linux-kernel - Re: [PATCH 05/22] kvm: mmu: Add functions to handle changed TDP SPTEs

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Message-ID: <91c07e10-72a9-7570-56a1-2cd50819ae3e@redhat.com>
Date:   Mon, 28 Sep 2020 19:23:51 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Ben Gardon <bgardon@...gle.com>, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Cc:     Cannon Matthews <cannonmatthews@...gle.com>,
        Peter Xu <peterx@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Peter Shier <pshier@...gle.com>,
        Peter Feiner <pfeiner@...gle.com>,
        Junaid Shahid <junaids@...gle.com>,
        Jim Mattson <jmattson@...gle.com>,
        Yulei Zhang <yulei.kernel@...il.com>,
        Wanpeng Li <kernellwp@...il.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Xiao Guangrong <xiaoguangrong.eric@...il.com>
Subject: Re: [PATCH 05/22] kvm: mmu: Add functions to handle changed TDP SPTEs

On 26/09/20 02:39, Paolo Bonzini wrote:
>> +			handle_changed_spte(kvm, as_id,
>> +				gfn + (i * KVM_PAGES_PER_HPAGE(level - 1)),
>> +				old_child_spte, 0, level - 1);
>> +		}
> Is it worth returning a "flush" value to the caller, to avoid multiple
> kvm_flush_remote_tlbs_with_address when e.g. zapping a 3rd-level PTE?

Nevermind, this is not possible since you are freeing the page
immediately after kvm_flush_remote_tlbs_with_address.

Paolo