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[142.162.112.119]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8c37f4a9a19sm66438685a.1.2026.01.05.17.02.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Jan 2026 17:02:00 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vcvSR-00000001EZP-3HUW; Mon, 05 Jan 2026 21:01:59 -0400 Date: Mon, 5 Jan 2026 21:01:59 -0400 From: Jason Gunthorpe To: Li Zhijian Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, zyjzyj2000@gmail.com, leon@kernel.org, Yi Zhang Subject: Re: [PATCH RFC] rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE Message-ID: <20260106010159.GN125261@ziepe.ca> References: <20251226095237.3047496-1-lizhijian@fujitsu.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: <20251226095237.3047496-1-lizhijian@fujitsu.com> On Fri, Dec 26, 2025 at 05:52:37PM +0800, Li Zhijian wrote: > The current implementation incorrectly handles memory regions (MRs) with > page sizes different from the system PAGE_SIZE. The core issue is that > rxe_set_page() is called with mr->page_size step increments, but the > page_list stores individual struct page pointers, each representing > PAGE_SIZE of memory. > > Problem scenarios with concrete examples: > > 1. mr->page_size > PAGE_SIZE (e.g., 64K MR with 4K system pages): Why does RXE even have mr->page_size at all? Real HW has this value to optimize for large page sizes, but I'm not sure we really need this for RXE.. Jason