From patchwork Thu Sep 10 10:56:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 11767555 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B925159D for ; Thu, 10 Sep 2020 10:56:40 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 7173B20BED for ; Thu, 10 Sep 2020 10:56:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7173B20BED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:45940 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kGKFr-0006Lm-9b for patchwork-qemu-devel@patchwork.kernel.org; Thu, 10 Sep 2020 06:56:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56166) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGKF4-0004gF-Lg for qemu-devel@nongnu.org; Thu, 10 Sep 2020 06:55:51 -0400 Received: from mga03.intel.com ([134.134.136.65]:26671) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kGKF2-0005xE-O4 for qemu-devel@nongnu.org; Thu, 10 Sep 2020 06:55:50 -0400 IronPort-SDR: LJCY7KNIsHcrNCH9XDDhjU9Lz1gftL+I0DFSlsabQgj2hFaXXX7ko21ALTMCFDd8p0ZmFBrgN8 PgQNMV87vkmQ== X-IronPort-AV: E=McAfee;i="6000,8403,9739"; a="158545512" X-IronPort-AV: E=Sophos;i="5.76,412,1592895600"; d="scan'208";a="158545512" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2020 03:54:40 -0700 IronPort-SDR: kXPcE/RYregj474ZLDMdnIXO7mGXl8z5RSZWRB/vBU/49Yfo93LjeSgIcnuv0B1es5baXZ+qgp DONZZRCja8+Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,412,1592895600"; d="scan'208";a="334140093" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga008.jf.intel.com with ESMTP; 10 Sep 2020 03:54:40 -0700 From: Liu Yi L To: qemu-devel@nongnu.org, alex.williamson@redhat.com, peterx@redhat.com, jasowang@redhat.com Subject: [RFC v10 20/25] intel_iommu: do not pass down pasid bind for PASID #0 Date: Thu, 10 Sep 2020 03:56:33 -0700 Message-Id: <1599735398-6829-21-git-send-email-yi.l.liu@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1599735398-6829-1-git-send-email-yi.l.liu@intel.com> References: <1599735398-6829-1-git-send-email-yi.l.liu@intel.com> Received-SPF: pass client-ip=134.134.136.65; envelope-from=yi.l.liu@intel.com; helo=mga03.intel.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/10 06:54:39 X-ACL-Warn: Detected OS = FreeBSD 9.x or newer [fuzzy] X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jean-philippe@linaro.org, kevin.tian@intel.com, yi.l.liu@intel.com, Yi Sun , Eduardo Habkost , kvm@vger.kernel.org, mst@redhat.com, jun.j.tian@intel.com, eric.auger@redhat.com, yi.y.sun@intel.com, Jacob Pan , pbonzini@redhat.com, hao.wu@intel.com, Richard Henderson , david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" RID_PASID field was introduced in VT-d 3.0 spec, it is used for DMA requests w/o PASID in scalable mode VT-d. It is also known as IOVA. And in VT-d 3.1 spec, there is definition on it: "Implementations not supporting RID_PASID capability (ECAP_REG.RPS is 0b), use a PASID value of 0 to perform address translation for requests without PASID." This patch adds a check against the PASIDs which are going to be bound to device. For PASID #0, it is not necessary to pass down pasid bind request for it since PASID #0 is used as RID_PASID for DMA requests without pasid. Further reason is current Intel vIOMMU supports gIOVA by shadowing guest 2nd level page table. However, in future, if guest IOMMU driver uses 1st level page table to store IOVA mappings, then guest IOVA support will also be done via nested translation. When gIOVA is over FLPT, then vIOMMU should pass down the pasid bind request for PASID #0 to host, host needs to bind the guest IOVA page table to a proper PASID. e.g. PASID value in RID_PASID field for PF/VF if ECAP_REG.RPS is clear or default PASID for ADI (Assignable Device Interface in Scalable IOV solution). IOVA over FLPT support on Intel VT-d: https://lore.kernel.org/linux-iommu/20191219031634.15168-1-baolu.lu@linux.intel.com/ Cc: Kevin Tian Cc: Jacob Pan Cc: Peter Xu Cc: Yi Sun Cc: Paolo Bonzini Cc: Richard Henderson Cc: Eduardo Habkost Reviewed-by: Peter Xu Signed-off-by: Liu Yi L --- hw/i386/intel_iommu.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 7bc9735..55623e8 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -1893,6 +1893,16 @@ static int vtd_bind_guest_pasid(IntelIOMMUState *s, VTDBus *vtd_bus, HostIOMMUContext *iommu_ctx; int ret = -1; + if (pasid < VTD_HPASID_MIN) { + /* + * If pasid < VTD_HPASID_MIN, this pasid is not allocated + * from host. No need to pass down the changes on it to host. + * TODO: when IOVA over FLPT is ready, this switch should be + * refined. + */ + return 0; + } + vtd_dev_icx = vtd_bus->dev_icx[devfn]; if (!vtd_dev_icx) { /* means no need to go further, e.g. for emulated devices */