[RFC v2 PATCH 09/13] KVM: Introduce kvm_memfd_invalidate_range
From: Chao Peng <hidden>
Date: 2021-11-19 13:49:52
Also in:
kvm, linux-fsdevel, lkml, qemu-devel
Subsystem:
kernel virtual machine (kvm), the rest · Maintainers:
Paolo Bonzini, Linus Torvalds
Invalidate on fd-based memslot can reuse the code from existing MMU notifier. Signed-off-by: Yu Zhang <redacted> Signed-off-by: Chao Peng <redacted> --- include/linux/kvm_host.h | 3 +++ virt/kvm/kvm_main.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 925c4d9f0a31..f0fd32f6eab3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h@@ -1883,4 +1883,7 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu) /* Max number of entries allowed for each kvm dirty ring */ #define KVM_DIRTY_RING_MAX_ENTRIES 65536 +int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end); + #endif
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d9a6890dd18a..090afbadb03f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c@@ -811,6 +811,35 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) return mmu_notifier_register(&kvm->mmu_notifier, current->mm); } +int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end) +{ + int ret; + const struct kvm_useraddr_range useraddr_range = { + .start = start, + .end = end, + .pte = __pte(0), + .handler = kvm_unmap_gfn_range, + .on_lock = (void *)kvm_null_fn, + .flush_on_ret = true, + .may_block = false, + }; + + + /* Prevent memslot modification */ + spin_lock(&kvm->mn_invalidate_lock); + kvm->mn_active_invalidate_count++; + spin_unlock(&kvm->mn_invalidate_lock); + + ret = __kvm_handle_useraddr_range(kvm, &useraddr_range); + + spin_lock(&kvm->mn_invalidate_lock); + kvm->mn_active_invalidate_count--; + spin_unlock(&kvm->mn_invalidate_lock); + + return ret; +} + #else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */ static int kvm_init_mmu_notifier(struct kvm *kvm)
@@ -818,6 +847,12 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) return 0; } +int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end) +{ + return 0; +} + #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
--
2.17.1