• Dexuan Cui's avatar
    hv_utils: Add the support of hibernation · 54e19d34
    Dexuan Cui authored
    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: default avatarDexuan Cui <decui@microsoft.com>
    Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    54e19d34
hv_snapshot.c 11 KB