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  1. 24 10月, 2016 6 次提交
  3. 18 10月, 2016 1 次提交
  5. 10 10月, 2016 5 次提交
  7. 14 9月, 2016 2 次提交
    • D
      hw: replace most use of qemu_chr_fe_write with qemu_chr_fe_write_all · 6ab3fc32
      由 Daniel P. Berrange 提交于 
      The qemu_chr_fe_write method will return -1 on EAGAIN if the
chardev backend write would block. Almost no callers of the
qemu_chr_fe_write() method check the return value, instead
blindly assuming data was successfully sent. In most cases
this will lead to silent data loss on interactive consoles,
but in some cases (eg RNG EGD) it'll just cause corruption
of the protocol being spoken.

We unfortunately can't fix the virtio-console code, due to
a bug in the Linux guest drivers, which would cause the
entire Linux kernel to hang if we delay processing of the
incoming data in any way. Fixing this requires first fixing
the guest driver to not hold spinlocks while writing to the
hvc device backend.

Fixes bug: https://bugs.launchpad.net/qemu/+bug/1586756Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-Id: <1473170165-540-4-git-send-email-berrange@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      6ab3fc32
    • D
      sclpconsolelm: remove bogus check for -EAGAIN · 7983e829
      由 Daniel P. Berrange 提交于 
      The write_console_data() method in sclpconsole-lm.c checks
whether the return value of qemu_chr_fe_write() has the
value of -EAGAIN and if so then increments the buffer offset
by the value of EAGAIN. Fortunately qemu_chr_fe_write() will
never return EAGAIN directly, rather it returns -1 with
errno set to EAGAIN, so this broken code path was not
reachable. The behaviour on EAGAIN was stil bad though,
causing the write_console_data() to busy_wait repeatedly
calling qemu_chr_fe_write() with no sleep between iters.

Just remove all this loop logic and replace with a call
to qemu_chr_fe_write_all().
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-Id: <1473170165-540-3-git-send-email-berrange@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      7983e829
  9. 08 9月, 2016 1 次提交
  11. 12 8月, 2016 1 次提交
  13. 11 8月, 2016 1 次提交
    • D
      virtio-console: set frontend open permanently for console devs · bce6261e
      由 Daniel P. Berrange 提交于 
      The virtio-console.c file handles both serial consoles
and interactive consoles, since they're backed by the
same device model.

Since serial devices are expected to be reliable and
need to notify the guest when the backend is opened
or closed, the virtio-console.c file wires up support
for chardev events. This affects both serial consoles
and interactive consoles, using a network connection
based chardev backend such as 'socket', but not when
using a PTY based backend or plain 'file' backends.

When the host side is not connected the handle_output()
method in virtio-serial-bus.c will drop any data sent
by the guest, before it even reaches the virtio-console.c
code. This means that if the chardev has a logfile
configured, the data will never get logged.

Consider for example, configuring a x86_64 guest with a
plain UART serial port

  -chardev socket,id=charserial1,host=127.0.0.1,port=9001,server,nowait,logfile=console1.log,logappend=on
  -device isa-serial,chardev=charserial1,id=serial1

vs a s390 guest which has to use the virtio-console port

  -chardev socket,id=charconsole1,host=127.0.0.1,port=9000,server,nowait,logfile=console2.log,logappend=on
  -device virtconsole,chardev=charconsole1,id=console1

The isa-serial one gets data written to the log regardless
of whether a client is connected, while the virtioconsole
one only gets data written to the log when a client is
connected.

There is no need for virtio-serial-bus.c to aggressively
drop the data for console devices, as the chardev code is
prefectly capable of discarding the data itself.

So this patch changes virtconsole devices so that they
are always marked as having the host side open. This
ensures that the guest OS will always send any data it
has (Linux virtio-console hvc driver actually ignores
the host open state and sends data regardless, but we
should not rely on that), and also prevents the
virtio-serial-bus code prematurely discarding data.

The behaviour of virtserialport devices is *not* changed,
only virtconsole, because for the former, it is important
that the guest OSknow exactly when the host side is opened
/ closed so it can do any protocol re-negotiation that may
be required.

Fixes bug: https://bugs.launchpad.net/qemu/+bug/1599214Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-Id: <1470241360-3574-2-git-send-email-berrange@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
      bce6261e
  15. 22 7月, 2016 2 次提交
  17. 12 7月, 2016 1 次提交
  19. 29 6月, 2016 6 次提交
  21. 27 6月, 2016 1 次提交
  23. 21 6月, 2016 2 次提交
  25. 17 6月, 2016 1 次提交
  27. 07 6月, 2016 1 次提交
  29. 06 6月, 2016 5 次提交
  31. 29 5月, 2016 4 次提交