On 19.09.16 09:52, Andrew Jones wrote: > On Fri, Sep 16, 2016 at 09:36:42PM +0200, Alexander Graf wrote: >> >> >>> Am 16.09.2016 um 15:46 schrieb Andrew Jones <drjones@xxxxxxxxxx>: >>> >>>> On Fri, Sep 16, 2016 at 03:30:27PM +0200, Christoffer Dall wrote: >>>>> On Fri, Sep 16, 2016 at 02:31:42PM +0200, Paolo Bonzini wrote: >>>>> >>>>> >>>>> On 16/09/2016 14:30, Christoffer Dall wrote: >>>>>>>>> This patch set allows user space to receive vtimer events as well as mask >>>>>>>>> them, so that we can handle all vtimer related interrupt injection from user >>>>>>>>> space, enabling us to use architected timer with user space gic emulation. >>>>>>>> >>>>>>>> I have already voiced my concerns in the past, including face to face, >>>>>>>> and I'm going to repeat it: I not keen at all on adding a new userspace >>>>>>>> interface that is going to bitrot extremely quickly. >>>>>>> >>>>>>> You don't have automated tests set up? It's not going to bitrot if you >>>>>>> test it, either with kvm-unit-tests or just by smoke-testing Linux. >>>>>>> It's _for_ the raspi, but it's not limited to it. >>>>>> >>>>>> Our automated testing situation is not great, no. Something we're >>>>>> looking at, but have resource problems with. >>>>> >>>>> But it's not a good reason to hold back a feature... >>>> >>>> I didn't say that exactly, but choosing not to merge something we cannot >>>> maintain and which we're not paid to look after and where there's a >>>> minimal interest, is not entirely unreasonable. >>>> >>>> That being said, I'm not categorically against these patches, but I >>>> share Marc's view that we've already seen that non-vgic support had been >>>> broken for multiple versions without anyone complaining, and without >>>> automated testing or substantial interest in the work, the patches >>>> really are likely to bit-rot. >>>> >>>> But I haven't even looked at the patches in detail, I was just replying >>>> to the comment about testing. >>> >>> This may be a great time to start encouraging feature writers to submit >>> kvm-unit-tests patches at the same time as the feature (Hi Alex :-) >> >> I actually started off implementing this with the help of kvm-unit-tests. It's awesome! >> >> I'm lacking actual irq support to make the test reasonable though and wanted to get the kernel bits out first :). But I'll sit down on that again soon I hope. > > I'm glad it looks like a good base for you. I need to get this series > https://github.com/rhdrjones/kvm-unit-tests/commits/arm/gic refreshed and > merged, and also it's time to start looking into adding interrupt > injection to chr-testdev. With those in place I hope it'll be an even > better base for you. Awesome. Let me know when you're further ahead with the gic work then so that we can actually trigger interrupts and measure irq latencies :). Until then, I sent the simplistic version that I used for bringup to the list. Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
