From patchwork Wed Apr 17 21:33:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906299 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 41E7117E0 for ; Wed, 17 Apr 2019 21:46:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2D2C228BAB for ; Wed, 17 Apr 2019 21:46:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2138028BAC; Wed, 17 Apr 2019 21:46:46 +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 C265728BAA for ; Wed, 17 Apr 2019 21:46:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387449AbfDQVmQ (ORCPT ); Wed, 17 Apr 2019 17:42:16 -0400 Received: from mga12.intel.com ([192.55.52.136]:20150 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfDQVmP (ORCPT ); Wed, 17 Apr 2019 17:42:15 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441128" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:13 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 01/21] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long Date: Wed, 17 Apr 2019 14:33:51 -0700 Message-Id: <1555536851-17462-2-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 cause the CPU to do a bus lock 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 will be 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 17 21:33:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906289 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 101C617E0 for ; Wed, 17 Apr 2019 21:46:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00FCC28A93 for ; Wed, 17 Apr 2019 21:46:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E950D28BA9; Wed, 17 Apr 2019 21:46:15 +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=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 8964728A93 for ; Wed, 17 Apr 2019 21:46:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387495AbfDQVmS (ORCPT ); Wed, 17 Apr 2019 17:42:18 -0400 Received: from mga12.intel.com ([192.55.52.136]:20155 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387475AbfDQVmR (ORCPT ); Wed, 17 Apr 2019 17:42:17 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441131" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:14 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 02/21] drivers/net/b44: Align pwol_mask to unsigned long for better performance Date: Wed, 17 Apr 2019 14:33:52 -0700 Message-Id: <1555536851-17462-3-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 locked access 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 17 21:33:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906291 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 5BF5917E0 for ; Wed, 17 Apr 2019 21:46:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 445F628A93 for ; Wed, 17 Apr 2019 21:46:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3838728BA9; Wed, 17 Apr 2019 21:46:24 +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 C718728A93 for ; Wed, 17 Apr 2019 21:46:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387592AbfDQVqP (ORCPT ); Wed, 17 Apr 2019 17:46:15 -0400 Received: from mga12.intel.com ([192.55.52.136]:20155 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387477AbfDQVmS (ORCPT ); Wed, 17 Apr 2019 17:42:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441137" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:15 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 03/21] wlcore: simplify/fix/optimize reg_ch_conf_pending operations Date: Wed, 17 Apr 2019 14:33:53 -0700 Message-Id: <1555536851-17462-4-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 17 21:33:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906297 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 5925F1390 for ; Wed, 17 Apr 2019 21:46:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 493B928A96 for ; Wed, 17 Apr 2019 21:46:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3C73E28BAC; Wed, 17 Apr 2019 21:46:35 +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 E4E8B28A96 for ; Wed, 17 Apr 2019 21:46:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387971AbfDQVq3 (ORCPT ); Wed, 17 Apr 2019 17:46:29 -0400 Received: from mga12.intel.com ([192.55.52.136]:20157 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387483AbfDQVmS (ORCPT ); Wed, 17 Apr 2019 17:42:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441141" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:16 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 04/21] x86/split_lock: Align x86_capability to unsigned long to avoid split locked access Date: Wed, 17 Apr 2019 14:33:54 -0700 Message-Id: <1555536851-17462-5-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 cause split lock. To fix the split lock issue, align x86_capability to size of 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 size of unsigned long. But this needs additional code changes. So choose the simpler solution by setting the array's 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 17 21:33:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906283 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 75E8E17E0 for ; Wed, 17 Apr 2019 21:45:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6558F28A93 for ; Wed, 17 Apr 2019 21:45:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 59B6E28BA9; Wed, 17 Apr 2019 21:45:56 +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 1631E28A93 for ; Wed, 17 Apr 2019 21:45:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387516AbfDQVmT (ORCPT ); Wed, 17 Apr 2019 17:42:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:20157 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387496AbfDQVmS (ORCPT ); Wed, 17 Apr 2019 17:42:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441145" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:16 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 05/21] x86/msr-index: Define MSR_IA32_CORE_CAPABILITY and split lock detection bit Date: Wed, 17 Apr 2019 14:33:55 -0700 Message-Id: <1555536851-17462-6-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 17 21:33:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906287 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 7AAD31390 for ; Wed, 17 Apr 2019 21:46:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A2FF28A93 for ; Wed, 17 Apr 2019 21:46:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5EA8C28BA9; Wed, 17 Apr 2019 21:46:10 +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 1975E28A93 for ; Wed, 17 Apr 2019 21:46:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387793AbfDQVqA (ORCPT ); Wed, 17 Apr 2019 17:46:00 -0400 Received: from mga12.intel.com ([192.55.52.136]:20160 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387503AbfDQVmT (ORCPT ); Wed, 17 Apr 2019 17:42:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441151" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:17 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 06/21] x86/cpufeatures: Enumerate MSR_IA32_CORE_CAPABILITY Date: Wed, 17 Apr 2019 14:33:56 -0700 Message-Id: <1555536851-17462-7-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 17 21:33:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906277 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 8035917E0 for ; Wed, 17 Apr 2019 21:45:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6AAE328A93 for ; Wed, 17 Apr 2019 21:45:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5E94428BAA; Wed, 17 Apr 2019 21:45:51 +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 BAD3B28A93 for ; Wed, 17 Apr 2019 21:45:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387854AbfDQVor (ORCPT ); Wed, 17 Apr 2019 17:44:47 -0400 Received: from mga12.intel.com ([192.55.52.136]:20162 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387522AbfDQVmU (ORCPT ); Wed, 17 Apr 2019 17:42:20 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:19 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441156" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:18 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 07/21] x86/split_lock: Enumerate split lock detection by MSR_IA32_CORE_CAPABILITY Date: Wed, 17 Apr 2019 14:33:57 -0700 Message-Id: <1555536851-17462-8-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 17 21:33:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906195 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 4917E1515 for ; Wed, 17 Apr 2019 21:44:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34BDB28BA9 for ; Wed, 17 Apr 2019 21:44:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2695428BAB; Wed, 17 Apr 2019 21:44:38 +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 C8E2928BA9 for ; Wed, 17 Apr 2019 21:44:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387692AbfDQVog (ORCPT ); Wed, 17 Apr 2019 17:44:36 -0400 Received: from mga12.intel.com ([192.55.52.136]:20162 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387525AbfDQVmV (ORCPT ); Wed, 17 Apr 2019 17:42:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441160" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:19 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 08/21] x86/split_lock: Enumerate split lock detection on Icelake mobile processor Date: Wed, 17 Apr 2019 14:33:58 -0700 Message-Id: <1555536851-17462-9-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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. In the future, a few other processors may also have the split lock detection 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..62f61a961eb6 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 17 21:33:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906193 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 4B8771515 for ; Wed, 17 Apr 2019 21:44:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B1E228BA9 for ; Wed, 17 Apr 2019 21:44:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2D7C928BAB; Wed, 17 Apr 2019 21:44:34 +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 DCBCF28BA9 for ; Wed, 17 Apr 2019 21:44:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387537AbfDQVmW (ORCPT ); Wed, 17 Apr 2019 17:42:22 -0400 Received: from mga12.intel.com ([192.55.52.136]:20150 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387475AbfDQVmV (ORCPT ); Wed, 17 Apr 2019 17:42:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441163" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:20 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 09/21] x86/split_lock: Define MSR TEST_CTL register Date: Wed, 17 Apr 2019 14:33:59 -0700 Message-Id: <1555536851-17462-10-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Setting bit 29 in MSR TEST_CTL (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..296eeb761ab6 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_SPLIT_LOCK_DETECT_SHIFT 29 +#define TEST_CTL_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 17 21:34:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906149 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 7AEF917E6 for ; Wed, 17 Apr 2019 21:42:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 68C4E28BA8 for ; Wed, 17 Apr 2019 21:42:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5C49728BAA; Wed, 17 Apr 2019 21:42:28 +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 1416128BA8 for ; Wed, 17 Apr 2019 21:42:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387584AbfDQVm0 (ORCPT ); Wed, 17 Apr 2019 17:42:26 -0400 Received: from mga12.intel.com ([192.55.52.136]:20165 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387556AbfDQVmY (ORCPT ); Wed, 17 Apr 2019 17:42:24 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441169" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:21 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu , Xiaoyao Li Subject: [PATCH v7 10/21] x86/split_lock: Define per CPU variable to cache MSR TEST_CTL Date: Wed, 17 Apr 2019 14:34:00 -0700 Message-Id: <1555536851-17462-11-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP MSR TEST_CTL (0x33) value is cached in per CPU variable msr_test_ctl_cache. The cached value will be used in virutalization to avoid costly MSR read. Signed-off-by: Fenghua Yu Signed-off-by: Xiaoyao Li --- arch/x86/include/asm/cpu.h | 1 + arch/x86/kernel/cpu/intel.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 4e03f53fc079..cd7493f20234 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -40,6 +40,7 @@ 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); +DECLARE_PER_CPU(u64, msr_test_ctl_cache); #ifdef CONFIG_CPU_SUP_INTEL void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c); #else diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 62f61a961eb6..997d683d3c27 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -31,6 +31,9 @@ #include #endif +DEFINE_PER_CPU(u64, msr_test_ctl_cache); +EXPORT_PER_CPU_SYMBOL_GPL(msr_test_ctl_cache); + /* * Just in case our CPU detection goes bad, or you have a weird system, * allow a way to override the automatic disabling of MPX. From patchwork Wed Apr 17 21:34:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906187 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 7F2551515 for ; Wed, 17 Apr 2019 21:44:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6AB6728BA9 for ; Wed, 17 Apr 2019 21:44:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5E89B28BAA; Wed, 17 Apr 2019 21:44:24 +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 E7E7C28BA8 for ; Wed, 17 Apr 2019 21:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387707AbfDQVoQ (ORCPT ); Wed, 17 Apr 2019 17:44:16 -0400 Received: from mga12.intel.com ([192.55.52.136]:20165 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387563AbfDQVmZ (ORCPT ); Wed, 17 Apr 2019 17:42:25 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441179" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:21 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 11/21] x86/split_lock: Handle #AC exception for split lock Date: Wed, 17 Apr 2019 14:34:01 -0700 Message-Id: <1555536851-17462-12-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index d26f9e9c3d83..c776bc0a47f5 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 +294,41 @@ 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"); + + 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. + */ + msr_clear_bit(MSR_TEST_CTL, TEST_CTL_SPLIT_LOCK_DETECT_SHIFT); + this_cpu_and(msr_test_ctl_cache, ~TEST_CTL_SPLIT_LOCK_DETECT); + 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 17 21:34:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906269 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 4C59117E0 for ; Wed, 17 Apr 2019 21:45:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3F21728A93 for ; Wed, 17 Apr 2019 21:45:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 33B5928BA9; Wed, 17 Apr 2019 21:45:45 +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=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 B04EE28A93 for ; Wed, 17 Apr 2019 21:45:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387951AbfDQVpa (ORCPT ); Wed, 17 Apr 2019 17:45:30 -0400 Received: from mga06.intel.com ([134.134.136.31]:13865 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387562AbfDQVp1 (ORCPT ); Wed, 17 Apr 2019 17:45:27 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441189" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:22 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Xiaoyao Li , Fenghua Yu Subject: [PATCH v7 12/21] kvm/x86: Emulate MSR IA32_CORE_CAPABILITY Date: Wed, 17 Apr 2019 14:34:02 -0700 Message-Id: <1555536851-17462-13-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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] enumerates 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 that plays the similar role as CPUID, it can be emulated 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 --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/cpuid.c | 6 ++++++ arch/x86/kvm/x86.c | 22 ++++++++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a9d03af34030..d4f9b13fcdd6 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 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 a0d1fc80ac5a..e88be97d47b9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1161,6 +1161,7 @@ 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, @@ -1200,6 +1201,7 @@ static u32 msr_based_features[] = { MSR_F10H_DECFG, MSR_IA32_UCODE_REV, + MSR_IA32_CORE_CAPABILITY, MSR_IA32_ARCH_CAPABILITIES, }; @@ -1227,9 +1229,17 @@ u64 kvm_get_arch_capabilities(void) } EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities); +static u64 kvm_get_core_capability(void) +{ + return 0; +} + 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; @@ -2453,6 +2463,11 @@ 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 */ @@ -2764,6 +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); @@ -8760,6 +8781,7 @@ 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 17 21:34:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906183 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 3D55E1390 for ; Wed, 17 Apr 2019 21:44:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2735428BA8 for ; Wed, 17 Apr 2019 21:44:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1B7FA28BAB; Wed, 17 Apr 2019 21:44:11 +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 8B35A28BA8 for ; Wed, 17 Apr 2019 21:44:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387817AbfDQVnz (ORCPT ); Wed, 17 Apr 2019 17:43:55 -0400 Received: from mga12.intel.com ([192.55.52.136]:20166 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387565AbfDQVm0 (ORCPT ); Wed, 17 Apr 2019 17:42:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441193" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:24 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Xiaoyao Li , Fenghua Yu Subject: [PATCH v7 13/21] kvm/vmx: Emulate MSR TEST_CTL Date: Wed, 17 Apr 2019 14:34:03 -0700 Message-Id: <1555536851-17462-14-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 emulates MSR TEST_CTL with vmx->msr_test_ctl and does the following: 1. As MSR TEST_CTL of guest is emulated, enable the related bit in CORE_CAPABILITY to correctly report this feature to guest. 2. Differentiate MSR TEST_CTL between host and guest. Signed-off-by: Xiaoyao Li Signed-off-by: Fenghua Yu --- arch/x86/kvm/vmx/vmx.c | 42 ++++++++++++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/vmx.h | 2 ++ arch/x86/kvm/x86.c | 19 ++++++++++++++++++- 3 files changed, 62 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index b4e7d645275a..bbb9859350b5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1663,6 +1663,11 @@ 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 (!vmx->msr_test_ctl_mask) + 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 +1802,12 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) u32 index; switch (msr_index) { + case MSR_TEST_CTL: + if (!vmx->msr_test_ctl_mask || + (data & vmx->msr_test_ctl_mask) != data) + return 1; + vmx->msr_test_ctl = data; + break; case MSR_EFER: ret = kvm_set_msr_common(vcpu, msr_info); break; @@ -4106,6 +4117,16 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx) } } +static u64 vmx_get_msr_test_ctl_mask(struct kvm_vcpu *vcpu) +{ + u64 mask = 0; + + if (vcpu->arch.core_capability & CORE_CAP_SPLIT_LOCK_DETECT) + mask |= TEST_CTL_SPLIT_LOCK_DETECT; + + return mask; +} + static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) { struct vcpu_vmx *vmx = to_vmx(vcpu); @@ -4114,6 +4135,8 @@ 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; + vmx->msr_test_ctl_mask = vmx_get_msr_test_ctl_mask(vcpu); vcpu->arch.microcode_version = 0x100000000ULL; vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); @@ -6313,6 +6336,23 @@ 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 (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) + return; + + host_msr_test_ctl = this_cpu_read(msr_test_ctl_cache); + + 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); @@ -6421,6 +6461,8 @@ 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 f879529906b4..8690a1295548 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -190,6 +190,8 @@ struct vcpu_vmx { u64 msr_guest_kernel_gs_base; #endif + u64 msr_test_ctl; + u64 msr_test_ctl_mask; u64 spec_ctrl; u32 vm_entry_controls_shadow; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e88be97d47b9..60aaf75d0fe5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1231,7 +1231,24 @@ EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities); static u64 kvm_get_core_capability(void) { - return 0; + u64 data = 0; + + if (boot_cpu_has(X86_FEATURE_CORE_CAPABILITY)) { + rdmsrl(MSR_IA32_CORE_CAPABILITY, data); + + /* mask non-virtualizable functions */ + data &= CORE_CAP_SPLIT_LOCK_DETECT; + } else if (boot_cpu_has(X86_FEATURE_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. + */ + data |= CORE_CAP_SPLIT_LOCK_DETECT; + } + + return data; } static int kvm_get_msr_feature(struct kvm_msr_entry *msr) From patchwork Wed Apr 17 21:34:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906181 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 BE4E11390 for ; Wed, 17 Apr 2019 21:44:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AF3B328BA8 for ; Wed, 17 Apr 2019 21:44:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A2DFB28BAA; Wed, 17 Apr 2019 21:44:07 +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 531B628BA8 for ; Wed, 17 Apr 2019 21:44:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387829AbfDQVn4 (ORCPT ); Wed, 17 Apr 2019 17:43:56 -0400 Received: from mga12.intel.com ([192.55.52.136]:20171 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387579AbfDQVm0 (ORCPT ); Wed, 17 Apr 2019 17:42:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441196" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:25 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 14/21] x86/split_lock: Enable split lock detection by default Date: Wed, 17 Apr 2019 14:34:04 -0700 Message-Id: <1555536851-17462-15-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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. Signed-off-by: Fenghua Yu --- arch/x86/kernel/cpu/intel.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 997d683d3c27..6a692d215bef 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -34,6 +34,8 @@ DEFINE_PER_CPU(u64, msr_test_ctl_cache); EXPORT_PER_CPU_SYMBOL_GPL(msr_test_ctl_cache); +static bool split_lock_detect_enable; + /* * Just in case our CPU detection goes bad, or you have a weird system, * allow a way to override the automatic disabling of MPX. @@ -164,6 +166,23 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c) return false; } +static void split_lock_update_msr(void *__unused) +{ + if (split_lock_detect_enable) { + msr_set_bit(MSR_TEST_CTL, TEST_CTL_SPLIT_LOCK_DETECT_SHIFT); + this_cpu_or(msr_test_ctl_cache, TEST_CTL_SPLIT_LOCK_DETECT); + } else { + msr_clear_bit(MSR_TEST_CTL, TEST_CTL_SPLIT_LOCK_DETECT_SHIFT); + this_cpu_and(msr_test_ctl_cache, ~TEST_CTL_SPLIT_LOCK_DETECT); + } +} + +static void init_split_lock_detect(struct cpuinfo_x86 *c) +{ + if (cpu_has(c, X86_FEATURE_SPLIT_LOCK_DETECT)) + split_lock_update_msr(NULL); +} + static void early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable; @@ -661,6 +680,8 @@ static void init_intel(struct cpuinfo_x86 *c) { early_init_intel(c); + init_split_lock_detect(c); + intel_workarounds(c); /* @@ -1032,9 +1053,22 @@ static const struct cpu_dev intel_cpu_dev = { cpu_dev_register(intel_cpu_dev); +#undef pr_fmt +#define pr_fmt(fmt) "x86/split lock detection: " fmt + +static void show_split_lock_detection_info(void) +{ + if (split_lock_detect_enable) + pr_info("enabled\n"); + else + pr_info("disabled\n"); +} + static void __init set_split_lock_detect(void) { setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); + split_lock_detect_enable = true; + show_split_lock_detection_info(); } void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) From patchwork Wed Apr 17 21:34:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906173 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 175A917E6 for ; Wed, 17 Apr 2019 21:43:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 06D8D28BA9 for ; Wed, 17 Apr 2019 21:43:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EED8428BAD; Wed, 17 Apr 2019 21:43:38 +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 9CF6828BA9 for ; Wed, 17 Apr 2019 21:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387617AbfDQVm3 (ORCPT ); Wed, 17 Apr 2019 17:42:29 -0400 Received: from mga12.intel.com ([192.55.52.136]:20166 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387596AbfDQVm2 (ORCPT ); Wed, 17 Apr 2019 17:42:28 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441200" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:26 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 15/21] x86/split_lock: Add a sysfs interface to enable/disable split lock detection during run time Date: Wed, 17 Apr 2019 14:34:05 -0700 Message-Id: <1555536851-17462-16-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 [yY1] or [oO][nN] to the file enables split lock detection and writing [nN0] or [oO][fF] 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 Signed-off-by: Fenghua Yu --- arch/x86/kernel/cpu/intel.c | 45 +++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 6a692d215bef..f2c04aa36d78 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -34,6 +34,7 @@ DEFINE_PER_CPU(u64, msr_test_ctl_cache); EXPORT_PER_CPU_SYMBOL_GPL(msr_test_ctl_cache); +static DEFINE_MUTEX(split_lock_detect_mutex); static bool split_lock_detect_enable; /* @@ -1097,3 +1098,47 @@ 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", split_lock_detect_enable); +} + +static ssize_t +split_lock_detect_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + bool val; + int ret; + + ret = strtobool(buf, &val); + if (ret) + return ret; + + mutex_lock(&split_lock_detect_mutex); + + split_lock_detect_enable = val; + + /* Update the split lock detection setting in MSR on all online CPUs. */ + on_each_cpu(split_lock_update_msr, NULL, 1); + + show_split_lock_detection_info(); + + mutex_unlock(&split_lock_detect_mutex); + + return count; +} + +static DEVICE_ATTR_RW(split_lock_detect); + +static int __init split_lock_init(void) +{ + if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) + return -ENODEV; + + return device_create_file(cpu_subsys.dev_root, + &dev_attr_split_lock_detect); +} +subsys_initcall(split_lock_init); From patchwork Wed Apr 17 21:34:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906175 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 E2B931390 for ; Wed, 17 Apr 2019 21:43:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE53E28BA8 for ; Wed, 17 Apr 2019 21:43:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C1F3D28BAA; Wed, 17 Apr 2019 21:43:45 +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 6E14628BA8 for ; Wed, 17 Apr 2019 21:43:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387800AbfDQVnj (ORCPT ); Wed, 17 Apr 2019 17:43:39 -0400 Received: from mga12.intel.com ([192.55.52.136]:20166 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387607AbfDQVm3 (ORCPT ); Wed, 17 Apr 2019 17:42:29 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441206" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:27 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 16/21] x86/split_lock: Document the new sysfs file for split lock detection Date: Wed, 17 Apr 2019 14:34:06 -0700 Message-Id: <1555536851-17462-17-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 9605dbd4b5b5..aad7b1698065 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -67,6 +67,28 @@ 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: (RW) Control split lock detection on Intel Tremont and + future CPUs + + Reads return split lock detection status: + 0: disabled + 1: enabled + + Writes enable or disable split lock detection: + The first character is one of 'Nn0' or [oO][fF] for off + disables the feature. + The first character is one of 'Yy1' or [oO][nN] for on + enables the feature. + + 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 17 21:34:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906163 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 4E81D1390 for ; Wed, 17 Apr 2019 21:43:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 391B428BA9 for ; Wed, 17 Apr 2019 21:43:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2C84028BAA; Wed, 17 Apr 2019 21:43:20 +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 A6C6B28BA8 for ; Wed, 17 Apr 2019 21:43:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387642AbfDQVma (ORCPT ); Wed, 17 Apr 2019 17:42:30 -0400 Received: from mga12.intel.com ([192.55.52.136]:20166 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387624AbfDQVm3 (ORCPT ); Wed, 17 Apr 2019 17:42:29 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441213" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:28 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 17/21] x86/clearcpuid: Support multiple clearcpuid options Date: Wed, 17 Apr 2019 14:34:07 -0700 Message-Id: <1555536851-17462-18-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 17 21:34:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906169 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 4C8061390 for ; Wed, 17 Apr 2019 21:43:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3C13B28BA8 for ; Wed, 17 Apr 2019 21:43:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3048528BA9; Wed, 17 Apr 2019 21:43:29 +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 D14B628BAB for ; Wed, 17 Apr 2019 21:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387782AbfDQVnV (ORCPT ); Wed, 17 Apr 2019 17:43:21 -0400 Received: from mga12.intel.com ([192.55.52.136]:20176 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387633AbfDQVma (ORCPT ); Wed, 17 Apr 2019 17:42:30 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441217" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:29 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 18/21] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Date: Wed, 17 Apr 2019 14:34:08 -0700 Message-Id: <1555536851-17462-19-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 17 21:34:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906151 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 3D2C51390 for ; Wed, 17 Apr 2019 21:42:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 26CDA28BA8 for ; Wed, 17 Apr 2019 21:42:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 17B5A28BAA; Wed, 17 Apr 2019 21:42:35 +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 B443828BA8 for ; Wed, 17 Apr 2019 21:42:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387666AbfDQVmd (ORCPT ); Wed, 17 Apr 2019 17:42:33 -0400 Received: from mga12.intel.com ([192.55.52.136]:20176 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387647AbfDQVmb (ORCPT ); Wed, 17 Apr 2019 17:42:31 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441220" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:30 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 19/21] x86/clearcpuid: Apply cleared feature bits that are forced set before Date: Wed, 17 Apr 2019 14:34:09 -0700 Message-Id: <1555536851-17462-20-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 cd7493f20234..261e8ff3e2fb 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 17 21:34:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906153 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 7643317E6 for ; Wed, 17 Apr 2019 21:42:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5C8E028BA8 for ; Wed, 17 Apr 2019 21:42:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5036E28BAB; Wed, 17 Apr 2019 21:42:55 +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 932EA28BA8 for ; Wed, 17 Apr 2019 21:42:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387722AbfDQVms (ORCPT ); Wed, 17 Apr 2019 17:42:48 -0400 Received: from mga12.intel.com ([192.55.52.136]:20176 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387653AbfDQVmd (ORCPT ); Wed, 17 Apr 2019 17:42:33 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441224" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:30 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 20/21] x86/clearcpuid: Clear CPUID bit in CPUID faulting Date: Wed, 17 Apr 2019 14:34:10 -0700 Message-Id: <1555536851-17462-21-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 f2c04aa36d78..3005a1e802b7 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 @@ -649,13 +652,60 @@ 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 c776bc0a47f5..99e9b15c37d0 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -551,6 +551,12 @@ 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) { @@ -565,6 +571,11 @@ 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 17 21:34:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10906159 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 81D811515 for ; Wed, 17 Apr 2019 21:43:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C6FF28BA9 for ; Wed, 17 Apr 2019 21:43:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 60B3328BB0; Wed, 17 Apr 2019 21:43:08 +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 DD6EC28BA9 for ; Wed, 17 Apr 2019 21:43:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387752AbfDQVnA (ORCPT ); Wed, 17 Apr 2019 17:43:00 -0400 Received: from mga12.intel.com ([192.55.52.136]:20177 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387667AbfDQVmd (ORCPT ); Wed, 17 Apr 2019 17:42:33 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Apr 2019 14:42:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,363,1549958400"; d="scan'208";a="224441229" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by orsmga001.jf.intel.com with ESMTP; 17 Apr 2019 14:42:31 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H Peter Anvin" , "Paolo Bonzini" , "Dave Hansen" , "Ashok Raj" , "Peter Zijlstra" , "Ravi V Shankar" , "Xiaoyao Li " , "Christopherson Sean J" , "Kalle Valo" , "Michael Chan" Cc: "linux-kernel" , "x86" , kvm@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Fenghua Yu Subject: [PATCH v7 21/21] x86/clearcpuid: Change document for kernel option clearcpuid Date: Wed, 17 Apr 2019 14:34:11 -0700 Message-Id: <1555536851-17462-22-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> References: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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]]]