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[2620:137:e000::1:20]) by mx.google.com with ESMTP id c4-20020a056402120400b00418c2b5befcsi2243682edw.478.2022.04.15.23.54.26; Fri, 15 Apr 2022 23:54:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20210309 header.b=cMcvUoLF; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229563AbiDPGJf (ORCPT + 99 others); Sat, 16 Apr 2022 02:09:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbiDPGJd (ORCPT ); Sat, 16 Apr 2022 02:09:33 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5175865404 for ; Fri, 15 Apr 2022 23:07:02 -0700 (PDT) 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=7q55fBD/If1zhZdmpRrkJ8LAPojnNiIN0sEvE05Ctwk=; b=cMcvUoLF9t8i+WPX8nbPrHKTpU B06E6ECDKRBlaNNA7/4Q6dRDnLjRFGOUX8wd8Q2KKhjuHBLFPV9+Zue4ho9wVEB6RS30D1zBioXtt V+Lp1o4dTv5oHaBbZVlDVRCWQUwOi4y++6lq9CNFsRHkBUsaMwrJ7yHeIh4axcp/jLCE81Q+dkQXH 6UwiBQxst4/dOqKM6Sf62txqv0VdU6kGjqWXmReVZcuCiaXZJC0kVaZ6qvGpFR5T8y5tPNfSVSm4b OXEoHMu6B0oPLJmJynm2f59ZyjZEkOocBrfRZD/q2Q/YyYMduY3sFwU4R8BNOZYm074q3ByEG86ZA ROsKlu+w==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nfbaG-00CK5x-5f; Sat, 16 Apr 2022 06:07:00 +0000 Date: Fri, 15 Apr 2022 23:07:00 -0700 From: Christoph Hellwig To: Stefano Stabellini Cc: Oleksandr Tyshchenko , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Oleksandr Tyshchenko , Boris Ostrovsky , Juergen Gross , Julien Grall Subject: Re: [RFC PATCH 6/6] arm/xen: Assign xen-virtio DMA ops for virtio devices in Xen guests Message-ID: References: <1649963973-22879-1-git-send-email-olekstysh@gmail.com> <1649963973-22879-7-git-send-email-olekstysh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 15, 2022 at 03:02:45PM -0700, Stefano Stabellini wrote: > This makes sense overall. Considering that the swiotlb-xen case and the > virtio case are mutually exclusive, I would write it like this: Curious question: Why can't the same grant scheme also be used for non-virtio devices? I really hate having virtio hooks in the arch dma code. Why can't Xen just say in DT/ACPI that grants can be used for a given device?