From: Fenghua Yu <fenghua.yu@intel.com>
To: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>, "H Peter Anvin" <hpa@zytor.com>,
"Dave Hansen" <dave.hansen@intel.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Ashok Raj" <ashok.raj@intel.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Xiaoyao Li " <xiaoyao.li@intel.com>,
"Michael Chan" <michael.chan@broadcom.com>,
"Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "linux-kernel" <linux-kernel@vger.kernel.org>,
"x86" <x86@kernel.org>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
kvm@vger.kernel.org, Fenghua Yu <fenghua.yu@intel.com>
Subject: [PATCH v5 12/18] x86/split_lock: Enable #AC for split lock by default
Date: Tue, 12 Mar 2019 16:00:30 -0700 [thread overview]
Message-ID: <1552431636-31511-13-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1552431636-31511-1-git-send-email-fenghua.yu@intel.com>
Split locked access locks bus and degradates overall memory access
performance. When split lock detection feature is enumerated, we want to
enable the feature by default to find any split lock issue and then fix
the issue.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
arch/x86/kernel/cpu/intel.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 889390d51c17..561f7d50246a 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -31,6 +31,11 @@
#include <asm/apic.h>
#endif
+#define DISABLE_SPLIT_LOCK_DETECT 0
+#define ENABLE_SPLIT_LOCK_DETECT 1
+
+static int split_lock_detect_val;
+
/*
* Just in case our CPU detection goes bad, or you have a weird system,
* allow a way to override the automatic disabling of MPX.
@@ -161,10 +166,35 @@ static bool bad_spectre_microcode(struct cpuinfo_x86 *c)
return false;
}
+static u32 new_sp_test_ctl_val(u32 test_ctl_val)
+{
+ /* Change the split lock setting. */
+ if (split_lock_detect_val == DISABLE_SPLIT_LOCK_DETECT)
+ test_ctl_val &= ~TEST_CTL_ENABLE_SPLIT_LOCK_DETECT;
+ else
+ test_ctl_val |= TEST_CTL_ENABLE_SPLIT_LOCK_DETECT;
+
+ return test_ctl_val;
+}
+
+static void init_split_lock_detect(struct cpuinfo_x86 *c)
+{
+ if (cpu_has(c, X86_FEATURE_SPLIT_LOCK_DETECT)) {
+ u32 l, h;
+
+ rdmsr(MSR_TEST_CTL, l, h);
+ l = new_sp_test_ctl_val(l);
+ wrmsr(MSR_TEST_CTL, l, h);
+ pr_info_once("#AC for split lock is enabled\n");
+ }
+}
+
static void early_init_intel(struct cpuinfo_x86 *c)
{
u64 misc_enable;
+ init_split_lock_detect(c);
+
/* Unmask CPUID levels if masked: */
if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
@@ -1048,6 +1078,8 @@ void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
*/
rdmsrl(MSR_IA32_CORE_CAPABILITY, ia32_core_cap);
- if (ia32_core_cap & CORE_CAP_SPLIT_LOCK_DETECT)
+ if (ia32_core_cap & CORE_CAP_SPLIT_LOCK_DETECT) {
setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT);
+ split_lock_detect_val = 1;
+ }
}
--
2.19.1
next prev parent reply other threads:[~2019-03-12 23:08 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-12 23:00 [PATCH v5 00/18] x86/split_lock: Enable #AC exception for split locked accesses Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 01/18] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 02/18] drivers/net/b44: Align pwol_mask to unsigned long for better performance Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 03/18] wlcore: simplify/fix/optimize reg_ch_conf_pending operations Fenghua Yu
2019-03-14 13:16 ` Kalle Valo
2019-03-14 23:16 ` Fenghua Yu
2019-03-15 17:17 ` Paolo Bonzini
2019-03-26 7:55 ` Kalle Valo
2019-03-12 23:00 ` [PATCH v5 04/18] x86/split_lock: Align x86_capability to unsigned long to avoid split locked access Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 05/18] x86/cpufeatures: Enumerate IA32_CORE_CAPABILITIES MSR Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 06/18] x86/msr-index: Define IA32_CORE_CAPABILITY MSR and #AC exception for split lock bit Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 07/18] x86/split_lock: Enumerate #AC for split lock by MSR IA32_CORE_CAPABILITY Fenghua Yu
2019-03-12 23:52 ` Dave Hansen
2019-03-13 0:56 ` Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 08/18] x86/split_lock: Define MSR TEST_CTL register Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 09/18] x86/split_lock: Handle #AC exception for split lock Fenghua Yu
2019-03-12 23:51 ` Dave Hansen
2019-03-13 0:49 ` Fenghua Yu
2019-03-13 16:22 ` Dave Hansen
2019-03-12 23:00 ` [PATCH v5 10/18] kvm/x86: Emulate MSR IA32_CORE_CAPABILITY Fenghua Yu
2019-03-13 8:15 ` Paolo Bonzini
2019-03-12 23:00 ` [PATCH v5 11/18] kvm/vmx: Emulate MSR TEST_CTL Fenghua Yu
2019-03-13 8:15 ` Paolo Bonzini
2019-03-12 23:00 ` Fenghua Yu [this message]
2019-03-12 23:43 ` [PATCH v5 12/18] x86/split_lock: Enable #AC for split lock by default Dave Hansen
2019-03-12 23:00 ` [PATCH v5 13/18] x86/split_lock: Add a sysfs interface to allow user to enable or disable split lock detection on all CPUs during run time Fenghua Yu
2019-03-12 23:48 ` Dave Hansen
2019-03-13 0:53 ` Fenghua Yu
2019-03-13 1:08 ` Dave Hansen
2019-03-12 23:00 ` [PATCH v5 14/18] x86/clearcpuid: Support multiple clearcpuid options Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 15/18] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 16/18] x86/clearcpuid: Apply cleared feature bits that are forced set before Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 17/18] x86/clearcpuid: Clear CPUID bit in CPUID faulting Fenghua Yu
2019-03-12 23:00 ` [PATCH v5 18/18] Change document for kernel option clearcpuid Fenghua Yu
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