[libvirt] [PATCH v2 1/6] tests: qemuxml2argv: remove some QEMU_CAPS_DEVICE problem cases

[Cole Robinson]

On 02/09/2016 02:28 PM, Laine Stump wrote:
> On 02/09/2016 01:46 PM, Cole Robinson wrote:
>> On 02/09/2016 01:31 PM, Laine Stump wrote:
>>> On 02/09/2016 10:58 AM, Cole Robinson wrote:
>>>> When we unconditionally enable QEMU_CAPS_DEVICE, these tests need
>>>> some massaging, so do it ahead of time to not mix it in with the
>>>> big test refresh.
>>>>
>>>> - minimal-s390 is not a real world working config, so drop it
>>>> - disk-usb was testing for an old code path that will be removed.
>>>>     instead use it to test lack of USB disk support, and rename it
>>>>     to disk-usb-nosupport. Switch xml2xml to use disk-usb-device for
>>>>     input.
>>>> - cputune-numatune was needlessly using q35, switch it to an older
>>>>     machine type
>>>> ---
>>>>    .../qemuxml2argv-cputune-numatune.args             |  7 +++----
>>>>    .../qemuxml2argv-cputune-numatune.xml              | 12 +----------
>>>>    .../qemuxml2argv-disk-usb-nosupport.xml}           |  0
>>>>    tests/qemuxml2argvdata/qemuxml2argv-disk-usb.args  | 23
>>>> ----------------------
>>>>    .../qemuxml2argv-minimal-s390.args                 | 21
>>>> --------------------
>>>>    .../qemuxml2argvdata/qemuxml2argv-minimal-s390.xml | 21
>>>> --------------------
>>>>    tests/qemuxml2argvtest.c                           |  5 ++---
>>>>    .../qemuxml2xmlout-cputune-numatune.xml            | 14 +++----------
>>>>    .../qemuxml2xmlout-disk-usb-device.xml}            |  6 ++----
>>>>    tests/qemuxml2xmltest.c                            |  2 +-
>>>>    10 files changed, 12 insertions(+), 99 deletions(-)
>>>>    rename tests/{qemuxml2xmloutdata/qemuxml2xmlout-disk-usb.xml =>
>>>> qemuxml2argvdata/qemuxml2argv-disk-usb-nosupport.xml} (100%)
>>>>    delete mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-usb.args
>>>>    delete mode 100644 tests/qemuxml2argvdata/qemuxml2argv-minimal-s390.args
>>>>    delete mode 100644 tests/qemuxml2argvdata/qemuxml2argv-minimal-s390.xml
>>>>    rename tests/{qemuxml2argvdata/qemuxml2argv-disk-usb.xml =>
>>>> qemuxml2xmloutdata/qemuxml2xmlout-disk-usb-device.xml} (90%)
>>>>
>>>> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-cputune-numatune.args
>>>> b/tests/qemuxml2argvdata/qemuxml2argv-cputune-numatune.args
>>>> index 7e5678d..bde6338 100644
>>>> --- a/tests/qemuxml2argvdata/qemuxml2argv-cputune-numatune.args
>>>> +++ b/tests/qemuxml2argvdata/qemuxml2argv-cputune-numatune.args
>>>> @@ -7,16 +7,15 @@ QEMU_AUDIO_DRV=none \
>>>>    /usr/bin/qemu-system-x86_64 \
>>>>    -name dummy2 \
>>>>    -S \
>>>> --M pc-q35-2.3 \
>>>> +-M pc-0.11 \
>>>>    -m 128 \
>>>>    -smp 2,maxcpus=6,sockets=6,cores=1,threads=1 \
>>>>    -object iothread,id=iothread1 \
>>>>    -object iothread,id=iothread2 \
>>>>    -uuid 4d92ec27-9ebf-400b-ae91-20c71c647c19 \
>>>>    -nographic \
>>>> +-nodefaults \
>>>>    -monitor unix:/tmp/test-monitor,server,nowait \
>>>>    -no-acpi \
>>>>    -boot c \
>>>> --net none \
>>>> --serial none \
>>>> --parallel none
>>>> +-usb
>>> Why did I think that we had eliminated all use of "-usb"? Is it that we're
>>> currently only using it in the tests? If so, that's another thing to eliminate
>>> - we should never be using -usb unless that's the only way to get a usb device
>>> for a particular qemu (and I don't know that that is *ever* the case).
>>>
>> The qemu_command.c chunk is:
>>
>>      if (usbcontroller == 0 &&
>>          !qemuDomainMachineIsQ35(def) &&
>>          !ARCH_IS_S390(def->os.arch))
>>          virCommandAddArg(cmd, "-usb")
>>
>> Where usbcontroller == 0 if we didn't build a -device string for a USB
>> controller. I'd need to dig into qemu to figure out what -usb actually maps to
>> to determine if that makes sense anymore
> 
> Okay, that's what I remember. usbcontroller will only be 0 if there was no
> <controller type='usb'/> in the xml, and that shouldn't happen because the
> post-parse will add a usb controller if there isn't any (except in a few cases
> - see qemuDomainDefAddDefaultDevices). So is the post-parse not happening for
> the qemuxml2argvtest? (there are dozens and dozens of "-usb" in the *.args files)
> 
> 

PostParse is triggered automatically via DomainDefParse. You can see in the
qemuxml2xml output that there's a USB controller added.

Looking deeper, that usbcontroller bit is only set if QEMU_CAPS_PIIX3_USB_UHCI
is available, otherwise it uses legacyusb aka -usb. Maybe that's another flag
that we can assume is available unconditionally for the qemu we support, I'd
need to dig a bit

- Cole