| /* |
| * Copyright (C) 2012,2013 - ARM Ltd |
| * Author: Marc Zyngier <marc.zyngier@arm.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #ifndef __ARM64_KVM_MMU_H__ |
| #define __ARM64_KVM_MMU_H__ |
| |
| #include <asm/page.h> |
| #include <asm/memory.h> |
| #include <asm/cpufeature.h> |
| |
| /* |
| * As ARMv8.0 only has the TTBR0_EL2 register, we cannot express |
| * "negative" addresses. This makes it impossible to directly share |
| * mappings with the kernel. |
| * |
| * Instead, give the HYP mode its own VA region at a fixed offset from |
| * the kernel by just masking the top bits (which are all ones for a |
| * kernel address). We need to find out how many bits to mask. |
| * |
| * We want to build a set of page tables that cover both parts of the |
| * idmap (the trampoline page used to initialize EL2), and our normal |
| * runtime VA space, at the same time. |
| * |
| * Given that the kernel uses VA_BITS for its entire address space, |
| * and that half of that space (VA_BITS - 1) is used for the linear |
| * mapping, we can also limit the EL2 space to (VA_BITS - 1). |
| * |
| * The main question is "Within the VA_BITS space, does EL2 use the |
| * top or the bottom half of that space to shadow the kernel's linear |
| * mapping?". As we need to idmap the trampoline page, this is |
| * determined by the range in which this page lives. |
| * |
| * If the page is in the bottom half, we have to use the top half. If |
| * the page is in the top half, we have to use the bottom half: |
| * |
| * T = __pa_symbol(__hyp_idmap_text_start) |
| * if (T & BIT(VA_BITS - 1)) |
| * HYP_VA_MIN = 0 //idmap in upper half |
| * else |
| * HYP_VA_MIN = 1 << (VA_BITS - 1) |
| * HYP_VA_MAX = HYP_VA_MIN + (1 << (VA_BITS - 1)) - 1 |
| * |
| * This of course assumes that the trampoline page exists within the |
| * VA_BITS range. If it doesn't, then it means we're in the odd case |
| * where the kernel idmap (as well as HYP) uses more levels than the |
| * kernel runtime page tables (as seen when the kernel is configured |
| * for 4k pages, 39bits VA, and yet memory lives just above that |
| * limit, forcing the idmap to use 4 levels of page tables while the |
| * kernel itself only uses 3). In this particular case, it doesn't |
| * matter which side of VA_BITS we use, as we're guaranteed not to |
| * conflict with anything. |
| * |
| * When using VHE, there are no separate hyp mappings and all KVM |
| * functionality is already mapped as part of the main kernel |
| * mappings, and none of this applies in that case. |
| */ |
| |
| #define HYP_PAGE_OFFSET_HIGH_MASK ((UL(1) << VA_BITS) - 1) |
| #define HYP_PAGE_OFFSET_LOW_MASK ((UL(1) << (VA_BITS - 1)) - 1) |
| |
| #ifdef __ASSEMBLY__ |
| |
| #include <asm/alternative.h> |
| #include <asm/cpufeature.h> |
| |
| /* |
| * Convert a kernel VA into a HYP VA. |
| * reg: VA to be converted. |
| * |
| * This generates the following sequences: |
| * - High mask: |
| * and x0, x0, #HYP_PAGE_OFFSET_HIGH_MASK |
| * nop |
| * - Low mask: |
| * and x0, x0, #HYP_PAGE_OFFSET_HIGH_MASK |
| * and x0, x0, #HYP_PAGE_OFFSET_LOW_MASK |
| * - VHE: |
| * nop |
| * nop |
| * |
| * The "low mask" version works because the mask is a strict subset of |
| * the "high mask", hence performing the first mask for nothing. |
| * Should be completely invisible on any viable CPU. |
| */ |
| .macro kern_hyp_va reg |
| alternative_if_not ARM64_HAS_VIRT_HOST_EXTN |
| and \reg, \reg, #HYP_PAGE_OFFSET_HIGH_MASK |
| alternative_else_nop_endif |
| alternative_if ARM64_HYP_OFFSET_LOW |
| and \reg, \reg, #HYP_PAGE_OFFSET_LOW_MASK |
| alternative_else_nop_endif |
| .endm |
| |
| #else |
| |
| #include <asm/pgalloc.h> |
| #include <asm/cachetype.h> |
| #include <asm/cacheflush.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgtable.h> |
| |
| static inline unsigned long __kern_hyp_va(unsigned long v) |
| { |
| asm volatile(ALTERNATIVE("and %0, %0, %1", |
| "nop", |
| ARM64_HAS_VIRT_HOST_EXTN) |
| : "+r" (v) |
| : "i" (HYP_PAGE_OFFSET_HIGH_MASK)); |
| asm volatile(ALTERNATIVE("nop", |
| "and %0, %0, %1", |
| ARM64_HYP_OFFSET_LOW) |
| : "+r" (v) |
| : "i" (HYP_PAGE_OFFSET_LOW_MASK)); |
| return v; |
| } |
| |
| #define kern_hyp_va(v) ((typeof(v))(__kern_hyp_va((unsigned long)(v)))) |
| |
| /* |
| * We currently only support a 40bit IPA. |
| */ |
| #define KVM_PHYS_SHIFT (40) |
| #define KVM_PHYS_SIZE (1UL << KVM_PHYS_SHIFT) |
| #define KVM_PHYS_MASK (KVM_PHYS_SIZE - 1UL) |
| |
| #include <asm/stage2_pgtable.h> |
| |
| int create_hyp_mappings(void *from, void *to, pgprot_t prot); |
| int create_hyp_io_mappings(void *from, void *to, phys_addr_t); |
| void free_hyp_pgds(void); |
| |
| void stage2_unmap_vm(struct kvm *kvm); |
| int kvm_alloc_stage2_pgd(struct kvm *kvm); |
| void kvm_free_stage2_pgd(struct kvm *kvm); |
| int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, |
| phys_addr_t pa, unsigned long size, bool writable); |
| |
| int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run); |
| |
| void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); |
| |
| phys_addr_t kvm_mmu_get_httbr(void); |
| phys_addr_t kvm_get_idmap_vector(void); |
| phys_addr_t kvm_get_idmap_start(void); |
| int kvm_mmu_init(void); |
| void kvm_clear_hyp_idmap(void); |
| |
| #define kvm_set_pte(ptep, pte) set_pte(ptep, pte) |
| #define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) |
| |
| static inline pte_t kvm_s2pte_mkwrite(pte_t pte) |
| { |
| pte_val(pte) |= PTE_S2_RDWR; |
| return pte; |
| } |
| |
| static inline pmd_t kvm_s2pmd_mkwrite(pmd_t pmd) |
| { |
| pmd_val(pmd) |= PMD_S2_RDWR; |
| return pmd; |
| } |
| |
| static inline void kvm_set_s2pte_readonly(pte_t *pte) |
| { |
| pteval_t pteval; |
| unsigned long tmp; |
| |
| asm volatile("// kvm_set_s2pte_readonly\n" |
| " prfm pstl1strm, %2\n" |
| "1: ldxr %0, %2\n" |
| " and %0, %0, %3 // clear PTE_S2_RDWR\n" |
| " orr %0, %0, %4 // set PTE_S2_RDONLY\n" |
| " stxr %w1, %0, %2\n" |
| " cbnz %w1, 1b\n" |
| : "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*pte)) |
| : "L" (~PTE_S2_RDWR), "L" (PTE_S2_RDONLY)); |
| } |
| |
| static inline bool kvm_s2pte_readonly(pte_t *pte) |
| { |
| return (pte_val(*pte) & PTE_S2_RDWR) == PTE_S2_RDONLY; |
| } |
| |
| static inline void kvm_set_s2pmd_readonly(pmd_t *pmd) |
| { |
| kvm_set_s2pte_readonly((pte_t *)pmd); |
| } |
| |
| static inline bool kvm_s2pmd_readonly(pmd_t *pmd) |
| { |
| return kvm_s2pte_readonly((pte_t *)pmd); |
| } |
| |
| static inline bool kvm_page_empty(void *ptr) |
| { |
| struct page *ptr_page = virt_to_page(ptr); |
| return page_count(ptr_page) == 1; |
| } |
| |
| #define hyp_pte_table_empty(ptep) kvm_page_empty(ptep) |
| |
| #ifdef __PAGETABLE_PMD_FOLDED |
| #define hyp_pmd_table_empty(pmdp) (0) |
| #else |
| #define hyp_pmd_table_empty(pmdp) kvm_page_empty(pmdp) |
| #endif |
| |
| #ifdef __PAGETABLE_PUD_FOLDED |
| #define hyp_pud_table_empty(pudp) (0) |
| #else |
| #define hyp_pud_table_empty(pudp) kvm_page_empty(pudp) |
| #endif |
| |
| struct kvm; |
| |
| #define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l)) |
| |
| static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu) |
| { |
| return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101; |
| } |
| |
| static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, |
| kvm_pfn_t pfn, |
| unsigned long size, |
| bool ipa_uncached) |
| { |
| void *va = page_address(pfn_to_page(pfn)); |
| |
| kvm_flush_dcache_to_poc(va, size); |
| |
| if (!icache_is_aliasing()) { /* PIPT */ |
| flush_icache_range((unsigned long)va, |
| (unsigned long)va + size); |
| } else if (!icache_is_aivivt()) { /* non ASID-tagged VIVT */ |
| /* any kind of VIPT cache */ |
| __flush_icache_all(); |
| } |
| } |
| |
| static inline void __kvm_flush_dcache_pte(pte_t pte) |
| { |
| struct page *page = pte_page(pte); |
| kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE); |
| } |
| |
| static inline void __kvm_flush_dcache_pmd(pmd_t pmd) |
| { |
| struct page *page = pmd_page(pmd); |
| kvm_flush_dcache_to_poc(page_address(page), PMD_SIZE); |
| } |
| |
| static inline void __kvm_flush_dcache_pud(pud_t pud) |
| { |
| struct page *page = pud_page(pud); |
| kvm_flush_dcache_to_poc(page_address(page), PUD_SIZE); |
| } |
| |
| #define kvm_virt_to_phys(x) __pa_symbol(x) |
| |
| void kvm_set_way_flush(struct kvm_vcpu *vcpu); |
| void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled); |
| |
| static inline bool __kvm_cpu_uses_extended_idmap(void) |
| { |
| return __cpu_uses_extended_idmap(); |
| } |
| |
| static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd, |
| pgd_t *hyp_pgd, |
| pgd_t *merged_hyp_pgd, |
| unsigned long hyp_idmap_start) |
| { |
| int idmap_idx; |
| |
| /* |
| * Use the first entry to access the HYP mappings. It is |
| * guaranteed to be free, otherwise we wouldn't use an |
| * extended idmap. |
| */ |
| VM_BUG_ON(pgd_val(merged_hyp_pgd[0])); |
| merged_hyp_pgd[0] = __pgd(__pa(hyp_pgd) | PMD_TYPE_TABLE); |
| |
| /* |
| * Create another extended level entry that points to the boot HYP map, |
| * which contains an ID mapping of the HYP init code. We essentially |
| * merge the boot and runtime HYP maps by doing so, but they don't |
| * overlap anyway, so this is fine. |
| */ |
| idmap_idx = hyp_idmap_start >> VA_BITS; |
| VM_BUG_ON(pgd_val(merged_hyp_pgd[idmap_idx])); |
| merged_hyp_pgd[idmap_idx] = __pgd(__pa(boot_hyp_pgd) | PMD_TYPE_TABLE); |
| } |
| |
| static inline unsigned int kvm_get_vmid_bits(void) |
| { |
| int reg = read_system_reg(SYS_ID_AA64MMFR1_EL1); |
| |
| return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8; |
| } |
| |
| /* |
| * We are not in the kvm->srcu critical section most of the time, so we take |
| * the SRCU read lock here. Since we copy the data from the user page, we |
| * can immediately drop the lock again. |
| */ |
| static inline int kvm_read_guest_lock(struct kvm *kvm, |
| gpa_t gpa, void *data, unsigned long len) |
| { |
| int srcu_idx = srcu_read_lock(&kvm->srcu); |
| int ret = kvm_read_guest(kvm, gpa, data, len); |
| |
| srcu_read_unlock(&kvm->srcu, srcu_idx); |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR |
| #include <asm/mmu.h> |
| |
| static inline void *kvm_get_hyp_vector(void) |
| { |
| struct bp_hardening_data *data = arm64_get_bp_hardening_data(); |
| void *vect = kvm_ksym_ref(__kvm_hyp_vector); |
| |
| if (data->fn) { |
| vect = __bp_harden_hyp_vecs_start + |
| data->hyp_vectors_slot * SZ_2K; |
| |
| if (!cpus_have_const_cap(ARM64_HAS_VIRT_HOST_EXTN)) |
| vect = lm_alias(vect); |
| } |
| |
| return vect; |
| } |
| |
| static inline int kvm_map_vectors(void) |
| { |
| return create_hyp_mappings(kvm_ksym_ref(__bp_harden_hyp_vecs_start), |
| kvm_ksym_ref(__bp_harden_hyp_vecs_end), |
| PAGE_HYP_EXEC); |
| } |
| |
| #else |
| static inline void *kvm_get_hyp_vector(void) |
| { |
| return kvm_ksym_ref(__kvm_hyp_vector); |
| } |
| |
| static inline int kvm_map_vectors(void) |
| { |
| return 0; |
| } |
| #endif |
| |
| #endif /* __ASSEMBLY__ */ |
| #endif /* __ARM64_KVM_MMU_H__ */ |