From: Fenghua Yu <fenghua.yu@intel.com>
To: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>, "H Peter Anvin" <hpa@zytor.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Dave Hansen" <dave.hansen@intel.com>,
"Ashok Raj" <ashok.raj@intel.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Ravi V Shankar" <ravi.v.shankar@intel.com>,
"Xiaoyao Li " <xiaoyao.li@intel.com>,
"Christopherson Sean J" <sean.j.christopherson@intel.com>,
"Kalle Valo" <kvalo@codeaurora.org>,
"Michael Chan" <michael.chan@broadcom.com>
Cc: "linux-kernel" <linux-kernel@vger.kernel.org>,
"x86" <x86@kernel.org>,
kvm@vger.kernel.org, netdev@vger.kernel.org,
linux-wireless@vger.kernel.org, Fenghua Yu <fenghua.yu@intel.com>
Subject: [PATCH v7 14/21] x86/split_lock: Enable split lock detection by default
Date: Wed, 17 Apr 2019 14:34:04 -0700 [thread overview]
Message-ID: <1555536851-17462-15-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1555536851-17462-1-git-send-email-fenghua.yu@intel.com>
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 <fenghua.yu@intel.com>
---
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)
--
2.19.1
next prev parent reply other threads:[~2019-04-17 21:44 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-17 21:33 [PATCH v7 00/21] x86/split_lock: Enable split lock detection Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 01/21] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 02/21] drivers/net/b44: Align pwol_mask to unsigned long for better performance Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 03/21] wlcore: simplify/fix/optimize reg_ch_conf_pending operations Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 04/21] x86/split_lock: Align x86_capability to unsigned long to avoid split locked access Fenghua Yu
2019-04-18 9:20 ` David Laight
2019-04-18 11:08 ` David Laight
2019-04-18 11:49 ` Thomas Gleixner
2019-04-18 13:14 ` David Laight
2019-04-18 13:26 ` David Laight
2019-04-17 21:33 ` [PATCH v7 05/21] x86/msr-index: Define MSR_IA32_CORE_CAPABILITY and split lock detection bit Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 06/21] x86/cpufeatures: Enumerate MSR_IA32_CORE_CAPABILITY Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 07/21] x86/split_lock: Enumerate split lock detection by MSR_IA32_CORE_CAPABILITY Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 08/21] x86/split_lock: Enumerate split lock detection on Icelake mobile processor Fenghua Yu
2019-04-17 21:33 ` [PATCH v7 09/21] x86/split_lock: Define MSR TEST_CTL register Fenghua Yu
2019-04-17 21:34 ` [PATCH v7 10/21] x86/split_lock: Define per CPU variable to cache MSR TEST_CTL Fenghua Yu
2019-04-17 22:14 ` Thomas Gleixner
2019-04-18 1:28 ` Fenghua Yu
2019-04-18 6:31 ` Thomas Gleixner
2019-04-17 21:34 ` [PATCH v7 11/21] x86/split_lock: Handle #AC exception for split lock Fenghua Yu
2019-04-17 21:34 ` [PATCH v7 12/21] kvm/x86: Emulate MSR IA32_CORE_CAPABILITY Fenghua Yu
2019-04-17 21:34 ` [PATCH v7 13/21] kvm/vmx: Emulate MSR TEST_CTL Fenghua Yu
2019-04-17 21:34 ` Fenghua Yu [this message]
2019-04-17 22:41 ` [PATCH v7 14/21] x86/split_lock: Enable split lock detection by default Thomas Gleixner
2019-04-17 21:34 ` [PATCH v7 15/21] x86/split_lock: Add a sysfs interface to enable/disable split lock detection during run time Fenghua Yu
2019-04-17 22:47 ` Thomas Gleixner
2019-04-18 0:57 ` Fenghua Yu
2019-04-18 6:41 ` Thomas Gleixner
2019-04-23 20:48 ` Fenghua Yu
2019-04-24 13:45 ` David Laight
2019-04-17 21:34 ` [PATCH v7 16/21] x86/split_lock: Document the new sysfs file for split lock detection Fenghua Yu
2019-04-17 21:34 ` [PATCH v7 17/21] x86/clearcpuid: Support multiple clearcpuid options Fenghua Yu
2019-04-17 23:05 ` Thomas Gleixner
2019-04-17 21:34 ` [PATCH v7 18/21] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Fenghua Yu
2019-04-17 23:19 ` Thomas Gleixner
2019-04-17 23:47 ` Fenghua Yu
2019-04-18 6:16 ` Thomas Gleixner
2019-04-17 21:34 ` [PATCH v7 19/21] x86/clearcpuid: Apply cleared feature bits that are forced set before Fenghua Yu
2019-04-17 21:34 ` [PATCH v7 20/21] x86/clearcpuid: Clear CPUID bit in CPUID faulting Fenghua Yu
2019-04-17 21:34 ` [PATCH v7 21/21] x86/clearcpuid: Change document for kernel option clearcpuid Fenghua Yu
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