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. > Hmph, starting a guest a couple of times and running hackbench inside the guest actually gave me (twice) the following error: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/0:0:4] (that is using your branch on Mustang). -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
