4.4-stable review patch. If anyone has any objections, please let me know.
------------------ [ Upstream commit ed9ba608e4851144af8c7061cbb19f751c73e998 ] The Backup integration service on WS2012 has appearently trouble to negotiate with a guest which does not support the provided util version. Currently the VSS driver supports only version 5/0. A WS2012 offers only version 1/x and 3/x, and vmbus_prep_negotiate_resp correctly returns an empty icframe_vercnt/icmsg_vercnt. But the host ignores that and continues to send ICMSGTYPE_NEGOTIATE messages. The result are weird errors during boot and general misbehaviour. Check the Windows version to work around the host bug, skip hv_vss_init on WS2012 and older. Signed-off-by: Olaf Hering <[email protected]> Signed-off-by: K. Y. Srinivasan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/hv/hv_snapshot.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -331,6 +331,11 @@ static void vss_on_reset(void) int hv_vss_init(struct hv_util_service *srv) { + if (vmbus_proto_version < VERSION_WIN8_1) { + pr_warn("Integration service 'Backup (volume snapshot)'" + " not supported on this host version.\n"); + return -ENOTSUPP; + } recv_buffer = srv->recv_buffer; /*
