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 B47752E888C for ; Fri, 9 Jan 2026 06:50:41 +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=1767941443; cv=none; b=drc74E7CtkCpsQuYHv11XO7iXPjc/eCx6B9jbiE+N2/fVDPHWh3Te44PTewNiNZDnelP9sak6A6PI6n9Sxz874PpB4R/YK4/ufAP9nbtSF12Fp6rpjGejMUzCmyGlzuruFXEXyG9W8aP0RvAbhoCbLfJIz3pQuY+O2WlTwivssQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767941443; c=relaxed/simple; bh=iEtJOvOiVU5aWrZjX18IWSGkBx5iBhYUuqRnUN225Nk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=r2AhDUFNK4+qAHAwI5ItrX6Ominr016swiEPV/IvSkg1pKWLmlK7p+sfn/4bwsYcR35ICWgLUGEFaQQ5D0T67/XI0eM1/JzGMhCIZZa2sMYnmHtX7a3gsvYok7r7Up8+5Ad2ZKBPEl4c3Y6hZLcTamnbpimzqM82ozjtM5J4qjs= 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=ED1d9ZEr; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=oeQfUp96; 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="ED1d9ZEr"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="oeQfUp96" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767941441; 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=ED1d9ZErWxDAGQVfbpinelcYDGvebTWCR5z1QE1qXVyy4pXFEEo2WpcuEoXTUnQM3ZqulG z8FCql49NFiaq0yjVHXM8AUltKfPMyKqdxLJIioyGTThXkKDiEkDMpt1qVzIDw43kHlWAf 61XTuzrq2wJKPnbHtyjZbav96YvamXA= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-313-d4oI_NNLNAatM1WwqKBXcg-1; Fri, 09 Jan 2026 01:50:39 -0500 X-MC-Unique: d4oI_NNLNAatM1WwqKBXcg-1 X-Mimecast-MFC-AGG-ID: d4oI_NNLNAatM1WwqKBXcg_1767941438 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-477cf25ceccso36664915e9.0 for ; Thu, 08 Jan 2026 22:50:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1767941438; x=1768546238; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=R+ceZQaBHtSWEXMLCYeIz4W2mWMzIw2cMZlyfXRW3eI=; b=oeQfUp96AmgpTP63XV37OoB6dX47fYm7QWFWSQzRTASNVWlOUZzcZZRMM0L8OQZbg3 HqxYeuyT5oO4OPvPcosLgQOvJYAq0KMf283+0e713ZQHbhirZapuieCZjd3k1ceHM877 LsaFFds9NggkzNFAC+ZigPyCrjgLP+5fKpLuDF4fJ7RDc98nkQ3TpgQ1E+xtQV42P2QW JeH/BELCDefTpaW7d0gh+q+zO9C9jsPpJz7yjqvM49k4xfkTUK52u6VwatoRVKLDX4aD A0SIw4BKXUzDZFu7mAqyHZq8jICuxUTy9jXhtCbyQxMC+7OPhuiBqAKxWQyS07lHWJ8S Hdmg== 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=fFMo/qbwZP1GnjDY8ebAXb9K1pKlrXrf2FmgvPd/7P3RHWE/fsJNxGGl7FPvu/8wot KHw+aUMcFDrNE5TgzxqlnAfaY9LHfCYgrhFeWAAWipiXYLlQtXiimYm9PPY3lcTGZ//s UfbEzguQXlP35o4WS/eGeJVXo6L34/7+Fux76hz787KSIRDWzwrdZWrsGIWpzMG9lj7M aP0Gn4yhnHa/0P6LdlWzgMSK5ypzmBZMid1/ldh1KdJZ3SLSTBy5oof76ibLEMgQrF0h axLc8lc1F3ybch8zKp0QFHOTBC5TEttLz1sCvilLQckGxcpFFZDCgb2hrqw2UC587XeO PImA== X-Forwarded-Encrypted: i=1; AJvYcCUw6Vjc1h9YiEY+UNNe9UX9IV5Zvjrtg9sAAUTNfO/r7FcQYuekWXEcfKKGRHYZKsY0+jB68ltfGxdFf0A=@vger.kernel.org X-Gm-Message-State: AOJu0YwU2z29BoyEk9nvva7Jycu4SLne6B7MkHFzNAXhISGFWpilW3j0 M4SjIgI8VT7Rkt2pOOP/WAasXRwigamLEtuuCDRnekXRZKjZEQnvc3g/iG1pnOgdd3semYl5xzd 9YSU6GeP+B7ZPRuDzaOzYEJDW0zfXLdNy2cVz6D3J06nwjgVO7XjRDNQ98YEOMk/CGA== X-Gm-Gg: AY/fxX7tceLhPw1Wam/iH6f3p3VM/nRJyM7OCjWw+fks9UkvQ7S320WJjuPEcaG56DK BaenU48gGlsE1NCx13Unn6Ck6lHbWAdrL0PMx1KG6+8sI8lna6oiw4x1IR8u7chkARUN/y9Tols CIdtXHmatFwvphZmVRTiPFpRPux+ThO8jXGwoI42RirZhHs2xjJmUMMjbsZZcBd8sVe0HtHtDjv 8jszKKaM7aEzr02djfokHu+1G9Yn2iF8kvpmT1minmlqnlNtwetRXRAZtW5M9swmF+GMBReSFcd fXmRNcQsXGCRgvlMbyIzqIHBzA47i81d+/sfJgXuoHXfm5zmeCSy6Sg16NKrq5qFzhzzSk/nw/B 846GYC25VNRJOek/s0uyPauC1Qc52ldlPMQ== X-Received: by 2002:a05:600c:1988:b0:477:fad:acd9 with SMTP id 5b1f17b1804b1-47d84b54025mr83032855e9.34.1767941437725; 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: 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, 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