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[159.2.239.150]) by smtp.gmail.com with ESMTPSA id af79cd13be357-93be0ed258esm134537385a.30.2026.09.18.06.24.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Sep 2026 06:24:54 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1x7YaD-00000001Cw0-3NeV; Fri, 18 Sep 2026 10:24:53 -0300 Date: Fri, 18 Sep 2026 10:24:53 -0300 From: Jason Gunthorpe To: Samiullah Khawaja Cc: Baolu Lu , David Woodhouse , Joerg Roedel , Will Deacon , Robin Murphy , Kevin Tian , Alex Williamson , Shuah Khan , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Pratyush Yadav , Pasha Tatashin , David Matlack , Andrew Morton , Pranjal Shrivastava , Vipin Sharma Subject: Re: [PATCH v4 12/18] iommu/vt-d: Handle reattach of the restored domain Message-ID: <20260918132453.GC11599@ziepe.ca> References: <20260808022723.3893618-1-skhawaja@google.com> <20260808022723.3893618-13-skhawaja@google.com> <5b920299-260b-4025-ac4f-e8f83beebf95@linux.intel.com> <20260828143546.GC3769797@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 Fri, Sep 18, 2026 at 02:59:43AM +0000, Samiullah Khawaja wrote: > On Fri, Aug 28, 2026 at 04:15:56PM +0000, Samiullah Khawaja wrote: > > On Fri, Aug 28, 2026 at 11:35:46AM -0300, Jason Gunthorpe wrote: > > > On Fri, Aug 28, 2026 at 09:55:18AM +0800, Baolu Lu wrote: > > > > That looks reasonable to me. I have no concerns about keeping ATS > > > > enabled on preserved devices across kexec reboot, as long as the > > > > software state is synchronized in the new kernel. > > > > > > The new kernel should issue an ATC flush when it changes away from the > > > inherented domain. > > > > Yes, I will make sure this happens when we do the retrieval side. It > > should mostly work well with the existing replace machinery. > > > > > > > By the way, is disabling ATS an option? > > > > > > No, many devices require ATS. > > > > Agreed on the ATS requirement. I had Nicolin's patch series for CXL > > devices in mind here. > > Having implemented this now, I am thinking about this again with respect > to the scope of this series. To limit the scope of this series I am > going to refuse preservation of devices that have ATS enabled. Once the > base preservation logic goes in, I can add a separate series on top of > it to add that support. That seems reasonable Jason