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[47.54.130.67]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-516456b6856sm194612161cf.7.2026.05.20.07.51.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 May 2026 07:51:42 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wPiGs-0000000HIHG-0eTP; Wed, 20 May 2026 11:51:42 -0300 Date: Wed, 20 May 2026 11:51:42 -0300 From: Jason Gunthorpe To: Pranjal Shrivastava Cc: iommu@lists.linux.dev, linux-pci@vger.kernel.org, Will Deacon , Joerg Roedel , Bjorn Helgaas , Robin Murphy , Mostafa Saleh , Nicolin Chen , Samiullah Khawaja , Daniel Mentz , Pasha Tatashin , David Matlack Subject: Re: [PATCH v3 3/3] iommu/arm-smmu-v3: Fix ATS state tracking via ats_prepared gate Message-ID: <20260520145142.GU7702@ziepe.ca> References: <20260519135323.1558777-1-praan@google.com> <20260519135323.1558777-4-praan@google.com> <20260519144430.GI7702@ziepe.ca> <20260519145947.GK7702@ziepe.ca> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, May 20, 2026 at 02:24:47PM +0000, Pranjal Shrivastava wrote: > However, I'm thinking what's the right thing to do if pci_enable_ats() > fails in attach_commit(): > > 1. Fail to attach but unmerging the invs_array entry is complicated. Is it? We should be able to keep the the original invs and not free it, just put the pointer back? > 2. Move the pci_enable_ats() to attach_prepare() IIRC ATS cannot be enabled until the invs are loaded with ATS invalidations, hence the issue. So you'd put the new invs list, turn on ATS, if it fails restore the invs list back to what it was and RCU free the new one(s). Jason