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-rw-r--r--arch/x86/kvm/mmu.h305
1 files changed, 305 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
new file mode 100644
index 000000000..59804be91
--- /dev/null
+++ b/arch/x86/kvm/mmu.h
@@ -0,0 +1,305 @@
+/* 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_WRITABLE_SHIFT 1
+#define PT_USER_SHIFT 2
+
+#define PT_PRESENT_MASK (1ULL << 0)
+#define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
+#define PT_USER_MASK (1ULL << PT_USER_SHIFT)
+#define PT_PWT_MASK (1ULL << 3)
+#define PT_PCD_MASK (1ULL << 4)
+#define PT_ACCESSED_SHIFT 5
+#define PT_ACCESSED_MASK (1ULL << PT_ACCESSED_SHIFT)
+#define PT_DIRTY_SHIFT 6
+#define PT_DIRTY_MASK (1ULL << PT_DIRTY_SHIFT)
+#define PT_PAGE_SIZE_SHIFT 7
+#define PT_PAGE_SIZE_MASK (1ULL << PT_PAGE_SIZE_SHIFT)
+#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 PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
+
+#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)
+#define KVM_MMU_EFER_ROLE_BITS (EFER_LME | EFER_NX)
+
+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);
+ else
+ 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);
+
+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)
+{
+ BUILD_BUG_ON((X86_CR3_PCID_MASK & PAGE_MASK) != 0);
+
+ return kvm_read_cr4_bits(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))
+ return;
+
+ static_call(kvm_x86_load_mmu_pgd)(vcpu, root_hpa,
+ vcpu->arch.mmu->root_role.level);
+}
+
+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)
+ return;
+
+ __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;
+
+ WARN_ON(pfec & (PFERR_PK_MASK | PFERR_RSVD_MASK));
+ 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
+static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return kvm->arch.tdp_mmu_enabled; }
+#else
+static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return false; }
+#endif
+
+static inline bool kvm_memslots_have_rmaps(struct kvm *kvm)
+{
+ return !is_tdp_mmu_enabled(kvm) || 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);
+}
+#endif