From patchwork Fri Nov 29 10:01:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Sun X-Patchwork-Id: 11266821 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 2105C921 for ; Fri, 29 Nov 2019 10:08:02 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 074B6206E0 for ; Fri, 29 Nov 2019 10:08:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 074B6206E0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iadAT-0007Qt-R7; Fri, 29 Nov 2019 10:06:29 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iadAS-0007Qo-Bi for xen-devel@lists.xenproject.org; Fri, 29 Nov 2019 10:06:28 +0000 X-Inumbo-ID: e6865dcb-128f-11ea-a3e0-12813bfff9fa Received: from mga07.intel.com (unknown [134.134.136.100]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id e6865dcb-128f-11ea-a3e0-12813bfff9fa; Fri, 29 Nov 2019 10:06:26 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Nov 2019 02:06:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,257,1571727600"; d="scan'208";a="217759365" Received: from yisun1-ubuntu2.bj.intel.com ([10.238.144.114]) by fmsmga001.fm.intel.com with ESMTP; 29 Nov 2019 02:06:23 -0800 From: Yi Sun To: xen-devel@lists.xenproject.org Date: Fri, 29 Nov 2019 18:01:38 +0800 Message-Id: <1575021698-10589-1-git-send-email-yi.y.sun@linux.intel.com> X-Mailer: git-send-email 1.9.1 Subject: [Xen-devel] [PATCH v3] psr: fix bug which may cause crash X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: andrew.cooper3@citrix.com, Yi Sun , jbeulich@suse.com MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" During test, we found a crash on Xen with below trace. (XEN) Xen call trace: (XEN) [] R psr.c#l3_cdp_write_msr+0x1e/0x22 (XEN) [] F psr.c#do_write_psr_msrs+0x6d/0x109 (XEN) [] F smp_call_function_interrupt+0x5a/0xac (XEN) [] F call_function_interrupt+0x20/0x34 (XEN) [] F do_IRQ+0x175/0x6ae (XEN) [] F common_interrupt+0x10a/0x120 (XEN) [] F cpu_idle.c#acpi_idle_do_entry+0x9d/0xb1 (XEN) [] F cpu_idle.c#acpi_processor_idle+0x41d/0x626 (XEN) [] F domain.c#idle_loop+0xa5/0xa7 (XEN) (XEN) (XEN) **************************************** (XEN) Panic on CPU 20: (XEN) GENERAL PROTECTION FAULT (XEN) [error_code=0000] (XEN) **************************************** The bug happens when CDP and MBA co-exist and MBA COS_MAX is bigger than CDP COS_MAX. E.g. MBA has 8 COS registers but CDP only have 6. When setting MBA throttling value for the 7th guest, the value array would be: +------------------+------------------+--------------+ | Data default val | Code default val | MBA throttle | +------------------+------------------+--------------+ Then, COS id 7 will be selected for writting the values. We should avoid writting CDP data/code valules to COS id 7 MSR because it exceeds the CDP COS_MAX. Signed-off-by: Yi Sun --- xen/arch/x86/psr.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c index 5866a26..943a1e0 100644 --- a/xen/arch/x86/psr.c +++ b/xen/arch/x86/psr.c @@ -1271,7 +1271,13 @@ static void do_write_psr_msrs(void *data) for ( j = 0; j < cos_num; j++, index++ ) { - if ( feat->cos_reg_val[cos * cos_num + j] != info->val[index] ) + /* + * Multiple RDT features may co-exist and their COS_MAX may be + * different. So we should prevent one feature to write COS + * register which exceeds its COS_MAX. Otherwise, panic may happen. + */ + if ( cos <= feat->cos_max && + feat->cos_reg_val[cos * cos_num + j] != info->val[index] ) { feat->cos_reg_val[cos * cos_num + j] = info->val[index]; props->write_msr(cos, info->val[index], props->type[j]);