Re: [PATCH v3 3/3] KVM: arm64: selftests: Check ID regs are immutable after a failed run

[Lorenzo Stoakes (ARM)]

On Mon, Sep 28, 2026 at 05:56:54PM +0100, Fuad Tabba wrote:
> Hi Lorenzo,
>
> On Mon, 28 Sep 2026 15:46:51 +0100, "Lorenzo Stoakes (ARM)"
> <ljs@xxxxxxxxxx> wrote:
> > On Tue, Sep 01, 2026 at 07:18:50PM +0100, Mark Brown wrote:
> [...]
> > > Assisted-by: Antigravity:gemini-3.1-pro
> >
> > NIT: we changed the rules for the Assisted-by tag, it only needs to be
> > 'Assisted-by: LLM' now. Not a huge big deal but FYI :>)
> >
> > https://docs.kernel.org/process/coding-assistants.html
>
> That tag dates from way back when the format was still
> AGENT_NAME:MODEL_VERSION :)

Ack yeah it's not a big deal :)

>
> [...]
> > > diff --git a/tools/testing/selftests/kvm/arm64/set_id_regs.c b/tools/testing/selftests/kvm/arm64/set_id_regs.c
> [...]
> > > +static void test_idreg_frozen_after_failed_run(void)
> [...]
> > > +        /* Creating an in-kernel irqchip would change the ID registers too. */
> > > +        if (kvm_supports_vgic_v3()) {
> > > +                r = __kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3);
> > > +                TEST_ASSERT(r < 0 && errno == EBUSY,
> > > +                            "vGIC creation after failed first run: r=%d errno=%d",
> > > +                            r, errno);
> >
> > I guess in general it's making sure - where there should now be finalisation on
> > reg setting that this is actually enforced?
>
> Yes. The test exercises each of the userspace-facing checks that 2/3
> moves to KVM_ARCH_FLAG_ID_REGS_FINAL: set_id_reg(), set_imp_id_reg()
> and kvm_vgic_create().

Great thanks! :)

>
> Thanks,
> /fuad

--
Cheers, Lorenzo