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[96.255.20.138]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-880828c4570sm25286656d6.10.2025.11.06.10.24.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Nov 2025 10:24:14 -0800 (PST) Date: Thu, 6 Nov 2025 13:24:12 -0500 From: Gregory Price To: "Zhijian Li (Fujitsu)" Cc: Nathan Fontenot , "Koralahalli Channabasappa, Smita" , "Bowman, Terry" , Alison Schofield , "linux-cxl@vger.kernel.org" , Jonathan Cameron , "dan.j.williams@intel.com" , "dave.jiang@intel.com" , "vishal.l.verma@intel.com" , Robert Richter , Fan Ni , Davidlohr Bueso , "Yasunori Gotou (Fujitsu)" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC] CXL/ACPI: Remove overlapping Soft Reserved regions before adding CFMW resources Message-ID: References: <2296acdf-de5d-4591-a165-d59f9f432dee@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org 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, Jul 11, 2025 at 05:34:27AM +0000, Zhijian Li (Fujitsu) wrote: > > > On 11/07/2025 05:15, Nathan Fontenot wrote: > In this case(with your V4 patch), we would see: > ``` > 5d0000000-6cfffffff : CXL Window 0 > 5d0000000-6cfffffff : region0 > ``` > Actually, it cannot be consumed by the hmem/dax_hmem neither. > > This made me realize that my current idea ignores the case of CXL_ACPI=y && CXL_REGION=n. I quickly tested it(I will take a deeper look later): > > After the OS boots, we can see this resource. Can anyone tell me how to create the corresponding dax_region? Because I tried using dax create-device without success. > ``` > 5d0000000-6cfffffff : CXL Window 0 > 5d0000000-6cfffffff : Soft Reserved > ``` > with CXL_REGION=n you cannot create the dax region. region0 --creates-> dax_region0 --creates-> dax0 all you've done here by setting CXL_REGION=N is break the probe chain but otherwise successfully attributed the memory to the CXL driver. ~Gregory