Re: [Qemu-devel] [Bug 1384892] Re: RTL8168 NIC VFIO not working anymore since QEMU 2.1

[Thorsten Kohfeldt <thorsten.kohfeldt@gmx.de>]

Current QEMU code is quite different now.
When I tested last (with QEMU 2.4) the problem still existed.
I had quite a discussion with Alex up to and around end of 2015,
but unfortunately since then I just did not have any spare time to
convince Alex to accept what I call 'the real fix', a series of patches.
I also could not test QEMU2.5 yet, but it does not *look* like it 
contains any additional fix towards the problem.

Just a hint about the 'underlying' problem:
Several subtypes of that card hang up DURING loading the assigned 
firmware, as QEMU does not correctly map all required i/o areas
for supporting the firmware load (unless i/o mmap is disabled).
The cards need to be power cycled then, reset is not enough.
The correct mapping cannot really be derived from looking at the
Linux driver code - it is rather to be deduced from access traces.

If a firmware is NOT accessible, the card doesn't hang,
but also it is running 'unpatched' i.e. might expose bugs that the
hardware designer/manufacturer has detected and fixed via firmware.

A better workaround is disabling i/o mmap when VFIO-attaching the card.
This is supported by newer QEMU versions.

So no,
the problem is not fixed yet,
but yes,
I guess you can close this bug if you feel like it.

Regards

Am 22.06.2016 um 13:10 schrieb T. Huth:
> Alex' patch has been included here:
> http://git.qemu.org/?p=qemu.git;a=commitdiff;h=69970fcef937bddd7f745
> ... so I assume this ticket could be closed now?

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https://bugs.launchpad.net/bugs/1384892

Title:
  RTL8168 NIC VFIO not working anymore since QEMU 2.1

Status in QEMU:
  New

Bug description:
  After upgrading QEMU from 2.0 to 2.1 (and libiscsi from 1.7.0 to 1.12 as a dependency) my two RTL8168 NICs stopped working.
  The NICs do not respond to any command and even the LEDs on the network connection turn off, a few seconds after the VM started.
  To get them back running I had to downgrade to 2.0 and restart the system.
  Unfortunately, I have no clue what to do or how to debug this problem since there are no specific errors logged.
  I tried two different VMs: Debian Wheezy and IPFire (see attachment for further details).
  The QEMU 2.1 changelog states "Support for RTL8168 NICs." so there were some major changes done, I guess.

  On the IPFire guest the kernel log shows many of these lines:
  r8169 0000:00:07.0 green1: rtl_eriar_cond == 1 (loop: 100, delay: 100)
  r8169 0000:00:07.0 green1: rtl_phy_reset_cond == 1 (loop: 100, delay: 1)

  On the Debian guest there is only:
  r8169 0000:00:07.0: firmware: agent loaded rtl_nic/rtl8168e-3.fw into memory
  r8169 0000:00:07.0: lan0: link down
  ADDRCONF(NETDEV_UP): lan0: link is not ready

  The commandline for IPFire can be seen in the attachment. It is the same for Debian.
  There are also the complete kernel logs for the working (2.0) and non-working (2.1) cases.

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