From: Quentin Perret Date: Wed, 21 May 2025 12:48:31 +0000 (+0100) Subject: KVM: arm64: Convert pkvm_mappings to interval tree X-Git-Tag: v6.16-rc1~129^2~2^2~6^2~3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b38c9775f73941ee59aebc0a489aa5c22e632def;p=thirdparty%2Fkernel%2Flinux.git KVM: arm64: Convert pkvm_mappings to interval tree In preparation for supporting stage-2 huge mappings for np-guest, let's convert pgt.pkvm_mappings to an interval tree. No functional change intended. Suggested-by: Vincent Donnefort Signed-off-by: Quentin Perret Signed-off-by: Vincent Donnefort Link: https://lore.kernel.org/r/20250521124834.1070650-8-vdonnefort@google.com Signed-off-by: Marc Zyngier --- diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 6b9d274052c7a..1b43bcd2a679a 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -413,7 +413,7 @@ static inline bool kvm_pgtable_walk_lock_held(void) */ struct kvm_pgtable { union { - struct rb_root pkvm_mappings; + struct rb_root_cached pkvm_mappings; struct { u32 ia_bits; s8 start_level; diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index d91bfcf2db56d..da75d41c948c1 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -173,6 +173,7 @@ struct pkvm_mapping { struct rb_node node; u64 gfn; u64 pfn; + u64 __subtree_last; /* Internal member for interval tree */ }; int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index f2c1d4c4e27ed..0562da0249c33 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -5,6 +5,7 @@ */ #include +#include #include #include #include @@ -275,80 +276,67 @@ static int __init finalize_pkvm(void) } device_initcall_sync(finalize_pkvm); -static int cmp_mappings(struct rb_node *node, const struct rb_node *parent) +static u64 __pkvm_mapping_start(struct pkvm_mapping *m) { - struct pkvm_mapping *a = rb_entry(node, struct pkvm_mapping, node); - struct pkvm_mapping *b = rb_entry(parent, struct pkvm_mapping, node); - - if (a->gfn < b->gfn) - return -1; - if (a->gfn > b->gfn) - return 1; - return 0; + return m->gfn * PAGE_SIZE; } -static struct rb_node *find_first_mapping_node(struct rb_root *root, u64 gfn) +static u64 __pkvm_mapping_end(struct pkvm_mapping *m) { - struct rb_node *node = root->rb_node, *prev = NULL; - struct pkvm_mapping *mapping; - - while (node) { - mapping = rb_entry(node, struct pkvm_mapping, node); - if (mapping->gfn == gfn) - return node; - prev = node; - node = (gfn < mapping->gfn) ? node->rb_left : node->rb_right; - } - - return prev; + return (m->gfn + 1) * PAGE_SIZE - 1; } +INTERVAL_TREE_DEFINE(struct pkvm_mapping, node, u64, __subtree_last, + __pkvm_mapping_start, __pkvm_mapping_end, static, + pkvm_mapping); + /* - * __tmp is updated to rb_next(__tmp) *before* entering the body of the loop to allow freeing - * of __map inline. + * __tmp is updated to iter_first(pkvm_mappings) *before* entering the body of the loop to allow + * freeing of __map inline. */ #define for_each_mapping_in_range_safe(__pgt, __start, __end, __map) \ - for (struct rb_node *__tmp = find_first_mapping_node(&(__pgt)->pkvm_mappings, \ - ((__start) >> PAGE_SHIFT)); \ + for (struct pkvm_mapping *__tmp = pkvm_mapping_iter_first(&(__pgt)->pkvm_mappings, \ + __start, __end - 1); \ __tmp && ({ \ - __map = rb_entry(__tmp, struct pkvm_mapping, node); \ - __tmp = rb_next(__tmp); \ + __map = __tmp; \ + __tmp = pkvm_mapping_iter_next(__map, __start, __end - 1); \ true; \ }); \ - ) \ - if (__map->gfn < ((__start) >> PAGE_SHIFT)) \ - continue; \ - else if (__map->gfn >= ((__end) >> PAGE_SHIFT)) \ - break; \ - else + ) int pkvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, struct kvm_pgtable_mm_ops *mm_ops) { - pgt->pkvm_mappings = RB_ROOT; + pgt->pkvm_mappings = RB_ROOT_CACHED; pgt->mmu = mmu; return 0; } -void pkvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) +static int __pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 start, u64 end) { struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu); pkvm_handle_t handle = kvm->arch.pkvm.handle; struct pkvm_mapping *mapping; - struct rb_node *node; + int ret; if (!handle) - return; + return 0; - node = rb_first(&pgt->pkvm_mappings); - while (node) { - mapping = rb_entry(node, struct pkvm_mapping, node); - kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn); - node = rb_next(node); - rb_erase(&mapping->node, &pgt->pkvm_mappings); + for_each_mapping_in_range_safe(pgt, start, end, mapping) { + ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn, 1); + if (WARN_ON(ret)) + return ret; + pkvm_mapping_remove(mapping, &pgt->pkvm_mappings); kfree(mapping); } + + return 0; +} + +void pkvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) +{ + __pkvm_pgtable_stage2_unmap(pgt, 0, ~(0ULL)); } int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, @@ -376,28 +364,16 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, swap(mapping, cache->mapping); mapping->gfn = gfn; mapping->pfn = pfn; - WARN_ON(rb_find_add(&mapping->node, &pgt->pkvm_mappings, cmp_mappings)); + pkvm_mapping_insert(mapping, &pgt->pkvm_mappings); return ret; } int pkvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size) { - struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu); - pkvm_handle_t handle = kvm->arch.pkvm.handle; - struct pkvm_mapping *mapping; - int ret = 0; - - lockdep_assert_held_write(&kvm->mmu_lock); - for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping) { - ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_guest, handle, mapping->gfn, 1); - if (WARN_ON(ret)) - break; - rb_erase(&mapping->node, &pgt->pkvm_mappings); - kfree(mapping); - } + lockdep_assert_held_write(&kvm_s2_mmu_to_kvm(pgt->mmu)->mmu_lock); - return ret; + return __pkvm_pgtable_stage2_unmap(pgt, addr, addr + size); } int pkvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)