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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5239BC433F4 for ; Mon, 13 Jul 2020 23:48:59 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 33CA72184D for ; Mon, 13 Jul 2020 23:48:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 33CA72184D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=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 whitealder.osuosl.org (Postfix) with ESMTP id 076918A4C2; Mon, 13 Jul 2020 23:48:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id cDZ2Ew8Q4Bvn; Mon, 13 Jul 2020 23:48:56 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id E72AD8A55B; Mon, 13 Jul 2020 23:48:51 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id C4C02C1818; Mon, 13 Jul 2020 23:48:51 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id EDD0BC0733 for ; Mon, 13 Jul 2020 23:48:48 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id DCC5489856 for ; Mon, 13 Jul 2020 23:48:48 +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 8jsLf8bjloZC for ; Mon, 13 Jul 2020 23:48:46 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by hemlock.osuosl.org (Postfix) with ESMTPS id 4CBAD89808 for ; Mon, 13 Jul 2020 23:48:46 +0000 (UTC) IronPort-SDR: zAl8vDENjRSTG3X+wFx38vln8tnYnnaGv7NcvoCPs3sK5pGErtehc65bR8YmhMQdDfmmI4Wtcj QEHq2Q2tQ0pw== X-IronPort-AV: E=McAfee;i="6000,8403,9681"; a="233607269" X-IronPort-AV: E=Sophos;i="5.75,349,1589266800"; d="scan'208";a="233607269" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jul 2020 16:48:46 -0700 IronPort-SDR: tV81P1EHE6ArAwCH7kXPVlxq4xceAQw5O+9OlkyrmpfO6wxzUFCly09pwe6KFnrxhA62MNEgS8 BWC0+8tcEbYw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,349,1589266800"; d="scan'208";a="281570462" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga003.jf.intel.com with ESMTP; 13 Jul 2020 16:48:45 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Joerg Roedel" , "Ingo Molnar" , "Borislav Petkov" , "Peter Zijlstra" , "H Peter Anvin" , "David Woodhouse" , "Lu Baolu" , "Felix Kuehling" , "Dave Hansen" , "Tony Luck" , "Jean-Philippe Brucker" , "Christoph Hellwig" , "Ashok Raj" , "Jacob Jun Pan" , "Dave Jiang" , "Sohil Mehta" , "Ravi V Shankar" Subject: [PATCH v6 09/12] x86/process: Clear PASID state for a newly forked/cloned thread Date: Mon, 13 Jul 2020 16:48:04 -0700 Message-Id: <1594684087-61184-10-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1594684087-61184-1-git-send-email-fenghua.yu@intel.com> References: <1594684087-61184-1-git-send-email-fenghua.yu@intel.com> Cc: Fenghua Yu , iommu@lists.linux-foundation.org, x86 , linux-kernel , amd-gfx 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: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" The PASID state has to be cleared on forks, since the child has a different address space. The PASID is also cleared for thread clone. While it would be correct to inherit the PASID in this case, it is unknown whether the new task will use ENQCMD. Giving it the PASID "just in case" would have the downside of increased context switch overhead to setting the PASID MSR. Since #GP faults have to be handled on any threads that were created before the PASID was assigned to the mm of the process, newly created threads might as well be treated in a consistent way. Suggested-by: Thomas Gleixner Signed-off-by: Fenghua Yu Reviewed-by: Tony Luck --- v2: - Modify init_task_pasid(). arch/x86/kernel/process.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index f362ce0d5ac0..1b1492e337a6 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -121,6 +121,21 @@ static int set_new_tls(struct task_struct *p, unsigned long tls) return do_set_thread_area_64(p, ARCH_SET_FS, tls); } +/* Initialize the PASID state for the forked/cloned thread. */ +static void init_task_pasid(struct task_struct *task) +{ + struct ia32_pasid_state *ppasid; + + /* + * Initialize the PASID state so that the PASID MSR will be + * initialized to its initial state (0) by XRSTORS when the task is + * scheduled for the first time. + */ + ppasid = get_xsave_addr(&task->thread.fpu.state.xsave, XFEATURE_PASID); + if (ppasid) + ppasid->pasid = INIT_PASID; +} + int copy_thread_tls(unsigned long clone_flags, unsigned long sp, unsigned long arg, struct task_struct *p, unsigned long tls) { @@ -174,6 +189,9 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp, task_user_gs(p) = get_user_gs(current_pt_regs()); #endif + if (static_cpu_has(X86_FEATURE_ENQCMD)) + init_task_pasid(p); + /* Set a new TLS for the child thread? */ if (clone_flags & CLONE_SETTLS) ret = set_new_tls(p, tls); -- 2.19.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu