From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELscaS8iDyB5M8068P493xnJbWy2RgaDDWKVvaDOrvEMBY/nJjR25WLGjRyrugA7T10jxFX7 ARC-Seal: i=1; a=rsa-sha256; t=1520295977; cv=none; d=google.com; s=arc-20160816; b=lOf3NzZE4ezif2z1sgm9qBKaU/97y3MUa4algRnQOaK680mYXSXoYW1sUk7CTWNDbx K7qaRhKiFG1J1nLYV1HaR0za2qXl33SlYd1Q0Cie+bMXEyqMQJQl8mQWB/VRiYt9Uz8w pZLlG/FgPu3KXnfOUMw77MZsiBSnavVX58wQJILl7n4J0WXDSmUypYLoklIRa3D1EU/4 mZVm6xPX1yK5PZq/8qHUmEYrWjsZvoHMuK9PwbzQYzctHLmnvWsWjelSjxysqq+1ltf3 fenna2WROiG/HKluzsbZv2xq7PsHsVDukt5nLvNzTg8H8bHpA9GnTN2qL8nN7H7Am9nl C4EA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:to:from :dkim-signature:arc-authentication-results; bh=NnoxVu0rYiqiDvjwEt6ao/PM8XzFNUz5pLfQ1GinYCw=; b=gDFyO1pF9TR/bc96NY+VpaLM3SstQOCKnyEUH6W/C2NzIEszqK8hpq3PiII5Yte/F4 O5yczark5oQ6OYo5elDtXaVv3zVQAG5WcLv/wojeiq4U5BP4JPXEj9MKjEhHa8lvgoyL Z4goT99nZTcP83qX4tewm2V9NjYSRxGlOG3ktppTGhuN7cxnOhtMY5cBvrKXcy6KwjTu gqnBge95gC7aXUByKolKaC2XXZu60eRrurOpNGr43yRXcj+7HNopOO/y4Vydw6cYLSDh OwVLeadiRlLlQXZO+DlmbunaXU1wTRW93BB7cntxM8vExQTZk2+hGD96tlYHB1JbbodI I4Xg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=ghz8Gs/o; spf=pass (google.com: domain of pasha.tatashin@oracle.com designates 141.146.126.79 as permitted sender) smtp.mailfrom=pasha.tatashin@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2017-10-26 header.b=ghz8Gs/o; spf=pass (google.com: domain of pasha.tatashin@oracle.com designates 141.146.126.79 as permitted sender) smtp.mailfrom=pasha.tatashin@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com From: Pavel Tatashin To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, linux-kernel@vger.kernel.org, Alexander.Levin@microsoft.com, dan.j.williams@intel.com, sathyanarayanan.kuppuswamy@intel.com, pankaj.laxminarayan.bharadiya@intel.com, akuster@mvista.com, cminyard@mvista.com, pasha.tatashin@oracle.com, gregkh@linuxfoundation.org, stable@vger.kernel.org Subject: [PATCH 4.1 19/65] x86/mm: Add the 'nopcid' boot option to turn off PCID Date: Mon, 5 Mar 2018 19:24:52 -0500 Message-Id: <20180306002538.1761-20-pasha.tatashin@oracle.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180306002538.1761-1-pasha.tatashin@oracle.com> References: <20180306002538.1761-1-pasha.tatashin@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8823 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1803060003 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594145875041863992?= X-GMAIL-MSGID: =?utf-8?q?1594145875041863992?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Andy Lutomirski commit 0790c9aad84901ca1bdc14746175549c8b5da215 upstream. The parameter is only present on x86_64 systems to save a few bytes, as PCID is always disabled on x86_32. Signed-off-by: Andy Lutomirski Reviewed-by: Nadav Amit Reviewed-by: Borislav Petkov Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dave Hansen Cc: Linus Torvalds Cc: Mel Gorman Cc: Peter Zijlstra Cc: Rik van Riel Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/8bbb2e65bcd249a5f18bfb8128b4689f08ac2b60.1498751203.git.luto@kernel.org Signed-off-by: Ingo Molnar Cc: Hugh Dickins Signed-off-by: Greg Kroah-Hartman (cherry picked from commit dcccd3c266e24ce80ecf592765315c54c222ac33) Signed-off-by: Pavel Tatashin --- Documentation/kernel-parameters.txt | 2 ++ arch/x86/kernel/cpu/common.c | 18 ++++++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ceaab09a279e..97bc24101896 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2471,6 +2471,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nopat [X86] Disable PAT (page attribute table extension of pagetables) support. + nopcid [X86-64] Disable the PCID cpu feature. + norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 90ef802d9d90..843be1de5ddb 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -172,6 +172,24 @@ static int __init x86_xsaves_setup(char *s) } __setup("noxsaves", x86_xsaves_setup); +#ifdef CONFIG_X86_64 +static int __init x86_pcid_setup(char *s) +{ + /* require an exact match without trailing characters */ + if (strlen(s)) + return 0; + + /* do not emit a message if the feature is not present */ + if (!boot_cpu_has(X86_FEATURE_PCID)) + return 1; + + setup_clear_cpu_cap(X86_FEATURE_PCID); + pr_info("nopcid: PCID feature disabled\n"); + return 1; +} +__setup("nopcid", x86_pcid_setup); +#endif + static int __init x86_noinvpcid_setup(char *s) { /* noinvpcid doesn't accept parameters */ -- 2.16.2