linux-kernel - Re: [PATCH 2/3] KVM: x86: Avoid guest page table walk when gpa

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Message-ID: <661ca6b5-bfb4-5377-d537-fb058d86ca0c@redhat.com>
Date:   Fri, 18 Aug 2017 14:37:51 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Radim Krčmář <rkrcmar@...hat.com>,
        David Hildenbrand <david@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        wanpeng.li@...mail.com, Brijesh Singh <brijesh.singh@....com>
Subject: Re: [PATCH 2/3] KVM: x86: Avoid guest page table walk when
 gpa_available is set

On 18/08/2017 14:36, Radim Krčmář wrote:
>>> +		gpa = vcpu->arch.gpa_val;
>>> +		ret = vcpu_is_mmio_gpa(vcpu, addr, gpa, write);
>>> +	} else {
>>> +		ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
>>>  	}
>>>  
>>> -	ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
>>> -
>>>  	if (ret < 0)
>>>  		return X86EMUL_PROPAGATE_FAULT;
>> just wondering if it makes sense to move this into the else branch (as
>> it logically only belongs to vcpu_mmio_gva_to_gpa)
>
> It does, I took the liberty to change that.

It was on purpose, but it's okay either way. :)

Paolo