diff options
author | Oliver Upton <oliver.upton@linux.dev> | 2023-06-15 16:02:11 +0300 |
---|---|---|
committer | Oliver Upton <oliver.upton@linux.dev> | 2023-06-15 16:02:11 +0300 |
commit | 83510396c0765cc15454eaf445fb98bad773634e (patch) | |
tree | fe4dc2e04b2ce203026123f48147323efa1df906 /arch/arm64/include/asm/kvm_pgtable.h | |
parent | 44c026a73be8038f03dbdeef028b642880cf1511 (diff) | |
parent | 14c3555f055dd0819381148bf5b569cc5ba9ddfb (diff) | |
download | linux-83510396c0765cc15454eaf445fb98bad773634e.tar.xz |
Merge branch kvm-arm64/eager-page-splitting into kvmarm/next
* kvm-arm64/eager-page-splitting:
: Eager Page Splitting, courtesy of Ricardo Koller.
:
: Dirty logging performance is dominated by the cost of splitting
: hugepages to PTE granularity. On systems that mere mortals can get their
: hands on, each fault incurs the cost of a full break-before-make
: pattern, wherein the broadcast invalidation and ensuing serialization
: significantly increases fault latency.
:
: The goal of eager page splitting is to move the cost of hugepage
: splitting out of the stage-2 fault path and instead into the ioctls
: responsible for managing the dirty log:
:
: - If manual protection is enabled for the VM, hugepage splitting
: happens in the KVM_CLEAR_DIRTY_LOG ioctl. This is desirable as it
: provides userspace granular control over hugepage splitting.
:
: - Otherwise, if userspace relies on the legacy dirty log behavior
: (clear on collection), hugepage splitting is done at the moment dirty
: logging is enabled for a particular memslot.
:
: Support for eager page splitting requires explicit opt-in from
: userspace, which is realized through the
: KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE capability.
arm64: kvm: avoid overflow in integer division
KVM: arm64: Use local TLBI on permission relaxation
KVM: arm64: Split huge pages during KVM_CLEAR_DIRTY_LOG
KVM: arm64: Open-code kvm_mmu_write_protect_pt_masked()
KVM: arm64: Split huge pages when dirty logging is enabled
KVM: arm64: Add kvm_uninit_stage2_mmu()
KVM: arm64: Refactor kvm_arch_commit_memory_region()
KVM: arm64: Add kvm_pgtable_stage2_split()
KVM: arm64: Add KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
KVM: arm64: Export kvm_are_all_memslots_empty()
KVM: arm64: Add helper for creating unlinked stage2 subtrees
KVM: arm64: Add KVM_PGTABLE_WALK flags for skipping CMOs and BBM TLBIs
KVM: arm64: Rename free_removed to free_unlinked
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/include/asm/kvm_pgtable.h')
-rw-r--r-- | arch/arm64/include/asm/kvm_pgtable.h | 79 |
1 files changed, 75 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index dc3c072e862f..a41581c985b7 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -92,6 +92,24 @@ static inline bool kvm_level_supports_block_mapping(u32 level) return level >= KVM_PGTABLE_MIN_BLOCK_LEVEL; } +static inline u32 kvm_supported_block_sizes(void) +{ + u32 level = KVM_PGTABLE_MIN_BLOCK_LEVEL; + u32 r = 0; + + for (; level < KVM_PGTABLE_MAX_LEVELS; level++) + r |= BIT(kvm_granule_shift(level)); + + return r; +} + +static inline bool kvm_is_block_size_supported(u64 size) +{ + bool is_power_of_two = IS_ALIGNED(size, size); + + return is_power_of_two && (size & kvm_supported_block_sizes()); +} + /** * struct kvm_pgtable_mm_ops - Memory management callbacks. * @zalloc_page: Allocate a single zeroed memory page. @@ -104,7 +122,7 @@ 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 + * @free_unlinked_table: Free an unlinked 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 @@ -124,7 +142,7 @@ 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 (*free_unlinked_table)(void *addr, u32 level); void (*get_page)(void *addr); void (*put_page)(void *addr); int (*page_count)(void *addr); @@ -195,6 +213,12 @@ typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u64 end, * with other software walkers. * @KVM_PGTABLE_WALK_HANDLE_FAULT: Indicates the page-table walk was * invoked from a fault handler. + * @KVM_PGTABLE_WALK_SKIP_BBM_TLBI: Visit and update table entries + * without Break-before-make's + * TLB invalidation. + * @KVM_PGTABLE_WALK_SKIP_CMO: Visit and update table entries + * without Cache maintenance + * operations required. */ enum kvm_pgtable_walk_flags { KVM_PGTABLE_WALK_LEAF = BIT(0), @@ -202,6 +226,8 @@ enum kvm_pgtable_walk_flags { KVM_PGTABLE_WALK_TABLE_POST = BIT(2), KVM_PGTABLE_WALK_SHARED = BIT(3), KVM_PGTABLE_WALK_HANDLE_FAULT = BIT(4), + KVM_PGTABLE_WALK_SKIP_BBM_TLBI = BIT(5), + KVM_PGTABLE_WALK_SKIP_CMO = BIT(6), }; struct kvm_pgtable_visit_ctx { @@ -441,7 +467,7 @@ 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. + * kvm_pgtable_stage2_free_unlinked() - Free an unlinked 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. @@ -449,7 +475,33 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt); * 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); +void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level); + +/** + * kvm_pgtable_stage2_create_unlinked() - Create an unlinked stage-2 paging structure. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init*(). + * @phys: Physical address of the memory to map. + * @level: Starting level of the stage-2 paging structure to be created. + * @prot: Permissions and attributes for the mapping. + * @mc: Cache of pre-allocated and zeroed memory from which to allocate + * page-table pages. + * @force_pte: Force mappings to PAGE_SIZE granularity. + * + * Returns an unlinked page-table tree. This new page-table tree is + * not reachable (i.e., it is unlinked) from the root pgd and it's + * therefore unreachableby the hardware page-table walker. No TLB + * invalidation or CMOs are performed. + * + * If device attributes are not explicitly requested in @prot, then the + * mapping will be normal, cacheable. + * + * Return: The fully populated (unlinked) stage-2 paging structure, or + * an ERR_PTR(error) on failure. + */ +kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt, + u64 phys, u32 level, + enum kvm_pgtable_prot prot, + void *mc, bool force_pte); /** * kvm_pgtable_stage2_map() - Install a mapping in a guest stage-2 page-table. @@ -621,6 +673,25 @@ bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr); int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size); /** + * kvm_pgtable_stage2_split() - Split a range of huge pages into leaf PTEs pointing + * to PAGE_SIZE guest pages. + * @pgt: Page-table structure initialised by kvm_pgtable_stage2_init(). + * @addr: Intermediate physical address from which to split. + * @size: Size of the range. + * @mc: Cache of pre-allocated and zeroed memory from which to allocate + * page-table pages. + * + * The function tries to split any level 1 or 2 entry that overlaps + * with the input range (given by @addr and @size). + * + * Return: 0 on success, negative error code on failure. Note that + * kvm_pgtable_stage2_split() is best effort: it tries to break as many + * blocks in the input range as allowed by @mc_capacity. + */ +int kvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size, + struct kvm_mmu_memory_cache *mc); + +/** * kvm_pgtable_walk() - Walk a page-table. * @pgt: Page-table structure initialised by kvm_pgtable_*_init(). * @addr: Input address for the start of the walk. |