diff options
Diffstat (limited to 'arch/arm64/include/asm/kvm_pgtable.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_pgtable.h | 175 |
1 files changed, 147 insertions, 28 deletions
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 3252eb50ecfe..63f81b27a4e3 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -42,6 +42,8 @@ typedef u64 kvm_pte_t; #define KVM_PTE_ADDR_MASK GENMASK(47, PAGE_SHIFT) #define KVM_PTE_ADDR_51_48 GENMASK(15, 12) +#define KVM_PHYS_INVALID (-1ULL) + static inline bool kvm_pte_valid(kvm_pte_t pte) { return pte & KVM_PTE_VALID; @@ -57,6 +59,18 @@ static inline u64 kvm_pte_to_phys(kvm_pte_t pte) return pa; } +static inline kvm_pte_t kvm_phys_to_pte(u64 pa) +{ + kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK; + + if (PAGE_SHIFT == 16) { + pa &= GENMASK(51, 48); + pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48); + } + + return pte; +} + static inline u64 kvm_granule_shift(u32 level) { /* Assumes KVM_PGTABLE_MAX_LEVELS is 4 */ @@ -85,6 +99,8 @@ static inline bool kvm_level_supports_block_mapping(u32 level) * allocation is physically contiguous. * @free_pages_exact: Free an exact number of memory pages previously * allocated by zalloc_pages_exact. + * @free_removed_table: Free a removed paging structure by unlinking and + * dropping references. * @get_page: Increment the refcount on a page. * @put_page: Decrement the refcount on a page. When the * refcount reaches 0 the page is automatically @@ -103,6 +119,7 @@ struct kvm_pgtable_mm_ops { void* (*zalloc_page)(void *arg); void* (*zalloc_pages_exact)(size_t size); void (*free_pages_exact)(void *addr, size_t size); + void (*free_removed_table)(void *addr, u32 level); void (*get_page)(void *addr); void (*put_page)(void *addr); int (*page_count)(void *addr); @@ -162,29 +179,6 @@ typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u64 end, enum kvm_pgtable_prot prot); /** - * struct kvm_pgtable - KVM page-table. - * @ia_bits: Maximum input address size, in bits. - * @start_level: Level at which the page-table walk starts. - * @pgd: Pointer to the first top-level entry of the page-table. - * @mm_ops: Memory management callbacks. - * @mmu: Stage-2 KVM MMU struct. Unused for stage-1 page-tables. - * @flags: Stage-2 page-table flags. - * @force_pte_cb: Function that returns true if page level mappings must - * be used instead of block mappings. - */ -struct kvm_pgtable { - u32 ia_bits; - u32 start_level; - kvm_pte_t *pgd; - struct kvm_pgtable_mm_ops *mm_ops; - - /* Stage-2 only */ - struct kvm_s2_mmu *mmu; - enum kvm_pgtable_stage2_flags flags; - kvm_pgtable_force_pte_cb_t force_pte_cb; -}; - -/** * enum kvm_pgtable_walk_flags - Flags to control a depth-first page-table walk. * @KVM_PGTABLE_WALK_LEAF: Visit leaf entries, including invalid * entries. @@ -192,17 +186,34 @@ struct kvm_pgtable { * children. * @KVM_PGTABLE_WALK_TABLE_POST: Visit table entries after their * children. + * @KVM_PGTABLE_WALK_SHARED: Indicates the page-tables may be shared + * with other software walkers. */ enum kvm_pgtable_walk_flags { KVM_PGTABLE_WALK_LEAF = BIT(0), KVM_PGTABLE_WALK_TABLE_PRE = BIT(1), KVM_PGTABLE_WALK_TABLE_POST = BIT(2), + KVM_PGTABLE_WALK_SHARED = BIT(3), +}; + +struct kvm_pgtable_visit_ctx { + kvm_pte_t *ptep; + kvm_pte_t old; + void *arg; + struct kvm_pgtable_mm_ops *mm_ops; + u64 addr; + u64 end; + u32 level; + enum kvm_pgtable_walk_flags flags; }; -typedef int (*kvm_pgtable_visitor_fn_t)(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg); +typedef int (*kvm_pgtable_visitor_fn_t)(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit); + +static inline bool kvm_pgtable_walk_shared(const struct kvm_pgtable_visit_ctx *ctx) +{ + return ctx->flags & KVM_PGTABLE_WALK_SHARED; +} /** * struct kvm_pgtable_walker - Hook into a page-table walk. @@ -217,6 +228,94 @@ struct kvm_pgtable_walker { const enum kvm_pgtable_walk_flags flags; }; +/* + * RCU cannot be used in a non-kernel context such as the hyp. As such, page + * table walkers used in hyp do not call into RCU and instead use other + * synchronization mechanisms (such as a spinlock). + */ +#if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__) + +typedef kvm_pte_t *kvm_pteref_t; + +static inline kvm_pte_t *kvm_dereference_pteref(struct kvm_pgtable_walker *walker, + kvm_pteref_t pteref) +{ + return pteref; +} + +static inline int kvm_pgtable_walk_begin(struct kvm_pgtable_walker *walker) +{ + /* + * Due to the lack of RCU (or a similar protection scheme), only + * non-shared table walkers are allowed in the hypervisor. + */ + if (walker->flags & KVM_PGTABLE_WALK_SHARED) + return -EPERM; + + return 0; +} + +static inline void kvm_pgtable_walk_end(struct kvm_pgtable_walker *walker) {} + +static inline bool kvm_pgtable_walk_lock_held(void) +{ + return true; +} + +#else + +typedef kvm_pte_t __rcu *kvm_pteref_t; + +static inline kvm_pte_t *kvm_dereference_pteref(struct kvm_pgtable_walker *walker, + kvm_pteref_t pteref) +{ + return rcu_dereference_check(pteref, !(walker->flags & KVM_PGTABLE_WALK_SHARED)); +} + +static inline int kvm_pgtable_walk_begin(struct kvm_pgtable_walker *walker) +{ + if (walker->flags & KVM_PGTABLE_WALK_SHARED) + rcu_read_lock(); + + return 0; +} + +static inline void kvm_pgtable_walk_end(struct kvm_pgtable_walker *walker) +{ + if (walker->flags & KVM_PGTABLE_WALK_SHARED) + rcu_read_unlock(); +} + +static inline bool kvm_pgtable_walk_lock_held(void) +{ + return rcu_read_lock_held(); +} + +#endif + +/** + * struct kvm_pgtable - KVM page-table. + * @ia_bits: Maximum input address size, in bits. + * @start_level: Level at which the page-table walk starts. + * @pgd: Pointer to the first top-level entry of the page-table. + * @mm_ops: Memory management callbacks. + * @mmu: Stage-2 KVM MMU struct. Unused for stage-1 page-tables. + * @flags: Stage-2 page-table flags. + * @force_pte_cb: Function that returns true if page level mappings must + * be used instead of block mappings. + */ +struct kvm_pgtable { + u32 ia_bits; + u32 start_level; + kvm_pteref_t pgd; + struct kvm_pgtable_mm_ops *mm_ops; + + /* Stage-2 only */ + struct kvm_s2_mmu *mmu; + enum kvm_pgtable_stage2_flags flags; + kvm_pgtable_force_pte_cb_t force_pte_cb; +}; + /** * kvm_pgtable_hyp_init() - Initialise a hypervisor stage-1 page-table. * @pgt: Uninitialised page-table structure to initialise. @@ -297,6 +396,14 @@ u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size); u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift); /** + * kvm_pgtable_stage2_pgd_size() - Helper to compute size of a stage-2 PGD + * @vtcr: Content of the VTCR register. + * + * Return: the size (in bytes) of the stage-2 PGD + */ +size_t kvm_pgtable_stage2_pgd_size(u64 vtcr); + +/** * __kvm_pgtable_stage2_init() - Initialise a guest stage-2 page-table. * @pgt: Uninitialised page-table structure to initialise. * @mmu: S2 MMU context for this S2 translation @@ -325,6 +432,17 @@ int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); /** + * kvm_pgtable_stage2_free_removed() - Free a removed stage-2 paging structure. + * @mm_ops: Memory management callbacks. + * @pgtable: Unlinked stage-2 paging structure to be freed. + * @level: Level of the stage-2 paging structure to be freed. + * + * The page-table is assumed to be unreachable by any hardware walkers prior to + * freeing and therefore no TLB invalidation is performed. + */ +void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level); + +/** * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table. * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). * @addr: Intermediate physical address at which to place the mapping. @@ -333,6 +451,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); * @prot: Permissions and attributes for the mapping. * @mc: Cache of pre-allocated and zeroed memory from which to allocate * page-table pages. + * @flags: Flags to control the page-table walk (ex. a shared walk) * * The offset of @addr within a page is ignored, @size is rounded-up to * the next page boundary and @phys is rounded-down to the previous page @@ -354,7 +473,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); */ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, enum kvm_pgtable_prot prot, - void *mc); + void *mc, enum kvm_pgtable_walk_flags flags); /** * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space to |