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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 6CD78C4338F for ; Mon, 26 Jul 2021 16:31:48 +0000 (UTC) Received: from smtp2.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 E5C6160F5E for ; Mon, 26 Jul 2021 16:31:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E5C6160F5E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=wantstofly.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id ACC38402A9; Mon, 26 Jul 2021 16:31:47 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 58y1GGazhLDP; Mon, 26 Jul 2021 16:31:46 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTPS id 8583F40240; Mon, 26 Jul 2021 16:31:46 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 59E50C0010; Mon, 26 Jul 2021 16:31:46 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 39829C000E for ; Mon, 26 Jul 2021 16:31:45 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 217BC60771 for ; Mon, 26 Jul 2021 16:31:45 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id bwg_0i307yW9 for ; Mon, 26 Jul 2021 16:31:43 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from mail.wantstofly.org (hmm.wantstofly.org [213.239.204.108]) by smtp3.osuosl.org (Postfix) with ESMTPS id 87744605F1 for ; Mon, 26 Jul 2021 16:31:43 +0000 (UTC) Received: by mail.wantstofly.org (Postfix, from userid 1000) id 26C057F46A; Mon, 26 Jul 2021 19:31:41 +0300 (EEST) Date: Mon, 26 Jul 2021 19:31:41 +0300 From: Lennert Buytenhek To: iommu@lists.linux-foundation.org, Joerg Roedel , Suravee Suthikulpanit Subject: [PATCH v2] iommu/amd: Use report_iommu_fault() Message-ID: MIME-Version: 1.0 Content-Disposition: inline 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" This patch makes iommu/amd call report_iommu_fault() when an I/O page fault occurs, which has two effects: 1) It allows device drivers to register a callback to be notified of I/O page faults, via the iommu_set_fault_handler() API. 2) It triggers the io_page_fault tracepoint in report_iommu_fault() when an I/O page fault occurs. I'm mainly interested in (2). We have a daemon with some rasdaemon-like functionality for handling platform errors, and being able to be notified of I/O page faults for initiating corrective action is very useful -- and receiving such events via event tracing is a lot nicer than having to scrape them from kmsg. A number of other IOMMU drivers already use report_iommu_fault(), and I/O page faults on those IOMMUs therefore already seem to trigger this tracepoint -- but this isn't (yet) the case for AMD-Vi and Intel DMAR. I copied the logic from the other callers of report_iommu_fault(), where if that function returns zero, the driver will have handled the fault, in which case we avoid logging information about the fault to the printk buffer from the IOMMU driver. With this patch I see io_page_fault event tracing entries as expected: irq/24-AMD-Vi-48 [002] .... 978.554289: io_page_fault: IOMMU:[drvname] 0000:05:00.0 iova=0x0000000091482640 flags=0x0000 irq/24-AMD-Vi-48 [002] .... 978.554294: io_page_fault: IOMMU:[drvname] 0000:05:00.0 iova=0x0000000091482650 flags=0x0000 irq/24-AMD-Vi-48 [002] .... 978.554299: io_page_fault: IOMMU:[drvname] 0000:05:00.0 iova=0x0000000091482660 flags=0x0000 irq/24-AMD-Vi-48 [002] .... 978.554305: io_page_fault: IOMMU:[drvname] 0000:05:00.0 iova=0x0000000091482670 flags=0x0000 irq/24-AMD-Vi-48 [002] .... 978.554310: io_page_fault: IOMMU:[drvname] 0000:05:00.0 iova=0x0000000091482680 flags=0x0000 irq/24-AMD-Vi-48 [002] .... 978.554315: io_page_fault: IOMMU:[drvname] 0000:05:00.0 iova=0x00000000914826a0 flags=0x0000 For determining IOMMU_FAULT_{READ,WRITE}, I followed the AMD IOMMU spec, but I haven't tested that bit of the code, as the page faults I encounter are all to non-present (!EVENT_FLAG_PR) mappings, in which case EVENT_FLAG_RW doesn't make sense. Signed-off-by: Lennert Buytenhek --- Changes since v1 RFC: - Don't call report_iommu_fault() for IRQ remapping faults. (Suggested by Joerg Roedel.) drivers/iommu/amd/amd_iommu_types.h | 4 ++++ drivers/iommu/amd/iommu.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h index 94c1a7a9876d..2f2c6630c24c 100644 --- a/drivers/iommu/amd/amd_iommu_types.h +++ b/drivers/iommu/amd/amd_iommu_types.h @@ -138,6 +138,10 @@ #define EVENT_DOMID_MASK_HI 0xf0000 #define EVENT_FLAGS_MASK 0xfff #define EVENT_FLAGS_SHIFT 0x10 +#define EVENT_FLAG_TR 0x100 +#define EVENT_FLAG_RW 0x020 +#define EVENT_FLAG_PR 0x010 +#define EVENT_FLAG_I 0x008 /* feature control bits */ #define CONTROL_IOMMU_EN 0x00ULL diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index a7d6d78147b7..d9fb2c22d44a 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -484,6 +484,34 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id, if (pdev) dev_data = dev_iommu_priv_get(&pdev->dev); + /* + * If this is a DMA fault (for which the I(nterrupt) bit will + * be unset), allow report_iommu_fault() to prevent logging it. + */ + if (dev_data && ((flags & EVENT_FLAG_I) == 0)) { + int report_flags; + + /* + * AMD I/O Virtualization Technology (IOMMU) Specification, + * revision 3.00, section 2.5.3 ("IO_PAGE_FAULT Event") says + * that the RW ("read-write") bit is only valid if the I/O + * page fault was caused by a memory transaction request + * referencing a page that was marked present. + */ + report_flags = 0; + if ((flags & (EVENT_FLAG_TR | EVENT_FLAG_PR)) == + EVENT_FLAG_PR) { + if (flags & EVENT_FLAG_RW) + report_flags |= IOMMU_FAULT_WRITE; + else + report_flags |= IOMMU_FAULT_READ; + } + + if (!report_iommu_fault(&dev_data->domain->domain, + &pdev->dev, address, report_flags)) + goto out; + } + if (dev_data) { if (__ratelimit(&dev_data->rs)) { pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n", @@ -495,6 +523,7 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id, domain_id, address, flags); } +out: if (pdev) pci_dev_put(pdev); } -- 2.31.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu