KVM: Provide common implementation for generic dirty log functions

Move the implementations of KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG
for CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT into common KVM code.
The arch specific implemenations are extremely similar, differing
only in whether the dirty log needs to be sync'd from hardware (x86)
and how the TLBs are flushed.  Add new arch hooks to handle sync
and TLB flush; the sync will also be used for non-generic dirty log
support in a future patch (s390).

The ulterior motive for providing a common implementation is to
eliminate the dependency between arch and common code with respect to
the memslot referenced by the dirty log, i.e. to make it obvious in the
code that the validity of the memslot is guaranteed, as a future patch
will rework memslot handling such that id_to_memslot() can return NULL.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 78f92c005f93..2adbc2fde382 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -570,8 +570,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	return r;
 }
 
-static void kvm_s390_sync_dirty_log(struct kvm *kvm,
-				    struct kvm_memory_slot *memslot)
+void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
 {
 	int i;
 	gfn_t cur_gfn, last_gfn;
@@ -631,7 +630,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	if (!memslot->dirty_bitmap)
 		goto out;
 
-	kvm_s390_sync_dirty_log(kvm, memslot);
+	kvm_arch_sync_dirty_log(kvm, memslot);
 	r = kvm_get_dirty_log(kvm, log, &is_dirty);
 	if (r)
 		goto out;