From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B2F13CD8CA4 for ; Tue, 9 Jun 2026 14:16:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/t/KVtkqwokTt2oNchcdf4xUUArUEApR4RsM4t4GGaI=; b=qJ0KjJ1G2C7uFuQivqN1GqhbER gVEII35QwlFtmC/Tn7zdOCcIX8yUXEG8x/lQp/zibJ8WYAkrXx3GJnTEN4LSZ5kp2Kdbdp8V3GTdN cf1SYcj7Z55BwWPugQNySjj6sRkMVIwG+r5XB/Rjs6aSZxFJwyZRqGoE/ceJzTjXcTJRGxeGXNs9E GEbMyk3v/d5p/xgSfsZ2dZCZnO8O6Ia64pWivxUKp5MLhz2sMv6AIoWNgc0ouSM+heqjXKBz70RKV TYXMCjXtDaBv5QuJ/M9iyKsBjyBw7ujBPTqemrktwb+ikUXavJMQhmR6CxJPp8lMHmGSq8QlC8Fgy qKYgRmug==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wWxFH-00000005kWs-2zKn; Tue, 09 Jun 2026 14:15:59 +0000 Received: from mail-qv1-xf2f.google.com ([2607:f8b0:4864:20::f2f]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wWxFB-00000005kWS-2qzL for linux-arm-kernel@lists.infradead.org; Tue, 09 Jun 2026 14:15:57 +0000 Received: by mail-qv1-xf2f.google.com with SMTP id 6a1803df08f44-8ccf18ef922so78968896d6.3 for ; Tue, 09 Jun 2026 07:15:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1781014552; x=1781619352; darn=lists.infradead.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=/t/KVtkqwokTt2oNchcdf4xUUArUEApR4RsM4t4GGaI=; b=Hh3cVAu83XKQfw23M35in0LmV/tSmk1HOT0f2FQgzUK2vwYAwoqjUAGDW142ACWcip VuecX3ZVcNwoQfJ30iXAONi2EhLQlGvFFpvvx/a7p5vICC2ab7wauWqIdWwWenC9NykM njoR3zWn6kSn4yt6w4gW6oZzihA0Sz9Q+NRi2xA2TdM5NJSJlUXYr8zslscwuPpSiIWo nTfa2oamWnEG0w3q2/d9lslqURRB3erTGpmK5A9vaDZhv/ThdCNoYpY9bnGwFe8+3z8P 4k820CyISactfybhZ2bBMcdtdpztjMlWWsA17Km89rqYbDk33E9By3LixSBnaOt36PMD 3UpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781014552; x=1781619352; 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=/t/KVtkqwokTt2oNchcdf4xUUArUEApR4RsM4t4GGaI=; b=sTxX22q11XhT+Kj7Dbt91J9oW5j3BMLx73OBGe7PAbW7TGP5yGtQRzA3rMCOxaMqpU u/EY5bl8RGMtJnyeqC14DEEk1AUSiWr+zhFLUeJzsQUTlSsMDQh7c8f1hoxE/knwUCy9 BC18xxlK5AuZR36fPtfAmgKBLd4dKPzWAFforR52iOdhRgAfdJ1cR1MXL7a9vZI218jk MuwOclAzaLJzVtXpRu2hUZ6nMAlkiXLYL9beTPUd4a1a9lekD8XkjOP+IMeu4Z9QNbFd FSPt2WJR2WusN/cGwivDChx3Q8PLvOI7ZPeoZMtVG+4IafuoojEpL/5gAZKsRH4Fyymt 4Tlg== X-Forwarded-Encrypted: i=1; AFNElJ88hEHDvMJLipNlLYEm3v6yOvVLotOOqnJMUEi9tha/8x+CfracSlpHWghtiIwBNZwXhIrRDRcswMx/rQrnzb0I@lists.infradead.org X-Gm-Message-State: AOJu0YzjYdGFBTls4iJH4sv3Bec99OZG2d6FMKL9hUFDyY5ZIhk0dTu9 l9NXuK0QQRRMfl3m4ARPE0Hyz+7HXYU7NAdQn3Pg1QBub3zMr9Tz+ieGj/yN0JDu6zI= X-Gm-Gg: Acq92OGa0eJQTe4JSSckRPbqL18XmBec3Hknm3rcTig4kT/CDQX+4BTPX9YhgJ8xabv zCL/gR5sgIQiV7sFBQE4FQw+xHvujdc5raS8LIrm1JnmqckYUhdv9egzo6nyTKAJBHylT6GAX8c qZ+TgR1vvyjdPPOv6/Wo4S6Sm8eDyvcUQnXkHaB1us4/GFlu+z2UMvgY4PM/RFhH8852umq+X6G WKL+PGiwRDZBZ9LJHxQTkW4aowh3R/e2H8h4+ieNfEazIcsE/L7QiyQkT/dU/i4dWoxQm+fenlp WXJbU4LwrQvfQA33KX5xcZBBF46M+lU+Vb34hvau4ya/pGN55vib6wxY0dUry6m3TzhQkGHdmgR SQqs1iB/SSthe8PiElBp8yODxbPNacdTaiqp/d0QbhrAKacKP5irlUUlescr0cuWJlS87HlyUQI 8ClQe86py//mNYGh/6ga8NsRdg2cRgJCYpmAI/n90RpfTbt3xXoGd8LqZ9RUigHZGQ3ZkdiTntF +oT5/O6B5xwfh3N X-Received: by 2002:a05:6214:626:b0:8ce:ba04:7bc2 with SMTP id 6a1803df08f44-8cee626f0eamr293032506d6.38.1781014535341; Tue, 09 Jun 2026 07:15:35 -0700 (PDT) Received: from ziepe.ca (crbknf0213w-47-54-130-67.pppoe-dynamic.high-speed.nl.bellaliant.net. [47.54.130.67]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8cecd077be8sm204702746d6.40.2026.06.09.07.15.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jun 2026 07:15:34 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wWxEs-000000021xL-0mOX; Tue, 09 Jun 2026 11:15:34 -0300 Date: Tue, 9 Jun 2026 11:15:34 -0300 From: Jason Gunthorpe To: "Aneesh Kumar K.V (Arm)" Cc: iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun , linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , x86@kernel.org, stable@vger.kernel.org, Michael Kelley Subject: Re: [PATCH v6 14/20] dma-direct: return struct page from dma_direct_alloc_from_pool() Message-ID: <20260609141534.GJ2764304@ziepe.ca> References: <20260604083959.1265923-1-aneesh.kumar@kernel.org> <20260604083959.1265923-15-aneesh.kumar@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260604083959.1265923-15-aneesh.kumar@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260609_071553_726315_337F1E04 X-CRM114-Status: GOOD ( 11.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jun 04, 2026 at 02:09:53PM +0530, Aneesh Kumar K.V (Arm) wrote: > @@ -270,9 +270,12 @@ void *dma_direct_alloc(struct device *dev, size_t size, > * the atomic pools instead if we aren't allowed block. > */ > if ((remap || (attrs & DMA_ATTR_CC_SHARED)) && > - dma_direct_use_pool(dev, gfp)) > - return dma_direct_alloc_from_pool(dev, size, dma_handle, > - gfp, attrs); > + dma_direct_use_pool(dev, gfp)) { > + page = dma_direct_alloc_from_pool(dev, size, > + dma_handle, &cpu_addr, > + gfp, attrs); > + return page ? cpu_addr : NULL; > + } You should probably put this at the start of the series so it can be backported Reviewed-by: Jason Gunthorpe To Petr's question I think this just shows nobody is really stressing the PCI dma paths on CC VMs today. if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp)) return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); For instance the places even calling dma_alloc_pages() don't look like things people would use in a CC VM. Jason