diff options
| -rw-r--r-- | include/linux/kvm_host.h | 1 | ||||
| -rw-r--r-- | virt/kvm/Kconfig | 4 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 23 |
3 files changed, 21 insertions, 7 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f34f4cfaa513..c28a6aa1f2ed 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -267,6 +267,7 @@ struct kvm_gfn_range { union kvm_mmu_notifier_arg arg; enum kvm_gfn_range_filter attr_filter; bool may_block; + bool lockless; }; bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range); bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range); diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 54e959e7d68f..746e1f466aa6 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -104,6 +104,10 @@ config KVM_ELIDE_TLB_FLUSH_IF_YOUNG depends on KVM_GENERIC_MMU_NOTIFIER bool +config KVM_MMU_LOCKLESS_AGING + depends on KVM_GENERIC_MMU_NOTIFIER + bool + config KVM_GENERIC_MEMORY_ATTRIBUTES depends on KVM_GENERIC_MMU_NOTIFIER bool diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0f94349f99e2..201c14ff476f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -517,6 +517,7 @@ struct kvm_mmu_notifier_range { on_lock_fn_t on_lock; bool flush_on_ret; bool may_block; + bool lockless; }; /* @@ -571,6 +572,10 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm, IS_KVM_NULL_FN(range->handler))) return r; + /* on_lock will never be called for lockless walks */ + if (WARN_ON_ONCE(range->lockless && !IS_KVM_NULL_FN(range->on_lock))) + return r; + idx = srcu_read_lock(&kvm->srcu); for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { @@ -607,15 +612,18 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm, gfn_range.start = hva_to_gfn_memslot(hva_start, slot); gfn_range.end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, slot); gfn_range.slot = slot; + gfn_range.lockless = range->lockless; if (!r.found_memslot) { r.found_memslot = true; - KVM_MMU_LOCK(kvm); - if (!IS_KVM_NULL_FN(range->on_lock)) - range->on_lock(kvm); - - if (IS_KVM_NULL_FN(range->handler)) - goto mmu_unlock; + if (!range->lockless) { + KVM_MMU_LOCK(kvm); + if (!IS_KVM_NULL_FN(range->on_lock)) + range->on_lock(kvm); + + if (IS_KVM_NULL_FN(range->handler)) + goto mmu_unlock; + } } r.ret |= range->handler(kvm, &gfn_range); } @@ -625,7 +633,7 @@ static __always_inline kvm_mn_ret_t kvm_handle_hva_range(struct kvm *kvm, kvm_flush_remote_tlbs(kvm); mmu_unlock: - if (r.found_memslot) + if (r.found_memslot && !range->lockless) KVM_MMU_UNLOCK(kvm); srcu_read_unlock(&kvm->srcu, idx); @@ -647,6 +655,7 @@ static __always_inline int kvm_age_hva_range(struct mmu_notifier *mn, .on_lock = (void *)kvm_null_fn, .flush_on_ret = flush_on_ret, .may_block = false, + .lockless = IS_ENABLED(CONFIG_KVM_MMU_LOCKLESS_AGING), }; return kvm_handle_hva_range(kvm, &range).ret; |