mirror of
https://github.com/mborgerson/xemu.git
synced 2026-03-02 22:37:41 +00:00
7e4480dde2
Commitf5f48a7891("migration/multifd: Separate SYNC request with normal jobs") changed the multifd source side to stop sending data along with the MULTIFD_FLAG_SYNC, effectively introducing the concept of a SYNC-only packet. Relying on that, commitd7e58f412c("migration/multifd: Don't send ram data during SYNC") later came along and skipped reading data from SYNC packets. In a versions timeline like this: 8.2f5f48a79.0 9.1d7e58f419.2 The issue arises that QEMUs < 9.0 still send data along with SYNC, but QEMUs > 9.1 don't gather that data anymore. This leads to various kinds of migration failures due to desync/missing data. Stop checking for a SYNC packet on the destination and unconditionally unfill the packet. >From now on: old -> new: the source sends data + sync, destination reads normally new -> new: source sends only sync, destination reads zeros new -> old: source sends only sync, destination reads zeros CC: qemu-stable@nongnu.org Fixes:d7e58f412c("migration/multifd: Don't send ram data during SYNC") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2720 Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Fabiano Rosas <farosas@suse.de> Message-Id: <20241213160120.23880-2-farosas@suse.de> Signed-off-by: Fabiano Rosas <farosas@suse.de> (cherry picked from commitb93d897ea2) Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>