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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KVM_X86_MMU_H
#define __KVM_X86_MMU_H
#include <linux/kvm_host.h>
#include "kvm_cache_regs.h"
#include "cpuid.h"
extern bool __read_mostly enable_mmio_caching;
#define PT_USER_SHIFT 2
#define PT_PRESENT_MASK (1ULL << 0)
#define PT_PWT_MASK (1ULL << 3)
#define PT_PCD_MASK (1ULL << 4)
#define PT_DIRTY_SHIFT 6
#define PT_PAT_MASK (1ULL << 7)
#define PT_GLOBAL_MASK (1ULL << 8)
#define PT64_NX_SHIFT 63
#define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
#define PT_PAT_SHIFT 7
#define PT_DIR_PAT_SHIFT 12
#define PT64_ROOT_5LEVEL 5
#define PT64_ROOT_4LEVEL 4
#define PT32_ROOT_LEVEL 2
#define PT32E_ROOT_LEVEL 3
#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PSE | X86_CR4_PAE | X86_CR4_LA57 | \
X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE)
#define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP)
static __always_inline u64 rsvd_bits(int s, int e)
BUILD_BUG_ON(__builtin_constant_p(e) && __builtin_constant_p(s) && e < s);
if (__builtin_constant_p(e))
BUILD_BUG_ON(e > 63);
e &= 63;
if (e < s)
return 0;
return ((2ULL << (e - s)) - 1) << s;
* The number of non-reserved physical address bits irrespective of features
* that repurpose legal bits, e.g. MKTME.
extern u8 __read_mostly shadow_phys_bits;
static inline gfn_t kvm_mmu_max_gfn(void)
* Note that this uses the host MAXPHYADDR, not the guest's.
* EPT/NPT cannot support GPAs that would exceed host.MAXPHYADDR;
* assuming KVM is running on bare metal, guest accesses beyond
* host.MAXPHYADDR will hit a #PF(RSVD) and never cause a vmexit
* (either EPT Violation/Misconfig or #NPF), and so KVM will never
* install a SPTE for such addresses. If KVM is running as a VM
* itself, on the other hand, it might see a MAXPHYADDR that is less
* than hardware's real MAXPHYADDR. Using the host MAXPHYADDR
* disallows such SPTEs entirely and simplifies the TDP MMU.
int max_gpa_bits = likely(tdp_enabled) ? shadow_phys_bits : 52;
return (1ULL << (max_gpa_bits - PAGE_SHIFT)) - 1;
static inline u8 kvm_get_shadow_phys_bits(void)
* boot_cpu_data.x86_phys_bits is reduced when MKTME or SME are detected
* in CPU detection code, but the processor treats those reduced bits as
* 'keyID' thus they are not reserved bits. Therefore KVM needs to look at
* the physical address bits reported by CPUID.
if (likely(boot_cpu_data.extended_cpuid_level >= 0x80000008))
return cpuid_eax(0x80000008) & 0xff;
* Quite weird to have VMX or SVM but not MAXPHYADDR; probably a VM with
* custom CPUID. Proceed with whatever the kernel found since these features
* aren't virtualizable (SME/SEV also require CPUIDs higher than 0x80000008).
return boot_cpu_data.x86_phys_bits;
void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask);
void kvm_mmu_set_me_spte_mask(u64 me_value, u64 me_mask);
void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only);
void kvm_init_mmu(struct kvm_vcpu *vcpu);
void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0,
unsigned long cr4, u64 efer, gpa_t nested_cr3);
void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
int huge_page_level, bool accessed_dirty,
gpa_t new_eptp);
bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
u64 fault_address, char *insn, int insn_len);
void __kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu);
int kvm_mmu_load(struct kvm_vcpu *vcpu);
void kvm_mmu_unload(struct kvm_vcpu *vcpu);
void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu);
void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu);
void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu);
void kvm_mmu_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
int bytes);
static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu)
if (likely(vcpu->arch.mmu->root.hpa != INVALID_PAGE))
return 0;
return kvm_mmu_load(vcpu);
static inline unsigned long kvm_get_pcid(struct kvm_vcpu *vcpu, gpa_t cr3)
return kvm_is_cr4_bit_set(vcpu, X86_CR4_PCIDE)
? cr3 & X86_CR3_PCID_MASK
: 0;
static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu *vcpu)
return kvm_get_pcid(vcpu, kvm_read_cr3(vcpu));
static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu)
u64 root_hpa = vcpu->arch.mmu->root.hpa;
if (!VALID_PAGE(root_hpa))
static_call(kvm_x86_load_mmu_pgd)(vcpu, root_hpa,
static inline void kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu)
* When EPT is enabled, KVM may passthrough CR0.WP to the guest, i.e.
* @mmu's snapshot of CR0.WP and thus all related paging metadata may
* be stale. Refresh CR0.WP and the metadata on-demand when checking
* for permission faults. Exempt nested MMUs, i.e. MMUs for shadowing
* nEPT and nNPT, as CR0.WP is ignored in both cases. Note, KVM does
* need to refresh nested_mmu, a.k.a. the walker used to translate L2
* GVAs to GPAs, as that "MMU" needs to honor L2's CR0.WP.
if (!tdp_enabled || mmu == &vcpu->arch.guest_mmu)
__kvm_mmu_refresh_passthrough_bits(vcpu, mmu);
* Check if a given access (described through the I/D, W/R and U/S bits of a
* page fault error code pfec) causes a permission fault with the given PTE
* access rights (in ACC_* format).
* Return zero if the access does not fault; return the page fault error code
* if the access faults.
static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
unsigned pte_access, unsigned pte_pkey,
u64 access)
/* strip nested paging fault error codes */
unsigned int pfec = access;
unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu);
* For explicit supervisor accesses, SMAP is disabled if EFLAGS.AC = 1.
* For implicit supervisor accesses, SMAP cannot be overridden.
* SMAP works on supervisor accesses only, and not_smap can
* be set or not set when user access with neither has any bearing
* on the result.
* We put the SMAP checking bit in place of the PFERR_RSVD_MASK bit;
* this bit will always be zero in pfec, but it will be one in index
* if SMAP checks are being disabled.
u64 implicit_access = access & PFERR_IMPLICIT_ACCESS;
bool not_smap = ((rflags & X86_EFLAGS_AC) | implicit_access) == X86_EFLAGS_AC;
int index = (pfec + (not_smap << PFERR_RSVD_BIT)) >> 1;
u32 errcode = PFERR_PRESENT_MASK;
bool fault;
kvm_mmu_refresh_passthrough_bits(vcpu, mmu);
fault = (mmu->permissions[index] >> pte_access) & 1;
if (unlikely(mmu->pkru_mask)) {
u32 pkru_bits, offset;
* PKRU defines 32 bits, there are 16 domains and 2
* attribute bits per domain in pkru. pte_pkey is the
* index of the protection domain, so pte_pkey * 2 is
* is the index of the first bit for the domain.
pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3;
/* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */
offset = (pfec & ~1) +
((pte_access & PT_USER_MASK) << (PFERR_RSVD_BIT - PT_USER_SHIFT));
pkru_bits &= mmu->pkru_mask >> offset;
errcode |= -pkru_bits & PFERR_PK_MASK;
fault |= (pkru_bits != 0);
return -(u32)fault & errcode;
void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end);
int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu);
int kvm_mmu_post_init_vm(struct kvm *kvm);
void kvm_mmu_pre_destroy_vm(struct kvm *kvm);
static inline bool kvm_shadow_root_allocated(struct kvm *kvm)
* Read shadow_root_allocated before related pointers. Hence, threads
* reading shadow_root_allocated in any lock context are guaranteed to
* see the pointers. Pairs with smp_store_release in
* mmu_first_shadow_root_alloc.
return smp_load_acquire(&kvm->arch.shadow_root_allocated);
#ifdef CONFIG_X86_64
extern bool tdp_mmu_enabled;
#define tdp_mmu_enabled false
static inline bool kvm_memslots_have_rmaps(struct kvm *kvm)
return !tdp_mmu_enabled || kvm_shadow_root_allocated(kvm);
static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
/* KVM_HPAGE_GFN_SHIFT(PG_LEVEL_4K) must be 0. */
return (gfn >> KVM_HPAGE_GFN_SHIFT(level)) -
(base_gfn >> KVM_HPAGE_GFN_SHIFT(level));
static inline unsigned long
__kvm_mmu_slot_lpages(struct kvm_memory_slot *slot, unsigned long npages,
int level)
return gfn_to_index(slot->base_gfn + npages - 1,
slot->base_gfn, level) + 1;
static inline unsigned long
kvm_mmu_slot_lpages(struct kvm_memory_slot *slot, int level)
return __kvm_mmu_slot_lpages(slot, slot->npages, level);
static inline void kvm_update_page_stats(struct kvm *kvm, int level, int count)
atomic64_add(count, &kvm->stat.pages[level - 1]);
gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u64 access,
struct x86_exception *exception);
static inline gpa_t kvm_translate_gpa(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu,
gpa_t gpa, u64 access,
struct x86_exception *exception)
if (mmu != &vcpu->arch.nested_mmu)
return gpa;
return translate_nested_gpa(vcpu, gpa, access, exception);