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author | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-06 12:27:39 -0500 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-12-09 09:12:12 +0100 |
commit | eb5618911af0ac069d2313b289d4c19ca3379401 (patch) | |
tree | 55f00bfaccf7aa55e0a8c074317d7e0b00a253b9 /arch | |
parent | 1e79a9e3ab96ecf8dbb8b6d237b3ae824bd79074 (diff) | |
parent | 753d734f3f347e7fc49b819472bbf61dcfc1a16f (diff) | |
download | linux-eb5618911af0ac069d2313b289d4c19ca3379401.tar.gz linux-eb5618911af0ac069d2313b289d4c19ca3379401.tar.bz2 linux-eb5618911af0ac069d2313b289d4c19ca3379401.zip |
Merge tag 'kvmarm-6.2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.2
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
- Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
option, which multi-process VMMs such as crosvm rely on.
- Merge the pKVM shadow vcpu state tracking that allows the hypervisor
to have its own view of a vcpu, keeping that state private.
- Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
- Fix a handful of minor issues around 52bit VA/PA support (64kB pages
only) as a prefix of the oncoming support for 4kB and 16kB pages.
- Add/Enable/Fix a bunch of selftests covering memslots, breakpoints,
stage-2 faults and access tracking. You name it, we got it, we
probably broke it.
- Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
As a side effect, this tag also drags:
- The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring
series
- A shared branch with the arm64 tree that repaints all the system
registers to match the ARM ARM's naming, and resulting in
interesting conflicts
Diffstat (limited to 'arch')
50 files changed, 3647 insertions, 1233 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 505c8a1ccbe0..cd93d0738425 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1965,6 +1965,7 @@ config ARM64_MTE depends on ARM64_PAN select ARCH_HAS_SUBPAGE_FAULTS select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_USES_PG_ARCH_X help Memory Tagging (part of the ARMv8.5 Extensions) provides architectural support for run-time, always-on detection of diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 8aa8492dafc0..0df3fc3a0173 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -135,7 +135,7 @@ * 40 bits wide (T0SZ = 24). Systems with a PARange smaller than 40 bits are * not known to exist and will break with this configuration. * - * The VTCR_EL2 is configured per VM and is initialised in kvm_arm_setup_stage2(). + * The VTCR_EL2 is configured per VM and is initialised in kvm_init_stage2_mmu. * * Note that when using 4K pages, we concatenate two first level page tables * together. With 16K pages, we concatenate 16 first level page tables. @@ -340,9 +340,13 @@ * We have * PAR [PA_Shift - 1 : 12] = PA [PA_Shift - 1 : 12] * HPFAR [PA_Shift - 9 : 4] = FIPA [PA_Shift - 1 : 12] + * + * Always assume 52 bit PA since at this point, we don't know how many PA bits + * the page table has been set up for. This should be safe since unused address + * bits in PAR are res0. */ #define PAR_TO_HPFAR(par) \ - (((par) & GENMASK_ULL(PHYS_MASK_SHIFT - 1, 12)) >> 8) + (((par) & GENMASK_ULL(52 - 1, 12)) >> 8) #define ECN(x) { ESR_ELx_EC_##x, #x } diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 53035763e48e..43c3bc0f9544 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -76,6 +76,9 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs, __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs, __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps, + __KVM_HOST_SMCCC_FUNC___pkvm_init_vm, + __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu, + __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm, }; #define DECLARE_KVM_VHE_SYM(sym) extern char sym[] @@ -106,7 +109,7 @@ enum __kvm_host_smccc_func { #define per_cpu_ptr_nvhe_sym(sym, cpu) \ ({ \ unsigned long base, off; \ - base = kvm_arm_hyp_percpu_base[cpu]; \ + base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu]; \ off = (unsigned long)&CHOOSE_NVHE_SYM(sym) - \ (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start); \ base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL; \ @@ -211,7 +214,7 @@ DECLARE_KVM_HYP_SYM(__kvm_hyp_vector); #define __kvm_hyp_init CHOOSE_NVHE_SYM(__kvm_hyp_init) #define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector) -extern unsigned long kvm_arm_hyp_percpu_base[NR_CPUS]; +extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[]; DECLARE_KVM_NVHE_SYM(__per_cpu_start); DECLARE_KVM_NVHE_SYM(__per_cpu_end); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 45e2136322ba..001c8abe87fc 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -73,6 +73,63 @@ u32 __attribute_const__ kvm_target_cpu(void); int kvm_reset_vcpu(struct kvm_vcpu *vcpu); void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu); +struct kvm_hyp_memcache { + phys_addr_t head; + unsigned long nr_pages; +}; + +static inline void push_hyp_memcache(struct kvm_hyp_memcache *mc, + phys_addr_t *p, + phys_addr_t (*to_pa)(void *virt)) +{ + *p = mc->head; + mc->head = to_pa(p); + mc->nr_pages++; +} + +static inline void *pop_hyp_memcache(struct kvm_hyp_memcache *mc, + void *(*to_va)(phys_addr_t phys)) +{ + phys_addr_t *p = to_va(mc->head); + + if (!mc->nr_pages) + return NULL; + + mc->head = *p; + mc->nr_pages--; + + return p; +} + +static inline int __topup_hyp_memcache(struct kvm_hyp_memcache *mc, + unsigned long min_pages, + void *(*alloc_fn)(void *arg), + phys_addr_t (*to_pa)(void *virt), + void *arg) +{ + while (mc->nr_pages < min_pages) { + phys_addr_t *p = alloc_fn(arg); + + if (!p) + return -ENOMEM; + push_hyp_memcache(mc, p, to_pa); + } + + return 0; +} + +static inline void __free_hyp_memcache(struct kvm_hyp_memcache *mc, + void (*free_fn)(void *virt, void *arg), + void *(*to_va)(phys_addr_t phys), + void *arg) +{ + while (mc->nr_pages) + free_fn(pop_hyp_memcache(mc, to_va), arg); +} + +void free_hyp_memcache(struct kvm_hyp_memcache *mc); +int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages); + struct kvm_vmid { atomic64_t id; }; @@ -115,6 +172,13 @@ struct kvm_smccc_features { unsigned long vendor_hyp_bmap; }; +typedef unsigned int pkvm_handle_t; + +struct kvm_protected_vm { + pkvm_handle_t handle; + struct kvm_hyp_memcache teardown_mc; +}; + struct kvm_arch { struct kvm_s2_mmu mmu; @@ -163,9 +227,19 @@ struct kvm_arch { u8 pfr0_csv2; u8 pfr0_csv3; + struct { + u8 imp:4; + u8 unimp:4; + } dfr0_pmuver; /* Hypercall features firmware registers' descriptor */ struct kvm_smccc_features smccc_feat; + + /* + * For an untrusted host VM, 'pkvm.handle' is used to lookup + * the associated pKVM instance in the hypervisor. + */ + struct kvm_protected_vm pkvm; }; struct kvm_vcpu_fault_info { @@ -915,8 +989,6 @@ int kvm_set_ipa_limit(void); #define __KVM_HAVE_ARCH_VM_ALLOC struct kvm *kvm_arch_alloc_vm(void); -int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type); - static inline bool kvm_vm_is_protected(struct kvm *kvm) { return false; diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index aa7fa2a08f06..6797eafe7890 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -123,4 +123,7 @@ extern u64 kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val); +extern unsigned long kvm_nvhe_sym(__icache_flags); +extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); + #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 7784081088e7..e4a7e6369499 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -166,7 +166,7 @@ int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size, void free_hyp_pgds(void); void stage2_unmap_vm(struct kvm *kvm); -int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu); +int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type); void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu); int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, phys_addr_t pa, unsigned long size, bool writable); 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 diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index 9f4ad2a8df59..01129b0d4c68 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -9,11 +9,49 @@ #include <linux/memblock.h> #include <asm/kvm_pgtable.h> +/* Maximum number of VMs that can co-exist under pKVM. */ +#define KVM_MAX_PVMS 255 + #define HYP_MEMBLOCK_REGIONS 128 +int pkvm_init_host_vm(struct kvm *kvm); +int pkvm_create_hyp_vm(struct kvm *kvm); +void pkvm_destroy_hyp_vm(struct kvm *kvm); + extern struct memblock_region kvm_nvhe_sym(hyp_memory)[]; extern unsigned int kvm_nvhe_sym(hyp_memblock_nr); +static inline unsigned long +hyp_vmemmap_memblock_size(struct memblock_region *reg, size_t vmemmap_entry_size) +{ + unsigned long nr_pages = reg->size >> PAGE_SHIFT; + unsigned long start, end; + + start = (reg->base >> PAGE_SHIFT) * vmemmap_entry_size; + end = start + nr_pages * vmemmap_entry_size; + start = ALIGN_DOWN(start, PAGE_SIZE); + end = ALIGN(end, PAGE_SIZE); + + return end - start; +} + +static inline unsigned long hyp_vmemmap_pages(size_t vmemmap_entry_size) +{ + unsigned long res = 0, i; + + for (i = 0; i < kvm_nvhe_sym(hyp_memblock_nr); i++) { + res += hyp_vmemmap_memblock_size(&kvm_nvhe_sym(hyp_memory)[i], + vmemmap_entry_size); + } + + return res >> PAGE_SHIFT; +} + +static inline unsigned long hyp_vm_table_pages(void) +{ + return PAGE_ALIGN(KVM_MAX_PVMS * sizeof(void *)) >> PAGE_SHIFT; +} + static inline unsigned long __hyp_pgtable_max_pages(unsigned long nr_pages) { unsigned long total = 0, i; diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index 760c62f8e22f..20dd06d70af5 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -25,7 +25,7 @@ unsigned long mte_copy_tags_to_user(void __user *to, void *from, unsigned long n); int mte_save_tags(struct page *page); void mte_save_page_tags(const void *page_addr, void *tag_storage); -bool mte_restore_tags(swp_entry_t entry, struct page *page); +void mte_restore_tags(swp_entry_t entry, struct page *page); void mte_restore_page_tags(void *page_addr, const void *tag_storage); void mte_invalidate_tags(int type, pgoff_t offset); void mte_invalidate_tags_area(int type); @@ -36,6 +36,58 @@ void mte_free_tag_storage(char *storage); /* track which pages have valid allocation tags */ #define PG_mte_tagged PG_arch_2 +/* simple lock to avoid multiple threads tagging the same page */ +#define PG_mte_lock PG_arch_3 + +static inline void set_page_mte_tagged(struct page *page) +{ + /* + * Ensure that the tags written prior to this function are visible + * before the page flags update. + */ + smp_wmb(); + set_bit(PG_mte_tagged, &page->flags); +} + +static inline bool page_mte_tagged(struct page *page) +{ + bool ret = test_bit(PG_mte_tagged, &page->flags); + + /* + * If the page is tagged, ensure ordering with a likely subsequent + * read of the tags. + */ + if (ret) + smp_rmb(); + return ret; +} + +/* |