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 <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 41c5801..692c89c 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1435,6 +1435,8 @@ struct hv_util_service {
void (*util_cb)(void *);
int (*util_init)(struct hv_util_service *);
void (*util_deinit)(void);
+ int (*util_pre_suspend)(void);
+ int (*util_pre_resume)(void);
};
struct vmbuspipe_hdr {
