4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> commit 2d0c3b5ad739697a68dc8a444f5b9f4817cf8f8f upstream. When the handshake with daemon is complete, we should poll the channel since during the handshake, we will not be processing any messages. This is a potential bug if the host is waiting for a response from the guest. I would like to thank Dexuan for pointing this out. Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hv/hv_kvp.c | 2 +- drivers/hv/hv_snapshot.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -155,7 +155,7 @@ static int kvp_handle_handshake(struct h pr_debug("KVP: userspace daemon ver. %d registered\n", KVP_OP_REGISTER); kvp_register(dm_reg_value); - kvp_transaction.state = HVUTIL_READY; + hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper); return 0; } --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -114,7 +114,7 @@ static int vss_handle_handshake(struct h default: return -EINVAL; } - vss_transaction.state = HVUTIL_READY; + hv_poll_channel(vss_transaction.recv_channel, vss_poll_wrapper); pr_debug("VSS: userspace daemon ver. %d registered\n", dm_reg_value); return 0; }