From: Peter Xu Date: Tue, 11 Oct 2022 21:55:45 +0000 (-0400) Subject: migration: Take bitmap mutex when completing ram migration X-Git-Tag: qemu-xen-4.18.0-rc5~389^2~14 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=c13221b56faaaf732de95d05a7742c1913363b48;p=qemu-xen.git migration: Take bitmap mutex when completing ram migration Any call to ram_find_and_save_block() needs to take the bitmap mutex. We used to not take it for most of ram_save_complete() because we thought we're the only one left using the bitmap, but it's not true after the preempt full patchset applied, since the return path can be taking it too. Signed-off-by: Peter Xu Reviewed-by: Juan Quintela Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Juan Quintela --- diff --git a/migration/ram.c b/migration/ram.c index 8aad17c429..cc72c24c18 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3406,6 +3406,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque) /* try transferring iterative blocks of memory */ /* flush all remaining blocks regardless of rate limiting */ + qemu_mutex_lock(&rs->bitmap_mutex); while (true) { int pages; @@ -3419,6 +3420,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque) break; } } + qemu_mutex_unlock(&rs->bitmap_mutex); flush_compressed_data(rs); ram_control_after_iterate(f, RAM_CONTROL_FINISH);