diff options
| -rw-r--r-- | migration/ram.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/migration/ram.c b/migration/ram.c index 92c7b788ae..680a5158aa 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1656,6 +1656,17 @@ static inline void populate_read_range(RAMBlock *block, ram_addr_t offset, } } +static inline int populate_read_section(MemoryRegionSection *section, + void *opaque) +{ + const hwaddr size = int128_get64(section->size); + hwaddr offset = section->offset_within_region; + RAMBlock *block = section->mr->ram_block; + + populate_read_range(block, offset, size); + return 0; +} + /* * ram_block_populate_read: preallocate page tables and populate pages in the * RAM block by reading a byte of each page. @@ -1665,9 +1676,32 @@ static inline void populate_read_range(RAMBlock *block, ram_addr_t offset, * * @block: RAM block to populate */ -static void ram_block_populate_read(RAMBlock *block) +static void ram_block_populate_read(RAMBlock *rb) { - populate_read_range(block, 0, block->used_length); + /* + * Skip populating all pages that fall into a discarded range as managed by + * a RamDiscardManager responsible for the mapped memory region of the + * RAMBlock. Such discarded ("logically unplugged") parts of a RAMBlock + * must not get populated automatically. We don't have to track + * modifications via userfaultfd WP reliably, because these pages will + * not be part of the migration stream either way -- see + * ramblock_dirty_bitmap_exclude_discarded_pages(). + * + * Note: The result is only stable while migrating (precopy/postcopy). + */ + if (rb->mr && memory_region_has_ram_discard_manager(rb->mr)) { + RamDiscardManager *rdm = memory_region_get_ram_discard_manager(rb->mr); + MemoryRegionSection section = { + .mr = rb->mr, + .offset_within_region = 0, + .size = rb->mr->size, + }; + + ram_discard_manager_replay_populated(rdm, §ion, + populate_read_section, NULL); + } else { + populate_read_range(rb, 0, rb->used_length); + } } /* |