From: Yan Zhao <yan.y.zhao@intel.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Yosry Ahmed <yosryahmed@google.com>,
"Mingwei Zhang" <mizhang@google.com>,
Ben Gardon <bgardon@google.com>
Subject: Re: [PATCH v2 4/6] KVM: x86/mmu: Track the number of TDP MMU pages, but not the actual pages
Date: Wed, 27 Jul 2022 10:41:39 +0800 [thread overview]
Message-ID: <YuCl48wyA1XkqMan@yzhao56-desk.sh.intel.com> (raw)
In-Reply-To: <20220723012325.1715714-5-seanjc@google.com>
On Sat, Jul 23, 2022 at 01:23:23AM +0000, Sean Christopherson wrote:
<snip>
> @@ -386,16 +385,18 @@ static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn,
> static void tdp_mmu_unlink_sp(struct kvm *kvm, struct kvm_mmu_page *sp,
> bool shared)
> {
> + atomic64_dec(&kvm->arch.tdp_mmu_pages);
> +
> + if (!sp->nx_huge_page_disallowed)
> + return;
> +
Does this read of sp->nx_huge_page_disallowed also need to be protected by
tdp_mmu_pages_lock in shared path?
Thanks
Yan
> if (shared)
> spin_lock(&kvm->arch.tdp_mmu_pages_lock);
> else
> lockdep_assert_held_write(&kvm->mmu_lock);
>
> - list_del(&sp->link);
> - if (sp->nx_huge_page_disallowed) {
> - sp->nx_huge_page_disallowed = false;
> - untrack_possible_nx_huge_page(kvm, sp);
> - }
> + sp->nx_huge_page_disallowed = false;
> + untrack_possible_nx_huge_page(kvm, sp);
>
> if (shared)
> spin_unlock(&kvm->arch.tdp_mmu_pages_lock);
> @@ -1132,9 +1133,7 @@ static int tdp_mmu_link_sp(struct kvm *kvm, struct tdp_iter *iter,
> tdp_mmu_set_spte(kvm, iter, spte);
> }
>
> - spin_lock(&kvm->arch.tdp_mmu_pages_lock);
> - list_add(&sp->link, &kvm->arch.tdp_mmu_pages);
> - spin_unlock(&kvm->arch.tdp_mmu_pages_lock);
> + atomic64_inc(&kvm->arch.tdp_mmu_pages);
>
> return 0;
> }
> --
> 2.37.1.359.gd136c6c3e2-goog
>
next prev parent reply other threads:[~2022-07-27 3:02 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-23 1:23 [PATCH v2 0/6] KVM: x86: Apply NX mitigation more precisely Sean Christopherson
2022-07-23 1:23 ` [PATCH v2 1/6] KVM: x86/mmu: Tag disallowed NX huge pages even if they're not tracked Sean Christopherson
2022-07-25 22:49 ` David Matlack
2022-07-25 23:26 ` Sean Christopherson
2022-07-25 23:45 ` David Matlack
2022-07-26 0:01 ` Sean Christopherson
2022-07-28 22:11 ` Paolo Bonzini
2022-07-23 1:23 ` [PATCH v2 2/6] KVM: x86/mmu: Properly account NX huge page workaround for nonpaging MMUs Sean Christopherson
2022-07-25 23:05 ` David Matlack
2022-07-25 23:08 ` David Matlack
2022-07-28 20:15 ` Paolo Bonzini
2022-07-23 1:23 ` [PATCH v2 3/6] KVM: x86/mmu: Set disallowed_nx_huge_page in TDP MMU before setting SPTE Sean Christopherson
2022-07-25 23:16 ` David Matlack
2022-07-23 1:23 ` [PATCH v2 4/6] KVM: x86/mmu: Track the number of TDP MMU pages, but not the actual pages Sean Christopherson
2022-07-25 23:21 ` David Matlack
2022-07-25 23:27 ` Sean Christopherson
2022-07-27 2:41 ` Yan Zhao [this message]
2022-07-27 19:04 ` Sean Christopherson
2022-07-29 1:02 ` Yan Zhao
2022-07-23 1:23 ` [PATCH v2 5/6] KVM: x86/mmu: Add helper to convert SPTE value to its shadow page Sean Christopherson
2022-07-25 23:23 ` David Matlack
2022-07-25 23:33 ` Sean Christopherson
2022-07-23 1:23 ` [PATCH v2 6/6] KVM: x86/mmu: explicitly check nx_hugepage in disallowed_hugepage_adjust() Sean Christopherson
2022-07-25 23:28 ` David Matlack
2022-07-26 5:37 ` [PATCH v2 0/6] KVM: x86: Apply NX mitigation more precisely Mingwei Zhang
2022-07-26 16:40 ` Sean Christopherson
2022-07-26 17:21 ` Sean Christopherson
2022-07-28 20:17 ` Paolo Bonzini
2022-07-28 21:20 ` Sean Christopherson
2022-07-28 21:41 ` Mingwei Zhang
2022-07-28 22:09 ` Paolo Bonzini
2022-07-28 22:15 ` Sean Christopherson
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