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>

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index be7694d..e48b4d7 100644 (file)
--- 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);
        }