On Mon, Sep 20, 2021 at 10:45:26AM +0100, Russell King (Oracle) wrote: > 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: Hi Russell, You may be interested in kvm selftests and this one[1] in particular. [1] tools/testing/selftests/kvm/aarch64/get-reg-list.c Thanks, drew > > 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! > _______________________________________________ > kvmarm mailing list > kvmarm@xxxxxxxxxxxxxxxxxxxxx > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm >
