[PATCH 0/5] Drivers: hv: Miscellaneous fixes

[K. Y. Srinivasan]

The Copy-VMFile cmdlet on the host may fail because the guest fcopy
driver state machine gets out of sync. This happens because the ->state
and ->context variables are accessed by the main thread and from
interrupt context. If an interrupt happens between fcopy_respond_to_host
and hv_poll_channel in fcopy_write, then hv_fcopy_onchannelcallback
called from that interrupt sees still state HVUTIL_USERSPACE_RECV. It
updates the context, but fcopy_write will not notice that update and
hv_poll_channel gets called with an empty context.  As a result
hv_fcopy_daemon gets no more data. After a timeout Copy-VMFile fails
with timeout.

In my initial testing for a fix I put a "mb()" after the last .state
change in fcopy_write. But this series implementes read/write memory
barriers as needed. Let me know if this is overdoing things.


Dexuan Cui (1):
  Drivers: hv: vmbus: fix init_vp_index() for reloading hv_netvsc

Olaf Hering (4):
  hv: add helpers to handle hv_util device state
  hv: fcopy: use wrappers to propagate state
  hv: kvp: use wrappers to propaigate state
  hv: vss: use wrappers to propagate state

 drivers/hv/channel_mgmt.c |   17 +++++++++++++++++
 drivers/hv/hv_fcopy.c     |   36 ++++++++++++++++++++----------------
 drivers/hv/hv_kvp.c       |   39 +++++++++++++++++++++------------------
 drivers/hv/hv_snapshot.c  |   37 ++++++++++++++++++++-----------------
 drivers/hv/hyperv_vmbus.h |   14 ++++++++++++++
 5 files changed, 92 insertions(+), 51 deletions(-)

-- 
1.7.4.1

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