On Mon, Dec 05, 2022, Isaku Yamahata wrote:
> On Wed, Nov 30, 2022 at 11:09:15PM +0000,
> > index 66f16458aa97..3571bc968cf8 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -9277,10 +9277,36 @@ static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
> > kvm_pmu_ops_update(ops->pmu_ops);
> > }
> >
> > +struct kvm_cpu_compat_check {
> > + struct kvm_x86_init_ops *ops;
> > + int *ret;
>
> minor nitpick: just int ret. I don't see the necessity of the pointer.
> Anyway overall it looks good to me.
...
> > @@ -9360,6 +9386,14 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
> > if (r != 0)
> > goto out_mmu_exit;
> >
> > + c.ret = &r;
> > + c.ops = ops;
> > + for_each_online_cpu(cpu) {
> > + smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &c, 1);
> > + if (r < 0)
>
> Here it can be "c.ret < 0".
No, because the below goto leads to "return r", i.e. "c.ret" needs to be propagated
to "r". That's why the code does the admittedly funky "int *ret" thing.
FWIW, this gets cleanup in the end. "struct kvm_cpu_compat_check" goes away and
"&r" is passed directly to kvm_x86_check_cpu_compat.
> > + goto out_hardware_unsetup;
