Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 8 Mar 2018 21:55:19 +0100
From:   Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
To:     Wanpeng Li <kernellwp@gmail.com>
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH 1/3] KVM: X86: Provides userspace with a capability to
 not intercept MWAIT
Message-ID: <20180308205519.GM12290@flask>
References: <1519897782-8124-1-git-send-email-wanpengli@tencent.com>
 <20180308203132.GJ12290@flask>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20180308203132.GJ12290@flask>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

2018-03-08 21:31+0100, Radim Krčmář:
> 2018-03-01 17:49+0800, Wanpeng Li:
> > @@ -264,10 +262,12 @@ static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
> >  	    __rem;						\
> >  	 })
> >  
> > -static inline bool kvm_mwait_in_guest(void)
> > +#define KVM_X86_DISABLE_EXITS_MWAIT          (1 << 0)
> > +#define KVM_X86_DISABLE_VALID_EXITS          (KVM_X86_DISABLE_EXITS_MWAIT)
> > +
> > +static inline bool kvm_mwait_in_guest(struct kvm *kvm)
> >  {
> > -	return boot_cpu_has(X86_FEATURE_MWAIT) &&
> > -		!boot_cpu_has_bug(X86_BUG_MONITOR);
> > +	return kvm->arch.mwait_in_guest;
> 
> With this nice variable, the wrapper actually makes the code harder to
> read.  Please use kvm->arch.mwait_in_guest directly (and the same for
> the other two future exits),

I take that back.  kvm->arch.mwait_in_guest looks ok, but it would be
vmx->vcpu.kvm->arch.mwait_in_guest elsewhere and that is just too bad.