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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2016-05-01 04:21:33 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-01 18:23:14 +0200 |
| commit | 4dbfc2e68004c60edab7e8fd26784383dd3ee9bc (patch) | |
| tree | 7fa8bef839b4f58926c7508e7411272194909854 /drivers/hv/hyperv_vmbus.h | |
| parent | misc: sram: fix check of devm_ioremap*() return value (diff) | |
| download | linux-4dbfc2e68004c60edab7e8fd26784383dd3ee9bc.tar.xz linux-4dbfc2e68004c60edab7e8fd26784383dd3ee9bc.zip | |
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.h | 5 |
1 files changed, 5 insertions, 0 deletions
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 @@ -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). */ |