4:21 a.m.
On Tue, Feb 09, 2016 at 02:42:53PM -0500, Cole Robinson wrote:
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
Just my two cents here. I remember that we were dealing with this
because of ppc64 with Andrea and I think we are using '-usb' in one
particular case even when there is the option to specify it as a
device. That case is when we know the default usb controller that used
to be added with '-usb' and that particular controller is not available
(listed) in the list of devices, so to keep the guest ABI the same, we
fallback to '-usb' because we have no other way to do that. However,
this will be a problem in the future when qemu changes the default
controller added with -usb. That's just another rabbit hole I don't
want to go too deep in. Maybe Andrea already knows more and started
doing something with it. Andrea?
- Cole