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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT 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 7A0A8C43464 for ; Thu, 17 Sep 2020 21:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37FED206BE for ; Thu, 17 Sep 2020 21:25:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="kpZurblB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726265AbgIQVZW (ORCPT ); Thu, 17 Sep 2020 17:25:22 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:33482 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726245AbgIQVZU (ORCPT ); Thu, 17 Sep 2020 17:25:20 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08HLF5VN012576; Thu, 17 Sep 2020 21:22:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=4A2NgPr0lNAqN2KX+a6SQbPtGt796V8wB46BXwl0c1g=; b=kpZurblBgqbsMoWgFKbQmSwZpXgHV+uwzRnNQMZRmZhY+803+b/45gFe27KS07tOGAUz bg0+nX7ZirJHcpvS1hpcRGSctCcllD4radLned8y8DAtAwdsPYS6gd4xbPQKOSrYxZya CDTW2fhrVnJuCvG3N8YlchjvtV2JhSD+ulQl9wIXTSmjngONzWIAZ7Din1HswrPc7gm/ iSkoVjzN4mbFQNymOoqMo3FpMJWztkMu34qC7EcoynZAu9cuuuYNjvcC5nvdUQzgzGHf LwDBINeOZhMi3pKcAEA2n8H1Ck3WfVNdsWPFvP67zW+hlWFetLQ7afT5TJLdCLSup4d9 iA== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 33gp9mku7h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 17 Sep 2020 21:22:33 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08HLAnfn018898; Thu, 17 Sep 2020 21:22:32 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 33mega3vn9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 17 Sep 2020 21:22:32 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 08HLMReF010132; Thu, 17 Sep 2020 21:22:27 GMT Received: from nsvm-sadhukhan-1.osdevelopmeniad.oraclevcn.com (/100.100.230.216) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 17 Sep 2020 21:22:27 +0000 From: Krish Sadhukhan To: kvm@vger.kernel.org Cc: pbonzini@redhat.com, jmattson@google.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, sean.j.christopherson@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, joro@8bytes.org, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org, hpa@zytor.com Subject: [PATCH 2/3 v4] x86: AMD: Don't flush cache if hardware enforces cache coherency across encryption domnains Date: Thu, 17 Sep 2020 21:20:37 +0000 Message-Id: <20200917212038.5090-3-krish.sadhukhan@oracle.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20200917212038.5090-1-krish.sadhukhan@oracle.com> References: <20200917212038.5090-1-krish.sadhukhan@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9747 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 mlxscore=0 spamscore=0 mlxlogscore=983 adultscore=0 bulkscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009170158 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9747 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxlogscore=998 adultscore=0 malwarescore=0 clxscore=1015 lowpriorityscore=0 phishscore=0 spamscore=0 priorityscore=1501 suspectscore=1 impostorscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009170158 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In some hardware implementations, coherency between the encrypted and unencrypted mappings of the same physical page is enforced. In such a system, it is not required for software to flush the page from all CPU caches in the system prior to changing the value of the C-bit for the page. Suggested-by: Tom Lendacky Signed-off-by: Krish Sadhukhan --- arch/x86/mm/pat/set_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index d1b2a889f035..40baa90e74f4 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -1999,7 +1999,7 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) /* * Before changing the encryption attribute, we need to flush caches. */ - cpa_flush(&cpa, 1); + cpa_flush(&cpa, !this_cpu_has(X86_FEATURE_SME_COHERENT)); ret = __change_page_attr_set_clr(&cpa, 1); -- 2.18.4