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Mon, 30 Mar 2026 07:40:50 +0000 Date: Mon, 30 Mar 2026 15:01:17 +0800 From: Yan Zhao To: Rick Edgecombe CC: , , , , , , , Subject: Re: [PATCH 14/17] KVM: x86/mmu: Remove KVM_BUG_ON() that checks lock when removing PTs Message-ID: Reply-To: Yan Zhao References: <20260327201421.2824383-1-rick.p.edgecombe@intel.com> <20260327201421.2824383-15-rick.p.edgecombe@intel.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20260327201421.2824383-15-rick.p.edgecombe@intel.com> X-ClientProxiedBy: SI2PR02CA0016.apcprd02.prod.outlook.com (2603:1096:4:194::9) To PH0PR11MB7472.namprd11.prod.outlook.com (2603:10b6:510:28c::12) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR11MB7472:EE_|DM4PR11MB8179:EE_ X-MS-Office365-Filtering-Correlation-Id: 516b16df-3db5-4262-0d8b-08de8e2faa69 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014|18002099003|22082099003|56012099003; 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This operations does not pass a shared bool for this "operations" --> "operation" ? > KVM_BUG_ON() to use in the logics future home. By "in the logics future home", do you mean "when this logic is moved to its future location"? > But even today there are already MMU write lockdep asserts that mostly > cover the case. Since the KVM_BUG_ON() is already a bit redundant, just > remove it instead of trying to plumb the bool into TDX code. > > Link: https://lore.kernel.org/kvm/aYUarHf3KEwHGuJe@google.com/ > Suggested-by: Sean Christopherson > Signed-off-by: Rick Edgecombe > --- > arch/x86/kvm/mmu/tdp_mmu.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index 991870789863..5dc9633c866e 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -473,10 +473,8 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared) > } > handle_changed_spte(kvm, sp, gfn, old_spte, FROZEN_SPTE, level, shared); > > - if (is_mirror_sp(sp)) { > - KVM_BUG_ON(shared, kvm); > + if (is_mirror_sp(sp)) > remove_external_spte(kvm, gfn, old_spte, level); > - } > } > > if (is_mirror_sp(sp) && > -- > 2.53.0 >