linux_dsm_epyc7002/drivers/hv
Vitaly Kuznetsov cd95aad557 Drivers: hv: vmbus: handle various crash scenarios
Kdump keeps biting. Turns out CHANNELMSG_UNLOAD_RESPONSE is always
delivered to the CPU which was used for initial contact or to CPU0
depending on host version. vmbus_wait_for_unload() doesn't account for
the fact that in case we're crashing on some other CPU we won't get the
CHANNELMSG_UNLOAD_RESPONSE message and our wait on the current CPU will
never end.

Do the following:
1) Check for completion_done() in the loop. In case interrupt handler is
   still alive we'll get the confirmation we need.

2) Read message pages for all CPUs message page as we're unsure where
   CHANNELMSG_UNLOAD_RESPONSE is going to be delivered to. We can race with
   still-alive interrupt handler doing the same, add cmpxchg() to
   vmbus_signal_eom() to not lose CHANNELMSG_UNLOAD_RESPONSE message.

3) Cleanup message pages on all CPUs. This is required (at least for the
   current CPU as we're clearing CPU0 messages now but we may want to bring
   up additional CPUs on crash) as new messages won't be delivered till we
   consume what's pending. On boot we'll place message pages somewhere else
   and we won't be able to read stale messages.

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>
2016-05-01 09:23:14 -07:00
..
channel_mgmt.c Drivers: hv: vmbus: handle various crash scenarios 2016-05-01 09:23:14 -07:00
channel.c Drivers: hv: vmbus: Give control over how the ring access is serialized 2016-02-07 21:34:12 -08:00
connection.c Drivers: hv: vmbus: Export the vmbus_set_event() API 2016-04-30 14:00:19 -07:00
hv_balloon.c Drivers: hv: balloon: Enable dynamic memory protocol negotiation with Windows 10 hosts 2015-08-04 22:28:39 -07:00
hv_fcopy.c Drivers: hv: util: Pass the channel information during the init call 2016-03-01 16:57:20 -08:00
hv_kvp.c Drivers: hv: kvp: fix IP Failover 2016-05-01 09:23:14 -07:00
hv_snapshot.c Drivers: hv: util: Pass the channel information during the init call 2016-03-01 16:57:20 -08:00
hv_util.c Drivers: hv: util: Pass the channel information during the init call 2016-03-01 16:57:20 -08:00
hv_utils_transport.c Drivers: hv: utils: Remove util transport handler from list if registration fails 2016-03-01 16:57:20 -08:00
hv_utils_transport.h Drivers: hv: utils: introduce HVUTIL_TRANSPORT_DESTROY mode 2015-12-14 19:27:30 -08:00
hv.c Drivers: hv: vmbus: Support handling messages on multiple CPUs 2016-03-01 16:57:20 -08:00
hyperv_vmbus.h Drivers: hv: vmbus: handle various crash scenarios 2016-05-01 09:23:14 -07:00
Kconfig x86: Make Linux guest support optional 2013-03-04 13:14:25 -08:00
Makefile Drivers: hv: util: introduce hv_utils_transport abstraction 2015-05-24 12:17:41 -07:00
ring_buffer.c Drivers: hv: vmbus: Implement APIs to support "in place" consumption of vmbus packets 2016-04-30 14:00:19 -07:00
vmbus_drv.c Drivers: hv: vmbus: handle various crash scenarios 2016-05-01 09:23:14 -07:00