From 5688fed649f15a232e75148afb0a28864046f44c Mon Sep 17 00:00:00 2001 From: Anthony Yznaga Date: Tue, 2 Jun 2020 13:07:28 -0700 Subject: [PATCH] KVM: x86: remove unnecessary rmap walk of read-only memslots There's no write access to remove. An existing memslot cannot be updated to set or clear KVM_MEM_READONLY, and any mappings established in a newly created or moved read-only memslot will already be read-only. Signed-off-by: Anthony Yznaga Message-Id: <1591128450-11977-2-git-send-email-anthony.yznaga@oracle.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9e41b51..e11e049 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10142,11 +10142,9 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, static void kvm_mmu_slot_apply_flags(struct kvm *kvm, struct kvm_memory_slot *new) { - /* Still write protect RO slot */ - if (new->flags & KVM_MEM_READONLY) { - kvm_mmu_slot_remove_write_access(kvm, new, PG_LEVEL_4K); + /* Nothing to do for RO slots */ + if (new->flags & KVM_MEM_READONLY) return; - } /* * Call kvm_x86_ops dirty logging hooks when they are valid. -- 2.7.4