[PATCH 0/3] Drivers: hv: vmbus: fix crashes on hv_vmbus load/unload path

[Vitaly Kuznetsov <vkuznets@redhat.com>]

It is possible (since 93e5bd06a953: "Drivers: hv: Make the vmbus driver
unloadable") to unload hv_vmbus driver if no other devices are connected.
1aec169673d7: "x86: Hyperv: Cleanup the irq mess" fixed doulble interrupt
gate setup. However, if we try to unload hv_vmbus and then load it back
crashes in different places of vmbus driver occur on both unload and second
load paths. Address those I saw in my testing.

Not everything is fixed though. MCE was hit once on Generation2 instance and
I neither understand what caused it nor do I know the way to reproduce it.
Anyway, here is the log:

[  204.846255] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0020001
[  204.846675] mce: [Hardware Error]: TSC 6b5cd64bc8 
[  204.846675] mce: [Hardware Error]: PROCESSOR 0:306e4 TIME 1421944123 SOCKET 0 APIC 0 microcode ffffffff
[  204.846675] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
[  204.846675] mce: [Hardware Error]: Machine check: Processor context corrupt
[  204.846675] Kernel panic - not syncing: Fatal Machine check
[  204.846675] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff)
[  204.846675] Rebooting in 30 seconds..
[  204.846675] ACPI MEMORY or I/O RESET_REG.

Vitaly Kuznetsov (3):
  Drivers: hv: vmbus: avoid double kfree for device_obj
  Drivers: hv: vmbus: introduce vmbus_acpi_remove
  Drivers: hv: vmbus: teardown hv_vmbus_con workqueue and
    vmbus_connection pages on shutdown

 drivers/hv/channel_mgmt.c |  1 -
 drivers/hv/connection.c   | 17 ++++++++++++-----
 drivers/hv/hyperv_vmbus.h |  1 +
 drivers/hv/vmbus_drv.c    | 16 ++++++++++++++++
 4 files changed, 29 insertions(+), 6 deletions(-)

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1.9.3