From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ben Gardon <bgardon@google.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Peter Xu <peterx@redhat.com>, Peter Shier <pshier@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>
Subject: Re: [PATCH v2 1/7] KVM: x86/mmu: Track if shadow MMU active
Date: Tue, 4 May 2021 20:36:09 +0000 [thread overview]
Message-ID: <YJGwOfzTtj4kJIVp@google.com> (raw)
In-Reply-To: <edfadb98-b86e-6d03-bdfc-9025fac73dee@redhat.com>
On Tue, May 04, 2021, Paolo Bonzini wrote:
> On 04/05/21 21:55, Sean Christopherson wrote:
> > But, I think we we can avoid bikeshedding by simply eliminating this flag. More
> > in later patches.
>
> Are you thinking of checking slot->arch.rmap[0] directly? That should work
> indeed.
>
> > > - kvm_mmu_init_tdp_mmu(kvm);
> > > + if (!kvm_mmu_init_tdp_mmu(kvm))
> > > + activate_shadow_mmu(kvm);
> > Doesn't come into play yet, but I would strongly prefer to open code setting the
> > necessary flag instead of relying on the helper to never fail.
> >
>
> You mean
>
> kvm->arch.shadow_mmu_active = !kvm_mmu_init_tdp_mmu(kvm);
>
> (which would assign to alloc_memslot_rmaps instead if shadow_mmu_active is
> removed)? That makes sense.
Ya, that or:
if (kvm_mmu_init_tdp_mmu(kvm))
kvm->arch.memslots_have_rmaps = true;
I don't have a preference between the two variants.
next prev parent reply other threads:[~2021-05-04 20:36 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-29 21:18 [PATCH v2 0/7] Lazily allocate memslot rmaps Ben Gardon
2021-04-29 21:18 ` [PATCH v2 1/7] KVM: x86/mmu: Track if shadow MMU active Ben Gardon
2021-05-03 13:42 ` Paolo Bonzini
2021-05-04 17:26 ` Ben Gardon
2021-05-04 20:18 ` Paolo Bonzini
2021-05-04 19:55 ` Sean Christopherson
2021-05-04 20:26 ` Paolo Bonzini
2021-05-04 20:36 ` Sean Christopherson [this message]
2021-04-29 21:18 ` [PATCH v2 2/7] KVM: x86/mmu: Skip rmap operations if shadow MMU inactive Ben Gardon
2021-04-29 21:18 ` [PATCH v2 3/7] KVM: x86/mmu: Deduplicate rmap freeing Ben Gardon
2021-04-29 21:18 ` [PATCH v2 4/7] KVM: x86/mmu: Factor out allocating memslot rmap Ben Gardon
2021-04-29 21:18 ` [PATCH v2 5/7] KVM: mmu: Refactor memslot copy Ben Gardon
2021-04-29 21:18 ` [PATCH v2 6/7] KVM: mmu: Add slots_arch_lock for memslot arch fields Ben Gardon
2021-05-03 13:29 ` Paolo Bonzini
2021-04-29 21:18 ` [PATCH v2 7/7] KVM: x86/mmu: Lazily allocate memslot rmaps Ben Gardon
2021-05-03 13:42 ` Paolo Bonzini
2021-05-03 17:29 ` Ben Gardon
2021-05-04 20:13 ` Sean Christopherson
2021-05-04 20:19 ` Paolo Bonzini
2021-05-04 20:34 ` Sean Christopherson
2021-05-04 20:22 ` Paolo Bonzini
2021-05-03 13:44 ` [PATCH v2 0/7] " Paolo Bonzini
2021-05-03 17:31 ` Ben Gardon
2021-05-04 7:21 ` Paolo Bonzini
2021-05-04 17:28 ` Ben Gardon
2021-05-04 18:17 ` Sean Christopherson
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