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 4DA6EC4338F for ; Fri, 20 Aug 2021 04:13:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34E77610E6 for ; Fri, 20 Aug 2021 04:13:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232699AbhHTEOX (ORCPT ); Fri, 20 Aug 2021 00:14:23 -0400 Received: from verein.lst.de ([213.95.11.211]:39594 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229457AbhHTEOW (ORCPT ); Fri, 20 Aug 2021 00:14:22 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 816B46736F; Fri, 20 Aug 2021 06:13:40 +0200 (CEST) Date: Fri, 20 Aug 2021 06:13:40 +0200 From: "hch@lst.de" To: Michael Kelley Cc: Tianyu Lan , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , "wei.liu@kernel.org" , Dexuan Cui , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "x86@kernel.org" , "hpa@zytor.com" , "dave.hansen@linux.intel.com" , "luto@kernel.org" , "peterz@infradead.org" , "konrad.wilk@oracle.com" , "boris.ostrovsky@oracle.com" , "jgross@suse.com" , "sstabellini@kernel.org" , "joro@8bytes.org" , "will@kernel.org" , "davem@davemloft.net" , "kuba@kernel.org" , "jejb@linux.ibm.com" , "martin.petersen@oracle.com" , "arnd@arndb.de" , "hch@lst.de" , "m.szyprowski@samsung.com" , "robin.murphy@arm.com" , "thomas.lendacky@amd.com" , "brijesh.singh@amd.com" , "ardb@kernel.org" , Tianyu Lan , "pgonda@google.com" , "martin.b.radev@gmail.com" , "akpm@linux-foundation.org" , "kirill.shutemov@linux.intel.com" , "rppt@kernel.org" , "sfr@canb.auug.org.au" , "saravanand@fb.com" , "krish.sadhukhan@oracle.com" , "aneesh.kumar@linux.ibm.com" , "xen-devel@lists.xenproject.org" , "rientjes@google.com" , "hannes@cmpxchg.org" , "tj@kernel.org" , "iommu@lists.linux-foundation.org" , "linux-arch@vger.kernel.org" , "linux-hyperv@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "netdev@vger.kernel.org" , vkuznets , "parri.andrea@gmail.com" , "dave.hansen@intel.com" Subject: Re: [PATCH V3 11/13] HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM Message-ID: <20210820041340.GA26450@lst.de> References: <20210809175620.720923-1-ltykernel@gmail.com> <20210809175620.720923-12-ltykernel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 19, 2021 at 06:11:30PM +0000, Michael Kelley wrote: > This function is manipulating page tables in the guest VM. It is not involved > in communicating with Hyper-V, or passing PFNs to Hyper-V. The pfn array > contains guest PFNs, not Hyper-V PFNs. So it should use PAGE_SIZE > instead of HV_HYP_PAGE_SIZE, and similarly PAGE_SHIFT and virt_to_pfn(). > If this code were ever to run on ARM64 in the future with PAGE_SIZE other > than 4 Kbytes, the use of PAGE_SIZE is correct choice. Yes. I just stumled over this yesterday. I think we can actually use a nicer helper ased around vmap_range() to simplify this exactly because it always uses the host page size. I hope I can draft up a RFC today. 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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 2213FC4338F for ; Fri, 20 Aug 2021 04:13:55 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 ABEA2610E6 for ; Fri, 20 Aug 2021 04:13:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org ABEA2610E6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 6D733613B7; Fri, 20 Aug 2021 04:13:54 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WRUV7buZEqnJ; Fri, 20 Aug 2021 04:13:50 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTPS id 342446139C; Fri, 20 Aug 2021 04:13:50 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 14E43C001A; Fri, 20 Aug 2021 04:13:50 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3EEC2C000E for ; Fri, 20 Aug 2021 04:13:48 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 24B7C402B7 for ; Fri, 20 Aug 2021 04:13:48 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6WanNC8L8pjk for ; Fri, 20 Aug 2021 04:13:47 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp2.osuosl.org (Postfix) with ESMTPS id CEA3D401B2 for ; Fri, 20 Aug 2021 04:13:46 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 816B46736F; Fri, 20 Aug 2021 06:13:40 +0200 (CEST) Date: Fri, 20 Aug 2021 06:13:40 +0200 From: "hch@lst.de" To: Michael Kelley Subject: Re: [PATCH V3 11/13] HV/IOMMU: Enable swiotlb bounce buffer for Isolation VM Message-ID: <20210820041340.GA26450@lst.de> References: <20210809175620.720923-1-ltykernel@gmail.com> <20210809175620.720923-12-ltykernel@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: "parri.andrea@gmail.com" , "linux-hyperv@vger.kernel.org" , "brijesh.singh@amd.com" , "peterz@infradead.org" , "dave.hansen@linux.intel.com" , vkuznets , "hpa@zytor.com" , KY Srinivasan , "will@kernel.org" , "boris.ostrovsky@oracle.com" , "linux-arch@vger.kernel.org" , "sfr@canb.auug.org.au" , "wei.liu@kernel.org" , "sstabellini@kernel.org" , Stephen Hemminger , "xen-devel@lists.xenproject.org" , "linux-scsi@vger.kernel.org" , "aneesh.kumar@linux.ibm.com" , "x86@kernel.org" , Dexuan Cui , Tianyu Lan , "hch@lst.de" , "mingo@redhat.com" , "pgonda@google.com" , "rientjes@google.com" , "kuba@kernel.org" , "jejb@linux.ibm.com" , "martin.b.radev@gmail.com" , "thomas.lendacky@amd.com" , Tianyu Lan , "arnd@arndb.de" , "konrad.wilk@oracle.com" , Haiyang Zhang , "bp@alien8.de" , "luto@kernel.org" , "krish.sadhukhan@oracle.com" , "tglx@linutronix.de" , "akpm@linux-foundation.org" , "jgross@suse.com" , "martin.petersen@oracle.com" , "saravanand@fb.com" , "netdev@vger.kernel.org" , "dave.hansen@intel.com" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "rppt@kernel.org" , "hannes@cmpxchg.org" , "tj@kernel.org" , "ardb@kernel.org" , "robin.murphy@arm.com" , "davem@davemloft.net" , "kirill.shutemov@linux.intel.com" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Thu, Aug 19, 2021 at 06:11:30PM +0000, Michael Kelley wrote: > This function is manipulating page tables in the guest VM. It is not involved > in communicating with Hyper-V, or passing PFNs to Hyper-V. The pfn array > contains guest PFNs, not Hyper-V PFNs. So it should use PAGE_SIZE > instead of HV_HYP_PAGE_SIZE, and similarly PAGE_SHIFT and virt_to_pfn(). > If this code were ever to run on ARM64 in the future with PAGE_SIZE other > than 4 Kbytes, the use of PAGE_SIZE is correct choice. Yes. I just stumled over this yesterday. I think we can actually use a nicer helper ased around vmap_range() to simplify this exactly because it always uses the host page size. I hope I can draft up a RFC today. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu