Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
Message-ID: <ad47de2b-84b6-aaca-2a01-ae4fd8248cad@redhat.com>
Date:   Fri, 11 Feb 2022 17:52:38 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH 06/12] KVM: MMU: rename kvm_mmu_reload
Content-Language: en-US
To:     Sean Christopherson <seanjc@google.com>
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        vkuznets@redhat.com, mlevitsk@redhat.com, dmatlack@google.com
References: <20220209170020.1775368-1-pbonzini@redhat.com>
 <20220209170020.1775368-7-pbonzini@redhat.com> <YgWtdUotsoBOOtXz@google.com>
 <4e05cfc5-55bb-1273-5309-46ed4fe52fed@redhat.com>
 <YgaLwvo2Gl565H3/@google.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <YgaLwvo2Gl565H3/@google.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2/11/22 17:16, Sean Christopherson wrote:
> The other nuance that I want to avoid is the implication that KVM is checking for
> a valid root because it doesn't trust what has happened before, i.e. that the call
> is there as a safeguard.  That's misleading for the most common path, vcpu_enter_guest(),
> because when the helper does do some work, it's usually because KVM deliberately
> invalidated the root.

Fair enough.

>> I also thought of "establish_valid_root", but it has the opposite
>> problem---it does not convey well, if at all, that the root could be valid
>> already.
> 
> Heh, I agree that "establish" would imply the root is always invalid, but amusingly
> "establish" is listed as a synonym for "ensure" on the few sites of checked. Yay English.

Well, synonyms rarely have a perfectly matching meaning.

> Can we put this on the backburner for now?

Yes, of course.

Paolo

> IMO, KVM_REQ_MMU_RELOAD is far more
> misleading than kvm_mmu_reload(), and I posted a series to remedy that (though I
> need to check if it's still viable since you vetoed adding the check for a pending
> request in the page fault handler).
> 
> https://lore.kernel.org/all/20211209060552.2956723-1-seanjc@google.com