On Sun, Sep 19, 2021 at 02:36:46PM +0100, Marc Zyngier wrote: > Urgh. That's a bummer. T1he PMU driver only comes up once it has found > its interrupt controller, which on the Armada 8040 is not the GIC, but > some weird thing on the side that doesn't actually serve any real > purpose. On HW where the PMU is directly wired into the GIC, it all > works fine, though by luck rather than by design. > > Anyway, rant over. This is a bug that needs addressing so that KVM can > initialise correctly irrespective of the probing order. This probably > means that the static key controlling KVM's behaviour wrt the PMU must > be controlled by the PMU infrastructure itself, rather than KVM trying > to probe for it. > > Can you please give the following hack a go (on top of 5.15-rc1)? I've > briefly tested it on my McBin, and it did the trick. I've also tested > it on the M1 (which really doesn't have an architectural PMU) to > verify that it was correctly failing. My test program that derives the number of registers qemu uses now reports 236 registers again and I see: kvm [7]: PMU detected and enabled in the kernel boot log. Tested-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
