From: Li Zhijian <lizhij...@cn.fujitsu.com> Prevously, if we hotplug a device(e.g. device_add e1000) during migration is processing in source side, qemu will add a new ram block but migration_bitmap is not extended. In this case, migration_bitmap will overflow and lead qemu abort unexpectedly.
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com> Signed-off-by: Wen Congyang <we...@cn.fujitsu.com> Signed-off-by: Juan Quintela <quint...@redhat.com> --- exec.c | 5 +++++ include/exec/exec-all.h | 3 +++ migration/ram.c | 15 +++++++++++++++ 3 files changed, 23 insertions(+) diff --git a/exec.c b/exec.c index f7883d2..1702544 100644 --- a/exec.c +++ b/exec.c @@ -1401,6 +1401,11 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) } } + new_ram_size = MAX(old_ram_size, + (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS); + if (new_ram_size > old_ram_size) { + migration_bitmap_extend(old_ram_size, new_ram_size); + } /* Keep the list sorted from biggest to smallest block. Unlike QTAILQ, * QLIST (which has an RCU-friendly variant) does not have insertion at * tail, so save the last element in last_block. diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 2573e8c..91ffa99 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -385,4 +385,7 @@ static inline bool cpu_can_do_io(CPUState *cpu) return cpu->can_do_io != 0; } +#if !defined(CONFIG_USER_ONLY) +void migration_bitmap_extend(ram_addr_t old, ram_addr_t new); +#endif #endif diff --git a/migration/ram.c b/migration/ram.c index 4754aa9..3e16ef8 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1063,6 +1063,21 @@ static void reset_ram_globals(void) #define MAX_WAIT 50 /* ms, half buffered_file limit */ +void migration_bitmap_extend(ram_addr_t old, ram_addr_t new) +{ + qemu_mutex_lock(&migration_bitmap_mutex); + if (migration_bitmap) { + unsigned long *old_bitmap = migration_bitmap, *bitmap; + bitmap = bitmap_new(new); + bitmap_copy(bitmap, old_bitmap, old); + bitmap_set(bitmap, old, new - old); + atomic_rcu_set(&migration_bitmap, bitmap); + migration_dirty_pages += new - old; + synchronize_rcu(); + g_free(old_bitmap); + } + qemu_mutex_unlock(&migration_bitmap_mutex); +} /* Each of ram_save_setup, ram_save_iterate and ram_save_complete has * long-running RCU critical section. When rcu-reclaims in the code -- 2.4.3