Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH 18/22] kvm: mmu: Support disabling dirty logging for the
 tdp MMU
To:     Ben Gardon <bgardon@google.com>
Cc:     LKML <linux-kernel@vger.kernel.org>, kvm <kvm@vger.kernel.org>,
        Cannon Matthews <cannonmatthews@google.com>,
        Peter Xu <peterx@redhat.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Peter Shier <pshier@google.com>,
        Peter Feiner <pfeiner@google.com>,
        Junaid Shahid <junaids@google.com>,
        Jim Mattson <jmattson@google.com>,
        Yulei Zhang <yulei.kernel@gmail.com>,
        Wanpeng Li <kernellwp@gmail.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Xiao Guangrong <xiaoguangrong.eric@gmail.com>
References: <20200925212302.3979661-1-bgardon@google.com>
 <20200925212302.3979661-19-bgardon@google.com>
 <44822999-f5dc-6116-db12-a41f5bd80dd8@redhat.com>
 <CANgfPd_dQ19sZz2wzSfz7-RzdbQrfP6cYJLpSYbyNyQW6Uf09Q@mail.gmail.com>
 <5dc72eec-a4bd-f31a-f439-cdf8c5b48c05@redhat.com>
 <CANgfPd8Nzi2Cb3cvh5nFoaXTPbfm7Y77e4iM6-zOp5Qa3wNJBw@mail.gmail.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <0dd49e95-181f-e6eb-5e3f-ed32d20c2196@redhat.com>
Date:   Wed, 7 Oct 2020 19:53:48 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.11.0
MIME-Version: 1.0
In-Reply-To: <CANgfPd8Nzi2Cb3cvh5nFoaXTPbfm7Y77e4iM6-zOp5Qa3wNJBw@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 07/10/20 19:28, Ben Gardon wrote:
>> No, that would be just another way to write the same thing.  That said,
>> making the iteration API more complicated also has disadvantages because
>> if get a Cartesian explosion of changes.
> I wouldn't be too worried about that. The only things I ever found
> worth making an iterator case for were:
> Every SPTE
> Every present SPTE
> Every present leaf SPTE

* (vcpu, root) * (all levels, large only)

We only need a small subset of these, but the naming would be more
complex at least.

Paolo