From: Peter Xu <pet...@redhat.com>
Some of the memory listener may want to do log synchronization without
being able to specify a range of memory to sync but always globally.
Such a memory listener should provide this new method instead of the
log_sync() method.
Obviously we can also achieve similar thing when we put the global
sync logic into a log_sync() handler. However that's not efficient
enough because otherwise memory_global_dirty_log_sync() may do the
global sync N times, where N is the number of flat ranges in the
address space.
Make this new method be exclusive to log_sync().
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Signed-off-by: Peter Xu <pet...@redhat.com>
Message-Id: <20210506160549.130416-2-pet...@redhat.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
include/exec/memory.h | 12 ++++++++++++
softmmu/memory.c | 33 +++++++++++++++++++++++----------
2 files changed, 35 insertions(+), 10 deletions(-)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index c8b9088924..e38b7e3dce 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -616,6 +616,18 @@ struct MemoryListener {
*/
void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section);
+ /**
+ * @log_sync_global:
+ *
+ * This is the global version of @log_sync when the listener does
+ * not have a way to synchronize the log with finer granularity.
+ * When the listener registers with @log_sync_global defined, then
+ * its @log_sync must be NULL. Vice versa.
+ *
+ * @listener: The #MemoryListener.
+ */
+ void (*log_sync_global)(MemoryListener *listener);
+
/**
* @log_clear:
*
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 3bb533c0bc..c19b0be6b1 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -2055,6 +2055,10 @@ void memory_region_set_dirty(MemoryRegion *mr, hwaddr
addr,
memory_region_get_dirty_log_mask(mr));
}
+/*
+ * If memory region `mr' is NULL, do global sync. Otherwise, sync
+ * dirty bitmap for the specified memory region.
+ */
static void memory_region_sync_dirty_bitmap(MemoryRegion *mr)
{
MemoryListener *listener;
@@ -2068,18 +2072,24 @@ static void
memory_region_sync_dirty_bitmap(MemoryRegion *mr)
* address space once.
*/
QTAILQ_FOREACH(listener, &memory_listeners, link) {
- if (!listener->log_sync) {
- continue;
- }
- as = listener->address_space;
- view = address_space_get_flatview(as);
- FOR_EACH_FLAT_RANGE(fr, view) {
- if (fr->dirty_log_mask && (!mr || fr->mr == mr)) {
- MemoryRegionSection mrs = section_from_flat_range(fr, view);
- listener->log_sync(listener, &mrs);
+ if (listener->log_sync) {
+ as = listener->address_space;
+ view = address_space_get_flatview(as);
+ FOR_EACH_FLAT_RANGE(fr, view) {
+ if (fr->dirty_log_mask && (!mr || fr->mr == mr)) {
+ MemoryRegionSection mrs = section_from_flat_range(fr,
view);
+ listener->log_sync(listener, &mrs);
+ }
}
+ flatview_unref(view);
+ } else if (listener->log_sync_global) {
+ /*
+ * No matter whether MR is specified, what we can do here
+ * is to do a global sync, because we are not capable to
+ * sync in a finer granularity.
+ */
+ listener->log_sync_global(listener);
}
- flatview_unref(view);
}
}
@@ -2767,6 +2777,9 @@ void memory_listener_register(MemoryListener *listener,
AddressSpace *as)
{
MemoryListener *other = NULL;
+ /* Only one of them can be defined for a listener */
+ assert(!(listener->log_sync && listener->log_sync_global));
+
listener->address_space = as;
if (QTAILQ_EMPTY(&memory_listeners)
|| listener->priority >= QTAILQ_LAST(&memory_listeners)->priority) {
--
2.31.1
