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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 69DA7C433E0 for ; Wed, 1 Jul 2020 01:50:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50F8220771 for ; Wed, 1 Jul 2020 01:50:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726171AbgGABuH (ORCPT ); Tue, 30 Jun 2020 21:50:07 -0400 Received: from mga05.intel.com ([192.55.52.43]:25314 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725763AbgGABuH (ORCPT ); Tue, 30 Jun 2020 21:50:07 -0400 IronPort-SDR: Z8R1RR7l14pHRT+G/L9/3SmR/5gsKibzUIXsvpNUVP0mtwXCkNeUawjVm/xtsdsyalHUcZR09T dZbg/afpgjHQ== X-IronPort-AV: E=McAfee;i="6000,8403,9668"; a="231299498" X-IronPort-AV: E=Sophos;i="5.75,298,1589266800"; d="scan'208";a="231299498" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2020 18:50:06 -0700 IronPort-SDR: P4q4STTHl8YHwzmESTyZkAcHTorHeACpmx8HN8RxpEoXVDCH+UGwm/Gnmgu6+NNvxTc3I6e5OM YRTDZXbcRj9A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,298,1589266800"; d="scan'208";a="265268574" Received: from allen-box.sh.intel.com (HELO [10.239.159.139]) ([10.239.159.139]) by fmsmga007.fm.intel.com with ESMTP; 30 Jun 2020 18:50:03 -0700 Cc: baolu.lu@linux.intel.com, iommu@lists.linux-foundation.org, LKML , Joerg Roedel , David Woodhouse , Yi Liu , "Tian, Kevin" , Raj Ashok , Eric Auger Subject: Re: [PATCH 6/7] iommu/vt-d: Warn on out-of-range invalidation address To: Jacob Pan References: <1592926996-47914-1-git-send-email-jacob.jun.pan@linux.intel.com> <1592926996-47914-7-git-send-email-jacob.jun.pan@linux.intel.com> <20200630103459.6c99c961@jacob-builder> From: Lu Baolu Message-ID: Date: Wed, 1 Jul 2020 09:45:40 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200630103459.6c99c961@jacob-builder> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacob, On 7/1/20 1:34 AM, Jacob Pan wrote: > On Thu, 25 Jun 2020 18:10:43 +0800 > Lu Baolu wrote: > >> Hi, >> >> On 2020/6/23 23:43, Jacob Pan wrote: >>> For guest requested IOTLB invalidation, address and mask are >>> provided as part of the invalidation data. VT-d HW silently ignores >>> any address bits below the mask. SW shall also allow such case but >>> give warning if address does not align with the mask. This patch >>> relax the fault handling from error to warning and proceed with >>> invalidation request with the given mask. >>> >>> Signed-off-by: Jacob Pan >>> --- >>> drivers/iommu/intel/iommu.c | 7 +++---- >>> 1 file changed, 3 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/iommu/intel/iommu.c >>> b/drivers/iommu/intel/iommu.c index 5ea5732d5ec4..50fc62413a35 >>> 100644 --- a/drivers/iommu/intel/iommu.c >>> +++ b/drivers/iommu/intel/iommu.c >>> @@ -5439,13 +5439,12 @@ intel_iommu_sva_invalidate(struct >>> iommu_domain *domain, struct device *dev, >>> switch (BIT(cache_type)) { >>> case IOMMU_CACHE_INV_TYPE_IOTLB: >>> + /* HW will ignore LSB bits based on >>> address mask */ if (inv_info->granularity == IOMMU_INV_GRANU_ADDR && >>> size && >>> (inv_info->addr_info.addr & >>> ((BIT(VTD_PAGE_SHIFT + size)) - 1))) { >>> - pr_err_ratelimited("Address out of >>> range, 0x%llx, size order %llu\n", >>> - >>> inv_info->addr_info.addr, size); >>> - ret = -ERANGE; >>> - goto out_unlock; >>> + WARN_ONCE(1, "Address out of >>> range, 0x%llx, size order %llu\n", >>> + >>> inv_info->addr_info.addr, size); >> I don't think WARN_ONCE() is suitable here. It makes users think it's >> a kernel bug. How about pr_warn_ratelimited()? >> > I think pr_warn_ratelimited might still be too chatty. There is no > functional issues, we just don't to silently ignore it. Perhaps just > say: > WARN_ONCE(1, "User provided address not page aligned, alignment forced") > ? > WARN() is normally used for reporting a kernel bug. It dumps kernel trace. And the users will report bug through bugzilla.kernel.org. In this case, it's actually an unexpected user input, we shouldn't treat it as a kernel bug and pr_err_ratelimited() is enough? Best regards, baolu