From 54e19d34011fea26d39aa74781131de0ce642a01 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Sat, 25 Jan 2020 21:49:44 -0800 Subject: hv_utils: Add the support of hibernation Add util_pre_suspend() and util_pre_resume() for some hv_utils devices (e.g. kvp/vss/fcopy), because they need special handling before util_suspend() calls vmbus_close(). For kvp, all the possible pending work items should be cancelled. For vss and fcopy, some extra clean-up needs to be done, i.e. fake a THAW message for hv_vss_daemon and fake a CANCEL_FCOPY message for hv_fcopy_daemon, otherwise when the VM resums back, the daemons can end up in an inconsistent state (i.e. the file systems are frozen but will never be thawed; the file transmitted via fcopy may not be complete). Note: there is an extra patch for the daemons: "Tools: hv: Reopen the devices if read() or write() returns errors", because the hv_utils driver can not guarantee the whole transaction finishes completely once util_suspend() starts to run (at this time, all the userspace processes are frozen). util_probe() disables channel->callback_event to avoid the race with the channel callback. Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin --- drivers/hv/hv_kvp.c | 43 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 41 insertions(+), 2 deletions(-) (limited to 'drivers/hv/hv_kvp.c') diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index ae7c028dc5a8..e74b144b8f3d 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -758,11 +758,50 @@ hv_kvp_init(struct hv_util_service *srv) return 0; } -void hv_kvp_deinit(void) +static void hv_kvp_cancel_work(void) { - kvp_transaction.state = HVUTIL_DEVICE_DYING; cancel_delayed_work_sync(&kvp_host_handshake_work); cancel_delayed_work_sync(&kvp_timeout_work); cancel_work_sync(&kvp_sendkey_work); +} + +int hv_kvp_pre_suspend(void) +{ + struct vmbus_channel *channel = kvp_transaction.recv_channel; + + tasklet_disable(&channel->callback_event); + + /* + * If there is a pending transtion, it's unnecessary to tell the host + * that the transaction will fail, because that is implied when + * util_suspend() calls vmbus_close() later. + */ + hv_kvp_cancel_work(); + + /* + * Forece the state to READY to handle the ICMSGTYPE_NEGOTIATE message + * later. The user space daemon may go out of order and its write() + * may fail with EINVAL: this doesn't matter since the daemon will + * reset the device by closing and re-opening it. + */ + kvp_transaction.state = HVUTIL_READY; + return 0; +} + +int hv_kvp_pre_resume(void) +{ + struct vmbus_channel *channel = kvp_transaction.recv_channel; + + tasklet_enable(&channel->callback_event); + + return 0; +} + +void hv_kvp_deinit(void) +{ + kvp_transaction.state = HVUTIL_DEVICE_DYING; + + hv_kvp_cancel_work(); + hvutil_transport_destroy(hvt); } -- cgit v1.2.3