Re: [PATCH 15/24] kvm: mmu: Wrap mmu_lock cond_resched and needbreak

[Paolo Bonzini]

On 27/01/21 22:20, Ben Gardon wrote:
> On Wed, Jan 27, 2021 at 12:55 PM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> > On 27/01/21 21:08, Ben Gardon wrote:
> > > I'm not entirely sure I understand this suggestion. Are you suggesting
> > > we'd have the spinlock and rwlock in a union in struct kvm but then
> > > use a static define to choose which one is used by other functions? It
> > > seems like if we're using static defines the union doesn't add value.
> >
> > Of course you're right.  You'd just place the #ifdef in the struct kvm
> > definition.
>
> Ah okay, thanks for clarifying.
>
> > You can place static inline functions for lock/unlock in
> > virt/kvm/mmu_lock.h, in order to avoid a proliferation of #ifdefs.
>
> Would you prefer to make that change in this series or at a later
> date? I'm assuming this would replace all the wrapper functions and
> mean that x86 is rwlock only.

Yes, exactly.  I would like to make tdp_mmu=1 the default as soon as 
parallel page faults are in (and thus scalability should be on par with 
the shadow MMU).

Paolo