Re: [Qemu-ppc] [Qemu-devel] [PATCH] PPC: Fix via-cuda memory registration

[Blue Swirl]

On Mon, Sep 12, 2011 at 1:53 PM, Avi Kivity <address@hidden> wrote:
> On 09/12/2011 04:46 PM, Lucas Meneghel Rodrigues wrote:
>>
>> On 09/12/2011 06:07 AM, Avi Kivity wrote:
>>>
>>> On 09/11/2011 02:38 PM, Alexander Graf wrote:
>>>>
>>>> Am 11.09.2011 um 12:41 schrieb Avi Kivity<address@hidden>:
>>>>
>>>> > On 09/08/2011 07:54 PM, Alexander Graf wrote:
>>>> >> PS: Please test your patches. This one could have been found with
>>>> an invocation
>>>> >> as simple as "qemu-system-ppc". We boot into the OpenBIOS prompt by
>>>> default,
>>>> >> so you wouldn't even have required a guest image or kernel.
>>>> >>
>>>> >
>>>> >
>>>> > Sorry about that.
>>>> >
>>>> > Note that it's pretty hard to test these patches. I often don't even
>>>> know which binary as the device->target relationship is not
>>>> immediately visible,
>>>>
>>>> The patch was explicitly to convert ppc ;).
>>>
>>> Yes, in this case. Not in the general case.
>>>
>>>> > and I don't really know what to expect from the guest.
>>>>
>>>> The very easy check-fundamentals thing to do for ppc is to execute
>>>> qemu-system-ppc without arguments. It should drop you into an OF
>>>> prompt. Both memory api bugs on ppc I've seen now would have been
>>>> exposed with that.
>>>>
>>>> I agree that we should have something slightly more sophisticated, but
>>>> doing such a bare minimum test is almost for free to the tester and
>>>> covers at least basic functionality :). I don't mind people
>>>> introducibg subtle bugs in corner cases - these things happen. But an
>>>> abort() when you execute the binary? That really shouldn't happen
>>>> ever. This one is almost as bad.
>>>
>>> Yeah.
>>>
>>>> > It would be best if we had a kvm-autotest testset for tcg, it would
>>>> probably run in just a few minutes and increase confidence in these
>>>> patches.
>>>>
>>>> Yeah, I am using kvm-autotest today for regression testing, but it's
>>>> very hard to tell it to run multiple different binaries. The target
>>>> program variable can only be set for an execution job, making it
>>>> impossible to run multiple targets in one autotest run.
>>
>> Alexander, I've started to work on this, I'm clearing out my request list,
>> last week I've implemented ticket 50, that was related to special block
>> configuration for the tests, now I want to make it possible to support
>> multiple binaries.
>>
>>> Probably best to tell autotest about the directory, and let it pick up
>>> the binary. Still need some configuration to choose between qemu-kvm and
>>> qemu-system-x86_64.
>>>
>>> Lucas?
>>
>> Yes, that would also work, having different variants with different qemu
>> and qemu-img paths. Those binaries would have to be already pre-built, but
>> then we miss the ability autotest has of building the binaries and prepare
>> the environment. It'd be like:
>>
>> variant1:
>>    qemu = /path/to/qemu1
>>    qemu-img = /path/to/qemu-img1
>>    extra_params = "--appropriate --extra --params2"
>>
>>
>> variant2:
>>    qemu = /path/to/qemu2
>>    qemu-img = /path/to/qemu-img2
>>    extra_params = "--appropriate --extra --params2"
>>
>> Something like that. It's a feasible intermediate solution until I finish
>> work on supporting multiple userspaces.
>>
>
> Another option is, now that the binary name 'qemu' is available for general
> use, make it possible to invoke everything with just one binary:
>
>  qemu -system -target mips ...
>  qemu-system -target mips ...
>  qemu-system-mips ...
>
> are all equivalent.  autotest should easily be able to pass different
> -target based on the test being run.

Great idea, the original goal of single binary would almost realize.
With 'qemu' defaulting to '-system' and '-target i386' we'd also be
compatible with previous versions too.