linux-toradex.git/drivers/hv/hv_fcopy.c, branch v5.10-rc6

hv_utils: Always execute the fcopy and vss callbacks in a tasklet

2020-04-23T13:17:11+00:00

The fcopy and vss callback functions could be running in a tasklet
at the same time they are called in hv_poll_channel().  Current code
serializes the invocations of these functions, and their accesses to
the channel ring buffer, by sending an IPI to the CPU that is allowed
to access the ring buffer, cf. hv_poll_channel().  This IPI mechanism
becomes infeasible if we allow changing the CPU that a channel will
interrupt.  Instead modify the callback wrappers to always execute
the fcopy and vss callbacks in a tasklet, thus mirroring the solution
for the kvp callback functions adopted since commit a3ade8cc474d8
("HV: properly delay KVP packets when negotiation is in progress").
This will ensure that the callback function can't run on two CPUs at
the same time.

Suggested-by: Michael Kelley 
Signed-off-by: Andrea Parri (Microsoft) 
Link: https://lore.kernel.org/r/20200406001514.19876-6-parri.andrea@gmail.com
Reviewed-by: Michael Kelley 
Signed-off-by: Wei Liu

hv_utils: Add the support of hibernation

2020-01-27T03:10:17+00:00

Add util_pre_suspend() and util_pre_resume() for some hv_utils devices
(e.g. kvp/vss/fcopy), because they need special handling before
util_suspend() calls vmbus_close().

For kvp, all the possible pending work items should be cancelled.

For vss and fcopy, some extra clean-up needs to be done, i.e. fake a
THAW message for hv_vss_daemon and fake a CANCEL_FCOPY message for
hv_fcopy_daemon, otherwise when the VM resums back, the daemons
can end up in an inconsistent state (i.e. the file systems are
frozen but will never be thawed; the file transmitted via fcopy
may not be complete). Note: there is an extra patch for the daemons:
"Tools: hv: Reopen the devices if read() or write() returns errors",
because the hv_utils driver can not guarantee the whole transaction
finishes completely once util_suspend() starts to run (at this time,
all the userspace processes are frozen).

util_probe() disables channel->callback_event to avoid the race with
the channel callback.

Signed-off-by: Dexuan Cui 
Reviewed-by: Michael Kelley 
Signed-off-by: Sasha Levin

Drivers: hv: Specify receive buffer size using Hyper-V page size

2019-11-22T01:10:45+00:00

The recv_buffer is used to retrieve data from the VMbus ring buffer.
VMbus ring buffers are sized based on the guest page size which
Hyper-V assumes to be 4KB. But it may be different on some
architectures. So use the Hyper-V page size to allocate the
recv_buffer and set the maximum size to receive.

Signed-off-by: Himadri Pandya 
Reviewed-by: Michael Kelley 
Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 280

2019-06-05T15:36:36+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose good title or non infringement see
  the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 9 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Alexios Zavras 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.459653302@linutronix.de
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: fcopy: restore correct transfer length

2017-09-22T08:29:54+00:00

Till recently the expected length of bytes read by the
daemon did depend on the context. It was either hv_start_fcopy or
hv_do_fcopy. The daemon had a buffer size of two pages, which was much
larger than needed.

Now the expected length of bytes read by the
daemon changed slightly. For START_FILE_COPY it is still the size of
hv_start_fcopy.  But for WRITE_TO_FILE and the other operations it is as
large as the buffer that arrived via vmbus. In case of WRITE_TO_FILE
that is slightly larger than a struct hv_do_fcopy. Since the buffer in
the daemon was still larger everything was fine.

Currently, the daemon reads only what is actually needed.
The new buffer layout is as large as a struct hv_do_fcopy, for the
WRITE_TO_FILE operation. Since the kernel expects a slightly larger
size, hvt_op_read will return -EINVAL because the daemon will read
slightly less than expected. Address this by restoring the expected
buffer size in case of WRITE_TO_FILE.

Fixes: 'c7e490fc23eb ("Drivers: hv: fcopy: convert to hv_utils_transport")'
Fixes: '3f2baa8a7d2e ("Tools: hv: update buffer handling in hv_fcopy_daemon")'

Signed-off-by: Olaf Hering 
Signed-off-by: K. Y. Srinivasan 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

Merge 4.11-rc4 into char-misc-next

2017-03-27T07:13:04+00:00

We want the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

vmbus: remove useless return's

2017-03-17T06:10:48+00:00

No need for empty return at end of void function

Signed-off-by: Stephen Hemminger 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: util: move waiting for release to hv_utils_transport itself

2017-03-16T07:42:00+00:00

Waiting for release_event in all three drivers introduced issues on release
as on_reset() hook is not always called. E.g. if the device was never
opened we will never get the completion.

Move the waiting code to hvutil_transport_destroy() and make sure it is
only called when the device is open. hvt->lock serialization should
guarantee the absence of races.

Fixes: 5a66fecbf6aa ("Drivers: hv: util: kvp: Fix a rescind processing issue")
Fixes: 20951c7535b5 ("Drivers: hv: util: Fcopy: Fix a rescind processing issue")
Fixes: d77044d142e9 ("Drivers: hv: util: Backup: Fix a rescind processing issue")

Reported-by: Dexuan Cui 
Tested-by: Dexuan Cui 
Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: Log the negotiated IC versions.

2017-01-31T10:05:59+00:00

Log the negotiated IC versions.

Signed-off-by: Alex Ng 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Use all supported IC versions to negotiate

2017-01-31T10:05:59+00:00

Previously, we were assuming that each IC protocol version was tied to a
specific host version. For example, some Windows 10 preview hosts only
support v3 TimeSync even though driver assumes v4 is supported by all
Windows 10 hosts.

The guest will stop trying to negotiate even though older supported
versions may still be offered by the host.

Make IC version negotiation more robust by going through all versions
that are supported by the guest.

Fixes: 3da0401b4d0e ("Drivers: hv: utils: Fix the mapping between host
version and protocol to use")

Reported-by: Rolf Neugebauer 
Signed-off-by: Alex Ng 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman