From b87eaa9b8237f4d97950ca0f78309407212cfdc5 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Thu, 6 May 2021 12:05:40 -0400 Subject: memory: Introduce log_sync_global() to memory listener 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 Signed-off-by: Peter Xu Message-Id: <20210506160549.130416-2-peterx@redhat.com> Signed-off-by: Paolo Bonzini --- 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 c8b9088..e38b7e3 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -617,6 +617,18 @@ 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: * * Called before reading the dirty memory bitmap for a diff --git a/softmmu/memory.c b/softmmu/memory.c index 3bb533c..c19b0be 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) { -- cgit v1.1