KVM: Remove write access permissions when dirty-page-logging is enabled

Enabling dirty page logging is done using KVM_SET_MEMORY_REGION ioctl.
If the memory region already exists, we need to remove write accesses,
so writes will be caught, and dirty pages will be logged.

Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index be7694db285d..e48b4d7a350e 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -748,6 +748,8 @@ raced:
                 vcpu = vcpu_load_slot(kvm, i);
                 if (!vcpu)
                         continue;
+                if (new.flags & KVM_MEM_LOG_DIRTY_PAGES)
+                        do_remove_write_access(vcpu, mem->slot);
                 kvm_mmu_reset_context(vcpu);
                 vcpu_put(vcpu);
         }