From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2591D2E8DEB for ; Fri, 9 Jan 2026 06:50:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767941445; cv=none; b=fog6tksGuIeboM5U+SdHk2m5FBQBhLgcBCCFpYGO26aANcAJZQzyzG0cDYQyZhfami4Oj0PlrchxMLY9ZEGtYvdTPheYBWTkTtqCbPpnbfCge6Vne5SB7fJe9bDWArvk2EkMt0jIPoJEBP+X8xN1kpjY7UUvHIaB6VTKdUynFX8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767941445; c=relaxed/simple; bh=iEtJOvOiVU5aWrZjX18IWSGkBx5iBhYUuqRnUN225Nk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: In-Reply-To:Content-Type:Content-Disposition; b=GPmYXDgADs+PMw3+1GQNFsHo1TPX1BzKPxzg3ApowUpICURJSN5LszujZ+RuhvQE+kfBaVOmi1ATJyih111zxXSySpnUeaPEDf3OGgKvpeQp62HLyWd9XAKYjSfPqkCwjKkxE8px8kHNUa5iS1Tjr8KjD0nujCS8cncUIRSWgM0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=KEqd4MEb; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KEqd4MEb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767941442; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=R+ceZQaBHtSWEXMLCYeIz4W2mWMzIw2cMZlyfXRW3eI=; b=KEqd4MEb1p3OpRUvlzeK8GSliegMbo+DVo5RQxG4mcvRZdT4c/m9DjytX0LHiY2pBYxidR c4oKvukteXLKnRQYcT3PNpE1a8Ekof3wb8nDD3I4zMmKbAHH7lCeTXihl/0n3m7z8QHZgd lNS8s7YCwx39VmQL//D0bPEeBqc29pw= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-313-sMC8NFX6MbKvwRgl1M4VmA-1; Fri, 09 Jan 2026 01:50:39 -0500 X-MC-Unique: sMC8NFX6MbKvwRgl1M4VmA-1 X-Mimecast-MFC-AGG-ID: sMC8NFX6MbKvwRgl1M4VmA_1767941438 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-4776079ada3so37602355e9.1 for ; Thu, 08 Jan 2026 22:50:38 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767941438; x=1768546238; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=R+ceZQaBHtSWEXMLCYeIz4W2mWMzIw2cMZlyfXRW3eI=; b=nl8ozrxT9RCgCy2uenFoAhLOlWlUmpD+uR8MoHzTWDSqwcByfDTx1cMR1+5ydbBJ// EBU8JTIEuvtxUJCnTr/y+desRD1tmqp6zQ/PDOXDhd6FiYBKP1kAymgxExsRLKQE8zKL vN/Psz70hXnbNyDzrFfkohgIKmdkke6l1PkcbxkROP8Kg/LLqHlV31izAAS0fEwcZhCL Mtyj4OYPIkON3Si6Ya4dQDhsFc/x4C/qMJBatl++Vge6r56LPGsDB6swyt1N7n3FsAAn qb9kLWiLuRT2rCiWOuwyAvTE3ixN5/J8Ax90AQGQkjP4LJtP8Btdh5pxKdGk8772Tb5j bnGg== X-Forwarded-Encrypted: i=1; AJvYcCXOkA4WT6d2HwUdEqZNyeqylp1ffjdKj/0OLbMIi0je+HIAtVvI6A5udRhRsaNwYg0kkf0ENgXJaQ1zYmFEkg==@lists.linux.dev X-Gm-Message-State: AOJu0YwEw5Hh/ZxUtPcwoo7UT9/uKp4breFngCeBPfLqVxufKkcqHyAK bOeCvdP7mzj9Aj/4KR7kBJidcMJlL4fMel76+KoeCoXiGN8R/Y1QGNnSKtjpm0HkVJsVyeIzJu4 6BG8Vo6WUVNM67DzCcEzRrgn4I1L2VA3iqHP+kZkL6jEld3fzn0NBKW//jWe1Osnh7tVj X-Gm-Gg: AY/fxX5S08v49reIhePvgkL8vGwNfBnz5UEQajz1ShqdSjSt7tZxCxGe8p1EIq81YXi 2qCU+QINVDK4f0tYPDR+p7HjhELjRl3iF8+keebs1VvTkajsFKYv7AYtRVLfZS+NHraC0nzmYTy HxblD1mO0jbiXDUznAXfRj5BTqxrPPmIpGFWrbjIiULHBHktwFo0SqnsQaw+Zt90FolRDaZLMkz fZeN1jFa/gq9xa1Fh4j4TNE89w1dDbK5d/NjltPZeuJc38RJOE1LKetP5MAekesFwjBRqLrlG9Z ubRi/DF/QKmnFwK/B8oCcM7mySoccuvt1yqFs041RFl3xop6aKxLDj/5tJEUYx7Z0FuDjRz3YiI sm6/T0CNT/GcEvd+TQ25q5yvFV4ZxiF+5ew== X-Received: by 2002:a05:600c:1988:b0:477:fad:acd9 with SMTP id 5b1f17b1804b1-47d84b54025mr83032915e9.34.1767941437753; Thu, 08 Jan 2026 22:50:37 -0800 (PST) X-Google-Smtp-Source: AGHT+IGPoTWz83P/iNwID/4Bvz08OjAhrzEJr6LK5HIHVnGFH5eW5Gjhe1uiWsZet3dbhgEY25lNqw== X-Received: by 2002:a05:600c:1988:b0:477:fad:acd9 with SMTP id 5b1f17b1804b1-47d84b54025mr83032605e9.34.1767941437006; Thu, 08 Jan 2026 22:50:37 -0800 (PST) Received: from redhat.com (IGLD-80-230-31-118.inter.net.il. [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: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: OGMVgX26mJnuxv9PPIHsdUKapvQbAWMe5deSsft0lJ0_1767941438 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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