From patchwork Fri Aug 8 17:03:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 4697261 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 97EB69F375 for ; Fri, 8 Aug 2014 17:06:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D1A6E2015E for ; Fri, 8 Aug 2014 17:06:42 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 091DD2010E for ; Fri, 8 Aug 2014 17:06:42 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XFnb9-0007ot-Tj; Fri, 08 Aug 2014 17:04:59 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XFnb7-0007hq-Bf for linux-arm-kernel@lists.infradead.org; Fri, 08 Aug 2014 17:04:57 +0000 X-IronPort-AV: E=Sophos;i="5.01,825,1400025600"; d="scan'208";a="160114134" Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.78) with Microsoft SMTP Server id 14.3.181.6; Fri, 8 Aug 2014 13:04:35 -0400 Received: from kaball.uk.xensource.com ([10.80.2.59]) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1XFnag-0001fY-44; Fri, 08 Aug 2014 18:04:30 +0100 From: Stefano Stabellini To: Subject: [PATCH v4 1/3] xen/arm: introduce XENFEAT_grant_map_identity Date: Fri, 8 Aug 2014 18:03:09 +0100 Message-ID: <1407517391-10490-1-git-send-email-stefano.stabellini@eu.citrix.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: MIME-Version: 1.0 X-DLP: MIA1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140808_100457_578968_0DC00130 X-CRM114-Status: UNSURE ( 8.77 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -5.7 (-----) Cc: Ian.Campbell@citrix.com, Stefano Stabellini , julien.grall@citrix.com, david.vrabel@citrix.com, v1ne2go@gmail.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The flag tells us that the hypervisor maps a grant page to guest physical address == machine address of the page in addition to the normal grant mapping address. It is needed to properly issue cache maintenance operation at the completion of a DMA operation involving a foreign grant. Signed-off-by: Stefano Stabellini Tested-by: Denis Schneider --- Changes in v3: - rename XENFEAT_grant_map_11 to XENFEAT_grant_map_identity. --- arch/arm/xen/enlighten.c | 6 ++++++ include/xen/interface/features.h | 3 +++ 2 files changed, 9 insertions(+) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index b96723e..eef324f 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -262,6 +262,12 @@ static int __init xen_guest_init(void) xen_domain_type = XEN_HVM_DOMAIN; xen_setup_features(); + + if (!xen_feature(XENFEAT_grant_map_identity)) { + pr_warn("Please upgrade your Xen.\n" + "If your platform has any non-coherent DMA devices, they won't work properly.\n"); + } + if (xen_feature(XENFEAT_dom0)) xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED; else diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h index 131a6cc..14334d0 100644 --- a/include/xen/interface/features.h +++ b/include/xen/interface/features.h @@ -53,6 +53,9 @@ /* operation as Dom0 is supported */ #define XENFEAT_dom0 11 +/* Xen also maps grant references at pfn = mfn */ +#define XENFEAT_grant_map_identity 12 + #define XENFEAT_NR_SUBMAPS 1 #endif /* __XEN_PUBLIC_FEATURES_H__ */