Merge tag 'kvm-x86-lam-6.8' of https://github.com/kvm-x86/linux into HEAD

[thirdparty/kernel/stable.git] / arch / x86 / kvm / svm / nested.c

// 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  <yaniv@qumranet.com>
 *   Avi Kivity   <avi@qumranet.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kvm_types.h>
#include <linux/kvm_host.h>
#include <linux/kernel.h>

#include <asm/msr-index.h>
#include <asm/debugreg.h>

#include "kvm_emulate.h"
#include "trace.h"
#include "mmu.h"
#include "x86.h"
#include "smm.h"
#include "cpuid.h"
#include "lapic.h"
#include "svm.h"
#include "hyperv.h"

#define CC KVM_NESTED_VMENTER_CONSISTENCY_CHECK

static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
                                       struct x86_exception *fault)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        struct vmcb *vmcb = svm->vmcb;

        if (vmcb->control.exit_code != SVM_EXIT_NPF) {
                /*
                 * TODO: track the cause of the nested page fault, and
                 * correctly fill in the high bits of exit_info_1.
                 */
                vmcb->control.exit_code = SVM_EXIT_NPF;
                vmcb->control.exit_code_hi = 0;
                vmcb->control.exit_info_1 = (1ULL << 32);
                vmcb->control.exit_info_2 = fault->address;
        }

        vmcb->control.exit_info_1 &= ~0xffffffffULL;
        vmcb->control.exit_info_1 |= fault->error_code;

        nested_svm_vmexit(svm);
}

static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        u64 cr3 = svm->nested.ctl.nested_cr3;
        u64 pdpte;
        int ret;

        ret = kvm_vcpu_read_guest_page(vcpu, gpa_to_gfn(cr3), &pdpte,
                                       offset_in_page(cr3) + index * 8, 8);
        if (ret)
                return 0;
        return pdpte;
}

static unsigned long nested_svm_get_tdp_cr3(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        return svm->nested.ctl.nested_cr3;
}

static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        WARN_ON(mmu_is_nested(vcpu));

        vcpu->arch.mmu = &vcpu->arch.guest_mmu;

        /*
         * The NPT format depends on L1's CR4 and EFER, which is in vmcb01.  Note,
         * when called via KVM_SET_NESTED_STATE, that state may _not_ match current
         * vCPU state.  CR0.WP is explicitly ignored, while CR0.PG is required.
         */
        kvm_init_shadow_npt_mmu(vcpu, X86_CR0_PG, svm->vmcb01.ptr->save.cr4,
                                svm->vmcb01.ptr->save.efer,
                                svm->nested.ctl.nested_cr3);
        vcpu->arch.mmu->get_guest_pgd     = nested_svm_get_tdp_cr3;
        vcpu->arch.mmu->get_pdptr         = nested_svm_get_tdp_pdptr;
        vcpu->arch.mmu->inject_page_fault = nested_svm_inject_npf_exit;
        vcpu->arch.walk_mmu              = &vcpu->arch.nested_mmu;
}

static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
{
        vcpu->arch.mmu = &vcpu->arch.root_mmu;
        vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;
}

static bool nested_vmcb_needs_vls_intercept(struct vcpu_svm *svm)
{
        if (!guest_can_use(&svm->vcpu, X86_FEATURE_V_VMSAVE_VMLOAD))
                return true;

        if (!nested_npt_enabled(svm))
                return true;

        if (!(svm->nested.ctl.virt_ext & VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK))
                return true;

        return false;
}

void recalc_intercepts(struct vcpu_svm *svm)
{
        struct vmcb_control_area *c, *h;
        struct vmcb_ctrl_area_cached *g;
        unsigned int i;

        vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);

        if (!is_guest_mode(&svm->vcpu))
                return;

        c = &svm->vmcb->control;
        h = &svm->vmcb01.ptr->control;
        g = &svm->nested.ctl;

        for (i = 0; i < MAX_INTERCEPT; i++)
                c->intercepts[i] = h->intercepts[i];

        if (g->int_ctl & V_INTR_MASKING_MASK) {
                /*
                 * If L2 is active and V_INTR_MASKING is enabled in vmcb12,
                 * disable intercept of CR8 writes as L2's CR8 does not affect
                 * any interrupt KVM may want to inject.
                 *
                 * Similarly, disable intercept of virtual interrupts (used to
                 * detect interrupt windows) if the saved RFLAGS.IF is '0', as
                 * the effective RFLAGS.IF for L1 interrupts will never be set
                 * while L2 is running (L2's RFLAGS.IF doesn't affect L1 IRQs).
                 */
                vmcb_clr_intercept(c, INTERCEPT_CR8_WRITE);
                if (!(svm->vmcb01.ptr->save.rflags & X86_EFLAGS_IF))
                        vmcb_clr_intercept(c, INTERCEPT_VINTR);
        }

        /*
         * We want to see VMMCALLs from a nested guest only when Hyper-V L2 TLB
         * flush feature is enabled.
         */
        if (!nested_svm_l2_tlb_flush_enabled(&svm->vcpu))
                vmcb_clr_intercept(c, INTERCEPT_VMMCALL);

        for (i = 0; i < MAX_INTERCEPT; i++)
                c->intercepts[i] |= g->intercepts[i];

        /* If SMI is not intercepted, ignore guest SMI intercept as well  */
        if (!intercept_smi)
                vmcb_clr_intercept(c, INTERCEPT_SMI);

        if (nested_vmcb_needs_vls_intercept(svm)) {
                /*
                 * If the virtual VMLOAD/VMSAVE is not enabled for the L2,
                 * we must intercept these instructions to correctly
                 * emulate them in case L1 doesn't intercept them.
                 */
                vmcb_set_intercept(c, INTERCEPT_VMLOAD);
                vmcb_set_intercept(c, INTERCEPT_VMSAVE);
        } else {
                WARN_ON(!(c->virt_ext & VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK));
        }
}

/*
 * Merge L0's (KVM) and L1's (Nested VMCB) MSR permission bitmaps. The function
 * is optimized in that it only merges the parts where KVM MSR permission bitmap
 * may contain zero bits.
 */
static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
{
        int i;

        /*
         * MSR bitmap update can be skipped when:
         * - MSR bitmap for L1 hasn't changed.
         * - Nested hypervisor (L1) is attempting to launch the same L2 as
         *   before.
         * - Nested hypervisor (L1) is using Hyper-V emulation interface and
         * tells KVM (L0) there were no changes in MSR bitmap for L2.
         */
#ifdef CONFIG_KVM_HYPERV
        if (!svm->nested.force_msr_bitmap_recalc) {
                struct hv_vmcb_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;

                if (kvm_hv_hypercall_enabled(&svm->vcpu) &&
                    hve->hv_enlightenments_control.msr_bitmap &&
                    (svm->nested.ctl.clean & BIT(HV_VMCB_NESTED_ENLIGHTENMENTS)))
                        goto set_msrpm_base_pa;
        }
#endif

        if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
                return true;

        for (i = 0; i < MSRPM_OFFSETS; i++) {
                u32 value, p;
                u64 offset;

                if (msrpm_offsets[i] == 0xffffffff)
                        break;

                p      = msrpm_offsets[i];

                /* x2apic msrs are intercepted always for the nested guest */
                if (is_x2apic_msrpm_offset(p))
                        continue;

                offset = svm->nested.ctl.msrpm_base_pa + (p * 4);

                if (kvm_vcpu_read_guest(&svm->vcpu, offset, &value, 4))
                        return false;

                svm->nested.msrpm[p] = svm->msrpm[p] | value;
        }

        svm->nested.force_msr_bitmap_recalc = false;

#ifdef CONFIG_KVM_HYPERV
set_msrpm_base_pa:
#endif
        svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));

        return true;
}

/*
 * Bits 11:0 of bitmap address are ignored by hardware
 */
static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size)
{
        u64 addr = PAGE_ALIGN(pa);

        return kvm_vcpu_is_legal_gpa(vcpu, addr) &&
            kvm_vcpu_is_legal_gpa(vcpu, addr + size - 1);
}

static bool nested_svm_check_tlb_ctl(struct kvm_vcpu *vcpu, u8 tlb_ctl)
{
        /* Nested FLUSHBYASID is not supported yet.  */
        switch(tlb_ctl) {
                case TLB_CONTROL_DO_NOTHING:
                case TLB_CONTROL_FLUSH_ALL_ASID:
                        return true;
                default:
                        return false;
        }
}

static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
                                         struct vmcb_ctrl_area_cached *control)
{
        if (CC(!vmcb12_is_intercept(control, INTERCEPT_VMRUN)))
                return false;

        if (CC(control->asid == 0))
                return false;

        if (CC((control->nested_ctl & SVM_NESTED_CTL_NP_ENABLE) && !npt_enabled))
                return false;

        if (CC(!nested_svm_check_bitmap_pa(vcpu, control->msrpm_base_pa,
                                           MSRPM_SIZE)))
                return false;
        if (CC(!nested_svm_check_bitmap_pa(vcpu, control->iopm_base_pa,
                                           IOPM_SIZE)))
                return false;

        if (CC(!nested_svm_check_tlb_ctl(vcpu, control->tlb_ctl)))
                return false;

        if (CC((control->int_ctl & V_NMI_ENABLE_MASK) &&
               !vmcb12_is_intercept(control, INTERCEPT_NMI))) {
                return false;
        }

        return true;
}

/* Common checks that apply to both L1 and L2 state.  */
static bool __nested_vmcb_check_save(struct kvm_vcpu *vcpu,
                                     struct vmcb_save_area_cached *save)
{
        if (CC(!(save->efer & EFER_SVME)))
                return false;

        if (CC((save->cr0 & X86_CR0_CD) == 0 && (save->cr0 & X86_CR0_NW)) ||
            CC(save->cr0 & ~0xffffffffULL))
                return false;

        if (CC(!kvm_dr6_valid(save->dr6)) || CC(!kvm_dr7_valid(save->dr7)))
                return false;

        /*
         * These checks are also performed by KVM_SET_SREGS,
         * except that EFER.LMA is not checked by SVM against
         * CR0.PG && EFER.LME.
         */
        if ((save->efer & EFER_LME) && (save->cr0 & X86_CR0_PG)) {
                if (CC(!(save->cr4 & X86_CR4_PAE)) ||
                    CC(!(save->cr0 & X86_CR0_PE)) ||
                    CC(!kvm_vcpu_is_legal_cr3(vcpu, save->cr3)))
                        return false;
        }

        /* Note, SVM doesn't have any additional restrictions on CR4. */
        if (CC(!__kvm_is_valid_cr4(vcpu, save->cr4)))
                return false;

        if (CC(!kvm_valid_efer(vcpu, save->efer)))
                return false;

        return true;
}

static bool nested_vmcb_check_save(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        struct vmcb_save_area_cached *save = &svm->nested.save;

        return __nested_vmcb_check_save(vcpu, save);
}

static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        struct vmcb_ctrl_area_cached *ctl = &svm->nested.ctl;

        return __nested_vmcb_check_controls(vcpu, ctl);
}

static
void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu,
                                         struct vmcb_ctrl_area_cached *to,
                                         struct vmcb_control_area *from)
{
        unsigned int i;

        for (i = 0; i < MAX_INTERCEPT; i++)
                to->intercepts[i] = from->intercepts[i];

        to->iopm_base_pa        = from->iopm_base_pa;
        to->msrpm_base_pa       = from->msrpm_base_pa;
        to->tsc_offset          = from->tsc_offset;
        to->tlb_ctl             = from->tlb_ctl;
        to->int_ctl             = from->int_ctl;
        to->int_vector          = from->int_vector;
        to->int_state           = from->int_state;
        to->exit_code           = from->exit_code;
        to->exit_code_hi        = from->exit_code_hi;
        to->exit_info_1         = from->exit_info_1;
        to->exit_info_2         = from->exit_info_2;
        to->exit_int_info       = from->exit_int_info;
        to->exit_int_info_err   = from->exit_int_info_err;
        to->nested_ctl          = from->nested_ctl;
        to->event_inj           = from->event_inj;
        to->event_inj_err       = from->event_inj_err;
        to->next_rip            = from->next_rip;
        to->nested_cr3          = from->nested_cr3;
        to->virt_ext            = from->virt_ext;
        to->pause_filter_count  = from->pause_filter_count;
        to->pause_filter_thresh = from->pause_filter_thresh;

        /* Copy asid here because nested_vmcb_check_controls will check it.  */
        to->asid           = from->asid;
        to->msrpm_base_pa &= ~0x0fffULL;
        to->iopm_base_pa  &= ~0x0fffULL;

#ifdef CONFIG_KVM_HYPERV
        /* Hyper-V extensions (Enlightened VMCB) */
        if (kvm_hv_hypercall_enabled(vcpu)) {
                to->clean = from->clean;
                memcpy(&to->hv_enlightenments, &from->hv_enlightenments,
                       sizeof(to->hv_enlightenments));
        }
#endif
}

void nested_copy_vmcb_control_to_cache(struct vcpu_svm *svm,
                                       struct vmcb_control_area *control)
{
        __nested_copy_vmcb_control_to_cache(&svm->vcpu, &svm->nested.ctl, control);
}

static void __nested_copy_vmcb_save_to_cache(struct vmcb_save_area_cached *to,
                                             struct vmcb_save_area *from)
{
        /*
         * Copy only fields that are validated, as we need them
         * to avoid TOC/TOU races.
         */
        to->efer = from->efer;
        to->cr0 = from->cr0;
        to->cr3 = from->cr3;
        to->cr4 = from->cr4;

        to->dr6 = from->dr6;
        to->dr7 = from->dr7;
}

void nested_copy_vmcb_save_to_cache(struct vcpu_svm *svm,
                                    struct vmcb_save_area *save)
{
        __nested_copy_vmcb_save_to_cache(&svm->nested.save, save);
}

/*
 * Synchronize fields that are written by the processor, so that
 * they can be copied back into the vmcb12.
 */
void nested_sync_control_from_vmcb02(struct vcpu_svm *svm)
{
        u32 mask;
        svm->nested.ctl.event_inj      = svm->vmcb->control.event_inj;
        svm->nested.ctl.event_inj_err  = svm->vmcb->control.event_inj_err;

        /* Only a few fields of int_ctl are written by the processor.  */
        mask = V_IRQ_MASK | V_TPR_MASK;
        /*
         * Don't sync vmcb02 V_IRQ back to vmcb12 if KVM (L0) is intercepting
         * virtual interrupts in order to request an interrupt window, as KVM
         * has usurped vmcb02's int_ctl.  If an interrupt window opens before
         * the next VM-Exit, svm_clear_vintr() will restore vmcb12's int_ctl.
         * If no window opens, V_IRQ will be correctly preserved in vmcb12's
         * int_ctl (because it was never recognized while L2 was running).
         */
        if (svm_is_intercept(svm, INTERCEPT_VINTR) &&
            !test_bit(INTERCEPT_VINTR, (unsigned long *)svm->nested.ctl.intercepts))
                mask &= ~V_IRQ_MASK;

        if (nested_vgif_enabled(svm))
                mask |= V_GIF_MASK;

        if (nested_vnmi_enabled(svm))
                mask |= V_NMI_BLOCKING_MASK | V_NMI_PENDING_MASK;

        svm->nested.ctl.int_ctl        &= ~mask;
        svm->nested.ctl.int_ctl        |= svm->vmcb->control.int_ctl & mask;
}

/*
 * Transfer any event that L0 or L1 wanted to inject into L2 to
 * EXIT_INT_INFO.
 */
static void nested_save_pending_event_to_vmcb12(struct vcpu_svm *svm,
                                                struct vmcb *vmcb12)
{
        struct kvm_vcpu *vcpu = &svm->vcpu;
        u32 exit_int_info = 0;
        unsigned int nr;

        if (vcpu->arch.exception.injected) {
                nr = vcpu->arch.exception.vector;
                exit_int_info = nr | SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_EXEPT;

                if (vcpu->arch.exception.has_error_code) {
                        exit_int_info |= SVM_EVTINJ_VALID_ERR;
                        vmcb12->control.exit_int_info_err =
                                vcpu->arch.exception.error_code;
                }

        } else if (vcpu->arch.nmi_injected) {
                exit_int_info = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_NMI;

        } else if (vcpu->arch.interrupt.injected) {
                nr = vcpu->arch.interrupt.nr;
                exit_int_info = nr | SVM_EVTINJ_VALID;

                if (vcpu->arch.interrupt.soft)
                        exit_int_info |= SVM_EVTINJ_TYPE_SOFT;
                else
                        exit_int_info |= SVM_EVTINJ_TYPE_INTR;
        }

        vmcb12->control.exit_int_info = exit_int_info;
}

static void nested_svm_transition_tlb_flush(struct kvm_vcpu *vcpu)
{
        /* Handle pending Hyper-V TLB flush requests */
        kvm_hv_nested_transtion_tlb_flush(vcpu, npt_enabled);

        /*
         * TODO: optimize unconditional TLB flush/MMU sync.  A partial list of
         * things to fix before this can be conditional:
         *
         *  - Flush TLBs for both L1 and L2 remote TLB flush
         *  - Honor L1's request to flush an ASID on nested VMRUN
         *  - Sync nested NPT MMU on VMRUN that flushes L2's ASID[*]
         *  - Don't crush a pending TLB flush in vmcb02 on nested VMRUN
         *  - Flush L1's ASID on KVM_REQ_TLB_FLUSH_GUEST
         *
         * [*] Unlike nested EPT, SVM's ASID management can invalidate nested
         *     NPT guest-physical mappings on VMRUN.
         */
        kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
        kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu);
}

/*
 * Load guest's/host's cr3 on nested vmentry or vmexit. @nested_npt is true
 * if we are emulating VM-Entry into a guest with NPT enabled.
 */
static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,
                               bool nested_npt, bool reload_pdptrs)
{
        if (CC(!kvm_vcpu_is_legal_cr3(vcpu, cr3)))
                return -EINVAL;

        if (reload_pdptrs && !nested_npt && is_pae_paging(vcpu) &&
            CC(!load_pdptrs(vcpu, cr3)))
                return -EINVAL;

        vcpu->arch.cr3 = cr3;

        /* Re-initialize the MMU, e.g. to pick up CR4 MMU role changes. */
        kvm_init_mmu(vcpu);

        if (!nested_npt)
                kvm_mmu_new_pgd(vcpu, cr3);

        return 0;
}

void nested_vmcb02_compute_g_pat(struct vcpu_svm *svm)
{
        if (!svm->nested.vmcb02.ptr)
                return;

        /* FIXME: merge g_pat from vmcb01 and vmcb12.  */
        svm->nested.vmcb02.ptr->save.g_pat = svm->vmcb01.ptr->save.g_pat;
}

static void nested_vmcb02_prepare_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
{
        bool new_vmcb12 = false;
        struct vmcb *vmcb01 = svm->vmcb01.ptr;
        struct vmcb *vmcb02 = svm->nested.vmcb02.ptr;
        struct kvm_vcpu *vcpu = &svm->vcpu;

        nested_vmcb02_compute_g_pat(svm);

        /* Load the nested guest state */
        if (svm->nested.vmcb12_gpa != svm->nested.last_vmcb12_gpa) {
                new_vmcb12 = true;
                svm->nested.last_vmcb12_gpa = svm->nested.vmcb12_gpa;
                svm->nested.force_msr_bitmap_recalc = true;
        }

        if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_SEG))) {
                vmcb02->save.es = vmcb12->save.es;
                vmcb02->save.cs = vmcb12->save.cs;
                vmcb02->save.ss = vmcb12->save.ss;
                vmcb02->save.ds = vmcb12->save.ds;
                vmcb02->save.cpl = vmcb12->save.cpl;
                vmcb_mark_dirty(vmcb02, VMCB_SEG);
        }

        if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_DT))) {
                vmcb02->save.gdtr = vmcb12->save.gdtr;
                vmcb02->save.idtr = vmcb12->save.idtr;
                vmcb_mark_dirty(vmcb02, VMCB_DT);
        }

        kvm_set_rflags(vcpu, vmcb12->save.rflags | X86_EFLAGS_FIXED);

        svm_set_efer(vcpu, svm->nested.save.efer);

        svm_set_cr0(vcpu, svm->nested.save.cr0);
        svm_set_cr4(vcpu, svm->nested.save.cr4);

        svm->vcpu.arch.cr2 = vmcb12->save.cr2;

        kvm_rax_write(vcpu, vmcb12->save.rax);
        kvm_rsp_write(vcpu, vmcb12->save.rsp);
        kvm_rip_write(vcpu, vmcb12->save.rip);

        /* In case we don't even reach vcpu_run, the fields are not updated */
        vmcb02->save.rax = vmcb12->save.rax;
        vmcb02->save.rsp = vmcb12->save.rsp;
        vmcb02->save.rip = vmcb12->save.rip;

        /* These bits will be set properly on the first execution when new_vmc12 is true */
        if (unlikely(new_vmcb12 || vmcb_is_dirty(vmcb12, VMCB_DR))) {
                vmcb02->save.dr7 = svm->nested.save.dr7 | DR7_FIXED_1;
                svm->vcpu.arch.dr6  = svm->nested.save.dr6 | DR6_ACTIVE_LOW;
                vmcb_mark_dirty(vmcb02, VMCB_DR);
        }

        if (unlikely(guest_can_use(vcpu, X86_FEATURE_LBRV) &&
                     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
                /*
                 * Reserved bits of DEBUGCTL are ignored.  Be consistent with
                 * svm_set_msr's definition of reserved bits.
                 */
                svm_copy_lbrs(vmcb02, vmcb12);
                vmcb02->save.dbgctl &= ~DEBUGCTL_RESERVED_BITS;
                svm_update_lbrv(&svm->vcpu);

        } else if (unlikely(vmcb01->control.virt_ext & LBR_CTL_ENABLE_MASK)) {
                svm_copy_lbrs(vmcb02, vmcb01);
        }
}

static inline bool is_evtinj_soft(u32 evtinj)
{
        u32 type = evtinj & SVM_EVTINJ_TYPE_MASK;
        u8 vector = evtinj & SVM_EVTINJ_VEC_MASK;

        if (!(evtinj & SVM_EVTINJ_VALID))
                return false;

        if (type == SVM_EVTINJ_TYPE_SOFT)
                return true;

        return type == SVM_EVTINJ_TYPE_EXEPT && kvm_exception_is_soft(vector);
}

static bool is_evtinj_nmi(u32 evtinj)
{
        u32 type = evtinj & SVM_EVTINJ_TYPE_MASK;

        if (!(evtinj & SVM_EVTINJ_VALID))
                return false;

        return type == SVM_EVTINJ_TYPE_NMI;
}

static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
                                          unsigned long vmcb12_rip,
                                          unsigned long vmcb12_csbase)
{
        u32 int_ctl_vmcb01_bits = V_INTR_MASKING_MASK;
        u32 int_ctl_vmcb12_bits = V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK;

        struct kvm_vcpu *vcpu = &svm->vcpu;
        struct vmcb *vmcb01 = svm->vmcb01.ptr;
        struct vmcb *vmcb02 = svm->nested.vmcb02.ptr;
        u32 pause_count12;
        u32 pause_thresh12;

        /*
         * Filled at exit: exit_code, exit_code_hi, exit_info_1, exit_info_2,
         * exit_int_info, exit_int_info_err, next_rip, insn_len, insn_bytes.
         */

        if (guest_can_use(vcpu, X86_FEATURE_VGIF) &&
            (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
                int_ctl_vmcb12_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
        else
                int_ctl_vmcb01_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);

        if (vnmi) {
                if (vmcb01->control.int_ctl & V_NMI_PENDING_MASK) {
                        svm->vcpu.arch.nmi_pending++;
                        kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
                }
                if (nested_vnmi_enabled(svm))
                        int_ctl_vmcb12_bits |= (V_NMI_PENDING_MASK |
                                                V_NMI_ENABLE_MASK |
                                                V_NMI_BLOCKING_MASK);
        }

        /* Copied from vmcb01.  msrpm_base can be overwritten later.  */
        vmcb02->control.nested_ctl = vmcb01->control.nested_ctl;
        vmcb02->control.iopm_base_pa = vmcb01->control.iopm_base_pa;
        vmcb02->control.msrpm_base_pa = vmcb01->control.msrpm_base_pa;

        /* Done at vmrun: asid.  */

        /* Also overwritten later if necessary.  */
        vmcb02->control.tlb_ctl = TLB_CONTROL_DO_NOTHING;

        /* nested_cr3.  */
        if (nested_npt_enabled(svm))
                nested_svm_init_mmu_context(vcpu);

        vcpu->arch.tsc_offset = kvm_calc_nested_tsc_offset(
                        vcpu->arch.l1_tsc_offset,
                        svm->nested.ctl.tsc_offset,
                        svm->tsc_ratio_msr);

        vmcb02->control.tsc_offset = vcpu->arch.tsc_offset;

        if (guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR) &&
            svm->tsc_ratio_msr != kvm_caps.default_tsc_scaling_ratio)
                nested_svm_update_tsc_ratio_msr(vcpu);

        vmcb02->control.int_ctl             =
                (svm->nested.ctl.int_ctl & int_ctl_vmcb12_bits) |
                (vmcb01->control.int_ctl & int_ctl_vmcb01_bits);

        vmcb02->control.int_vector          = svm->nested.ctl.int_vector;
        vmcb02->control.int_state           = svm->nested.ctl.int_state;
        vmcb02->control.event_inj           = svm->nested.ctl.event_inj;
        vmcb02->control.event_inj_err       = svm->nested.ctl.event_inj_err;

        /*
         * next_rip is consumed on VMRUN as the return address pushed on the
         * stack for injected soft exceptions/interrupts.  If nrips is exposed
         * to L1, take it verbatim from vmcb12.  If nrips is supported in
         * hardware but not exposed to L1, stuff the actual L2 RIP to emulate
         * what a nrips=0 CPU would do (L1 is responsible for advancing RIP
         * prior to injecting the event).
         */
        if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
                vmcb02->control.next_rip    = svm->nested.ctl.next_rip;
        else if (boot_cpu_has(X86_FEATURE_NRIPS))
                vmcb02->control.next_rip    = vmcb12_rip;

        svm->nmi_l1_to_l2 = is_evtinj_nmi(vmcb02->control.event_inj);
        if (is_evtinj_soft(vmcb02->control.event_inj)) {
                svm->soft_int_injected = true;
                svm->soft_int_csbase = vmcb12_csbase;
                svm->soft_int_old_rip = vmcb12_rip;
                if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
                        svm->soft_int_next_rip = svm->nested.ctl.next_rip;
                else
                        svm->soft_int_next_rip = vmcb12_rip;
        }

        vmcb02->control.virt_ext            = vmcb01->control.virt_ext &
                                              LBR_CTL_ENABLE_MASK;
        if (guest_can_use(vcpu, X86_FEATURE_LBRV))
                vmcb02->control.virt_ext  |=
                        (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK);

        if (!nested_vmcb_needs_vls_intercept(svm))
                vmcb02->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK;

        if (guest_can_use(vcpu, X86_FEATURE_PAUSEFILTER))
                pause_count12 = svm->nested.ctl.pause_filter_count;
        else
                pause_count12 = 0;
        if (guest_can_use(vcpu, X86_FEATURE_PFTHRESHOLD))
                pause_thresh12 = svm->nested.ctl.pause_filter_thresh;
        else
                pause_thresh12 = 0;
        if (kvm_pause_in_guest(svm->vcpu.kvm)) {
                /* use guest values since host doesn't intercept PAUSE */
                vmcb02->control.pause_filter_count = pause_count12;
                vmcb02->control.pause_filter_thresh = pause_thresh12;

        } else {
                /* start from host values otherwise */
                vmcb02->control.pause_filter_count = vmcb01->control.pause_filter_count;
                vmcb02->control.pause_filter_thresh = vmcb01->control.pause_filter_thresh;

                /* ... but ensure filtering is disabled if so requested.  */
                if (vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_PAUSE)) {
                        if (!pause_count12)
                                vmcb02->control.pause_filter_count = 0;
                        if (!pause_thresh12)
                                vmcb02->control.pause_filter_thresh = 0;
                }
        }

        nested_svm_transition_tlb_flush(vcpu);

        /* Enter Guest-Mode */
        enter_guest_mode(vcpu);

        /*
         * Merge guest and host intercepts - must be called with vcpu in
         * guest-mode to take effect.
         */
        recalc_intercepts(svm);
}

static void nested_svm_copy_common_state(struct vmcb *from_vmcb, struct vmcb *to_vmcb)
{
        /*
         * Some VMCB state is shared between L1 and L2 and thus has to be
         * moved at the time of nested vmrun and vmexit.
         *
         * VMLOAD/VMSAVE state would also belong in this category, but KVM
         * always performs VMLOAD and VMSAVE from the VMCB01.
         */
        to_vmcb->save.spec_ctrl = from_vmcb->save.spec_ctrl;
}

int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa,
                         struct vmcb *vmcb12, bool from_vmrun)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        int ret;

        trace_kvm_nested_vmenter(svm->vmcb->save.rip,
                                 vmcb12_gpa,
                                 vmcb12->save.rip,
                                 vmcb12->control.int_ctl,
                                 vmcb12->control.event_inj,
                                 vmcb12->control.nested_ctl,
                                 vmcb12->control.nested_cr3,
                                 vmcb12->save.cr3,
                                 KVM_ISA_SVM);

        trace_kvm_nested_intercepts(vmcb12->control.intercepts[INTERCEPT_CR] & 0xffff,
                                    vmcb12->control.intercepts[INTERCEPT_CR] >> 16,
                                    vmcb12->control.intercepts[INTERCEPT_EXCEPTION],
                                    vmcb12->control.intercepts[INTERCEPT_WORD3],
                                    vmcb12->control.intercepts[INTERCEPT_WORD4],
                                    vmcb12->control.intercepts[INTERCEPT_WORD5]);


        svm->nested.vmcb12_gpa = vmcb12_gpa;

        WARN_ON(svm->vmcb == svm->nested.vmcb02.ptr);

        nested_svm_copy_common_state(svm->vmcb01.ptr, svm->nested.vmcb02.ptr);

        svm_switch_vmcb(svm, &svm->nested.vmcb02);
        nested_vmcb02_prepare_control(svm, vmcb12->save.rip, vmcb12->save.cs.base);
        nested_vmcb02_prepare_save(svm, vmcb12);

        ret = nested_svm_load_cr3(&svm->vcpu, svm->nested.save.cr3,
                                  nested_npt_enabled(svm), from_vmrun);
        if (ret)
                return ret;

        if (!from_vmrun)
                kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);

        svm_set_gif(svm, true);

        if (kvm_vcpu_apicv_active(vcpu))
                kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);

        nested_svm_hv_update_vm_vp_ids(vcpu);

        return 0;
}

int nested_svm_vmrun(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        int ret;
        struct vmcb *vmcb12;
        struct kvm_host_map map;
        u64 vmcb12_gpa;
        struct vmcb *vmcb01 = svm->vmcb01.ptr;

        if (!svm->nested.hsave_msr) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        if (is_smm(vcpu)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        /* This fails when VP assist page is enabled but the supplied GPA is bogus */
        ret = kvm_hv_verify_vp_assist(vcpu);
        if (ret) {
                kvm_inject_gp(vcpu, 0);
                return ret;
        }

        vmcb12_gpa = svm->vmcb->save.rax;
        ret = kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map);
        if (ret == -EINVAL) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        } else if (ret) {
                return kvm_skip_emulated_instruction(vcpu);
        }

        ret = kvm_skip_emulated_instruction(vcpu);

        vmcb12 = map.hva;

        if (WARN_ON_ONCE(!svm->nested.initialized))
                return -EINVAL;

        nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
        nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);

        if (!nested_vmcb_check_save(vcpu) ||
            !nested_vmcb_check_controls(vcpu)) {
                vmcb12->control.exit_code    = SVM_EXIT_ERR;
                vmcb12->control.exit_code_hi = 0;
                vmcb12->control.exit_info_1  = 0;
                vmcb12->control.exit_info_2  = 0;
                goto out;
        }

        /*
         * Since vmcb01 is not in use, we can use it to store some of the L1
         * state.
         */
        vmcb01->save.efer   = vcpu->arch.efer;
        vmcb01->save.cr0    = kvm_read_cr0(vcpu);
        vmcb01->save.cr4    = vcpu->arch.cr4;
        vmcb01->save.rflags = kvm_get_rflags(vcpu);
        vmcb01->save.rip    = kvm_rip_read(vcpu);

        if (!npt_enabled)
                vmcb01->save.cr3 = kvm_read_cr3(vcpu);

        svm->nested.nested_run_pending = 1;

        if (enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, true))
                goto out_exit_err;

        if (nested_svm_vmrun_msrpm(svm))
                goto out;

out_exit_err:
        svm->nested.nested_run_pending = 0;
        svm->nmi_l1_to_l2 = false;
        svm->soft_int_injected = false;

        svm->vmcb->control.exit_code    = SVM_EXIT_ERR;
        svm->vmcb->control.exit_code_hi = 0;
        svm->vmcb->control.exit_info_1  = 0;
        svm->vmcb->control.exit_info_2  = 0;

        nested_svm_vmexit(svm);

out:
        kvm_vcpu_unmap(vcpu, &map, true);

        return ret;
}

/* Copy state save area fields which are handled by VMRUN */
void svm_copy_vmrun_state(struct vmcb_save_area *to_save,
                          struct vmcb_save_area *from_save)
{
        to_save->es = from_save->es;
        to_save->cs = from_save->cs;
        to_save->ss = from_save->ss;
        to_save->ds = from_save->ds;
        to_save->gdtr = from_save->gdtr;
        to_save->idtr = from_save->idtr;
        to_save->rflags = from_save->rflags | X86_EFLAGS_FIXED;
        to_save->efer = from_save->efer;
        to_save->cr0 = from_save->cr0;
        to_save->cr3 = from_save->cr3;
        to_save->cr4 = from_save->cr4;
        to_save->rax = from_save->rax;
        to_save->rsp = from_save->rsp;
        to_save->rip = from_save->rip;
        to_save->cpl = 0;
}

void svm_copy_vmloadsave_state(struct vmcb *to_vmcb, struct vmcb *from_vmcb)
{
        to_vmcb->save.fs = from_vmcb->save.fs;
        to_vmcb->save.gs = from_vmcb->save.gs;
        to_vmcb->save.tr = from_vmcb->save.tr;
        to_vmcb->save.ldtr = from_vmcb->save.ldtr;
        to_vmcb->save.kernel_gs_base = from_vmcb->save.kernel_gs_base;
        to_vmcb->save.star = from_vmcb->save.star;
        to_vmcb->save.lstar = from_vmcb->save.lstar;
        to_vmcb->save.cstar = from_vmcb->save.cstar;
        to_vmcb->save.sfmask = from_vmcb->save.sfmask;
        to_vmcb->save.sysenter_cs = from_vmcb->save.sysenter_cs;
        to_vmcb->save.sysenter_esp = from_vmcb->save.sysenter_esp;
        to_vmcb->save.sysenter_eip = from_vmcb->save.sysenter_eip;
}

int nested_svm_vmexit(struct vcpu_svm *svm)
{
        struct kvm_vcpu *vcpu = &svm->vcpu;
        struct vmcb *vmcb01 = svm->vmcb01.ptr;
        struct vmcb *vmcb02 = svm->nested.vmcb02.ptr;
        struct vmcb *vmcb12;
        struct kvm_host_map map;
        int rc;

        rc = kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.vmcb12_gpa), &map);
        if (rc) {
                if (rc == -EINVAL)
                        kvm_inject_gp(vcpu, 0);
                return 1;
        }

        vmcb12 = map.hva;

        /* Exit Guest-Mode */
        leave_guest_mode(vcpu);
        svm->nested.vmcb12_gpa = 0;
        WARN_ON_ONCE(svm->nested.nested_run_pending);

        kvm_clear_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);

        /* in case we halted in L2 */
        svm->vcpu.arch.mp_state = KVM_MP_STATE_RUNNABLE;

        /* Give the current vmcb to the guest */

        vmcb12->save.es     = vmcb02->save.es;
        vmcb12->save.cs     = vmcb02->save.cs;
        vmcb12->save.ss     = vmcb02->save.ss;
        vmcb12->save.ds     = vmcb02->save.ds;
        vmcb12->save.gdtr   = vmcb02->save.gdtr;
        vmcb12->save.idtr   = vmcb02->save.idtr;
        vmcb12->save.efer   = svm->vcpu.arch.efer;
        vmcb12->save.cr0    = kvm_read_cr0(vcpu);
        vmcb12->save.cr3    = kvm_read_cr3(vcpu);
        vmcb12->save.cr2    = vmcb02->save.cr2;
        vmcb12->save.cr4    = svm->vcpu.arch.cr4;
        vmcb12->save.rflags = kvm_get_rflags(vcpu);
        vmcb12->save.rip    = kvm_rip_read(vcpu);
        vmcb12->save.rsp    = kvm_rsp_read(vcpu);
        vmcb12->save.rax    = kvm_rax_read(vcpu);
        vmcb12->save.dr7    = vmcb02->save.dr7;
        vmcb12->save.dr6    = svm->vcpu.arch.dr6;
        vmcb12->save.cpl    = vmcb02->save.cpl;

        vmcb12->control.int_state         = vmcb02->control.int_state;
        vmcb12->control.exit_code         = vmcb02->control.exit_code;
        vmcb12->control.exit_code_hi      = vmcb02->control.exit_code_hi;
        vmcb12->control.exit_info_1       = vmcb02->control.exit_info_1;
        vmcb12->control.exit_info_2       = vmcb02->control.exit_info_2;

        if (vmcb12->control.exit_code != SVM_EXIT_ERR)
                nested_save_pending_event_to_vmcb12(svm, vmcb12);

        if (guest_can_use(vcpu, X86_FEATURE_NRIPS))
                vmcb12->control.next_rip  = vmcb02->control.next_rip;

        vmcb12->control.int_ctl           = svm->nested.ctl.int_ctl;
        vmcb12->control.event_inj         = svm->nested.ctl.event_inj;
        vmcb12->control.event_inj_err     = svm->nested.ctl.event_inj_err;

        if (!kvm_pause_in_guest(vcpu->kvm)) {
                vmcb01->control.pause_filter_count = vmcb02->control.pause_filter_count;
                vmcb_mark_dirty(vmcb01, VMCB_INTERCEPTS);

        }

        nested_svm_copy_common_state(svm->nested.vmcb02.ptr, svm->vmcb01.ptr);

        svm_switch_vmcb(svm, &svm->vmcb01);

        /*
         * Rules for synchronizing int_ctl bits from vmcb02 to vmcb01:
         *
         * V_IRQ, V_IRQ_VECTOR, V_INTR_PRIO_MASK, V_IGN_TPR:  If L1 doesn't
         * intercept interrupts, then KVM will use vmcb02's V_IRQ (and related
         * flags) to detect interrupt windows for L1 IRQs (even if L1 uses
         * virtual interrupt masking).  Raise KVM_REQ_EVENT to ensure that
         * KVM re-requests an interrupt window if necessary, which implicitly
         * copies this bits from vmcb02 to vmcb01.
         *
         * V_TPR: If L1 doesn't use virtual interrupt masking, then L1's vTPR
         * is stored in vmcb02, but its value doesn't need to be copied from/to
         * vmcb01 because it is copied from/to the virtual APIC's TPR register
         * on each VM entry/exit.
         *
         * V_GIF: If nested vGIF is not used, KVM uses vmcb02's V_GIF for L1's
         * V_GIF.  However, GIF is architecturally clear on each VM exit, thus
         * there is no need to copy V_GIF from vmcb02 to vmcb01.
         */
        if (!nested_exit_on_intr(svm))
                kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);

        if (unlikely(guest_can_use(vcpu, X86_FEATURE_LBRV) &&
                     (svm->nested.ctl.virt_ext & LBR_CTL_ENABLE_MASK))) {
                svm_copy_lbrs(vmcb12, vmcb02);
                svm_update_lbrv(vcpu);
        } else if (unlikely(vmcb01->control.virt_ext & LBR_CTL_ENABLE_MASK)) {
                svm_copy_lbrs(vmcb01, vmcb02);
                svm_update_lbrv(vcpu);
        }

        if (vnmi) {
                if (vmcb02->control.int_ctl & V_NMI_BLOCKING_MASK)
                        vmcb01->control.int_ctl |= V_NMI_BLOCKING_MASK;
                else
                        vmcb01->control.int_ctl &= ~V_NMI_BLOCKING_MASK;

                if (vcpu->arch.nmi_pending) {
                        vcpu->arch.nmi_pending--;
                        vmcb01->control.int_ctl |= V_NMI_PENDING_MASK;
                } else {
                        vmcb01->control.int_ctl &= ~V_NMI_PENDING_MASK;
                }
        }

        /*
         * On vmexit the  GIF is set to false and
         * no event can be injected in L1.
         */
        svm_set_gif(svm, false);
        vmcb01->control.exit_int_info = 0;

        svm->vcpu.arch.tsc_offset = svm->vcpu.arch.l1_tsc_offset;
        if (vmcb01->control.tsc_offset != svm->vcpu.arch.tsc_offset) {
                vmcb01->control.tsc_offset = svm->vcpu.arch.tsc_offset;
                vmcb_mark_dirty(vmcb01, VMCB_INTERCEPTS);
        }

        if (kvm_caps.has_tsc_control &&
            vcpu->arch.tsc_scaling_ratio != vcpu->arch.l1_tsc_scaling_ratio) {
                vcpu->arch.tsc_scaling_ratio = vcpu->arch.l1_tsc_scaling_ratio;
                svm_write_tsc_multiplier(vcpu);
        }

        svm->nested.ctl.nested_cr3 = 0;

        /*
         * Restore processor state that had been saved in vmcb01
         */
        kvm_set_rflags(vcpu, vmcb01->save.rflags);
        svm_set_efer(vcpu, vmcb01->save.efer);
        svm_set_cr0(vcpu, vmcb01->save.cr0 | X86_CR0_PE);
        svm_set_cr4(vcpu, vmcb01->save.cr4);
        kvm_rax_write(vcpu, vmcb01->save.rax);
        kvm_rsp_write(vcpu, vmcb01->save.rsp);
        kvm_rip_write(vcpu, vmcb01->save.rip);

        svm->vcpu.arch.dr7 = DR7_FIXED_1;
        kvm_update_dr7(&svm->vcpu);

        trace_kvm_nested_vmexit_inject(vmcb12->control.exit_code,
                                       vmcb12->control.exit_info_1,
                                       vmcb12->control.exit_info_2,
                                       vmcb12->control.exit_int_info,
                                       vmcb12->control.exit_int_info_err,
                                       KVM_ISA_SVM);

        kvm_vcpu_unmap(vcpu, &map, true);

        nested_svm_transition_tlb_flush(vcpu);

        nested_svm_uninit_mmu_context(vcpu);

        rc = nested_svm_load_cr3(vcpu, vmcb01->save.cr3, false, true);
        if (rc)
                return 1;

        /*
         * Drop what we picked up for L2 via svm_complete_interrupts() so it
         * doesn't end up in L1.
         */
        svm->vcpu.arch.nmi_injected = false;
        kvm_clear_exception_queue(vcpu);
        kvm_clear_interrupt_queue(vcpu);

        /*
         * If we are here following the completion of a VMRUN that
         * is being single-stepped, queue the pending #DB intercept
         * right now so that it an be accounted for before we execute
         * L1's next instruction.
         */
        if (unlikely(vmcb01->save.rflags & X86_EFLAGS_TF))
                kvm_queue_exception(&(svm->vcpu), DB_VECTOR);

        /*
         * Un-inhibit the AVIC right away, so that other vCPUs can start
         * to benefit from it right away.
         */
        if (kvm_apicv_activated(vcpu->kvm))
                __kvm_vcpu_update_apicv(vcpu);

        return 0;
}

static void nested_svm_triple_fault(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        if (!vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SHUTDOWN))
                return;

        kvm_clear_request(KVM_REQ_TRIPLE_FAULT, vcpu);
        nested_svm_simple_vmexit(to_svm(vcpu), SVM_EXIT_SHUTDOWN);
}

int svm_allocate_nested(struct vcpu_svm *svm)
{
        struct page *vmcb02_page;

        if (svm->nested.initialized)
                return 0;

        vmcb02_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
        if (!vmcb02_page)
                return -ENOMEM;
        svm->nested.vmcb02.ptr = page_address(vmcb02_page);
        svm->nested.vmcb02.pa = __sme_set(page_to_pfn(vmcb02_page) << PAGE_SHIFT);

        svm->nested.msrpm = svm_vcpu_alloc_msrpm();
        if (!svm->nested.msrpm)
                goto err_free_vmcb02;
        svm_vcpu_init_msrpm(&svm->vcpu, svm->nested.msrpm);

        svm->nested.initialized = true;
        return 0;

err_free_vmcb02:
        __free_page(vmcb02_page);
        return -ENOMEM;
}

void svm_free_nested(struct vcpu_svm *svm)
{
        if (!svm->nested.initialized)
                return;

        if (WARN_ON_ONCE(svm->vmcb != svm->vmcb01.ptr))
                svm_switch_vmcb(svm, &svm->vmcb01);

        svm_vcpu_free_msrpm(svm->nested.msrpm);
        svm->nested.msrpm = NULL;

        __free_page(virt_to_page(svm->nested.vmcb02.ptr));
        svm->nested.vmcb02.ptr = NULL;

        /*
         * When last_vmcb12_gpa matches the current vmcb12 gpa,
         * some vmcb12 fields are not loaded if they are marked clean
         * in the vmcb12, since in this case they are up to date already.
         *
         * When the vmcb02 is freed, this optimization becomes invalid.
         */
        svm->nested.last_vmcb12_gpa = INVALID_GPA;

        svm->nested.initialized = false;
}

void svm_leave_nested(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        if (is_guest_mode(vcpu)) {
                svm->nested.nested_run_pending = 0;
                svm->nested.vmcb12_gpa = INVALID_GPA;

                leave_guest_mode(vcpu);

                svm_switch_vmcb(svm, &svm->vmcb01);

                nested_svm_uninit_mmu_context(vcpu);
                vmcb_mark_all_dirty(svm->vmcb);

                if (kvm_apicv_activated(vcpu->kvm))
                        kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
        }

        kvm_clear_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);
}

static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
{
        u32 offset, msr, value;
        int write, mask;

        if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
                return NESTED_EXIT_HOST;

        msr    = svm->vcpu.arch.regs[VCPU_REGS_RCX];
        offset = svm_msrpm_offset(msr);
        write  = svm->vmcb->control.exit_info_1 & 1;
        mask   = 1 << ((2 * (msr & 0xf)) + write);

        if (offset == MSR_INVALID)
                return NESTED_EXIT_DONE;

        /* Offset is in 32 bit units but need in 8 bit units */
        offset *= 4;

        if (kvm_vcpu_read_guest(&svm->vcpu, svm->nested.ctl.msrpm_base_pa + offset, &value, 4))
                return NESTED_EXIT_DONE;

        return (value & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
}

static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
{
        unsigned port, size, iopm_len;
        u16 val, mask;
        u8 start_bit;
        u64 gpa;

        if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_IOIO_PROT)))
                return NESTED_EXIT_HOST;

        port = svm->vmcb->control.exit_info_1 >> 16;
        size = (svm->vmcb->control.exit_info_1 & SVM_IOIO_SIZE_MASK) >>
                SVM_IOIO_SIZE_SHIFT;
        gpa  = svm->nested.ctl.iopm_base_pa + (port / 8);
        start_bit = port % 8;
        iopm_len = (start_bit + size > 8) ? 2 : 1;
        mask = (0xf >> (4 - size)) << start_bit;
        val = 0;

        if (kvm_vcpu_read_guest(&svm->vcpu, gpa, &val, iopm_len))
                return NESTED_EXIT_DONE;

        return (val & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
}

static int nested_svm_intercept(struct vcpu_svm *svm)
{
        u32 exit_code = svm->vmcb->control.exit_code;
        int vmexit = NESTED_EXIT_HOST;

        switch (exit_code) {
        case SVM_EXIT_MSR:
                vmexit = nested_svm_exit_handled_msr(svm);
                break;
        case SVM_EXIT_IOIO:
                vmexit = nested_svm_intercept_ioio(svm);
                break;
        case SVM_EXIT_READ_CR0 ... SVM_EXIT_WRITE_CR8: {
                if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
                        vmexit = NESTED_EXIT_DONE;
                break;
        }
        case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
                if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
                        vmexit = NESTED_EXIT_DONE;
                break;
        }
        case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
                /*
                 * Host-intercepted exceptions have been checked already in
                 * nested_svm_exit_special.  There is nothing to do here,
                 * the vmexit is injected by svm_check_nested_events.
                 */
                vmexit = NESTED_EXIT_DONE;
                break;
        }
        case SVM_EXIT_ERR: {
                vmexit = NESTED_EXIT_DONE;
                break;
        }
        default: {
                if (vmcb12_is_intercept(&svm->nested.ctl, exit_code))
                        vmexit = NESTED_EXIT_DONE;
        }
        }

        return vmexit;
}

int nested_svm_exit_handled(struct vcpu_svm *svm)
{
        int vmexit;

        vmexit = nested_svm_intercept(svm);

        if (vmexit == NESTED_EXIT_DONE)
                nested_svm_vmexit(svm);

        return vmexit;
}

int nested_svm_check_permissions(struct kvm_vcpu *vcpu)
{
        if (!(vcpu->arch.efer & EFER_SVME) || !is_paging(vcpu)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        if (to_svm(vcpu)->vmcb->save.cpl) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        return 0;
}

static bool nested_svm_is_exception_vmexit(struct kvm_vcpu *vcpu, u8 vector,
                                           u32 error_code)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        return (svm->nested.ctl.intercepts[INTERCEPT_EXCEPTION] & BIT(vector));
}

static void nested_svm_inject_exception_vmexit(struct kvm_vcpu *vcpu)
{
        struct kvm_queued_exception *ex = &vcpu->arch.exception_vmexit;
        struct vcpu_svm *svm = to_svm(vcpu);
        struct vmcb *vmcb = svm->vmcb;

        vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + ex->vector;
        vmcb->control.exit_code_hi = 0;

        if (ex->has_error_code)
                vmcb->control.exit_info_1 = ex->error_code;

        /*
         * EXITINFO2 is undefined for all exception intercepts other
         * than #PF.
         */
        if (ex->vector == PF_VECTOR) {
                if (ex->has_payload)
                        vmcb->control.exit_info_2 = ex->payload;
                else
                        vmcb->control.exit_info_2 = vcpu->arch.cr2;
        } else if (ex->vector == DB_VECTOR) {
                /* See kvm_check_and_inject_events().  */
                kvm_deliver_exception_payload(vcpu, ex);

                if (vcpu->arch.dr7 & DR7_GD) {
                        vcpu->arch.dr7 &= ~DR7_GD;
                        kvm_update_dr7(vcpu);
                }
        } else {
                WARN_ON(ex->has_payload);
        }

        nested_svm_vmexit(svm);
}

static inline bool nested_exit_on_init(struct vcpu_svm *svm)
{
        return vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_INIT);
}

static int svm_check_nested_events(struct kvm_vcpu *vcpu)
{
        struct kvm_lapic *apic = vcpu->arch.apic;
        struct vcpu_svm *svm = to_svm(vcpu);
        /*
         * Only a pending nested run blocks a pending exception.  If there is a
         * previously injected event, the pending exception occurred while said
         * event was being delivered and thus needs to be handled.
         */
        bool block_nested_exceptions = svm->nested.nested_run_pending;
        /*
         * New events (not exceptions) are only recognized at instruction
         * boundaries.  If an event needs reinjection, then KVM is handling a
         * VM-Exit that occurred _during_ instruction execution; new events are
         * blocked until the instruction completes.
         */
        bool block_nested_events = block_nested_exceptions ||
                                   kvm_event_needs_reinjection(vcpu);

        if (lapic_in_kernel(vcpu) &&
            test_bit(KVM_APIC_INIT, &apic->pending_events)) {
                if (block_nested_events)
                        return -EBUSY;
                if (!nested_exit_on_init(svm))
                        return 0;
                nested_svm_simple_vmexit(svm, SVM_EXIT_INIT);
                return 0;
        }

        if (vcpu->arch.exception_vmexit.pending) {
                if (block_nested_exceptions)
                        return -EBUSY;
                nested_svm_inject_exception_vmexit(vcpu);
                return 0;
        }

        if (vcpu->arch.exception.pending) {
                if (block_nested_exceptions)
                        return -EBUSY;
                return 0;
        }

#ifdef CONFIG_KVM_SMM
        if (vcpu->arch.smi_pending && !svm_smi_blocked(vcpu)) {
                if (block_nested_events)
                        return -EBUSY;
                if (!nested_exit_on_smi(svm))
                        return 0;
                nested_svm_simple_vmexit(svm, SVM_EXIT_SMI);
                return 0;
        }
#endif

        if (vcpu->arch.nmi_pending && !svm_nmi_blocked(vcpu)) {
                if (block_nested_events)
                        return -EBUSY;
                if (!nested_exit_on_nmi(svm))
                        return 0;
                nested_svm_simple_vmexit(svm, SVM_EXIT_NMI);
                return 0;
        }

        if (kvm_cpu_has_interrupt(vcpu) && !svm_interrupt_blocked(vcpu)) {
                if (block_nested_events)
                        return -EBUSY;
                if (!nested_exit_on_intr(svm))
                        return 0;
                trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
                nested_svm_simple_vmexit(svm, SVM_EXIT_INTR);
                return 0;
        }

        return 0;
}

int nested_svm_exit_special(struct vcpu_svm *svm)
{
        u32 exit_code = svm->vmcb->control.exit_code;
        struct kvm_vcpu *vcpu = &svm->vcpu;

        switch (exit_code) {
        case SVM_EXIT_INTR:
        case SVM_EXIT_NMI:
        case SVM_EXIT_NPF:
                return NESTED_EXIT_HOST;
        case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
                u32 excp_bits = 1 << (exit_code - SVM_EXIT_EXCP_BASE);

                if (svm->vmcb01.ptr->control.intercepts[INTERCEPT_EXCEPTION] &
                    excp_bits)
                        return NESTED_EXIT_HOST;
                else if (exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR &&
                         svm->vcpu.arch.apf.host_apf_flags)
                        /* Trap async PF even if not shadowing */
                        return NESTED_EXIT_HOST;
                break;
        }
        case SVM_EXIT_VMMCALL:
                /* Hyper-V L2 TLB flush hypercall is handled by L0 */
                if (guest_hv_cpuid_has_l2_tlb_flush(vcpu) &&
                    nested_svm_l2_tlb_flush_enabled(vcpu) &&
                    kvm_hv_is_tlb_flush_hcall(vcpu))
                        return NESTED_EXIT_HOST;
                break;
        default:
                break;
        }

        return NESTED_EXIT_CONTINUE;
}

void nested_svm_update_tsc_ratio_msr(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        vcpu->arch.tsc_scaling_ratio =
                kvm_calc_nested_tsc_multiplier(vcpu->arch.l1_tsc_scaling_ratio,
                                               svm->tsc_ratio_msr);
        svm_write_tsc_multiplier(vcpu);
}

/* Inverse operation of nested_copy_vmcb_control_to_cache(). asid is copied too. */
static void nested_copy_vmcb_cache_to_control(struct vmcb_control_area *dst,
                                              struct vmcb_ctrl_area_cached *from)
{
        unsigned int i;

        memset(dst, 0, sizeof(struct vmcb_control_area));

        for (i = 0; i < MAX_INTERCEPT; i++)
                dst->intercepts[i] = from->intercepts[i];

        dst->iopm_base_pa         = from->iopm_base_pa;
        dst->msrpm_base_pa        = from->msrpm_base_pa;
        dst->tsc_offset           = from->tsc_offset;
        dst->asid                 = from->asid;
        dst->tlb_ctl              = from->tlb_ctl;
        dst->int_ctl              = from->int_ctl;
        dst->int_vector           = from->int_vector;
        dst->int_state            = from->int_state;
        dst->exit_code            = from->exit_code;
        dst->exit_code_hi         = from->exit_code_hi;
        dst->exit_info_1          = from->exit_info_1;
        dst->exit_info_2          = from->exit_info_2;
        dst->exit_int_info        = from->exit_int_info;
        dst->exit_int_info_err    = from->exit_int_info_err;
        dst->nested_ctl           = from->nested_ctl;
        dst->event_inj            = from->event_inj;
        dst->event_inj_err        = from->event_inj_err;
        dst->next_rip             = from->next_rip;
        dst->nested_cr3           = from->nested_cr3;
        dst->virt_ext              = from->virt_ext;
        dst->pause_filter_count   = from->pause_filter_count;
        dst->pause_filter_thresh  = from->pause_filter_thresh;
        /* 'clean' and 'hv_enlightenments' are not changed by KVM */
}

static int svm_get_nested_state(struct kvm_vcpu *vcpu,
                                struct kvm_nested_state __user *user_kvm_nested_state,
                                u32 user_data_size)
{
        struct vcpu_svm *svm;
        struct vmcb_control_area *ctl;
        unsigned long r;
        struct kvm_nested_state kvm_state = {
                .flags = 0,
                .format = KVM_STATE_NESTED_FORMAT_SVM,
                .size = sizeof(kvm_state),
        };
        struct vmcb __user *user_vmcb = (struct vmcb __user *)
                &user_kvm_nested_state->data.svm[0];

        if (!vcpu)
                return kvm_state.size + KVM_STATE_NESTED_SVM_VMCB_SIZE;

        svm = to_svm(vcpu);

        if (user_data_size < kvm_state.size)
                goto out;

        /* First fill in the header and copy it out.  */
        if (is_guest_mode(vcpu)) {
                kvm_state.hdr.svm.vmcb_pa = svm->nested.vmcb12_gpa;
                kvm_state.size += KVM_STATE_NESTED_SVM_VMCB_SIZE;
                kvm_state.flags |= KVM_STATE_NESTED_GUEST_MODE;

                if (svm->nested.nested_run_pending)
                        kvm_state.flags |= KVM_STATE_NESTED_RUN_PENDING;
        }

        if (gif_set(svm))
                kvm_state.flags |= KVM_STATE_NESTED_GIF_SET;

        if (copy_to_user(user_kvm_nested_state, &kvm_state, sizeof(kvm_state)))
                return -EFAULT;

        if (!is_guest_mode(vcpu))
                goto out;

        /*
         * Copy over the full size of the VMCB rather than just the size
         * of the structs.
         */
        if (clear_user(user_vmcb, KVM_STATE_NESTED_SVM_VMCB_SIZE))
                return -EFAULT;

        ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
        if (!ctl)
                return -ENOMEM;

        nested_copy_vmcb_cache_to_control(ctl, &svm->nested.ctl);
        r = copy_to_user(&user_vmcb->control, ctl,
                         sizeof(user_vmcb->control));
        kfree(ctl);
        if (r)
                return -EFAULT;

        if (copy_to_user(&user_vmcb->save, &svm->vmcb01.ptr->save,
                         sizeof(user_vmcb->save)))
                return -EFAULT;
out:
        return kvm_state.size;
}

static int svm_set_nested_state(struct kvm_vcpu *vcpu,
                                struct kvm_nested_state __user *user_kvm_nested_state,
                                struct kvm_nested_state *kvm_state)
{
        struct vcpu_svm *svm = to_svm(vcpu);
        struct vmcb __user *user_vmcb = (struct vmcb __user *)
                &user_kvm_nested_state->data.svm[0];
        struct vmcb_control_area *ctl;
        struct vmcb_save_area *save;
        struct vmcb_save_area_cached save_cached;
        struct vmcb_ctrl_area_cached ctl_cached;
        unsigned long cr0;
        int ret;

        BUILD_BUG_ON(sizeof(struct vmcb_control_area) + sizeof(struct vmcb_save_area) >
                     KVM_STATE_NESTED_SVM_VMCB_SIZE);

        if (kvm_state->format != KVM_STATE_NESTED_FORMAT_SVM)
                return -EINVAL;

        if (kvm_state->flags & ~(KVM_STATE_NESTED_GUEST_MODE |
                                 KVM_STATE_NESTED_RUN_PENDING |
                                 KVM_STATE_NESTED_GIF_SET))
                return -EINVAL;

        /*
         * If in guest mode, vcpu->arch.efer actually refers to the L2 guest's
         * EFER.SVME, but EFER.SVME still has to be 1 for VMRUN to succeed.
         */
        if (!(vcpu->arch.efer & EFER_SVME)) {
                /* GIF=1 and no guest mode are required if SVME=0.  */
                if (kvm_state->flags != KVM_STATE_NESTED_GIF_SET)
                        return -EINVAL;
        }

        /* SMM temporarily disables SVM, so we cannot be in guest mode.  */
        if (is_smm(vcpu) && (kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
                return -EINVAL;

        if (!(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE)) {
                svm_leave_nested(vcpu);
                svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));
                return 0;
        }

        if (!page_address_valid(vcpu, kvm_state->hdr.svm.vmcb_pa))
                return -EINVAL;
        if (kvm_state->size < sizeof(*kvm_state) + KVM_STATE_NESTED_SVM_VMCB_SIZE)
                return -EINVAL;

        ret  = -ENOMEM;
        ctl  = kzalloc(sizeof(*ctl),  GFP_KERNEL_ACCOUNT);
        save = kzalloc(sizeof(*save), GFP_KERNEL_ACCOUNT);
        if (!ctl || !save)
                goto out_free;

        ret = -EFAULT;
        if (copy_from_user(ctl, &user_vmcb->control, sizeof(*ctl)))
                goto out_free;
        if (copy_from_user(save, &user_vmcb->save, sizeof(*save)))
                goto out_free;

        ret = -EINVAL;
        __nested_copy_vmcb_control_to_cache(vcpu, &ctl_cached, ctl);
        if (!__nested_vmcb_check_controls(vcpu, &ctl_cached))
                goto out_free;

        /*
         * Processor state contains L2 state.  Check that it is
         * valid for guest mode (see nested_vmcb_check_save).
         */
        cr0 = kvm_read_cr0(vcpu);
        if (((cr0 & X86_CR0_CD) == 0) && (cr0 & X86_CR0_NW))
                goto out_free;

        /*
         * Validate host state saved from before VMRUN (see
         * nested_svm_check_permissions).
         */
        __nested_copy_vmcb_save_to_cache(&save_cached, save);
        if (!(save->cr0 & X86_CR0_PG) ||
            !(save->cr0 & X86_CR0_PE) ||
            (save->rflags & X86_EFLAGS_VM) ||
            !__nested_vmcb_check_save(vcpu, &save_cached))
                goto out_free;


        /*
         * All checks done, we can enter guest mode. Userspace provides
         * vmcb12.control, which will be combined with L1 and stored into
         * vmcb02, and the L1 save state which we store in vmcb01.
         * L2 registers if needed are moved from the current VMCB to VMCB02.
         */

        if (is_guest_mode(vcpu))
                svm_leave_nested(vcpu);
        else
                svm->nested.vmcb02.ptr->save = svm->vmcb01.ptr->save;

        svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));

        svm->nested.nested_run_pending =
                !!(kvm_state->flags & KVM_STATE_NESTED_RUN_PENDING);

        svm->nested.vmcb12_gpa = kvm_state->hdr.svm.vmcb_pa;

        svm_copy_vmrun_state(&svm->vmcb01.ptr->save, save);
        nested_copy_vmcb_control_to_cache(svm, ctl);

        svm_switch_vmcb(svm, &svm->nested.vmcb02);
        nested_vmcb02_prepare_control(svm, svm->vmcb->save.rip, svm->vmcb->save.cs.base);

        /*
         * While the nested guest CR3 is already checked and set by
         * KVM_SET_SREGS, it was set when nested state was yet loaded,
         * thus MMU might not be initialized correctly.
         * Set it again to fix this.
         */

        ret = nested_svm_load_cr3(&svm->vcpu, vcpu->arch.cr3,
                                  nested_npt_enabled(svm), false);
        if (WARN_ON_ONCE(ret))
                goto out_free;

        svm->nested.force_msr_bitmap_recalc = true;

        kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);
        ret = 0;
out_free:
        kfree(save);
        kfree(ctl);

        return ret;
}

static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
{
        struct vcpu_svm *svm = to_svm(vcpu);

        if (WARN_ON(!is_guest_mode(vcpu)))
                return true;

        if (!vcpu->arch.pdptrs_from_userspace &&
            !nested_npt_enabled(svm) && is_pae_paging(vcpu))
                /*
                 * Reload the guest's PDPTRs since after a migration
                 * the guest CR3 might be restored prior to setting the nested
                 * state which can lead to a load of wrong PDPTRs.
                 */
                if (CC(!load_pdptrs(vcpu, vcpu->arch.cr3)))
                        return false;

        if (!nested_svm_vmrun_msrpm(svm)) {
                vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                vcpu->run->internal.suberror =
                        KVM_INTERNAL_ERROR_EMULATION;
                vcpu->run->internal.ndata = 0;
                return false;
        }

        if (kvm_hv_verify_vp_assist(vcpu))
                return false;

        return true;
}

struct kvm_x86_nested_ops svm_nested_ops = {
        .leave_nested = svm_leave_nested,
        .is_exception_vmexit = nested_svm_is_exception_vmexit,
        .check_events = svm_check_nested_events,
        .triple_fault = nested_svm_triple_fault,
        .get_nested_state_pages = svm_get_nested_state_pages,
        .get_state = svm_get_nested_state,
        .set_state = svm_set_nested_state,
        .hv_inject_synthetic_vmexit_post_tlb_flush = svm_hv_inject_synthetic_vmexit_post_tlb_flush,
};