From patchwork Mon Jul 22 15:45:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Roger_Pau_Monn=C3=A9?= X-Patchwork-Id: 11052843 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B9B10746 for ; Mon, 22 Jul 2019 15:47:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A8F7A212E8 for ; Mon, 22 Jul 2019 15:47:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9D8D128414; Mon, 22 Jul 2019 15:47:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 496F6212E8 for ; Mon, 22 Jul 2019 15:47:25 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hpaVm-0001wK-Jc; Mon, 22 Jul 2019 15:46:02 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hpaVl-0001wF-4M for xen-devel@lists.xenproject.org; Mon, 22 Jul 2019 15:46:01 +0000 X-Inumbo-ID: cb657796-ac97-11e9-b7ad-7f89531b4d9e Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id cb657796-ac97-11e9-b7ad-7f89531b4d9e; Mon, 22 Jul 2019 15:45:56 +0000 (UTC) Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=roger.pau@citrix.com; spf=Pass smtp.mailfrom=roger.pau@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa2.hc3370-68.iphmx.com: no sender authenticity information available from domain of roger.pau@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="roger.pau@citrix.com"; x-sender="roger.pau@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa2.hc3370-68.iphmx.com: domain of roger.pau@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="roger.pau@citrix.com"; x-sender="roger.pau@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ~all" Received-SPF: None (esa2.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa2.hc3370-68.iphmx.com; envelope-from="roger.pau@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: YS0JACkc1xe+TWd6wLIoWNGm5hlhYOAXRuhRvFH+wBaSRyZE4Y7AGS50PzBxzp/OrRpcLf+Ebv Q8tmpHMksKKX1fS+oPLCaf7J5koNI6ZIP/mRYk/zf3b5RYgxKMxZ8AWyoHD/fevVv6eKNfT3MU cz1BlrD/OLP/DToPqrloln03n80kgIBGZ10tc4Nqjxjc6130/PcIWWwNO/9ZjWVzFzdsd3MxBL KabgdLq5KDcJPtOa9FOR8k8hXebpaKQtaNd2AkS2pCB2eqQwMOOHWeSpALMau6r19W1lmZ50yH DmY= X-SBRS: 2.7 X-MesageID: 3268059 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.64,295,1559534400"; d="scan'208";a="3268059" From: Roger Pau Monne To: Date: Mon, 22 Jul 2019 17:45:52 +0200 Message-ID: <20190722154552.73458-1-roger.pau@citrix.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) MIME-Version: 1.0 Subject: [Xen-devel] [PATCH] x86/iommu: add comment regarding setting of need_sync X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Jan Beulich , Roger Pau Monne Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Clarify why relaxed hardware domains don't need iommu page-table syncing. Signed-off-by: Roger Pau Monné Acked-by: Jan Beulich --- Cc: Jan Beulich --- xen/drivers/passthrough/iommu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c index 79ec6719f5..f8c3bf53bd 100644 --- a/xen/drivers/passthrough/iommu.c +++ b/xen/drivers/passthrough/iommu.c @@ -185,6 +185,10 @@ void __hwdom_init iommu_hwdom_init(struct domain *d) register_keyhandler('o', &iommu_dump_p2m_table, "dump iommu p2m table", 0); hd->status = IOMMU_STATUS_initializing; + /* + * NB: relaxed hw domains don't need sync because all ram is already + * mapped in the iommu page tables. + */ hd->need_sync = iommu_hwdom_strict && !iommu_use_hap_pt(d); if ( need_iommu_pt_sync(d) ) {