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[80.230.31.118]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-47d865f84besm59137085e9.1.2026.01.08.22.50.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Jan 2026 22:50:36 -0800 (PST) Date: Fri, 9 Jan 2026 01:50:33 -0500 From: "Michael S. Tsirkin" To: Jason Wang Cc: Vishwanath Seshagiri , Xuan Zhuo , Eugenio =?iso-8859-1?Q?P=E9rez?= , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Wei , netdev@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] virtio_net: add page pool support for buffer allocation Message-ID: <20260109014836-mutt-send-email-mst@kernel.org> References: <20260106221924.123856-1-vishs@meta.com> <20260106221924.123856-2-vishs@meta.com> Precedence: bulk X-Mailing-List: netdev@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, Jan 09, 2026 at 11:16:39AM +0800, Jason Wang wrote: > > My concern was that virtio has its own DMA abstraction > > vdev->map->map_page() (used by VDUSE), and I wasn't sure if page_pool's > > standard dma_map_page() would be compatible with all virtio backends. > > You are right, DMA is unware about virtio mappings, so we can't use that. Or maybe we could add an API saying whether virtio mappings are DMA ones and then enable that conditionally? Because on some platforms, mapping in the pool can save *a lot* of cycles. -- MST