From patchwork Wed Apr 3 21:21:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884487 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3D02A1575 for ; Wed, 3 Apr 2019 21:32:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2713D28450 for ; Wed, 3 Apr 2019 21:32:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1AC08285B7; Wed, 3 Apr 2019 21:32:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE20028450 for ; Wed, 3 Apr 2019 21:32:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726880AbfDCVb7 (ORCPT ); Wed, 3 Apr 2019 17:31:59 -0400 Received: from mga05.intel.com ([192.55.52.43]:37332 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726723AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754231" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:10 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 01/20] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long Date: Wed, 3 Apr 2019 14:21:47 -0700 Message-Id: <1554326526-172295-2-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP cpu_caps_cleared and cpu_caps_set may not be aligned to unsigned long. Atomic operations (i.e. set_bit and clear_bit) on the bitmaps may access two cache lines (a.k.a. split lock) and lock the bus to block all memory accesses from other processors to ensure atomicity. To avoid the overall performance degradation from the bus locking, align the two variables to unsigned long. Defining the variables as unsigned long may also fix the issue because they are naturally aligned to unsigned long. But that needs additional code changes. Adding __aligned(unsigned long) is a simpler fix. Signed-off-by: Fenghua Yu Reviewed-by: Borislav Petkov --- arch/x86/kernel/cpu/common.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cb28e98a0659..3716e2bb028b 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -488,8 +488,9 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c) return NULL; /* Not found */ } -__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS]; -__u32 cpu_caps_set[NCAPINTS + NBUGINTS]; +/* Aligned to unsigned long to avoid split lock in atomic bitmap ops */ +__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS] __aligned(sizeof(unsigned long)); +__u32 cpu_caps_set[NCAPINTS + NBUGINTS] __aligned(sizeof(unsigned long)); void load_percpu_segment(int cpu) { From patchwork Wed Apr 3 21:21:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884495 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EFCBC1575 for ; Wed, 3 Apr 2019 21:32:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D7D7C28450 for ; Wed, 3 Apr 2019 21:32:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CBDD7285B7; Wed, 3 Apr 2019 21:32:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6FCF828450 for ; Wed, 3 Apr 2019 21:32:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728648AbfDCVcK (ORCPT ); Wed, 3 Apr 2019 17:32:10 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726711AbfDCVaU (ORCPT ); Wed, 3 Apr 2019 17:30:20 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754232" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:10 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 02/20] drivers/net/b44: Align pwol_mask to unsigned long for better performance Date: Wed, 3 Apr 2019 14:21:48 -0700 Message-Id: <1554326526-172295-3-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Peter Zijlstra A bit in pwol_mask is set in b44_magic_pattern by atomic set_bit. But since pwol_mask is local and never exposed to concurrency, there is no need to set bit in pwol_mask atomically. set_bit sets the bit in a single unsigned long location. Because pwol_mask may not be aligned to unsigned long, the location may cross two cache lines. On x86, accessing two cache lines in locked instruction in set_bit is called split lock and can cause overall performance degradation. So use non atomic __set_bit to set pwol_mask bits. __set_bit won't hit split lock issue on x86. Signed-off-by: Peter Zijlstra Signed-off-by: Fenghua Yu --- drivers/net/ethernet/broadcom/b44.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c index 97ab0dd25552..5738ab963dfb 100644 --- a/drivers/net/ethernet/broadcom/b44.c +++ b/drivers/net/ethernet/broadcom/b44.c @@ -1520,7 +1520,7 @@ static int b44_magic_pattern(u8 *macaddr, u8 *ppattern, u8 *pmask, int offset) memset(ppattern + offset, 0xff, magicsync); for (j = 0; j < magicsync; j++) - set_bit(len++, (unsigned long *) pmask); + __set_bit(len++, (unsigned long *)pmask); for (j = 0; j < B44_MAX_PATTERNS; j++) { if ((B44_PATTERN_SIZE - len) >= ETH_ALEN) @@ -1532,7 +1532,7 @@ static int b44_magic_pattern(u8 *macaddr, u8 *ppattern, u8 *pmask, int offset) for (k = 0; k< ethaddr_bytes; k++) { ppattern[offset + magicsync + (j * ETH_ALEN) + k] = macaddr[k]; - set_bit(len++, (unsigned long *) pmask); + __set_bit(len++, (unsigned long *)pmask); } } return len - 1; From patchwork Wed Apr 3 21:21:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884491 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D44A61708 for ; Wed, 3 Apr 2019 21:32:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B94C6285C8 for ; Wed, 3 Apr 2019 21:32:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AD0A9285B7; Wed, 3 Apr 2019 21:32:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C025284C7 for ; Wed, 3 Apr 2019 21:32:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728669AbfDCVcL (ORCPT ); Wed, 3 Apr 2019 17:32:11 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726656AbfDCVaU (ORCPT ); Wed, 3 Apr 2019 17:30:20 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754233" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:10 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 03/20] wlcore: simplify/fix/optimize reg_ch_conf_pending operations Date: Wed, 3 Apr 2019 14:21:49 -0700 Message-Id: <1554326526-172295-4-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Paolo Bonzini Bitmaps are defined on unsigned longs, so the usage of u32[2] in the wlcore driver is incorrect. As noted by Peter Zijlstra, casting arrays to a bitmap is incorrect for big-endian architectures. When looking at it I observed that: - operations on reg_ch_conf_pending is always under the wl_lock mutex, so set_bit is overkill - the only case where reg_ch_conf_pending is accessed a u32 at a time is unnecessary too. This patch cleans up everything in this area, and changes tmp_ch_bitmap to have the proper alignment. Signed-off-by: Paolo Bonzini Signed-off-by: Fenghua Yu --- drivers/net/wireless/ti/wlcore/cmd.c | 15 ++++++--------- drivers/net/wireless/ti/wlcore/wlcore.h | 4 ++-- 2 files changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/ti/wlcore/cmd.c b/drivers/net/wireless/ti/wlcore/cmd.c index 348be0aed97e..0415a064f6e2 100644 --- a/drivers/net/wireless/ti/wlcore/cmd.c +++ b/drivers/net/wireless/ti/wlcore/cmd.c @@ -1700,14 +1700,14 @@ void wlcore_set_pending_regdomain_ch(struct wl1271 *wl, u16 channel, ch_bit_idx = wlcore_get_reg_conf_ch_idx(band, channel); if (ch_bit_idx >= 0 && ch_bit_idx <= WL1271_MAX_CHANNELS) - set_bit(ch_bit_idx, (long *)wl->reg_ch_conf_pending); + __set_bit_le(ch_bit_idx, (long *)wl->reg_ch_conf_pending); } int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) { struct wl12xx_cmd_regdomain_dfs_config *cmd = NULL; int ret = 0, i, b, ch_bit_idx; - u32 tmp_ch_bitmap[2]; + __le32 tmp_ch_bitmap[2] __aligned(sizeof(unsigned long)); struct wiphy *wiphy = wl->hw->wiphy; struct ieee80211_supported_band *band; bool timeout = false; @@ -1717,7 +1717,7 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) wl1271_debug(DEBUG_CMD, "cmd reg domain config"); - memset(tmp_ch_bitmap, 0, sizeof(tmp_ch_bitmap)); + memcpy(tmp_ch_bitmap, wl->reg_ch_conf_pending, sizeof(tmp_ch_bitmap)); for (b = NL80211_BAND_2GHZ; b <= NL80211_BAND_5GHZ; b++) { band = wiphy->bands[b]; @@ -1738,13 +1738,10 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) if (ch_bit_idx < 0) continue; - set_bit(ch_bit_idx, (long *)tmp_ch_bitmap); + __set_bit_le(ch_bit_idx, (long *)tmp_ch_bitmap); } } - tmp_ch_bitmap[0] |= wl->reg_ch_conf_pending[0]; - tmp_ch_bitmap[1] |= wl->reg_ch_conf_pending[1]; - if (!memcmp(tmp_ch_bitmap, wl->reg_ch_conf_last, sizeof(tmp_ch_bitmap))) goto out; @@ -1754,8 +1751,8 @@ int wlcore_cmd_regdomain_config_locked(struct wl1271 *wl) goto out; } - cmd->ch_bit_map1 = cpu_to_le32(tmp_ch_bitmap[0]); - cmd->ch_bit_map2 = cpu_to_le32(tmp_ch_bitmap[1]); + cmd->ch_bit_map1 = tmp_ch_bitmap[0]; + cmd->ch_bit_map2 = tmp_ch_bitmap[1]; cmd->dfs_region = wl->dfs_region; wl1271_debug(DEBUG_CMD, diff --git a/drivers/net/wireless/ti/wlcore/wlcore.h b/drivers/net/wireless/ti/wlcore/wlcore.h index dd14850b0603..870eea3e7a27 100644 --- a/drivers/net/wireless/ti/wlcore/wlcore.h +++ b/drivers/net/wireless/ti/wlcore/wlcore.h @@ -320,9 +320,9 @@ struct wl1271 { bool watchdog_recovery; /* Reg domain last configuration */ - u32 reg_ch_conf_last[2] __aligned(8); + DECLARE_BITMAP(reg_ch_conf_last, 64); /* Reg domain pending configuration */ - u32 reg_ch_conf_pending[2]; + DECLARE_BITMAP(reg_ch_conf_pending, 64); /* Pointer that holds DMA-friendly block for the mailbox */ void *mbox; From patchwork Wed Apr 3 21:21:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884499 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E4CA41708 for ; Wed, 3 Apr 2019 21:32:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D018728450 for ; Wed, 3 Apr 2019 21:32:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C454D285C7; Wed, 3 Apr 2019 21:32:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C98228450 for ; Wed, 3 Apr 2019 21:32:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726682AbfDCVaU (ORCPT ); Wed, 3 Apr 2019 17:30:20 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726628AbfDCVaT (ORCPT ); Wed, 3 Apr 2019 17:30:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754234" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:10 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 04/20] x86/split_lock: Align x86_capability to unsigned long to avoid split locked access Date: Wed, 3 Apr 2019 14:21:50 -0700 Message-Id: <1554326526-172295-5-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP set_cpu_cap() calls locked BTS and clear_cpu_cap() calls locked BTR to operate on bitmap defined in x86_capability. Locked BTS/BTR accesses a single unsigned long location. In 64-bit mode, the location is at: base address of x86_capability + (bit offset in x86_capability / 64) * 8 Since base address of x86_capability may not be aligned to unsigned long, the single unsigned long location may cross two cache lines and accessing the location by locked BTS/BTR introductions will trigger #AC. To fix the split lock issue, align x86_capability to unsigned long so that the location will be always within one cache line. Changing x86_capability[]'s type to unsigned long may also fix the issue because x86_capability[] will be naturally aligned to unsigned long. But this needs additional code changes. So choose the simpler solution by setting alignment to size of unsigned long. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/processor.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 2bb3a648fc12..7c62b9ad6e5a 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -93,7 +93,9 @@ struct cpuinfo_x86 { __u32 extended_cpuid_level; /* Maximum supported CPUID level, -1=no CPUID: */ int cpuid_level; - __u32 x86_capability[NCAPINTS + NBUGINTS]; + /* Aligned to size of unsigned long to avoid split lock in atomic ops */ + __u32 x86_capability[NCAPINTS + NBUGINTS] + __aligned(sizeof(unsigned long)); char x86_vendor_id[16]; char x86_model_id[64]; /* in KB - valid for CPUS which support this call: */ From patchwork Wed Apr 3 21:21:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884475 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E50A1575 for ; Wed, 3 Apr 2019 21:31:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 80B1728450 for ; Wed, 3 Apr 2019 21:31:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 71456285B7; Wed, 3 Apr 2019 21:31:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2203A28450 for ; Wed, 3 Apr 2019 21:31:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728487AbfDCVbZ (ORCPT ); Wed, 3 Apr 2019 17:31:25 -0400 Received: from mga05.intel.com ([192.55.52.43]:37332 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754235" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:10 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 05/20] x86/msr-index: Define MSR_IA32_CORE_CAPABILITY and split lock detection bit Date: Wed, 3 Apr 2019 14:21:51 -0700 Message-Id: <1554326526-172295-6-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A new MSR_IA32_CORE_CAPABILITY (0xcf) is defined. Each bit in the MSR enumerates a model specific feature. Currently bit 5 enumerates split lock detection. When bit 5 is 1, split lock detection is supported. When the bit is 0, split lock detection is not supported. Please check the latest Intel 64 and IA-32 Architectures Software Developer's Manual for more detailed information on the MSR and the split lock detection bit. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/msr-index.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index ca5bc0eacb95..f65ef6f783d2 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -59,6 +59,9 @@ #define MSR_PLATFORM_INFO_CPUID_FAULT_BIT 31 #define MSR_PLATFORM_INFO_CPUID_FAULT BIT_ULL(MSR_PLATFORM_INFO_CPUID_FAULT_BIT) +#define MSR_IA32_CORE_CAPABILITY 0x000000cf +#define CORE_CAP_SPLIT_LOCK_DETECT BIT(5) /* Detect split lock */ + #define MSR_PKG_CST_CONFIG_CONTROL 0x000000e2 #define NHM_C3_AUTO_DEMOTE (1UL << 25) #define NHM_C1_AUTO_DEMOTE (1UL << 26) From patchwork Wed Apr 3 21:21:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884481 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 26C3317E9 for ; Wed, 3 Apr 2019 21:31:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15B7C285B7 for ; Wed, 3 Apr 2019 21:31:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0A21F284C7; Wed, 3 Apr 2019 21:31:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AFABA285B7 for ; Wed, 3 Apr 2019 21:31:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726950AbfDCVbY (ORCPT ); Wed, 3 Apr 2019 17:31:24 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726752AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754236" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:10 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 06/20] x86/cpufeatures: Enumerate MSR_IA32_CORE_CAPABILITY Date: Wed, 3 Apr 2019 14:21:52 -0700 Message-Id: <1554326526-172295-7-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP MSR_IA32_CORE_CAPABILITY (0xcf) contains bits that enumerate some model specific features. The MSR 0xcf itself is enumerated by CPUID.(EAX=0x7,ECX=0):EDX[30]. When this CPUID bit is 1, the MSR 0xcf exists. Detailed information on the CPUID bit and the MSR can be found in the latest Intel 64 and IA-32 Architectures Software Developer's Manual. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpufeatures.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 981ff9479648..eff25e2015a5 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -350,6 +350,7 @@ #define X86_FEATURE_INTEL_STIBP (18*32+27) /* "" Single Thread Indirect Branch Predictors */ #define X86_FEATURE_FLUSH_L1D (18*32+28) /* Flush L1D cache */ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ +#define X86_FEATURE_CORE_CAPABILITY (18*32+30) /* "" IA32_CORE_CAPABILITY MSR */ #define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */ /* From patchwork Wed Apr 3 21:21:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884485 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6ABD817E9 for ; Wed, 3 Apr 2019 21:31:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 595C328450 for ; Wed, 3 Apr 2019 21:31:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4CD14284C7; Wed, 3 Apr 2019 21:31:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B37B7285C7 for ; Wed, 3 Apr 2019 21:31:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726761AbfDCVbs (ORCPT ); Wed, 3 Apr 2019 17:31:48 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726725AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754238" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 07/20] x86/split_lock: Enumerate split lock detection by MSR_IA32_CORE_CAPABILITY Date: Wed, 3 Apr 2019 14:21:53 -0700 Message-Id: <1554326526-172295-8-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Bits in MSR_IA32_CORE_CAPABILITY enumerate a few features that are not enumerated through CPUID. Currently bit 5 is defined to enumerate feature of split lock detection. All other bits are reserved now. When bit 5 is 1, the feature is supported and feature bit X86_FEATURE_SPLIT_LOCK_DETECT is set. Otherwise, the feature is not available. The MSR_IA32_CORE_CAPABILITY itself is enumerated by CPUID.(EAX=0x7,ECX=0):EDX[30]. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpu.h | 5 ++ arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/common.c | 2 + arch/x86/kernel/cpu/cpuid-deps.c | 79 +++++++++++++++--------------- arch/x86/kernel/cpu/intel.c | 21 ++++++++ 5 files changed, 69 insertions(+), 39 deletions(-) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index adc6cc86b062..4e03f53fc079 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -40,4 +40,9 @@ int mwait_usable(const struct cpuinfo_x86 *); unsigned int x86_family(unsigned int sig); unsigned int x86_model(unsigned int sig); unsigned int x86_stepping(unsigned int sig); +#ifdef CONFIG_CPU_SUP_INTEL +void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c); +#else +static inline void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) {} +#endif #endif /* _ASM_X86_CPU_H */ diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index eff25e2015a5..db0c1826d7ad 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -221,6 +221,7 @@ #define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */ #define X86_FEATURE_L1TF_PTEINV ( 7*32+29) /* "" L1TF workaround PTE inversion */ #define X86_FEATURE_IBRS_ENHANCED ( 7*32+30) /* Enhanced IBRS */ +#define X86_FEATURE_SPLIT_LOCK_DETECT ( 7*32+31) /* #AC for split lock */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 3716e2bb028b..bbdd69dd4f5f 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1105,6 +1105,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) cpu_set_bug_bits(c); + cpu_set_core_cap_bits(c); + fpu__init_system(c); #ifdef CONFIG_X86_32 diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 2c0bd38a44ab..3d633f67fbd7 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -20,45 +20,46 @@ struct cpuid_dep { * but it's difficult to tell that to the init reference checker. */ static const struct cpuid_dep cpuid_deps[] = { - { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE }, - { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE }, - { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE }, - { X86_FEATURE_AVX, X86_FEATURE_XSAVE }, - { X86_FEATURE_PKU, X86_FEATURE_XSAVE }, - { X86_FEATURE_MPX, X86_FEATURE_XSAVE }, - { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE }, - { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR }, - { X86_FEATURE_XMM, X86_FEATURE_FXSR }, - { X86_FEATURE_XMM2, X86_FEATURE_XMM }, - { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, - { X86_FEATURE_XMM4_1, X86_FEATURE_XMM2 }, - { X86_FEATURE_XMM4_2, X86_FEATURE_XMM2 }, - { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, - { X86_FEATURE_PCLMULQDQ, X86_FEATURE_XMM2 }, - { X86_FEATURE_SSSE3, X86_FEATURE_XMM2, }, - { X86_FEATURE_F16C, X86_FEATURE_XMM2, }, - { X86_FEATURE_AES, X86_FEATURE_XMM2 }, - { X86_FEATURE_SHA_NI, X86_FEATURE_XMM2 }, - { X86_FEATURE_FMA, X86_FEATURE_AVX }, - { X86_FEATURE_AVX2, X86_FEATURE_AVX, }, - { X86_FEATURE_AVX512F, X86_FEATURE_AVX, }, - { X86_FEATURE_AVX512IFMA, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512PF, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512ER, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512CD, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512DQ, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512BW, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512VL, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512VBMI, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512_VBMI2, X86_FEATURE_AVX512VL }, - { X86_FEATURE_GFNI, X86_FEATURE_AVX512VL }, - { X86_FEATURE_VAES, X86_FEATURE_AVX512VL }, - { X86_FEATURE_VPCLMULQDQ, X86_FEATURE_AVX512VL }, - { X86_FEATURE_AVX512_VNNI, X86_FEATURE_AVX512VL }, - { X86_FEATURE_AVX512_BITALG, X86_FEATURE_AVX512VL }, - { X86_FEATURE_AVX512_4VNNIW, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512_4FMAPS, X86_FEATURE_AVX512F }, - { X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F }, + { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE }, + { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE }, + { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE }, + { X86_FEATURE_AVX, X86_FEATURE_XSAVE }, + { X86_FEATURE_PKU, X86_FEATURE_XSAVE }, + { X86_FEATURE_MPX, X86_FEATURE_XSAVE }, + { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE }, + { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR }, + { X86_FEATURE_XMM, X86_FEATURE_FXSR }, + { X86_FEATURE_XMM2, X86_FEATURE_XMM }, + { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, + { X86_FEATURE_XMM4_1, X86_FEATURE_XMM2 }, + { X86_FEATURE_XMM4_2, X86_FEATURE_XMM2 }, + { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, + { X86_FEATURE_PCLMULQDQ, X86_FEATURE_XMM2 }, + { X86_FEATURE_SSSE3, X86_FEATURE_XMM2, }, + { X86_FEATURE_F16C, X86_FEATURE_XMM2, }, + { X86_FEATURE_AES, X86_FEATURE_XMM2 }, + { X86_FEATURE_SHA_NI, X86_FEATURE_XMM2 }, + { X86_FEATURE_FMA, X86_FEATURE_AVX }, + { X86_FEATURE_AVX2, X86_FEATURE_AVX, }, + { X86_FEATURE_AVX512F, X86_FEATURE_AVX, }, + { X86_FEATURE_AVX512IFMA, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512PF, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512ER, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512CD, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512DQ, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512BW, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512VL, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512VBMI, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512_VBMI2, X86_FEATURE_AVX512VL }, + { X86_FEATURE_GFNI, X86_FEATURE_AVX512VL }, + { X86_FEATURE_VAES, X86_FEATURE_AVX512VL }, + { X86_FEATURE_VPCLMULQDQ, X86_FEATURE_AVX512VL }, + { X86_FEATURE_AVX512_VNNI, X86_FEATURE_AVX512VL }, + { X86_FEATURE_AVX512_BITALG, X86_FEATURE_AVX512VL }, + { X86_FEATURE_AVX512_4VNNIW, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512_4FMAPS, X86_FEATURE_AVX512F }, + { X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F }, + { X86_FEATURE_SPLIT_LOCK_DETECT, X86_FEATURE_CORE_CAPABILITY}, {} }; diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index fc3c07fe7df5..ad3f72d106fc 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1029,3 +1029,24 @@ static const struct cpu_dev intel_cpu_dev = { cpu_dev_register(intel_cpu_dev); +static void __init set_split_lock_detect(void) +{ + setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); +} + +void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) +{ + u64 ia32_core_cap = 0; + + if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITY)) + return; + + /* + * If MSR_IA32_CORE_CAPABILITY exists, enumerate features that are + * reported in the MSR. + */ + rdmsrl(MSR_IA32_CORE_CAPABILITY, ia32_core_cap); + + if (ia32_core_cap & CORE_CAP_SPLIT_LOCK_DETECT) + set_split_lock_detect(); +} From patchwork Wed Apr 3 21:21:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884467 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F2AB11575 for ; Wed, 3 Apr 2019 21:31:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC81E284C7 for ; Wed, 3 Apr 2019 21:31:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CFFE5285C7; Wed, 3 Apr 2019 21:31:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 77C9E284C7 for ; Wed, 3 Apr 2019 21:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727951AbfDCVbF (ORCPT ); Wed, 3 Apr 2019 17:31:05 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726772AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754243" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 08/20] x86/split_lock: Enumerate split lock detection on Icelake mobile processor Date: Wed, 3 Apr 2019 14:21:54 -0700 Message-Id: <1554326526-172295-9-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Icelake mobile processor can detect split lock operations although the processor doesn't have MSR_IA32_CORE_CAPABILITY and split lock detection bit in the MSR. Set split lock detection feature bit X86_FEATURE_SPLIT_LOCK_DETECT on the processor based on its family/model/stepping. A few other processors may also have the feature but don't have MSR_IA32_CORE_CAPABILITY. The feature will be enumerated on those processors once their family/model/stepping information is released. Signed-off-by: Fenghua Yu --- arch/x86/kernel/cpu/intel.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index ad3f72d106fc..7f6943af35dc 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1038,8 +1038,18 @@ void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) { u64 ia32_core_cap = 0; - if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITY)) + if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITY)) { + /* + * The following processors have split lock detection feature. + * But since they don't have MSR_IA32_CORE_CAPABILITY, the + * feature cannot be enumerated by the MSR. So enumerate the + * feature by family/model/stepping. + */ + if (c->x86 == 6 && c->x86_model == INTEL_FAM6_ICELAKE_MOBILE) + set_split_lock_detect(); + return; + } /* * If MSR_IA32_CORE_CAPABILITY exists, enumerate features that are From patchwork Wed Apr 3 21:21:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884471 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EDF2B1708 for ; Wed, 3 Apr 2019 21:31:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D79A628450 for ; Wed, 3 Apr 2019 21:31:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CB27A285B7; Wed, 3 Apr 2019 21:31:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 832E128450 for ; Wed, 3 Apr 2019 21:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727525AbfDCVbE (ORCPT ); Wed, 3 Apr 2019 17:31:04 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726785AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754246" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 09/20] x86/split_lock: Define MSR_TEST_CTL register Date: Wed, 3 Apr 2019 14:21:55 -0700 Message-Id: <1554326526-172295-10-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Setting bit 29 in MSR_TEST_CTL register 0x33 enables split lock detection and clearing the bit disables split lock detection. Define the MSR and the bit. The definitions will be used in enabling or disabling split lock detection. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/msr-index.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index f65ef6f783d2..25fa808de9e2 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -39,6 +39,10 @@ /* Intel MSRs. Some also available on other CPUs */ +#define MSR_TEST_CTL 0x00000033 +#define TEST_CTL_ENABLE_SPLIT_LOCK_DETECT_SHIFT 29 +#define TEST_CTL_ENABLE_SPLIT_LOCK_DETECT BIT(29) + #define MSR_IA32_SPEC_CTRL 0x00000048 /* Speculation Control */ #define SPEC_CTRL_IBRS (1 << 0) /* Indirect Branch Restricted Speculation */ #define SPEC_CTRL_STIBP_SHIFT 1 /* Single Thread Indirect Branch Predictor (STIBP) bit */ From patchwork Wed Apr 3 21:21:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884455 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5B42F1575 for ; Wed, 3 Apr 2019 21:30:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 446DC28450 for ; Wed, 3 Apr 2019 21:30:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 38F65285C8; Wed, 3 Apr 2019 21:30:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 256DB28450 for ; Wed, 3 Apr 2019 21:30:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726849AbfDCVaW (ORCPT ); Wed, 3 Apr 2019 17:30:22 -0400 Received: from mga05.intel.com ([192.55.52.43]:37332 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726790AbfDCVaV (ORCPT ); Wed, 3 Apr 2019 17:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754249" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 10/20] x86/split_lock: Handle #AC exception for split lock Date: Wed, 3 Apr 2019 14:21:56 -0700 Message-Id: <1554326526-172295-11-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There may be different considerations on how to handle #AC for split lock, e.g. how to handle system hang caused by split lock issue in firmware, how to emulate faulting instruction, etc. We use a simple method to handle user and kernel split lock and may extend the method in the future. When #AC exception for split lock is triggered from user process, the process is killed by SIGBUS. To execute the process properly, a user application developer needs to fix the split lock issue. When #AC exception for split lock is triggered from a kernel instruction, disable split lock detection on local CPU and warn the split lock issue. After the exception, the faulting instruction will be executed and kernel execution continues. Split lock detection is only disabled on the local CPU, not globally. It will be re-enabled if the CPU is offline and then online or through sysfs interface. A kernel/driver developer should check the warning, which contains helpful faulting address, context, and callstack info, and fix the split lock issues. Then further split lock issues may be captured and fixed. After bit 29 in MSR_TEST_CTL is set to 1 in kernel, firmware inherits the setting when firmware is executed in S4, S5, run time services, SMI, etc. If there is a split lock operation in firmware, it will triggers #AC and may hang the system depending on how firmware handles the #AC. It's up to a firmware developer to fix split lock issues in firmware. Signed-off-by: Fenghua Yu --- arch/x86/kernel/traps.c | 43 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index d26f9e9c3d83..0ac992bfa287 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -61,6 +61,7 @@ #include #include #include +#include #ifdef CONFIG_X86_64 #include @@ -293,9 +294,49 @@ DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, 0, NULL, "coprocessor segment overru DO_ERROR(X86_TRAP_TS, SIGSEGV, 0, NULL, "invalid TSS", invalid_TSS) DO_ERROR(X86_TRAP_NP, SIGBUS, 0, NULL, "segment not present", segment_not_present) DO_ERROR(X86_TRAP_SS, SIGBUS, 0, NULL, "stack segment", stack_segment) -DO_ERROR(X86_TRAP_AC, SIGBUS, BUS_ADRALN, NULL, "alignment check", alignment_check) #undef IP +dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code) +{ + unsigned int trapnr = X86_TRAP_AC; + char str[] = "alignment check"; + int signr = SIGBUS; + + RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); + + /* + * WARN*()s end up here; fix them up before we call the + * notifier chain. + */ + if (!user_mode(regs) && fixup_bug(regs, trapnr)) + return; + + if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) == + NOTIFY_STOP) + return; + + cond_local_irq_enable(regs); + if (!user_mode(regs) && + static_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) { + /* + * Only split lock can generate #AC from kernel at this point. + * Warn and disable split lock detection on this CPU. The + * faulting instruction will be executed without generating + * another #AC fault. User needs to check the warning and + * fix the split lock issue in the faulting instruction. + */ + msr_clear_bit(MSR_TEST_CTL, + TEST_CTL_ENABLE_SPLIT_LOCK_DETECT_SHIFT); + WARN_ONCE(1, "split lock operation detected\n"); + + return; + } + + /* Handle #AC generated in any other cases. */ + do_trap(X86_TRAP_AC, SIGBUS, "alignment check", regs, + error_code, BUS_ADRALN, NULL); +} + #ifdef CONFIG_VMAP_STACK __visible void __noreturn handle_stack_overflow(const char *message, struct pt_regs *regs, From patchwork Wed Apr 3 21:21:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884521 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF2DD1575 for ; Wed, 3 Apr 2019 21:33:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ADD8928450 for ; Wed, 3 Apr 2019 21:33:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A1D2E285B7; Wed, 3 Apr 2019 21:33:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3607228450 for ; Wed, 3 Apr 2019 21:33:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727523AbfDCVdS (ORCPT ); Wed, 3 Apr 2019 17:33:18 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726151AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754253" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Xiaoyao Li , Fenghua Yu Subject: [PATCH v6 11/20] kvm/x86: Emulate MSR IA32_CORE_CAPABILITY Date: Wed, 3 Apr 2019 14:21:57 -0700 Message-Id: <1554326526-172295-12-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Xiaoyao Li MSR IA32_CORE_CAPABILITY is a feature-enumerating MSR, bit 5 of which reports the capability of enabling detection of split locks (will be supported on future processors based on Tremont microarchitecture and later). CPUID.(EAX=7H,ECX=0):EDX[30] will enumerate the presence of the IA32_CORE_CAPABILITY MSR. Please check the latest Intel 64 and IA-32 Architectures Software Developer's Manual for more detailed information on the MSR and the split lock bit. Since MSR_IA32_CORE_CAPABILITY is a feature-enumerating MSR, emulate it in software regardless of host's capability. What we need to do is to set the right value of it to report the capability of guest. In this patch, just set the guest's core_capability as 0, because we haven't added support of the features it indicates to guest. It's for bisectability. Signed-off-by: Xiaoyao Li Signed-off-by: Fenghua Yu Acked-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/cpuid.c | 6 ++++++ arch/x86/kvm/x86.c | 24 ++++++++++++++++++++++++ 3 files changed, 32 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 159b5988292f..e28626f6a2e0 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -570,6 +570,7 @@ struct kvm_vcpu_arch { u64 ia32_xss; u64 microcode_version; u64 arch_capabilities; + u64 core_capability; /* * Paging state of the vcpu @@ -1527,6 +1528,7 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low, unsigned long icr, int op_64_bit); u64 kvm_get_arch_capabilities(void); +u64 kvm_get_core_capability(void); void kvm_define_shared_msr(unsigned index, u32 msr); int kvm_set_shared_msr(unsigned index, u64 val, u64 mask); diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index fd3951638ae4..4a2f7892ea31 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -505,6 +505,12 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, * if the host doesn't support it. */ entry->edx |= F(ARCH_CAPABILITIES); + /* + * Since we emulate MSR IA32_CORE_CAPABILITY in + * software, we can always enable it for guest + * regardless of host's capability. + */ + entry->edx |= F(CORE_CAPABILITY); } else { entry->ebx = 0; entry->ecx = 0; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 099b851dabaf..4459115eb0ec 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1159,6 +1159,7 @@ static u32 emulated_msrs[] = { MSR_IA32_TSC_ADJUST, MSR_IA32_TSCDEADLINE, MSR_IA32_ARCH_CAPABILITIES, + MSR_IA32_CORE_CAPABILITY, MSR_IA32_MISC_ENABLE, MSR_IA32_MCG_STATUS, MSR_IA32_MCG_CTL, @@ -1198,6 +1199,7 @@ static u32 msr_based_features[] = { MSR_F10H_DECFG, MSR_IA32_UCODE_REV, + MSR_IA32_CORE_CAPABILITY, MSR_IA32_ARCH_CAPABILITIES, }; @@ -1225,9 +1227,18 @@ u64 kvm_get_arch_capabilities(void) } EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities); +u64 kvm_get_core_capability(void) +{ + return 0; +} +EXPORT_SYMBOL_GPL(kvm_get_core_capability); + static int kvm_get_msr_feature(struct kvm_msr_entry *msr) { switch (msr->index) { + case MSR_IA32_CORE_CAPABILITY: + msr->data = kvm_get_core_capability(); + break; case MSR_IA32_ARCH_CAPABILITIES: msr->data = kvm_get_arch_capabilities(); break; @@ -2451,6 +2462,12 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_EFER: return set_efer(vcpu, data); + case MSR_IA32_CORE_CAPABILITY: + if (!msr_info->host_initiated) + return 1; + + vcpu->arch.core_capability = data; + break; case MSR_K7_HWCR: data &= ~(u64)0x40; /* ignore flush filter disable */ data &= ~(u64)0x100; /* ignore ignne emulation enable */ @@ -2762,6 +2779,12 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_TSC: msr_info->data = kvm_scale_tsc(vcpu, rdtsc()) + vcpu->arch.tsc_offset; break; + case MSR_IA32_CORE_CAPABILITY: + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_CORE_CAPABILITY)) + return 1; + msr_info->data = vcpu->arch.core_capability; + break; case MSR_MTRRcap: case 0x200 ... 0x2ff: return kvm_mtrr_get_msr(vcpu, msr_info->index, &msr_info->data); @@ -8762,6 +8785,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) { vcpu->arch.arch_capabilities = kvm_get_arch_capabilities(); + vcpu->arch.core_capability = kvm_get_core_capability(); vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT; kvm_vcpu_mtrr_init(vcpu); vcpu_load(vcpu); From patchwork Wed Apr 3 21:21:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884459 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CDA361575 for ; Wed, 3 Apr 2019 21:30:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B4AC828450 for ; Wed, 3 Apr 2019 21:30:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A914B285C7; Wed, 3 Apr 2019 21:30:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2613528450 for ; Wed, 3 Apr 2019 21:30:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727025AbfDCVaj (ORCPT ); Wed, 3 Apr 2019 17:30:39 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726800AbfDCVaW (ORCPT ); Wed, 3 Apr 2019 17:30:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754256" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Xiaoyao Li , Fenghua Yu Subject: [PATCH v6 12/20] kvm/vmx: Emulate MSR TEST_CTL Date: Wed, 3 Apr 2019 14:21:58 -0700 Message-Id: <1554326526-172295-13-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Xiaoyao Li A control bit (bit 29) in TEST_CTL MSR 0x33 will be introduced in future x86 processors. When bit 29 is set, the processor causes #AC exception for split locked accesses at all CPL. Please check the latest Intel 64 and IA-32 Architectures Software Developer's Manual for more detailed information on the MSR and the split lock bit. This patch emulate MSR TEST_CTL with vmx->msr_test_ctl and does the following: 1. As MSR TEST_CTL of guest is emulated, enable the related bits in CORE_CAPABILITY to corretly report this feature to guest. 2. Differentiate MSR TEST_CTL between host and guest. Signed-off-by: Xiaoyao Li Signed-off-by: Fenghua Yu Acked-by: Paolo Bonzini --- arch/x86/kvm/vmx/vmx.c | 35 +++++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/vmx.h | 1 + arch/x86/kvm/x86.c | 17 ++++++++++++++++- 3 files changed, 52 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ab432a930ae8..309ccf593f0d 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1663,6 +1663,12 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) u32 index; switch (msr_info->index) { + case MSR_TEST_CTL: + if (!msr_info->host_initiated && + !(vcpu->arch.core_capability & CORE_CAP_SPLIT_LOCK_DETECT)) + return 1; + msr_info->data = vmx->msr_test_ctl; + break; #ifdef CONFIG_X86_64 case MSR_FS_BASE: msr_info->data = vmcs_readl(GUEST_FS_BASE); @@ -1797,6 +1803,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) u32 index; switch (msr_index) { + case MSR_TEST_CTL: + if (!(vcpu->arch.core_capability & CORE_CAP_SPLIT_LOCK_DETECT)) + return 1; + + if (data & ~TEST_CTL_ENABLE_SPLIT_LOCK_DETECT) + return 1; + vmx->msr_test_ctl = data; + break; case MSR_EFER: ret = kvm_set_msr_common(vcpu, msr_info); break; @@ -4077,6 +4091,9 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) ++vmx->nmsrs; } + /* disable AC split lock by default */ + vmx->msr_test_ctl = 0; + vm_exit_controls_init(vmx, vmx_vmexit_ctrl()); /* 22.2.1, 20.8.1 */ @@ -4114,6 +4131,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) vmx->rmode.vm86_active = 0; vmx->spec_ctrl = 0; + vmx->msr_test_ctl = 0; vcpu->arch.microcode_version = 0x100000000ULL; vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); @@ -6313,6 +6331,21 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx) msrs[i].host, false); } +static void atomic_switch_msr_test_ctl(struct vcpu_vmx *vmx) +{ + u64 host_msr_test_ctl; + + /* if TEST_CTL MSR doesn't exist on the hardware, do nothing */ + if (rdmsrl_safe(MSR_TEST_CTL, &host_msr_test_ctl)) + return; + + if (host_msr_test_ctl == vmx->msr_test_ctl) + clear_atomic_switch_msr(vmx, MSR_TEST_CTL); + else + add_atomic_switch_msr(vmx, MSR_TEST_CTL, vmx->msr_test_ctl, + host_msr_test_ctl, false); +} + static void vmx_arm_hv_timer(struct vcpu_vmx *vmx, u32 val) { vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, val); @@ -6419,6 +6452,8 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu) atomic_switch_perf_msrs(vmx); + atomic_switch_msr_test_ctl(vmx); + vmx_update_hv_timer(vcpu); /* diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index a1e00d0a2482..6091a8b9de74 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -190,6 +190,7 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif + u64 msr_test_ctl; u64 spec_ctrl; u32 vm_entry_controls_shadow; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4459115eb0ec..e93c2f620cdb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1229,7 +1229,22 @@ EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities); u64 kvm_get_core_capability(void) { - return 0; + u64 data; + + rdmsrl_safe(MSR_IA32_CORE_CAPABILITY, &data); + + /* mask non-virtualizable functions */ + data &= CORE_CAP_SPLIT_LOCK_DETECT; + + /* + * There will be a list of FMS values that have split lock detection + * but lack the CORE CAPABILITY MSR. In this case, set + * CORE_CAP_SPLIT_LOCK_DETECT since we emulate MSR CORE_CAPABILITY. + */ + if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) + data |= CORE_CAP_SPLIT_LOCK_DETECT; + + return data; } EXPORT_SYMBOL_GPL(kvm_get_core_capability); From patchwork Wed Apr 3 21:21:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884463 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B1691708 for ; Wed, 3 Apr 2019 21:30:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 135BE28450 for ; Wed, 3 Apr 2019 21:30:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 06AC8285B7; Wed, 3 Apr 2019 21:30:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9FEF728450 for ; Wed, 3 Apr 2019 21:30:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727152AbfDCVav (ORCPT ); Wed, 3 Apr 2019 17:30:51 -0400 Received: from mga05.intel.com ([192.55.52.43]:37332 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726805AbfDCVaW (ORCPT ); Wed, 3 Apr 2019 17:30:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754263" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:11 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 13/20] x86/split_lock: Enable split lock detection by default Date: Wed, 3 Apr 2019 14:21:59 -0700 Message-Id: <1554326526-172295-14-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A split locked access locks bus and degrades overall memory access performance. When split lock detection feature is enumerated, enable the feature by default to find any split lock issue and then fix the issue. Signed-off-by: Fenghua Yu --- arch/x86/kernel/cpu/intel.c | 42 +++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 7f6943af35dc..ae3e327d5e35 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -31,6 +31,12 @@ #include #endif +#define DISABLE_SPLIT_LOCK_DETECT 0 +#define ENABLE_SPLIT_LOCK_DETECT 1 + +static DEFINE_MUTEX(split_lock_detect_mutex); +static int split_lock_detect_val; + /* * Just in case our CPU detection goes bad, or you have a weird system, * allow a way to override the automatic disabling of MPX. @@ -161,10 +167,45 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c) return false; } +static u32 new_sp_test_ctl_val(u32 test_ctl_val) +{ + /* Change the split lock setting. */ + if (READ_ONCE(split_lock_detect_val) == DISABLE_SPLIT_LOCK_DETECT) + test_ctl_val &= ~TEST_CTL_ENABLE_SPLIT_LOCK_DETECT; + else + test_ctl_val |= TEST_CTL_ENABLE_SPLIT_LOCK_DETECT; + + return test_ctl_val; +} + +static inline void show_split_lock_detection_info(void) +{ + if (READ_ONCE(split_lock_detect_val)) + pr_info_once("x86/split_lock: split lock detection enabled\n"); + else + pr_info_once("x86/split_lock: split lock detection disabled\n"); +} + +static void init_split_lock_detect(struct cpuinfo_x86 *c) +{ + if (cpu_has(c, X86_FEATURE_SPLIT_LOCK_DETECT)) { + u32 l, h; + + mutex_lock(&split_lock_detect_mutex); + rdmsr(MSR_TEST_CTL, l, h); + l = new_sp_test_ctl_val(l); + wrmsr(MSR_TEST_CTL, l, h); + show_split_lock_detection_info(); + mutex_unlock(&split_lock_detect_mutex); + } +} + static void early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable; + init_split_lock_detect(c); + /* Unmask CPUID levels if masked: */ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { if (msr_clear_bit(MSR_IA32_MISC_ENABLE, @@ -1032,6 +1073,7 @@ cpu_dev_register(intel_cpu_dev); static void __init set_split_lock_detect(void) { setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); + split_lock_detect_val = 1; } void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) From patchwork Wed Apr 3 21:22:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884505 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 65E9E1575 for ; Wed, 3 Apr 2019 21:32:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 538ED28450 for ; Wed, 3 Apr 2019 21:32:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 47DC8285B7; Wed, 3 Apr 2019 21:32:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E327328450 for ; Wed, 3 Apr 2019 21:32:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728642AbfDCVcn (ORCPT ); Wed, 3 Apr 2019 17:32:43 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726636AbfDCVaT (ORCPT ); Wed, 3 Apr 2019 17:30:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754267" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:12 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 14/20] x86/split_lock: Add a sysfs interface to enable/disable split lock detection during run time Date: Wed, 3 Apr 2019 14:22:00 -0700 Message-Id: <1554326526-172295-15-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The interface /sys/device/system/cpu/split_lock_detect is added to allow user to control split lock detection and show current split lock detection setting. Writing 1 to the file enables split lock detection and writing 0 disables split lock detection. Split lock detection is enabled or disabled on all CPUs. Reading the file returns current global split lock detection setting: 0: disabled 1: enabled Please note the interface only shows global setting. During run time, split lock detection on one CPU may be disabled if split lock in kernel code happens on the CPU. The interface doesn't show split lock detection status on individual CPU. User can run rdmsr on 0x33 to check split lock detection on each CPU. Signed-off-by: Fenghua Yu --- arch/x86/kernel/cpu/intel.c | 66 +++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index ae3e327d5e35..166033fa8423 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1102,3 +1102,69 @@ void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) if (ia32_core_cap & CORE_CAP_SPLIT_LOCK_DETECT) set_split_lock_detect(); } + +static ssize_t +split_lock_detect_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", READ_ONCE(split_lock_detect_val)); +} + +static ssize_t +split_lock_detect_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + u32 val, l, h; + int cpu, ret; + + ret = kstrtou32(buf, 10, &val); + if (ret) + return ret; + + if (val != DISABLE_SPLIT_LOCK_DETECT && val != ENABLE_SPLIT_LOCK_DETECT) + return -EINVAL; + + /* + * Since split lock could be disabled by kernel #AC handler or user + * may directly change bit 29 in MSR_TEST_CTL, split lock setting on + * each CPU may be different from global setting split_lock_detect_val + * by now. Update MSR on each CPU, so all of CPUs will have same split + * lock setting. + */ + mutex_lock(&split_lock_detect_mutex); + + WRITE_ONCE(split_lock_detect_val, val); + + /* + * Get MSR_TEST_CTL on this CPU, assuming all CPUs have same value + * in the MSR except split lock detection bit (bit 29). + */ + rdmsr(MSR_TEST_CTL, l, h); + l = new_sp_test_ctl_val(l); + /* Update the split lock detection setting on all online CPUs. */ + for_each_online_cpu(cpu) + wrmsr_on_cpu(cpu, MSR_TEST_CTL, l, h); + + mutex_unlock(&split_lock_detect_mutex); + + return count; +} + +static DEVICE_ATTR_RW(split_lock_detect); + +static int __init split_lock_init(void) +{ + int ret; + + if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) + return -ENODEV; + + ret = device_create_file(cpu_subsys.dev_root, + &dev_attr_split_lock_detect); + if (ret) + return ret; + + return 0; +} + +subsys_initcall(split_lock_init); From patchwork Wed Apr 3 21:22:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884513 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2A24B1708 for ; Wed, 3 Apr 2019 21:33:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1388D28450 for ; Wed, 3 Apr 2019 21:33:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 06BBD285B7; Wed, 3 Apr 2019 21:33:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9714128450 for ; Wed, 3 Apr 2019 21:33:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726905AbfDCVdG (ORCPT ); Wed, 3 Apr 2019 17:33:06 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726580AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754270" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:12 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 15/20] x86/split_lock: Document the new sysfs file for split lock detection Date: Wed, 3 Apr 2019 14:22:01 -0700 Message-Id: <1554326526-172295-16-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add an ABI document entry for /sys/devices/system/cpu/split_lock_detect. Signed-off-by: Fenghua Yu --- .../ABI/testing/sysfs-devices-system-cpu | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 9605dbd4b5b5..a4e8c2e2e1ac 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -67,6 +67,21 @@ Description: Discover NUMA node a CPU belongs to /sys/devices/system/cpu/cpu42/node2 -> ../../node/node2 +What: /sys/devices/system/cpu/split_lock_detect +Date: March 2019 +Contact: Linux kernel mailing list +Description: Control split lock detection on Intel Tremont and future CPUs + + Read/write interface to control split lock detection: + "0" disable split lock detection on all CPUs + "1" enable split lock detection on all CPUs + + Please note the interface only shows or controls global setting. + During run time, split lock detection on one CPU may be + disabled if split lock operation in kernel code happens on + the CPU. The interface doesn't show or control split lock + detection on individual CPU. + What: /sys/devices/system/cpu/cpu#/topology/core_id /sys/devices/system/cpu/cpu#/topology/core_siblings /sys/devices/system/cpu/cpu#/topology/core_siblings_list From patchwork Wed Apr 3 21:22:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884509 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CDEBF1575 for ; Wed, 3 Apr 2019 21:33:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BA4EA28450 for ; Wed, 3 Apr 2019 21:33:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AEBA5285B7; Wed, 3 Apr 2019 21:33:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3F32028450 for ; Wed, 3 Apr 2019 21:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727019AbfDCVcn (ORCPT ); Wed, 3 Apr 2019 17:32:43 -0400 Received: from mga05.intel.com ([192.55.52.43]:37332 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726653AbfDCVaT (ORCPT ); Wed, 3 Apr 2019 17:30:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754274" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:12 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 16/20] x86/clearcpuid: Support multiple clearcpuid options Date: Wed, 3 Apr 2019 14:22:02 -0700 Message-Id: <1554326526-172295-17-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently only one kernel option "clearcpuid=" can be picked up by kernel during boot time. In some cases, user may want to clear a few cpu caps. This may be useful to replace endless (new) kernel options like nosmep, nosmap, etc. Add support of multiple clearcpuid options to allow user to clear multiple cpu caps. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cmdline.h | 3 +++ arch/x86/kernel/fpu/init.c | 30 ++++++++++++++++++++---------- arch/x86/lib/cmdline.c | 17 +++++++++++++++-- 3 files changed, 38 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/cmdline.h b/arch/x86/include/asm/cmdline.h index 6faaf27e8899..059e29558bb3 100644 --- a/arch/x86/include/asm/cmdline.h +++ b/arch/x86/include/asm/cmdline.h @@ -5,5 +5,8 @@ int cmdline_find_option_bool(const char *cmdline_ptr, const char *option); int cmdline_find_option(const char *cmdline_ptr, const char *option, char *buffer, int bufsize); +int cmdline_find_option_in_range(const char *cmdline_ptr, int cmdline_size, + const char *option, char *buffer, int bufsize, + char **arg_pos); #endif /* _ASM_X86_CMDLINE_H */ diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 6abd83572b01..88bbba7ee96a 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -243,16 +243,31 @@ static void __init fpu__init_system_ctx_switch(void) WARN_ON_FPU(current->thread.fpu.initialized); } +static void __init clear_cpuid(void) +{ + char arg[32], *argptr, *option_pos, clearcpuid_option[] = "clearcpuid"; + int bit, cmdline_size; + + /* Find each option in boot_command_line and clear specified cpu cap. */ + cmdline_size = COMMAND_LINE_SIZE; + while (cmdline_find_option_in_range(boot_command_line, cmdline_size, + clearcpuid_option, arg, + sizeof(arg), &option_pos) >= 0) { + /* Chang command line range for next search. */ + cmdline_size = option_pos - boot_command_line + 1; + argptr = arg; + if (get_option(&argptr, &bit) && + bit >= 0 && bit < NCAPINTS * 32) + setup_clear_cpu_cap(bit); + } +} + /* * We parse fpu parameters early because fpu__init_system() is executed * before parse_early_param(). */ static void __init fpu__init_parse_early_param(void) { - char arg[32]; - char *argptr = arg; - int bit; - if (cmdline_find_option_bool(boot_command_line, "no387")) setup_clear_cpu_cap(X86_FEATURE_FPU); @@ -271,12 +286,7 @@ static void __init fpu__init_parse_early_param(void) if (cmdline_find_option_bool(boot_command_line, "noxsaves")) setup_clear_cpu_cap(X86_FEATURE_XSAVES); - if (cmdline_find_option(boot_command_line, "clearcpuid", arg, - sizeof(arg)) && - get_option(&argptr, &bit) && - bit >= 0 && - bit < NCAPINTS * 32) - setup_clear_cpu_cap(bit); + clear_cpuid(); } /* diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c index 3261abb21ef4..9cf1a0773877 100644 --- a/arch/x86/lib/cmdline.c +++ b/arch/x86/lib/cmdline.c @@ -114,13 +114,15 @@ __cmdline_find_option_bool(const char *cmdline, int max_cmdline_size, * @option: option string to look for * @buffer: memory buffer to return the option argument * @bufsize: size of the supplied memory buffer + * @option_pos: pointer to the option if found * * Returns the length of the argument (regardless of if it was * truncated to fit in the buffer), or -1 on not found. */ static int __cmdline_find_option(const char *cmdline, int max_cmdline_size, - const char *option, char *buffer, int bufsize) + const char *option, char *buffer, int bufsize, + char **arg_pos) { char c; int pos = 0, len = -1; @@ -164,6 +166,9 @@ __cmdline_find_option(const char *cmdline, int max_cmdline_size, len = 0; bufptr = buffer; state = st_bufcpy; + if (arg_pos) + *arg_pos = (char *)cmdline - + strlen(option) - 1; break; } else if (c == *opptr++) { /* @@ -211,5 +216,13 @@ int cmdline_find_option(const char *cmdline, const char *option, char *buffer, int bufsize) { return __cmdline_find_option(cmdline, COMMAND_LINE_SIZE, option, - buffer, bufsize); + buffer, bufsize, NULL); +} + +int cmdline_find_option_in_range(const char *cmdline, int cmdline_size, + char *option, char *buffer, int bufsize, + char **arg_pos) +{ + return __cmdline_find_option(cmdline, cmdline_size, option, buffer, + bufsize, arg_pos); } From patchwork Wed Apr 3 21:22:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884511 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 87B1D1708 for ; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7243328450 for ; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6616C285B7; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0989028450 for ; Wed, 3 Apr 2019 21:33:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726606AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726562AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754277" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:12 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 17/20] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Date: Wed, 3 Apr 2019 14:22:03 -0700 Message-Id: <1554326526-172295-18-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The kernel option clearcpuid currently only takes feature bit which can be changed from kernel to kernel. Extend clearcpuid to use cap flag string, which is defined in x86_cap_flags[] and won't be changed from kernel to kernel. And user can easily get the cap flag string from /proc/cpuinfo. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/cpuid-deps.c | 26 ++++++++++++++++++++++++++ arch/x86/kernel/fpu/init.c | 3 ++- 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 0e56ff7e4848..823c4ab82e12 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -133,6 +133,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; extern void setup_clear_cpu_cap(unsigned int bit); extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); +bool find_cpu_cap(char *cap_flag, unsigned int *pfeature); #define setup_force_cpu_cap(bit) do { \ set_cpu_cap(&boot_cpu_data, bit); \ diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 3d633f67fbd7..1a71434f7b46 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -120,3 +120,29 @@ void setup_clear_cpu_cap(unsigned int feature) { do_clear_cpu_cap(NULL, feature); } + +/** + * find_cpu_cap - Given a cap flag string, find its corresponding feature bit. + * @cap_flag: cap flag string as defined in x86_cap_flags[] + * @pfeature: feature bit + * + * Return: true if the feature is found. false if not found + */ +bool find_cpu_cap(char *cap_flag, unsigned int *pfeature) +{ +#ifdef CONFIG_X86_FEATURE_NAMES + unsigned int feature; + + for (feature = 0; feature < NCAPINTS * 32; feature++) { + if (!x86_cap_flags[feature]) + continue; + + if (strcmp(cap_flag, x86_cap_flags[feature]) == 0) { + *pfeature = feature; + + return true; + } + } +#endif + return false; +} diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 88bbba7ee96a..99b895eea166 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -256,7 +256,8 @@ static void __init clear_cpuid(void) /* Chang command line range for next search. */ cmdline_size = option_pos - boot_command_line + 1; argptr = arg; - if (get_option(&argptr, &bit) && + /* cpu cap can be specified by either feature bit or string */ + if ((get_option(&argptr, &bit) || find_cpu_cap(arg, &bit)) && bit >= 0 && bit < NCAPINTS * 32) setup_clear_cpu_cap(bit); } From patchwork Wed Apr 3 21:22:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884523 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BD2831575 for ; Wed, 3 Apr 2019 21:33:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A551328450 for ; Wed, 3 Apr 2019 21:33:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 97E47285B7; Wed, 3 Apr 2019 21:33:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 41B9828450 for ; Wed, 3 Apr 2019 21:33:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726948AbfDCVdi (ORCPT ); Wed, 3 Apr 2019 17:33:38 -0400 Received: from mga05.intel.com ([192.55.52.43]:37323 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726206AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754281" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:13 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 18/20] x86/clearcpuid: Apply cleared feature bits that are forced set before Date: Wed, 3 Apr 2019 14:22:04 -0700 Message-Id: <1554326526-172295-19-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Some CPU feature bits are forced set and stored in cpuinfo_x86 before handling clearcpuid options. To clear those bits from cpuinfo_x86, apply_forced_cap() is called after handling the options. Please note, apply_forced_cap() is called twice on boot CPU. But this code is simple and there is no functionality issue. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpu.h | 2 ++ arch/x86/kernel/cpu/common.c | 5 +++-- arch/x86/kernel/fpu/init.c | 2 ++ 3 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 4e03f53fc079..bfa5ac6b7502 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -26,6 +26,8 @@ struct x86_cpu { struct cpu cpu; }; +void apply_forced_caps(struct cpuinfo_x86 *c); + #ifdef CONFIG_HOTPLUG_CPU extern int arch_register_cpu(int num); extern void arch_unregister_cpu(int); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index bbdd69dd4f5f..e1d41405c27b 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -758,13 +758,14 @@ void cpu_detect(struct cpuinfo_x86 *c) } } -static void apply_forced_caps(struct cpuinfo_x86 *c) +void apply_forced_caps(struct cpuinfo_x86 *c) { int i; for (i = 0; i < NCAPINTS + NBUGINTS; i++) { - c->x86_capability[i] &= ~cpu_caps_cleared[i]; + /* Bits may be cleared after they are set. */ c->x86_capability[i] |= cpu_caps_set[i]; + c->x86_capability[i] &= ~cpu_caps_cleared[i]; } } diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 99b895eea166..9c2801b605e3 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -5,6 +5,7 @@ #include #include #include +#include #include #include @@ -261,6 +262,7 @@ static void __init clear_cpuid(void) bit >= 0 && bit < NCAPINTS * 32) setup_clear_cpu_cap(bit); } + apply_forced_caps(&boot_cpu_data); } /* From patchwork Wed Apr 3 21:22:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884527 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 64A811575 for ; Wed, 3 Apr 2019 21:33:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C4C928450 for ; Wed, 3 Apr 2019 21:33:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 407B0285C7; Wed, 3 Apr 2019 21:33:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 89A2728450 for ; Wed, 3 Apr 2019 21:33:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726789AbfDCVdt (ORCPT ); Wed, 3 Apr 2019 17:33:49 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726183AbfDCVaS (ORCPT ); Wed, 3 Apr 2019 17:30:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754286" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:13 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 19/20] x86/clearcpuid: Clear CPUID bit in CPUID faulting Date: Wed, 3 Apr 2019 14:22:05 -0700 Message-Id: <1554326526-172295-20-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Peter Zijlstra After kernel clears a CPUID bit through clearcpuid or other kernel options, CPUID instruction executed from user space should see the same value for the bit. The CPUID faulting handler returns the cleared bit to user. Signed-off-by: Peter Zijlstra Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpufeature.h | 4 +++ arch/x86/kernel/cpu/common.c | 2 ++ arch/x86/kernel/cpu/cpuid-deps.c | 52 ++++++++++++++++++++++++++++ arch/x86/kernel/cpu/intel.c | 56 +++++++++++++++++++++++++++++-- arch/x86/kernel/cpu/scattered.c | 17 ++++++++++ arch/x86/kernel/process.c | 3 ++ arch/x86/kernel/traps.c | 11 ++++++ 7 files changed, 142 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 823c4ab82e12..53875fd13f5a 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -228,5 +228,9 @@ static __always_inline __pure bool _static_cpu_has(u16 bit) #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ boot_cpu_data.x86_model +extern int cpuid_fault; +u32 scattered_cpuid_mask(u32 leaf, u32 count, enum cpuid_regs_idx reg); +u32 cpuid_cap_mask(u32 leaf, u32 count, enum cpuid_regs_idx reg); + #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ #endif /* _ASM_X86_CPUFEATURE_H */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index e1d41405c27b..020597bca252 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1503,6 +1503,8 @@ void print_cpu_info(struct cpuinfo_x86 *c) pr_cont(")\n"); } +int cpuid_fault; + /* * clearcpuid= was already parsed in fpu__init_parse_early_param. * But we need to keep a dummy __setup around otherwise it would diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 1a71434f7b46..d42aa4fa3021 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -113,9 +113,61 @@ static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature) void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature) { + if (boot_cpu_has(feature)) + cpuid_fault = 1; do_clear_cpu_cap(c, feature); } +u32 cpuid_cap_mask(u32 leaf, u32 count, enum cpuid_regs_idx reg) +{ + switch (leaf) { + case 0x1: + if (reg == CPUID_EDX) + return ~cpu_caps_cleared[CPUID_1_EDX]; + if (reg == CPUID_ECX) + return ~cpu_caps_cleared[CPUID_1_ECX]; + break; + + case 0x6: + if (reg == CPUID_EAX) + return ~cpu_caps_cleared[CPUID_6_EAX]; + break; + + case 0x7: + if (reg == CPUID_EDX) + return ~cpu_caps_cleared[CPUID_7_EDX]; + if (reg == CPUID_ECX) + return ~cpu_caps_cleared[CPUID_7_ECX]; + if (reg == CPUID_EBX && count == 0) + return ~cpu_caps_cleared[CPUID_7_0_EBX]; + break; + + case 0xD: + if (reg == CPUID_EAX) + return ~cpu_caps_cleared[CPUID_D_1_EAX]; + break; + + case 0xF: + if (reg == CPUID_EDX) { + if (count == 0) + return ~cpu_caps_cleared[CPUID_F_0_EDX]; + if (count == 1) + return ~cpu_caps_cleared[CPUID_F_0_EDX]; + } + break; + + case 0x80000007: + if (reg == CPUID_EDX) { + if (test_bit(X86_FEATURE_CONSTANT_TSC, + (unsigned long *)cpu_caps_cleared)) + return ~(1 << 8); + } + break; + } + + return scattered_cpuid_mask(leaf, count, reg); +} + void setup_clear_cpu_cap(unsigned int feature) { do_clear_cpu_cap(NULL, feature); diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 166033fa8423..aa1cfcc81323 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -19,6 +19,9 @@ #include #include #include +#include +#include +#include #ifdef CONFIG_X86_64 #include @@ -667,13 +670,60 @@ static void intel_bsp_resume(struct cpuinfo_x86 *c) init_intel_energy_perf(c); } +bool fixup_cpuid_exception(struct pt_regs *regs) +{ + unsigned int leaf, count, eax, ebx, ecx, edx; + unsigned long seg_base = 0; + unsigned char buf[2]; + int not_copied; + + if (!cpuid_fault) + return false; + + if (test_thread_flag(TIF_NOCPUID)) + return false; + + if (!user_64bit_mode(regs)) + seg_base = insn_get_seg_base(regs, INAT_SEG_REG_CS); + + if (seg_base == -1L) + return false; + + not_copied = copy_from_user(buf, (void __user *)(seg_base + regs->ip), + sizeof(buf)); + if (not_copied) + return false; + + if (buf[0] != 0x0F || buf[1] != 0xA2) /* CPUID - OF A2 */ + return false; + + leaf = regs->ax; + count = regs->cx; + + cpuid_count(leaf, count, &eax, &ebx, &ecx, &edx); + + regs->ip += 2; + regs->ax = eax & cpuid_cap_mask(leaf, count, CPUID_EAX); + regs->bx = ebx & cpuid_cap_mask(leaf, count, CPUID_EBX); + regs->cx = ecx & cpuid_cap_mask(leaf, count, CPUID_ECX); + regs->dx = edx & cpuid_cap_mask(leaf, count, CPUID_EDX); + + return true; +} + static void init_cpuid_fault(struct cpuinfo_x86 *c) { u64 msr; - if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) { - if (msr & MSR_PLATFORM_INFO_CPUID_FAULT) - set_cpu_cap(c, X86_FEATURE_CPUID_FAULT); + if (rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) + return; + + if (msr & MSR_PLATFORM_INFO_CPUID_FAULT) { + set_cpu_cap(c, X86_FEATURE_CPUID_FAULT); + if (cpuid_fault) { + this_cpu_or(msr_misc_features_shadow, + MSR_MISC_FEATURES_ENABLES_CPUID_FAULT); + } } } diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index 94aa1c72ca98..353756c27096 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -62,3 +62,20 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c) set_cpu_cap(c, cb->feature); } } + +u32 scattered_cpuid_mask(u32 leaf, u32 count, enum cpuid_regs_idx reg) +{ + const struct cpuid_bit *cb; + u32 mask = ~0U; + + for (cb = cpuid_bits; cb->feature; cb++) { + if (cb->level == leaf && cb->sub_leaf == count && + cb->reg == reg) { + if (test_bit(cb->feature, + (unsigned long *)cpu_caps_cleared)) + mask &= ~BIT(cb->bit); + } + } + + return mask; +} diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 58ac7be52c7a..2b1dfd7ae65d 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -196,6 +196,9 @@ static void set_cpuid_faulting(bool on) { u64 msrval; + if (cpuid_fault) + return; + msrval = this_cpu_read(msr_misc_features_shadow); msrval &= ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; msrval |= (on << MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 0ac992bfa287..d887da1e8050 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -559,6 +559,12 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, 0, NULL); } +#ifdef CONFIG_CPU_SUP_INTEL +extern bool fixup_cpuid_exception(struct pt_regs *regs); +#else +static inline bool fixup_cpuid_exception(struct pt_regs *regs) { return false; } +#endif + dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code) { @@ -573,6 +579,11 @@ do_general_protection(struct pt_regs *regs, long error_code) return; } + if (static_cpu_has(X86_FEATURE_CPUID_FAULT)) { + if (user_mode(regs) && fixup_cpuid_exception(regs)) + return; + } + if (v8086_mode(regs)) { local_irq_enable(); handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); From patchwork Wed Apr 3 21:22:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10884451 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2E2BC1708 for ; Wed, 3 Apr 2019 21:30:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0820E28450 for ; Wed, 3 Apr 2019 21:30:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EE380285B7; Wed, 3 Apr 2019 21:30:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D928F28450 for ; Wed, 3 Apr 2019 21:30:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726948AbfDCVa1 (ORCPT ); Wed, 3 Apr 2019 17:30:27 -0400 Received: from mga05.intel.com ([192.55.52.43]:37312 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726825AbfDCVaW (ORCPT ); Wed, 3 Apr 2019 17:30:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 14:30:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="334754289" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga005.fm.intel.com with ESMTP; 03 Apr 2019 14:30:13 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Kalle Valo" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v6 20/20] x86/clearcpuid: Change document for kernel option clearcpuid Date: Wed, 3 Apr 2019 14:22:06 -0700 Message-Id: <1554326526-172295-21-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> References: <1554326526-172295-1-git-send-email-fenghua.yu@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Since kernel option clearcpuid now supports multiple options and CPU capability flags, the document needs to be changed. Signed-off-by: Fenghua Yu --- .../admin-guide/kernel-parameters.txt | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2b8ee90bb644..0cbeda6d7f16 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -563,17 +563,21 @@ loops can be debugged more effectively on production systems. - clearcpuid=BITNUM [X86] + clearcpuid=BITNUM | FLAG [X86] Disable CPUID feature X for the kernel. See arch/x86/include/asm/cpufeatures.h for the valid bit - numbers. Note the Linux specific bits are not necessarily + numbers or /proc/cpuinfo for valid CPU flags. + Multiple options can be used to disable a few features. + This prevents the feature from being used by the + kernel or shown in /proc/cpuinfo or shown in CPUID + called directly by user programs. + A few notes: + - The Linux specific bits are not necessarily stable over kernel options, but the vendor specific ones should be. - Also note that user programs calling CPUID directly - or using the feature without checking anything - will still see it. This just prevents it from - being used by the kernel or shown in /proc/cpuinfo. - Also note the kernel might malfunction if you disable + - User programs using the feature without checking + anything will still use it. + - The kernel might malfunction if you disable some critical bits. cma=nn[MG]@[start[MG][-end[MG]]]