From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id D57BF45026; Mon, 20 May 2024 14:07:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716214037; cv=none; b=fFo7hhFcbhd1TaQsgNdI77dvKPpl6U+FuCuvuEjnHVqi7kx0uwVC3eQUB3aZePmaLiePnohksU7X+mOaxBvQ7DEQITkAV4Bqtqr6OypZwlMi2S7di6UKqvibEtBg8nV13eSyPBbn1lsiQUHTWACFwCi9fgTrisKQWMNw6evzta8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716214037; c=relaxed/simple; bh=w4T6LcRjlCHTTZIBTqyyyFIHQt2VX43DOdStKH+dMjo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WFLWUfJfl2p/+J2Y+7xaEqlIwqSFkjQ+OTWrEYjESxf7Q+nENKnl6qVLNDoX++mHDgKtR+rwcI3tCNexPZucW/KbS+J43TDreVjnVXhsZ3BwHWGonZdE2IZwNibmR3KIWJc+xmVq/DW39FVSHivMCu8ILj32qsgVRnM5sYRDk7E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=nzXujvLQ; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nzXujvLQ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=wpWEoUMWnFLJr+MkLtPIZ/EXAlokieryuSaCz8a6I3M=; b=nzXujvLQghLXfJUbZl0u3JiQ/V njxgWrULaemEv1rhjj7uGwTNzAM865guFORckfkd4Elr/e93FJxZ7xTyAiIdHg5YdZ5fZ5uXnfPLZ CkqyBZ+Fnjku555e7eD3RcC1Zsq4vNK1IowWSRMEcMyM/9W+5QQhEQob/6fQ6CZLxDh8rF+J2mz7B ne6Lxk1tkPc4pO11ZuBp7Vn+3Cjy+Gsmh1kKjw1cn5zxMQmGVEIK5F3Q+mhhHaOwFlPewXynlVCI6 yLaq/aRiNH+FsLzpdW2E0VFX3q2kB5KFtFAoFVn5xw4OdNAZXy5oqxQlyYTJG9vVi3+f7x+gT2JRa Z5hYlxBA==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1s93fS-0000000EfNO-3kiZ; Mon, 20 May 2024 14:07:10 +0000 Date: Mon, 20 May 2024 07:07:10 -0700 From: Christoph Hellwig To: Yan Zhao Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com, iommu@lists.linux.dev, pbonzini@redhat.com, seanjc@google.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, corbet@lwn.net, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, baolu.lu@linux.intel.com, yi.l.liu@intel.com, Russell King Subject: Re: [PATCH 3/5] x86/mm: Introduce and export interface arch_clean_nonsnoop_dma() Message-ID: References: <20240507061802.20184-1-yan.y.zhao@intel.com> <20240507062044.20399-1-yan.y.zhao@intel.com> Precedence: bulk X-Mailing-List: kvm@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: <20240507062044.20399-1-yan.y.zhao@intel.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, May 07, 2024 at 02:20:44PM +0800, Yan Zhao wrote: > Introduce and export interface arch_clean_nonsnoop_dma() to flush CPU > caches for memory involved in non-coherent DMAs (DMAs that lack CPU cache > snooping). Err, no. There should really be no exported cache manipulation macros, as drivers are almost guaranteed to get this wrong. I've added Russell to the Cc list who has been extremtly vocal about this at least for arm.