From 983899eab4939dc4dff67fa4d822c5b4df7eae21 Mon Sep 17 00:00:00 2001 From: "Chaney, Ben" Date: Mon, 16 Jun 2025 20:56:50 +0000 Subject: [PATCH] migration: Don't sync volatile memory after migration completes Syncing volatile memory provides no benefit, instead it can cause performance issues in some cases. Only sync memory that is marked as non-volatile after migration completes on destination. Signed-off-by: Ben Chaney Fixes: bd108a44bc29 (migration: ram: Switch to ram block writeback) Link: https://lore.kernel.org/r/1CC43F59-336F-4A12-84AD-DB89E0A17A95@akamai.com Signed-off-by: Peter Xu --- migration/ram.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index fd8d83b63c..024d8b3d03 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3680,7 +3680,9 @@ static int ram_load_cleanup(void *opaque) RAMBlock *rb; RAMBLOCK_FOREACH_NOT_IGNORED(rb) { - qemu_ram_block_writeback(rb); + if (memory_region_is_nonvolatile(rb->mr)) { + qemu_ram_block_writeback(rb); + } } xbzrle_load_cleanup();