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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 0442DC4338F for ; Mon, 2 Aug 2021 13:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF9BE6112D for ; Mon, 2 Aug 2021 13:20:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233797AbhHBNUf (ORCPT ); Mon, 2 Aug 2021 09:20:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233691AbhHBNUe (ORCPT ); Mon, 2 Aug 2021 09:20:34 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 743D4C06175F; Mon, 2 Aug 2021 06:20:24 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 69583379; Mon, 2 Aug 2021 15:20:20 +0200 (CEST) Date: Mon, 2 Aug 2021 15:20:03 +0200 From: Joerg Roedel To: Tianyu Lan Cc: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, 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, 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@microsoft.com, rientjes@google.com, martin.b.radev@gmail.com, akpm@linux-foundation.org, rppt@kernel.org, kirill.shutemov@linux.intel.com, aneesh.kumar@linux.ibm.com, krish.sadhukhan@oracle.com, saravanand@fb.com, xen-devel@lists.xenproject.org, pgonda@google.com, david@redhat.com, keescook@chromium.org, hannes@cmpxchg.org, sfr@canb.auug.org.au, michael.h.kelley@microsoft.com, 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@redhat.com, anparri@microsoft.com Subject: Re: [PATCH 13/13] HV/Storvsc: Add Isolation VM support for storvsc driver Message-ID: References: <20210728145232.285861-1-ltykernel@gmail.com> <20210728145232.285861-14-ltykernel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210728145232.285861-14-ltykernel@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Wed, Jul 28, 2021 at 10:52:28AM -0400, Tianyu Lan wrote: > In Isolation VM, all shared memory with host needs to mark visible > to host via hvcall. vmbus_establish_gpadl() has already done it for > storvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_ > mpb_desc() still need to handle. Use DMA API to map/umap these > memory during sending/receiving packet and Hyper-V DMA ops callback > will use swiotlb function to allocate bounce buffer and copy data > from/to bounce buffer. I am wondering why you dont't use DMA-API unconditionally? It provides enough abstraction to do the right thing for isolated and legacy VMs. Regards, Joerg