diff --git a/exec.c b/exec.c index 3a00698cc0..3e78de3b8f 100644 --- a/exec.c +++ b/exec.c @@ -1358,6 +1358,8 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, DirtyMemoryBlocks *blocks; unsigned long end, page; bool dirty = false; + RAMBlock *ramblock; + uint64_t mr_offset, mr_size; if (length == 0) { return false; @@ -1369,6 +1371,10 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, rcu_read_lock(); blocks = atomic_rcu_read(&ram_list.dirty_memory[client]); + ramblock = qemu_get_ram_block(start); + /* Range sanity check on the ramblock */ + assert(start >= ramblock->offset && + start + length <= ramblock->offset + ramblock->used_length); while (page < end) { unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE; @@ -1380,6 +1386,10 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, page += num; } + mr_offset = (ram_addr_t)(page << TARGET_PAGE_BITS) - ramblock->offset; + mr_size = (end - page) << TARGET_PAGE_BITS; + memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size); + rcu_read_unlock(); if (dirty && tcg_enabled()) { @@ -1435,6 +1445,8 @@ DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty tlb_reset_dirty_range_all(start, length); } + memory_region_clear_dirty_bitmap(mr, offset, length); + return snap; } diff --git a/include/exec/memory.h b/include/exec/memory.h index 70d6f7e451..bb0961ddb9 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -416,6 +416,7 @@ struct MemoryListener { void (*log_stop)(MemoryListener *listener, MemoryRegionSection *section, int old, int new); void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section); + void (*log_clear)(MemoryListener *listener, MemoryRegionSection *section); void (*log_global_start)(MemoryListener *listener); void (*log_global_stop)(MemoryListener *listener); void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section, @@ -1269,6 +1270,22 @@ void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client); void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr, hwaddr size); +/** + * memory_region_clear_dirty_bitmap - clear dirty bitmap for memory range + * + * This function is called when the caller wants to clear the remote + * dirty bitmap of a memory range within the memory region. This can + * be used by e.g. KVM to manually clear dirty log when + * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is declared support by the host + * kernel. + * + * @mr: the memory region to clear the dirty log upon + * @start: start address offset within the memory region + * @len: length of the memory region to clear dirty bitmap + */ +void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start, + hwaddr len); + /** * memory_region_snapshot_and_clear_dirty: Get a snapshot of the dirty * bitmap and clear it. diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 1843b6f2d3..222b4338fb 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -462,6 +462,9 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb, idx++; } } + + /* TODO: split the huge bitmap into smaller chunks */ + memory_region_clear_dirty_bitmap(rb->mr, start, length); } else { ram_addr_t offset = rb->offset; diff --git a/memory.c b/memory.c index 71fcaf2d00..beac26e173 100644 --- a/memory.c +++ b/memory.c @@ -2064,6 +2064,57 @@ static void memory_region_sync_dirty_bitmap(MemoryRegion *mr) } } +void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start, + hwaddr len) +{ + MemoryRegionSection mrs; + MemoryListener *listener; + AddressSpace *as; + FlatView *view; + FlatRange *fr; + hwaddr sec_start, sec_end, sec_size; + + QTAILQ_FOREACH(listener, &memory_listeners, link) { + if (!listener->log_clear) { + continue; + } + as = listener->address_space; + view = address_space_get_flatview(as); + FOR_EACH_FLAT_RANGE(fr, view) { + if (!fr->dirty_log_mask || fr->mr != mr) { + /* + * Clear dirty bitmap operation only applies to those + * regions whose dirty logging is at least enabled + */ + continue; + } + + mrs = section_from_flat_range(fr, view); + + sec_start = MAX(mrs.offset_within_region, start); + sec_end = mrs.offset_within_region + int128_get64(mrs.size); + sec_end = MIN(sec_end, start + len); + + if (sec_start >= sec_end) { + /* + * If this memory region section has no intersection + * with the requested range, skip. + */ + continue; + } + + /* Valid case; shrink the section if needed */ + mrs.offset_within_address_space += + sec_start - mrs.offset_within_region; + mrs.offset_within_region = sec_start; + sec_size = sec_end - sec_start; + mrs.size = int128_make64(sec_size); + listener->log_clear(listener, &mrs); + } + flatview_unref(view); + } +} + DirtyBitmapSnapshot *memory_region_snapshot_and_clear_dirty(MemoryRegion *mr, hwaddr addr, hwaddr size,