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Date:   Fri, 4 Nov 2022 00:18:19 -0700
From:   Isaku Yamahata <isaku.yamahata@gmail.com>
To:     Sean Christopherson <seanjc@google.com>
Cc:     Isaku Yamahata <isaku.yamahata@gmail.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Marc Zyngier <maz@kernel.org>,
        Huacai Chen <chenhuacai@kernel.org>,
        Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>,
        Anup Patel <anup@brainfault.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
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        James Morse <james.morse@arm.com>,
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        Isaku Yamahata <isaku.yamahata@intel.com>,
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        Chao Gao <chao.gao@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Yuan Yao <yuan.yao@intel.com>
Subject: Re: [PATCH 36/44] KVM: x86: Do compatibility checks when onlining CPU
Message-ID: <20221104071819.GD1063309@ls.amr.corp.intel.com>
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 <Y2RB4qT02EkhMjPL@google.com>
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On Thu, Nov 03, 2022 at 10:34:10PM +0000,
Sean Christopherson <seanjc@google.com> wrote:

> On Thu, Nov 03, 2022, Isaku Yamahata wrote:
> > On Wed, Nov 02, 2022 at 11:19:03PM +0000,
> > Sean Christopherson <seanjc@google.com> wrote:
> > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> > > index f223c845ed6e..c99222b71fcc 100644
> > > --- a/arch/x86/include/asm/kvm_host.h
> > > +++ b/arch/x86/include/asm/kvm_host.h
> > > @@ -1666,7 +1666,7 @@ struct kvm_x86_nested_ops {
> > >  };
> > >  
> > >  struct kvm_x86_init_ops {
> > > -	int (*check_processor_compatibility)(void);
> > > +	int (*check_processor_compatibility)(int cpu);
> > 
> > Is this cpu argument used only for error message to include cpu number
> > with avoiding repeating raw_smp_processor_id() in pr_err()?
> 
> Yep.
> 
> > The actual check is done on the current executing cpu.
> > 
> > If cpu != raw_smp_processor_id(), cpu is wrong. Although the function is called
> > in non-preemptive context, it's a bit confusing. So voting to remove it and
> > to use.
> 
> What if I rename the param is this_cpu?  I 100% agree the argument is confusing
> as-is, but forcing all the helpers to manually grab the cpu is quite annoying.

Makes sense. Let's settle it with this_cpu.
-- 
Isaku Yamahata <isaku.yamahata@gmail.com>