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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 DE1B2C3F68F for ; Fri, 10 Jan 2020 01:17:08 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 B275720678 for ; Fri, 10 Jan 2020 01:17:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B275720678 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 8B6F588391; Fri, 10 Jan 2020 01:17:08 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id oZeMyE5gGuFd; Fri, 10 Jan 2020 01:17:07 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id E658A8838C; Fri, 10 Jan 2020 01:17:07 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id C224EC1796; Fri, 10 Jan 2020 01:17:07 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 74FC8C0881 for ; Fri, 10 Jan 2020 01:17:06 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 5E66286ACE for ; Fri, 10 Jan 2020 01:17:06 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1sEWtBp9oT0r for ; Fri, 10 Jan 2020 01:17:05 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 3FA9D86ACB for ; Fri, 10 Jan 2020 01:17:05 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Jan 2020 17:17:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,414,1571727600"; d="scan'208";a="246846711" Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by fmsmga004.fm.intel.com with ESMTP; 09 Jan 2020 17:17:02 -0800 Subject: Re: [PATCH v8 02/10] iommu/vt-d: Add nested translation helper function To: Jacob Pan References: <1576524252-79116-1-git-send-email-jacob.jun.pan@linux.intel.com> <1576524252-79116-3-git-send-email-jacob.jun.pan@linux.intel.com> <6192b57c-12ab-ec6c-ab95-d9b9bff3efad@linux.intel.com> <20200109103908.4c306b06@jacob-builder> From: Lu Baolu Message-ID: <89cc7a91-f645-e331-8f02-62c281c0ea3d@linux.intel.com> Date: Fri, 10 Jan 2020 09:15:45 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200109103908.4c306b06@jacob-builder> Content-Language: en-US Cc: Yi L , "Tian, Kevin" , Raj Ashok , LKML , iommu@lists.linux-foundation.org, David Woodhouse X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Jacob, On 1/10/20 2:39 AM, Jacob Pan wrote: > On Wed, 18 Dec 2019 10:41:53 +0800 > Lu Baolu wrote: > >> Hi again, >> >> On 12/17/19 3:24 AM, Jacob Pan wrote: >>> +/** >>> + * intel_pasid_setup_nested() - Set up PASID entry for nested >>> translation >>> + * which is used for vSVA. The first level page tables are used for >>> + * GVA-GPA or GIOVA-GPA translation in the guest, second level >>> page tables >>> + * are used for GPA-HPA translation. >>> + * >>> + * @iommu: Iommu which the device belong to >>> + * @dev: Device to be set up for translation >>> + * @gpgd: FLPTPTR: First Level Page translation pointer in >>> GPA >>> + * @pasid: PASID to be programmed in the device PASID table >>> + * @pasid_data: Additional PASID info from the guest bind request >>> + * @domain: Domain info for setting up second level page tables >>> + * @addr_width: Address width of the first level (guest) >>> + */ >>> +int intel_pasid_setup_nested(struct intel_iommu *iommu, >>> + struct device *dev, pgd_t *gpgd, >>> + int pasid, struct >>> iommu_gpasid_bind_data_vtd *pasid_data, >>> + struct dmar_domain *domain, >>> + int addr_width) >>> +{ >>> + struct pasid_entry *pte; >>> + struct dma_pte *pgd; >>> + u64 pgd_val; >>> + int agaw; >>> + u16 did; >>> + >>> + if (!ecap_nest(iommu->ecap)) { >>> + pr_err("IOMMU: %s: No nested translation >>> support\n", >>> + iommu->name); >>> + return -EINVAL; >>> + } >>> + >>> + pte = intel_pasid_get_entry(dev, pasid); >>> + if (WARN_ON(!pte)) >>> + return -EINVAL; >>> + >>> + pasid_clear_entry(pte); >> >> In some cases, e.g. nested mode for GIOVA-HPA, the PASID entry might >> have already been setup for second level translation. (This could be >> checked with the Present bit.) Hence, it's safe to flush caches here. >> >> Or, maybe intel_pasid_tear_down_entry() is more suitable? >> > We don't allow binding the same device-PASID twice, so if the PASID > entry was used for GIOVA/RID2PASID, it should unbind first, and > teardown flush included, right? > Fair enough. Can you please add this as a comment to this function? So that the caller of this interface can know this. Or add a check in this function which returns error if the pasid entry has already been bond. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu