVAL; + + if (!svm->vcpu.arch.apic->regs) + return -EINVAL; + + svm->avic_backing_page = virt_to_page(svm->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 = READ_ONCE(*entry); + new_entry = (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; +} + +static void avic_vm_destroy(struct kvm *kvm) +{ + struct kvm_arch *vm_data = &kvm->arch; + + 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); +} + +static int avic_vm_init(struct kvm *kvm) +{ + int err = -ENOMEM; + struct kvm_arch *vm_data = &kvm->arch; + struct page *p_page; + struct page *l_page; + + if (!avic) + return 0; + + /* Allocating physical APIC ID table (4KB) */ + p_page = alloc_page(GFP_KERNEL); + if (!p_page) + goto free_avic; + + vm_data->avic_physical_id_table_page = p_page; + clear_page(page_address(p_page)); + + /* Allocating logical APIC ID table (4KB) */ + l_page = alloc_page(GFP_KERNEL); + if (!l_page) + goto free_avic; + + vm_data->avic_logical_id_table_page = l_page; + clear_page(page_address(l_page)); + + return 0; + +free_avic: + avic_vm_destroy(kvm); + return err; } static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) @@ -1131,6 +1313,9 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) kvm_cpuid(vcpu, &eax, &dummy, &dummy, &dummy); kvm_register_write(vcpu, VCPU_REGS_RDX, eax); + + if (kvm_vcpu_apicv_active(vcpu) && !init_event) + avic_update_vapic_bar(svm, APIC_DEFAULT_PHYS_BASE); } static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) @@ -1169,6 +1354,12 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) if (!hsave_page) goto free_page3; + if (avic) { + err = avic_init_backing_page(&svm->vcpu); + if (err) + goto free_page4; + } + svm->nested.hsave = page_address(hsave_page); svm->msrpm = page_address(msrpm_pages); @@ -1187,6 +1378,8 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) return &svm->vcpu; +free_page4: + __free_page(hsave_page); free_page3: __free_pages(nested_msrpm_pages, MSRPM_ALLOC_ORDER); free_page2: @@ -3212,6 +3405,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) case MSR_VM_IGNNE: vcpu_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data); break; + case MSR_IA32_APICBASE: + if (kvm_vcpu_apicv_active(vcpu)) + avic_update_vapic_bar(to_svm(vcpu), data); + /* Follow through */ default: return kvm_set_msr_common(vcpu, msr); } @@ -3375,10 +3572,14 @@ static void dump_vmcb(struct kvm_vcpu *vcpu) pr_err("%-20s%08x\n", "exit_int_info_err:", control->exit_int_info_err); pr_err("%-20s%lld\n", "nested_ctl:", control->nested_ctl); pr_err("%-20s%016llx\n", "nested_cr3:", control->nested_cr3); + pr_err("%-20s%016llx\n", "avic_vapic_bar:", control->avic_vapic_bar); pr_err("%-20s%08x\n", "event_inj:", control->event_inj); pr_err("%-20s%08x\n", "event_inj_err:", control->event_inj_err); pr_err("%-20s%lld\n", "lbr_ctl:", control->lbr_ctl); pr_err("%-20s%016llx\n", "next_rip:", control->next_rip); + pr_err("%-20s%016llx\n", "avic_backing_page:", control->avic_backing_page); + pr_err("%-20s%016llx\n", "avic_logical_id:", control->avic_logical_id); + pr_err("%-20s%016llx\n", "avic_physical_id:", control->avic_physical_id); pr_err("VMCB State Save Area:\n"); pr_err("%-5s s: %04x a: %04x l: %08x b: %016llx\n", "es:", @@ -3606,11 +3807,28 @@ static void svm_set_virtual_x2apic_mode(struct kvm_vcpu *vcpu, bool set) static bool svm_get_enable_apicv(void) { - return false; + return avic; } +static void svm_hwapic_irr_update(struct kvm_vcpu *vcpu, int max_irr) +{ +} + +static void svm_hwapic_isr_update(struct kvm *kvm, int isr) +{ +} + +/* Note: Currently only used by Hyper-V. */ static void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) { + struct vcpu_svm *svm = to_svm(vcpu); + struct vmcb *vmcb = svm->vmcb; + + if (!avic) + return; + + vmcb->control.int_ctl &= ~AVIC_ENABLE_MASK; + mark_dirty(vmcb, VMCB_INTR); } static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap) @@ -4322,6 +4540,9 @@ static struct kvm_x86_ops svm_x86_ops = { .vcpu_free = svm_free_vcpu, .vcpu_reset = svm_vcpu_reset, + .vm_init = avic_vm_init, + .vm_destroy = avic_vm_destroy, + .prepare_guest_switch = svm_prepare_guest_switch, .vcpu_load = svm_vcpu_load, .vcpu_put = svm_vcpu_put, @@ -4382,6 +4603,8 @@ static struct kvm_x86_ops svm_x86_ops = { .refresh_apicv_exec_ctrl = svm_refresh_apicv_exec_ctrl, .load_eoi_exitmap = svm_load_eoi_exitmap, .sync_pir_to_irr = svm_sync_pir_to_irr, + .hwapic_irr_update = svm_hwapic_irr_update, + .hwapic_isr_update = svm_hwapic_isr_update, .set_tss_addr = svm_set_tss_addr, .get_tdp_level = get_npt_level,