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;
IronPort-SDR: B0QKe2KVWswrKI5VgIzJyYwm2KFJbeSBWYwbXz7EV80dWUgryHONmjyY0Ps4r2oiR02PhFPfke
 8jTdxft7Rctg==
IronPort-SDR: TUcmWrm43qUGmO9EuUS72JpqKgmzOA1tf4ziybRypb0LtWcAbP2isrydyxFq4LXZgcUVGH14o3
 09w080pSh6Ww==
Date:   Mon, 22 Jun 2020 18:15:41 -0700
From:   Sean Christopherson <sean.j.christopherson@intel.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: x86/mmu: Don't put invalid SPs back on the list of
 active pages
Message-ID: <20200623011541.GD6151@linux.intel.com>
References: <20200622191850.8529-1-sean.j.christopherson@intel.com>
 <d1916978-6efb-2839-d45a-c39ff2f6dc1f@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <d1916978-6efb-2839-d45a-c39ff2f6dc1f@redhat.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Jun 23, 2020 at 02:23:53AM +0200, Paolo Bonzini wrote:
> On 22/06/20 21:18, Sean Christopherson wrote:
> > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> > index fdd05c233308..fa5bd3f987dd 100644
> > --- a/arch/x86/kvm/mmu/mmu.c
> > +++ b/arch/x86/kvm/mmu/mmu.c
> > @@ -2757,10 +2757,13 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
> >  	if (!sp->root_count) {
> >  		/* Count self */
> >  		(*nr_zapped)++;
> > -		list_move(&sp->link, invalid_list);
> > +		if (sp->role.invalid)
> > +			list_add(&sp->link, invalid_list);
> > +		else
> > +			list_move(&sp->link, invalid_list);
> 
> It's late here, but I think this part needs a comment anyway...

No argument here.  I'll spin a v2, I just realized there is a separate
optimization that can build on this patch.  I was planning on sending it
separately, but I misread the loop in make_mmu_pages_available().