diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 449 |
1 files changed, 254 insertions, 195 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 0d094da4954..931467881da 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -22,6 +22,7 @@ #include "mmu.h" #include "x86.h" #include "kvm_cache_regs.h" +#include "cpuid.h" #include <linux/kvm_host.h> #include <linux/types.h> @@ -132,8 +133,8 @@ module_param(dbg, bool, 0644); (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \ * PT32_LEVEL_BITS))) - 1)) -#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \ - | PT64_NX_MASK) +#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | shadow_user_mask \ + | shadow_x_mask | shadow_nx_mask) #define ACC_EXEC_MASK 1 #define ACC_WRITE_MASK PT_WRITABLE_MASK @@ -331,11 +332,6 @@ static int is_large_pte(u64 pte) return pte & PT_PAGE_SIZE_MASK; } -static int is_dirty_gpte(unsigned long pte) -{ - return pte & PT_DIRTY_MASK; -} - static int is_rmap_spte(u64 pte) { return is_shadow_present_pte(pte); @@ -600,7 +596,8 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) * we always atomicly update it, see the comments in * spte_has_volatile_bits(). */ - if (is_writable_pte(old_spte) && !is_writable_pte(new_spte)) + if (spte_is_locklessly_modifiable(old_spte) && + !is_writable_pte(new_spte)) ret = true; if (!shadow_accessed_mask) @@ -1181,8 +1178,7 @@ static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) /* * Write-protect on the specified @sptep, @pt_protect indicates whether - * spte writ-protection is caused by protecting shadow page table. - * @flush indicates whether tlb need be flushed. + * spte write-protection is caused by protecting shadow page table. * * Note: write protection is difference between drity logging and spte * protection: @@ -1191,10 +1187,9 @@ static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep) * - for spte protection, the spte can be writable only after unsync-ing * shadow page. * - * Return true if the spte is dropped. + * Return true if tlb need be flushed. */ -static bool -spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush, bool pt_protect) +static bool spte_write_protect(struct kvm *kvm, u64 *sptep, bool pt_protect) { u64 spte = *sptep; @@ -1204,17 +1199,11 @@ spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush, bool pt_protect) rmap_printk("rmap_write_protect: spte %p %llx\n", sptep, *sptep); - if (__drop_large_spte(kvm, sptep)) { - *flush |= true; - return true; - } - if (pt_protect) spte &= ~SPTE_MMU_WRITEABLE; spte = spte & ~PT_WRITABLE_MASK; - *flush |= mmu_spte_update(sptep, spte); - return false; + return mmu_spte_update(sptep, spte); } static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, @@ -1226,11 +1215,8 @@ static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp, for (sptep = rmap_get_first(*rmapp, &iter); sptep;) { BUG_ON(!(*sptep & PT_PRESENT_MASK)); - if (spte_write_protect(kvm, sptep, &flush, pt_protect)) { - sptep = rmap_get_first(*rmapp, &iter); - continue; - } + flush |= spte_write_protect(kvm, sptep, pt_protect); sptep = rmap_get_next(&iter); } @@ -2052,12 +2038,18 @@ static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) return __shadow_walk_next(iterator, *iterator->sptep); } -static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp) +static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp, bool accessed) { u64 spte; + BUILD_BUG_ON(VMX_EPT_READABLE_MASK != PT_PRESENT_MASK || + VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK); + spte = __pa(sp->spt) | PT_PRESENT_MASK | PT_WRITABLE_MASK | - shadow_user_mask | shadow_x_mask | shadow_accessed_mask; + shadow_user_mask | shadow_x_mask; + + if (accessed) + spte |= shadow_accessed_mask; mmu_spte_set(sptep, spte); } @@ -2569,19 +2561,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, kvm_release_pfn_clean(pfn); } -static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) -{ - mmu_free_roots(vcpu); -} - -static bool is_rsvd_bits_set(struct kvm_mmu *mmu, u64 gpte, int level) -{ - int bit7; - - bit7 = (gpte >> 7) & 1; - return (gpte & mmu->rsvd_bits_mask[bit7][level-1]) != 0; -} - static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, bool no_dirty_log) { @@ -2594,26 +2573,6 @@ static pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, return gfn_to_pfn_memslot_atomic(slot, gfn); } -static bool prefetch_invalid_gpte(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp, u64 *spte, - u64 gpte) -{ - if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL)) - goto no_present; - - if (!is_present_gpte(gpte)) - goto no_present; - - if (!(gpte & PT_ACCESSED_MASK)) - goto no_present; - - return false; - -no_present: - drop_spte(vcpu->kvm, spte); - return true; -} - static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, u64 *start, u64 *end) @@ -2691,6 +2650,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, int emulate = 0; gfn_t pseudo_gfn; + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return 0; + for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) { if (iterator.level == level) { mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, @@ -2701,6 +2663,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, break; } + drop_large_spte(vcpu, iterator.sptep); if (!is_shadow_present_pte(*iterator.sptep)) { u64 base_addr = iterator.addr; @@ -2710,7 +2673,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, iterator.level - 1, 1, ACC_ALL, iterator.sptep); - link_shadow_page(iterator.sptep, sp); + link_shadow_page(iterator.sptep, sp, true); } } return emulate; @@ -2808,9 +2771,16 @@ exit: return ret; } -static bool page_fault_can_be_fast(struct kvm_vcpu *vcpu, u32 error_code) +static bool page_fault_can_be_fast(u32 error_code) { /* + * Do not fix the mmio spte with invalid generation number which + * need to be updated by slow page fault path. + */ + if (unlikely(error_code & PFERR_RSVD_MASK)) + return false; + + /* * #PF can be fast only if the shadow page table is present and it * is caused by write-protect, that means we just need change the * W bit of the spte which can be done out of mmu-lock. @@ -2823,9 +2793,9 @@ static bool page_fault_can_be_fast(struct kvm_vcpu *vcpu, u32 error_code) } static bool -fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 spte) +fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, + u64 *sptep, u64 spte) { - struct kvm_mmu_page *sp = page_header(__pa(sptep)); gfn_t gfn; WARN_ON(!sp->role.direct); @@ -2851,10 +2821,14 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, u32 error_code) { struct kvm_shadow_walk_iterator iterator; + struct kvm_mmu_page *sp; bool ret = false; u64 spte = 0ull; - if (!page_fault_can_be_fast(vcpu, error_code)) + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return false; + + if (!page_fault_can_be_fast(error_code)) return false; walk_shadow_page_lockless_begin(vcpu); @@ -2871,7 +2845,8 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, goto exit; } - if (!is_last_spte(spte, level)) + sp = page_header(__pa(iterator.sptep)); + if (!is_last_spte(spte, sp->role.level)) goto exit; /* @@ -2893,11 +2868,24 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, goto exit; /* + * Do not fix write-permission on the large spte since we only dirty + * the first page into the dirty-bitmap in fast_pf_fix_direct_spte() + * that means other pages are missed if its slot is dirty-logged. + * + * Instead, we let the slow page fault path create a normal spte to + * fix the access. + * + * See the comments in kvm_arch_commit_memory_region(). + */ + if (sp->role.level > PT_PAGE_TABLE_LEVEL) + goto exit; + + /* * Currently, fast page fault only works for direct mapping since * the gfn is not stable for indirect shadow page. * See Documentation/virtual/kvm/locking.txt to get more detail. */ - ret = fast_pf_fix_direct_spte(vcpu, iterator.sptep, spte); + ret = fast_pf_fix_direct_spte(vcpu, sp, iterator.sptep, spte); exit: trace_fast_page_fault(vcpu, gva, error_code, iterator.sptep, spte, ret); @@ -3202,6 +3190,7 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) mmu_sync_roots(vcpu); spin_unlock(&vcpu->kvm->mmu_lock); } +EXPORT_SYMBOL_GPL(kvm_mmu_sync_roots); static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access, struct x86_exception *exception) @@ -3248,6 +3237,9 @@ static u64 walk_shadow_page_get_mmio_spte(struct kvm_vcpu *vcpu, u64 addr) struct kvm_shadow_walk_iterator iterator; u64 spte = 0ull; + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return spte; + walk_shadow_page_lockless_begin(vcpu); for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) if (!is_shadow_present_pte(spte)) @@ -3343,7 +3335,7 @@ static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn) arch.direct_map = vcpu->arch.mmu.direct_map; arch.cr3 = vcpu->arch.mmu.get_cr3(vcpu); - return kvm_setup_async_pf(vcpu, gva, gfn, &arch); + return kvm_setup_async_pf(vcpu, gva, gfn_to_hva(vcpu->kvm, gfn), &arch); } static bool can_do_async_pf(struct kvm_vcpu *vcpu) @@ -3443,18 +3435,11 @@ out_unlock: return 0; } -static void nonpaging_free(struct kvm_vcpu *vcpu) -{ - mmu_free_roots(vcpu); -} - -static int nonpaging_init_context(struct kvm_vcpu *vcpu, - struct kvm_mmu *context) +static void nonpaging_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - context->new_cr3 = nonpaging_new_cr3; context->page_fault = nonpaging_page_fault; context->gva_to_gpa = nonpaging_gva_to_gpa; - context->free = nonpaging_free; context->sync_page = nonpaging_sync_page; context->invlpg = nonpaging_invlpg; context->update_pte = nonpaging_update_pte; @@ -3463,7 +3448,6 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu, context->root_hpa = INVALID_PAGE; context->direct_map = true; context->nx = false; - return 0; } void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) @@ -3471,10 +3455,10 @@ void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) ++vcpu->stat.tlb_flush; kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); } +EXPORT_SYMBOL_GPL(kvm_mmu_flush_tlb); -static void paging_new_cr3(struct kvm_vcpu *vcpu) +void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu) { - pgprintk("%s: cr3 %lx\n", __func__, kvm_read_cr3(vcpu)); mmu_free_roots(vcpu); } @@ -3489,23 +3473,6 @@ static void inject_page_fault(struct kvm_vcpu *vcpu, vcpu->arch.mmu.inject_page_fault(vcpu, fault); } -static void paging_free(struct kvm_vcpu *vcpu) -{ - nonpaging_free(vcpu); -} - -static inline void protect_clean_gpte(unsigned *access, unsigned gpte) -{ - unsigned mask; - - BUILD_BUG_ON(PT_WRITABLE_MASK != ACC_WRITE_MASK); - - mask = (unsigned)~ACC_WRITE_MASK; - /* Allow write access to dirty gptes */ - mask |= (gpte >> (PT_DIRTY_SHIFT - PT_WRITABLE_SHIFT)) & PT_WRITABLE_MASK; - *access &= mask; -} - static bool sync_mmio_spte(struct kvm *kvm, u64 *sptep, gfn_t gfn, unsigned access, int *nr_present) { @@ -3523,16 +3490,6 @@ static bool sync_mmio_spte(struct kvm *kvm, u64 *sptep, gfn_t gfn, return false; } -static inline unsigned gpte_access(struct kvm_vcpu *vcpu, u64 gpte) -{ - unsigned access; - - access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK; - access &= ~(gpte >> PT64_NX_SHIFT); - - return access; -} - static inline bool is_last_gpte(struct kvm_mmu *mmu, unsigned level, unsigned gpte) { unsigned index; @@ -3542,6 +3499,11 @@ static inline bool is_last_gpte(struct kvm_mmu *mmu, unsigned level, unsigned gp return mmu->last_pte_bitmap & (1 << index); } +#define PTTYPE_EPT 18 /* arbitrary */ +#define PTTYPE PTTYPE_EPT +#include "paging_tmpl.h" +#undef PTTYPE + #define PTTYPE 64 #include "paging_tmpl.h" #undef PTTYPE @@ -3555,9 +3517,14 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, { int maxphyaddr = cpuid_maxphyaddr(vcpu); u64 exb_bit_rsvd = 0; + u64 gbpages_bit_rsvd = 0; + + context->bad_mt_xwr = 0; if (!context->nx) exb_bit_rsvd = rsvd_bits(63, 63); + if (!guest_cpuid_has_gbpages(vcpu)) + gbpages_bit_rsvd = rsvd_bits(7, 7); switch (context->root_level) { case PT32_ROOT_LEVEL: /* no rsvd bits for 2 level 4K page table entries */ @@ -3580,7 +3547,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, case PT32E_ROOT_LEVEL: context->rsvd_bits_mask[0][2] = rsvd_bits(maxphyaddr, 63) | - rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */ + rsvd_bits(5, 8) | rsvd_bits(1, 2); /* PDPTE */ context->rsvd_bits_mask[0][1] = exb_bit_rsvd | rsvd_bits(maxphyaddr, 62); /* PDE */ context->rsvd_bits_mask[0][0] = exb_bit_rsvd | @@ -3592,16 +3559,16 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, break; case PT64_ROOT_LEVEL: context->rsvd_bits_mask[0][3] = exb_bit_rsvd | - rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); + rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7); context->rsvd_bits_mask[0][2] = exb_bit_rsvd | - rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); + gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][1] = exb_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[0][0] = exb_bit_rsvd | rsvd_bits(maxphyaddr, 51); context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3]; context->rsvd_bits_mask[1][2] = exb_bit_rsvd | - rsvd_bits(maxphyaddr, 51) | + gbpages_bit_rsvd | rsvd_bits(maxphyaddr, 51) | rsvd_bits(13, 29); context->rsvd_bits_mask[1][1] = exb_bit_rsvd | rsvd_bits(maxphyaddr, 51) | @@ -3611,32 +3578,97 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, } } -static void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) +static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, + struct kvm_mmu *context, bool execonly) +{ + int maxphyaddr = cpuid_maxphyaddr(vcpu); + int pte; + + context->rsvd_bits_mask[0][3] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 7); + context->rsvd_bits_mask[0][2] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 6); + context->rsvd_bits_mask[0][1] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 6); + context->rsvd_bits_mask[0][0] = rsvd_bits(maxphyaddr, 51); + + /* large page */ + context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3]; + context->rsvd_bits_mask[1][2] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 29); + context->rsvd_bits_mask[1][1] = + rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 20); + context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[0][0]; + + for (pte = 0; pte < 64; pte++) { + int rwx_bits = pte & 7; + int mt = pte >> 3; + if (mt == 0x2 || mt == 0x3 || mt == 0x7 || + rwx_bits == 0x2 || rwx_bits == 0x6 || + (rwx_bits == 0x4 && !execonly)) + context->bad_mt_xwr |= (1ull << pte); + } +} + +void update_permission_bitmask(struct kvm_vcpu *vcpu, + struct kvm_mmu *mmu, bool ept) { unsigned bit, byte, pfec; u8 map; - bool fault, x, w, u, wf, uf, ff, smep; + bool fault, x, w, u, wf, uf, ff, smapf, cr4_smap, cr4_smep, smap = 0; - smep = kvm_read_cr4_bits(vcpu, X86_CR4_SMEP); + cr4_smep = kvm_read_cr4_bits(vcpu, X86_CR4_SMEP); + cr4_smap = kvm_read_cr4_bits(vcpu, X86_CR4_SMAP); for (byte = 0; byte < ARRAY_SIZE(mmu->permissions); ++byte) { pfec = byte << 1; map = 0; wf = pfec & PFERR_WRITE_MASK; uf = pfec & PFERR_USER_MASK; ff = pfec & PFERR_FETCH_MASK; + /* + * PFERR_RSVD_MASK bit is set in PFEC if the access is not + * subject to SMAP restrictions, and cleared otherwise. The + * bit is only meaningful if the SMAP bit is set in CR4. + */ + smapf = !(pfec & PFERR_RSVD_MASK); for (bit = 0; bit < 8; ++bit) { x = bit & ACC_EXEC_MASK; w = bit & ACC_WRITE_MASK; u = bit & ACC_USER_MASK; - /* Not really needed: !nx will cause pte.nx to fault */ - x |= !mmu->nx; - /* Allow supervisor writes if !cr0.wp */ - w |= !is_write_protection(vcpu) && !uf; - /* Disallow supervisor fetches of user code if cr4.smep */ - x &= !(smep && u && !uf); - - fault = (ff && !x) || (uf && !u) || (wf && !w); + if (!ept) { + /* Not really needed: !nx will cause pte.nx to fault */ + x |= !mmu->nx; + /* Allow supervisor writes if !cr0.wp */ + w |= !is_write_protection(vcpu) && !uf; + /* Disallow supervisor fetches of user code if cr4.smep */ + x &= !(cr4_smep && u && !uf); + + /* + * SMAP:kernel-mode data accesses from user-mode + * mappings should fault. A fault is considered + * as a SMAP violation if all of the following + * conditions are ture: + * - X86_CR4_SMAP is set in CR4 + * - An user page is accessed + * - Page fault in kernel mode + * - if CPL = 3 or X86_EFLAGS_AC is clear + * + * Here, we cover the first three conditions. + * The fourth is computed dynamically in + * permission_fault() and is in smapf. + * + * Also, SMAP does not affect instruction + * fetches, add the !ff check here to make it + * clearer. + */ + smap = cr4_smap && u && !uf && !ff; + } else + /* Not really needed: no U/S accesses on ept */ + u = 1; + + fault = (ff && !x) || (uf && !u) || (wf && !w) || + (smapf && smap); map |= fault << bit; } mmu->permissions[byte] = map; @@ -3661,74 +3693,66 @@ static void update_last_pte_bitmap(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) mmu->last_pte_bitmap = map; } -static int paging64_init_context_common(struct kvm_vcpu *vcpu, - struct kvm_mmu *context, - int level) +static void paging64_init_context_common(struct kvm_vcpu *vcpu, + struct kvm_mmu *context, + int level) { context->nx = is_nx(vcpu); context->root_level = level; reset_rsvds_bits_mask(vcpu, context); - update_permission_bitmask(vcpu, context); + update_permission_bitmask(vcpu, context, false); update_last_pte_bitmap(vcpu, context); ASSERT(is_pae(vcpu)); - context->new_cr3 = paging_new_cr3; context->page_fault = paging64_page_fault; context->gva_to_gpa = paging64_gva_to_gpa; context->sync_page = paging64_sync_page; context->invlpg = paging64_invlpg; context->update_pte = paging64_update_pte; - context->free = paging_free; context->shadow_root_level = level; context->root_hpa = INVALID_PAGE; context->direct_map = false; - return 0; } -static int paging64_init_context(struct kvm_vcpu *vcpu, - struct kvm_mmu *context) +static void paging64_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - return paging64_init_context_common(vcpu, context, PT64_ROOT_LEVEL); + paging64_init_context_common(vcpu, context, PT64_ROOT_LEVEL); } -static int paging32_init_context(struct kvm_vcpu *vcpu, - struct kvm_mmu *context) +static void paging32_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { context->nx = false; context->root_level = PT32_ROOT_LEVEL; reset_rsvds_bits_mask(vcpu, context); - update_permission_bitmask(vcpu, context); + update_permission_bitmask(vcpu, context, false); update_last_pte_bitmap(vcpu, context); - context->new_cr3 = paging_new_cr3; context->page_fault = paging32_page_fault; context->gva_to_gpa = paging32_gva_to_gpa; - context->free = paging_free; context->sync_page = paging32_sync_page; context->invlpg = paging32_invlpg; context->update_pte = paging32_update_pte; context->shadow_root_level = PT32E_ROOT_LEVEL; context->root_hpa = INVALID_PAGE; context->direct_map = false; - return 0; } -static int paging32E_init_context(struct kvm_vcpu *vcpu, - struct kvm_mmu *context) +static void paging32E_init_context(struct kvm_vcpu *vcpu, + struct kvm_mmu *context) { - return paging64_init_context_common(vcpu, context, PT32E_ROOT_LEVEL); + paging64_init_context_common(vcpu, context, PT32E_ROOT_LEVEL); } -static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) +static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) { struct kvm_mmu *context = vcpu->arch.walk_mmu; context->base_role.word = 0; - context->new_cr3 = nonpaging_new_cr3; context->page_fault = tdp_page_fault; - context->free = nonpaging_free; context->sync_page = nonpaging_sync_page; context->invlpg = nonpaging_invlpg; context->update_pte = nonpaging_update_pte; @@ -3761,51 +3785,66 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->gva_to_gpa = paging32_gva_to_gpa; } - update_permission_bitmask(vcpu, context); + update_permission_bitmask(vcpu, context, false); update_last_pte_bitmap(vcpu, context); - - return 0; } -int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context) +void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context) { - int r; bool smep = kvm_read_cr4_bits(vcpu, X86_CR4_SMEP); ASSERT(vcpu); ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); if (!is_paging(vcpu)) - r = nonpaging_init_context(vcpu, context); + nonpaging_init_context(vcpu, context); else if (is_long_mode(vcpu)) - r = paging64_init_context(vcpu, context); + paging64_init_context(vcpu, context); else if (is_pae(vcpu)) - r = paging32E_init_context(vcpu, context); + paging32E_init_context(vcpu, context); else - r = paging32_init_context(vcpu, context); + paging32_init_context(vcpu, context); vcpu->arch.mmu.base_role.nxe = is_nx(vcpu); vcpu->arch.mmu.base_role.cr4_pae = !!is_pae(vcpu); vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu); vcpu->arch.mmu.base_role.smep_andnot_wp = smep && !is_write_protection(vcpu); - - return r; } EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu); -static int init_kvm_softmmu(struct kvm_vcpu *vcpu) +void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context, + bool execonly) { - int r = kvm_init_shadow_mmu(vcpu, vcpu->arch.walk_mmu); + ASSERT(vcpu); + ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); + + context->shadow_root_level = kvm_x86_ops->get_tdp_level(); + + context->nx = true; + context->page_fault = ept_page_fault; + context->gva_to_gpa = ept_gva_to_gpa; + context->sync_page = ept_sync_page; + context->invlpg = ept_invlpg; + context->update_pte = ept_update_pte; + context->root_level = context->shadow_root_level; + context->root_hpa = INVALID_PAGE; + context->direct_map = false; + update_permission_bitmask(vcpu, context, true); + reset_rsvds_bits_mask_ept(vcpu, context, execonly); +} +EXPORT_SYMBOL_GPL(kvm_init_shadow_ept_mmu); + +static void init_kvm_softmmu(struct kvm_vcpu *vcpu) +{ + kvm_init_shadow_mmu(vcpu, vcpu->arch.walk_mmu); vcpu->arch.walk_mmu->set_cr3 = kvm_x86_ops->set_cr3; vcpu->arch.walk_mmu->get_cr3 = get_cr3; vcpu->arch.walk_mmu->get_pdptr = kvm_pdptr_read; vcpu->arch.walk_mmu->inject_page_fault = kvm_inject_page_fault; - - return r; } -static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu) +static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu) { struct kvm_mmu *g_context = &vcpu->arch.nested_mmu; @@ -3840,13 +3879,11 @@ static int init_kvm_nested_mmu(struct kvm_vcpu *vcpu) g_context->gva_to_gpa = paging32_gva_to_gpa_nested; } - update_permission_bitmask(vcpu, g_context); + update_permission_bitmask(vcpu, g_context, false); update_last_pte_bitmap(vcpu, g_context); - - return 0; } -static int init_kvm_mmu(struct kvm_vcpu *vcpu) +static void init_kvm_mmu(struct kvm_vcpu *vcpu) { if (mmu_is_nested(vcpu)) return init_kvm_nested_mmu(vcpu); @@ -3856,18 +3893,12 @@ static int init_kvm_mmu(struct kvm_vcpu *vcpu) return init_kvm_softmmu(vcpu); } -static void destroy_kvm_mmu(struct kvm_vcpu *vcpu) +void kvm_mmu_reset_context(struct kvm_vcpu *vcpu) { ASSERT(vcpu); - if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) - /* mmu.free() should set root_hpa = INVALID_PAGE */ - vcpu->arch.mmu.free(vcpu); -} -int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) -{ - destroy_kvm_mmu(vcpu); - return init_kvm_mmu(vcpu); + kvm_mmu_unload(vcpu); + init_kvm_mmu(vcpu); } EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); @@ -3892,6 +3923,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_load); void kvm_mmu_unload(struct kvm_vcpu *vcpu) { mmu_free_roots(vcpu); + WARN_ON(VALID_PAGE(vcpu->arch.mmu.root_hpa)); } EXPORT_SYMBOL_GPL(kvm_mmu_unload); @@ -3916,8 +3948,8 @@ static bool need_remote_flush(u64 old, u64 new) return true; if ((old ^ new) & PT64_BASE_ADDR_MASK) return true; - old ^= PT64_NX_MASK; - new ^= PT64_NX_MASK; + old ^= shadow_nx_mask; + new ^= shadow_nx_mask; return (old & ~new & PT64_PERM_MASK) != 0; } @@ -4175,7 +4207,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code, switch (er) { case EMULATE_DONE: return 1; - case EMULATE_DO_MMIO: + case EMULATE_USER_EXIT: ++vcpu->stat.mmio_exits; /* fall through */ case EMULATE_FAIL: @@ -4250,12 +4282,12 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu) return alloc_mmu_pages(vcpu); } -int kvm_mmu_setup(struct kvm_vcpu *vcpu) +void kvm_mmu_setup(struct kvm_vcpu *vcpu) { ASSERT(vcpu); ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); - return init_kvm_mmu(vcpu); + init_kvm_mmu(vcpu); } void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) @@ -4281,15 +4313,32 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) if (*rmapp) __rmap_write_protect(kvm, rmapp, false); - if (need_resched() || spin_needbreak(&kvm->mmu_lock)) { - kvm_flush_remote_tlbs(kvm); + if (need_resched() || spin_needbreak(&kvm->mmu_lock)) cond_resched_lock(&kvm->mmu_lock); - } } } - kvm_flush_remote_tlbs(kvm); spin_unlock(&kvm->mmu_lock); + + /* + * kvm_mmu_slot_remove_write_access() and kvm_vm_ioctl_get_dirty_log() + * which do tlb flush out of mmu-lock should be serialized by + * kvm->slots_lock otherwise tlb flush would be missed. + */ + lockdep_assert_held(&kvm->slots_lock); + + /* + * We can flush all the TLBs out of the mmu lock without TLB + * corruption since we just change the spte from writable to + * readonly so that we only need to care the case of changing + * spte from present to present (changing the spte from present + * to nonpresent will flush all the TLBs immediately), in other + * words, the only case we care is mmu_spte_update() where we + * haved checked SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE + * instead of PT_WRITABLE_MASK, that means it does not depend + * on PT_WRITABLE_MASK anymore. + */ + kvm_flush_remote_tlbs(kvm); } #define BATCH_ZAP_PAGES 10 @@ -4383,25 +4432,21 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm) /* * The very rare case: if the generation-number is round, * zap all shadow pages. - * - * The max value is MMIO_MAX_GEN - 1 since it is not called - * when mark memslot invalid. */ - if (unlikely(kvm_current_mmio_generation(kvm) >= (MMIO_MAX_GEN - 1))) { + if (unlikely(kvm_current_mmio_generation(kvm) >= MMIO_MAX_GEN)) { printk_ratelimited(KERN_INFO "kvm: zapping shadow pages for mmio generation wraparound\n"); kvm_mmu_invalidate_zap_all_pages(kvm); } } -static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc) +static unsigned long +mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { struct kvm *kvm; int nr_to_scan = sc->nr_to_scan; + unsigned long freed = 0; - if (nr_to_scan == 0) - goto out; - - raw_spin_lock(&kvm_lock); + spin_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { int idx; @@ -4434,25 +4479,36 @@ static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc) goto unlock; } - prepare_zap_oldest_mmu_page(kvm, &invalid_list); + if (prepare_zap_oldest_mmu_page(kvm, &invalid_list)) + freed++; kvm_mmu_commit_zap_page(kvm, &invalid_list); unlock: spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); + /* + * unfair on small ones + * per-vm shrinkers cry out + * sadness comes quickly + */ list_move_tail(&kvm->vm_list, &vm_list); break; } - raw_spin_unlock(&kvm_lock); + spin_unlock(&kvm_lock); + return freed; +} -out: +static unsigned long +mmu_shrink_count(struct shrinker *shrink, struct shrink_control *sc) +{ return percpu_counter_read_positive(&kvm_total_used_mmu_pages); } static struct shrinker mmu_shrinker = { - .shrink = mmu_shrink, + .count_objects = mmu_shrink_count, + .scan_objects = mmu_shrink_scan, .seeks = DEFAULT_SEEKS * 10, }; @@ -4518,6 +4574,9 @@ int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]) u64 spte; int nr_sptes = 0; + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return nr_sptes; + walk_shadow_page_lockless_begin(vcpu); for_each_shadow_entry_lockless(vcpu, addr, iterator, spte) { sptes[iterator.level-1] = spte; @@ -4535,7 +4594,7 @@ void kvm_mmu_destroy(struct kvm_vcpu *vcpu) { ASSERT(vcpu); - destroy_kvm_mmu(vcpu); + kvm_mmu_unload(vcpu); free_mmu_pages(vcpu); mmu_free_memory_caches(vcpu); } |
