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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79755C48BE8 for ; Fri, 18 Jun 2021 14:32:43 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CFB3761154 for ; Fri, 18 Jun 2021 14:32:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFB3761154 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4G61bs6lk9z3c0S for ; Sat, 19 Jun 2021 00:32:41 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4G61bT5N1Zz3bvR for ; Sat, 19 Jun 2021 00:32:20 +1000 (AEST) Received: by verein.lst.de (Postfix, from userid 2407) id 64B2C68D08; Fri, 18 Jun 2021 16:32:12 +0200 (CEST) Date: Fri, 18 Jun 2021 16:32:12 +0200 From: Christoph Hellwig To: Tom Lendacky Subject: Re: [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions Message-ID: <20210618143212.GA19284@lst.de> References: <20210617062635.1660944-1-tientzu@chromium.org> <20210617062635.1660944-2-tientzu@chromium.org> <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, Frank Rowand , mingo@kernel.org, Marek Szyprowski , Stefano Stabellini , Saravana Kannan , Joerg Roedel , "Rafael J . Wysocki" , Christoph Hellwig , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , Jianxiong Gao , Daniel Vetter , Will Deacon , Konrad Rzeszutek Wilk , maarten.lankhorst@linux.intel.com, airlied@linux.ie, Dan Williams , linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com, Rob Herring , rodrigo.vivi@intel.com, Bjorn Helgaas , Claire Chang , boris.ostrovsky@oracle.com, Andy Shevchenko , jgross@suse.com, Nicolas Boichat , Greg KH , Randy Dunlap , lkml , Tomasz Figa , "list@263.net:IOMMU DRIVERS" , Jim Quinlan , xypron.glpk@gmx.de, Robin Murphy , bauerman@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Jun 18, 2021 at 09:09:17AM -0500, Tom Lendacky wrote: > > swiotlb_init_with_tbl uses memblock_alloc to allocate the io_tlb_mem > > and memblock_alloc[1] will do memset in memblock_alloc_try_nid[2], so > > swiotlb_init_with_tbl is also good. > > I'm happy to add the memset in swiotlb_init_io_tlb_mem if you think > > it's clearer and safer. > > On x86, if the memset is done before set_memory_decrypted() and memory > encryption is active, then the memory will look like ciphertext afterwards > and not be zeroes. If zeroed memory is required, then a memset must be > done after the set_memory_decrypted() calls. Which should be fine - we don't care that the memory is cleared to 0, just that it doesn't leak other data. Maybe a comment would be useful, though,