Re: [PATCH 1/2] KVM: X86: Fix setup the virt_spin_lock_key before static key get initialized

From: Davidlohr Bueso
Date: Mon Mar 26 2018 - 18:44:55 EST


On Mon, 26 Mar 2018, Wanpeng Li wrote:

I didn't see any issue when testing this patch, could you elaborate
what's the bulky mechanism and how it conflicts with early smp bootup
stages? In addition, do you mean the xen fix is also not suitable?

I have nothing against your patch (or the xen one for that matter), other than
the fact that both seem like band-aid solutions to being able to move up the jump
label init call. I was actually peddling a similar patch but didn't want to add
the extra callback just for that -- at least xen already had smp_ops.smp_prepare_cpus.

Instead of dropping the patches in -tip (ie: delaying the feature), I have nothing
against these fixes being merged. If a better solution is available later, we can
always move dealing with virt_spin_lock_key back into smp_prepare_boot_cpu().

Also a bit unrelated, but am I correct to assume that KVM_HINTS_DEDICATED can be
used via qemu? I've only been dealing with kernel parameters.

Thanks,
Davidlohr