From 4dbfc2e68004c60edab7e8fd26784383dd3ee9bc Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 30 Apr 2016 19:21:33 -0700 Subject: Drivers: hv: kvp: fix IP Failover Hyper-V VMs can be replicated to another hosts and there is a feature to set different IP for replicas, it is called 'Failover TCP/IP'. When such guest starts Hyper-V host sends it KVP_OP_SET_IP_INFO message as soon as we finish negotiation procedure. The problem is that it can happen (and it actually happens) before userspace daemon connects and we reply with HV_E_FAIL to the message. As there are no repetitions we fail to set the requested IP. Solve the issue by postponing our reply to the negotiation message till userspace daemon is connected. We can't wait too long as there is a host-side timeout (cca. 75 seconds) and if we fail to reply in this time frame the whole KVP service will become inactive. The solution is not ideal - if it takes userspace daemon more than 60 seconds to connect IP Failover will still fail but I don't see a solution with our current separation between kernel and userspace parts. Other two modules (VSS and FCOPY) don't require such delay, leave them untouched. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hyperv_vmbus.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/hv/hyperv_vmbus.h') diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index e5c586fab0e5..e5203e4d6782 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -35,6 +35,11 @@ */ #define HV_UTIL_TIMEOUT 30 +/* + * Timeout for guest-host handshake for services. + */ +#define HV_UTIL_NEGO_TIMEOUT 60 + /* * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent * is set by CPUID(HVCPUID_VERSION_FEATURES). -- cgit v1.2.3