diff options
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 2 | ||||
| -rw-r--r-- | arch/riscv/kvm/mmu.c | 5 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 1 | ||||
| -rw-r--r-- | include/linux/kvm_types.h | 6 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 33 |
5 files changed, 38 insertions, 9 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index f5651a05b6a8..87f1cd0df36e 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -786,7 +786,7 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, { phys_addr_t addr; int ret = 0; - struct kvm_mmu_memory_cache cache = { 0, __GFP_ZERO, NULL, }; + struct kvm_mmu_memory_cache cache = { .gfp_zero = __GFP_ZERO }; struct kvm_pgtable *pgt = kvm->arch.mmu.pgt; enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE | KVM_PGTABLE_PROT_R | diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 1c00695ebee7..081f8d2b9cf3 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -350,10 +350,7 @@ static int gstage_ioremap(struct kvm *kvm, gpa_t gpa, phys_addr_t hpa, int ret = 0; unsigned long pfn; phys_addr_t addr, end; - struct kvm_mmu_memory_cache pcache; - - memset(&pcache, 0, sizeof(pcache)); - pcache.gfp_zero = __GFP_ZERO; + struct kvm_mmu_memory_cache pcache = { .gfp_zero = __GFP_ZERO }; end = (gpa + size + PAGE_SIZE - 1) & PAGE_MASK; pfn = __phys_to_pfn(hpa); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a2bbdf3ab086..3554e48406e4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1356,6 +1356,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm); #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min); +int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min); int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc); void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc); void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc); diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h index f328a01db4fe..4d933518060f 100644 --- a/include/linux/kvm_types.h +++ b/include/linux/kvm_types.h @@ -85,12 +85,16 @@ struct gfn_to_pfn_cache { * MMU flows is problematic, as is triggering reclaim, I/O, etc... while * holding MMU locks. Note, these caches act more like prefetch buffers than * classical caches, i.e. objects are not returned to the cache on being freed. + * + * The @capacity field and @objects array are lazily initialized when the cache + * is topped up (__kvm_mmu_topup_memory_cache()). */ struct kvm_mmu_memory_cache { int nobjs; gfp_t gfp_zero; struct kmem_cache *kmem_cache; - void *objects[KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE]; + int capacity; + void **objects; }; #endif diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5b8ae83e09d7..45188d11812c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -396,14 +396,31 @@ static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc, return (void *)__get_free_page(gfp_flags); } -int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min) +int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min) { + gfp_t gfp = GFP_KERNEL_ACCOUNT; void *obj; if (mc->nobjs >= min) return 0; - while (mc->nobjs < ARRAY_SIZE(mc->objects)) { - obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT); + + if (unlikely(!mc->objects)) { + if (WARN_ON_ONCE(!capacity)) + return -EIO; + + mc->objects = kvmalloc_array(sizeof(void *), capacity, gfp); + if (!mc->objects) + return -ENOMEM; + + mc->capacity = capacity; + } + + /* It is illegal to request a different capacity across topups. */ + if (WARN_ON_ONCE(mc->capacity != capacity)) + return -EIO; + + while (mc->nobjs < mc->capacity) { + obj = mmu_memory_cache_alloc_obj(mc, gfp); if (!obj) return mc->nobjs >= min ? 0 : -ENOMEM; mc->objects[mc->nobjs++] = obj; @@ -411,6 +428,11 @@ int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min) return 0; } +int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min) +{ + return __kvm_mmu_topup_memory_cache(mc, KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE, min); +} + int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc) { return mc->nobjs; @@ -424,6 +446,11 @@ void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) else free_page((unsigned long)mc->objects[--mc->nobjs]); } + + kvfree(mc->objects); + + mc->objects = NULL; + mc->capacity = 0; } void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) |