Hi Andre, On Fri, Mar 25, 2016 at 02:04:23AM +0000, Andre Przywara wrote: > This series is a joint effort to re-implement KVM's GIC emulation. > > While the current implementation is centered around providing > efficient MMIO emulation, the hot path for most guests is actually > the guest entry and exit, which currently is rather costly. > Also the existing emulation has a global distributor lock, which > quickly becomes a bottleneck once the number of VCPUs increases. > Additionally the emulation was originally designed for GICv2, adding > GICv3 ITS emulation support to this proved to be rather painful. > Last, but not least the existing code became less and less > maintainable, with many special cases handled explicitly. > > The new implementation is build around a struct vgic_irq data data > structure, which holds all information about a virtual interrupt. > Interruts which should be injected are hold in a per-VCPU list, this > make the entry/exit path much more efficient. Also the new structure > allows to have more fine grained locking - per IRQ and per VCPU - > getting rid of the global distributor lock. > As a result of the new design ITS emulation fits in more nicely, the > respective code will be provided as a follow-up series. > > This series implements the same feature set as the existing emulation, > as a goodie we now implement priorities correctly. > To allow an easy transition with good test coverage, but still maintain > stability, both implementations live side by side, selectable via a > Kconfig option. The default is the new implementation. > If this code proves to be reliable, we will later remove the current > implementation with an extra patch set. > > Please have a look at the series, review it and give the code some > serious testing (and possibly debugging). All feedback is appreciated. > Huge thanks for all the hard work in putting this together, I'm sure it hasn't been easy. I have gone through this series and I think we're overall in pretty good shape. I haven't reviewed the code in detail, checked every bitfield etc., but focused on the overall design choices, locking correctness etc. A number of patches don't have have commit message and some commit messages could be clarified, but it is what it is. I've given this a quick test on Mustang and on TC2, and it builds and appears to run decently stable. Obviously we should give this some more rigorous testing, but I will wait until v2 with that. I'll probably send the timer/vgic interface changes bits as patches for you to base the next series on, assuming you and the others agreed with my comments and suggestions on that part here. Thanks, -Christoffer -- 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
