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authorVitaly Kuznetsov <vkuznets@redhat.com>2016-04-30 19:21:33 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-05-01 09:23:14 -0700
commit4dbfc2e68004c60edab7e8fd26784383dd3ee9bc (patch)
tree7fa8bef839b4f58926c7508e7411272194909854 /drivers/hv/hyperv_vmbus.h
parentd449d69d216854a8cab049fe035ffefbf383a2e1 (diff)
downloadop-kernel-dev-4dbfc2e68004c60edab7e8fd26784383dd3ee9bc.zip
op-kernel-dev-4dbfc2e68004c60edab7e8fd26784383dd3ee9bc.tar.gz
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 <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv/hyperv_vmbus.h')
-rw-r--r--drivers/hv/hyperv_vmbus.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index e5c586f..e5203e4 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -36,6 +36,11 @@
#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).
*/
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