linux-kernel - Re: [RFC PATCH 00/10] KVM: x86/mmu: simplify argument to kvm page fault handler

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Message-ID: <20210610220056.GA642297@private.email.ne.jp>
Date:   Thu, 10 Jun 2021 15:00:56 -0700
From:   Isaku Yamahata <isaku.yamahata@...il.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Isaku Yamahata <isaku.yamahata@...el.com>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>, isaku.yamahata@...il.com
Subject: Re: [RFC PATCH 00/10] KVM: x86/mmu: simplify argument to kvm page
 fault handler

Thanks for feedback. Let me respin it.

On Thu, Jun 10, 2021 at 02:45:55PM +0200,
Paolo Bonzini <pbonzini@...hat.com> wrote:

> On 26/05/21 23:10, Sean Christopherson wrote:
> >    - Have kvm_mmu_do_page_fault() handle initialization of the struct.  That
> >      will allow making most of the fields const, and will avoid the rather painful
> >      kvm_page_fault_init().
> > 
> >    - Pass @vcpu separately.  Yes, it's associated with the fault, but literally
> >      the first line in every consumer is "struct kvm_vcpu *vcpu = kpf->vcpu;".
> > 
> >    - Use "fault" instead of "kpf", mostly because it reads better for people that
> >      aren't intimately familiar with the code, but also to avoid having to refactor
> >      a huge amount of code if we decide to rename kvm_page_fault, e.g. if we decide
> >      to use that name to return fault information to userspace.
> > 
> >    - Snapshot anything that is computed in multiple places, even if it is
> >      derivative of existing info.  E.g. it probably makes sense to grab
> 
> I agree with all of these (especially it was a bit weird not to see vcpu in
> the prototypes).  Thanks Sean for the review!
> 
> Paolo
> 

-- 
Isaku Yamahata <isaku.yamahata@...il.com>