From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
hpa@zytor.com, Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Andy Lutomirski <luto@kernel.org>,
tony.luck@intel.com
Cc: peterz@infradead.org, fenghua.yu@intel.com, x86@kernel.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Xiaoyao Li <xiaoyao.li@intel.com>
Subject: [PATCH v3 3/8] x86/split_lock: Cache the value of MSR_TEST_CTRL in percpu data
Date: Thu, 6 Feb 2020 15:04:07 +0800 [thread overview]
Message-ID: <20200206070412.17400-4-xiaoyao.li@intel.com> (raw)
In-Reply-To: <20200206070412.17400-1-xiaoyao.li@intel.com>
Cache the value of MSR_TEST_CTRL in percpu data msr_test_ctrl_cache,
which will be used by KVM module.
It also avoids an expensive RDMSR instruction if SLD needs to be context
switched.
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
arch/x86/include/asm/cpu.h | 2 ++
arch/x86/kernel/cpu/intel.c | 19 ++++++++++++-------
2 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index ff567afa6ee1..2b20829db450 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -27,6 +27,8 @@ struct x86_cpu {
};
#ifdef CONFIG_HOTPLUG_CPU
+DECLARE_PER_CPU(u64, msr_test_ctrl_cache);
+
extern int arch_register_cpu(int num);
extern void arch_unregister_cpu(int);
extern void start_cpu0(void);
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 49535ed81c22..ff27d026cb4a 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -46,6 +46,9 @@ enum split_lock_detect_state {
*/
static enum split_lock_detect_state sld_state = sld_off;
+DEFINE_PER_CPU(u64, msr_test_ctrl_cache);
+EXPORT_PER_CPU_SYMBOL_GPL(msr_test_ctrl_cache);
+
/*
* Processors which have self-snooping capability can handle conflicting
* memory type across CPUs by snooping its own cache. However, there exists
@@ -1043,20 +1046,22 @@ static void __init split_lock_setup(void)
*/
static void __sld_msr_set(bool on)
{
- u64 test_ctrl_val;
-
- rdmsrl(MSR_TEST_CTRL, test_ctrl_val);
-
if (on)
- test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
+ this_cpu_or(msr_test_ctrl_cache, MSR_TEST_CTRL_SPLIT_LOCK_DETECT);
else
- test_ctrl_val &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT;
+ this_cpu_and(msr_test_ctrl_cache, ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT);
- wrmsrl(MSR_TEST_CTRL, test_ctrl_val);
+ wrmsrl(MSR_TEST_CTRL, this_cpu_read(msr_test_ctrl_cache));
}
static void split_lock_init(void)
{
+ u64 test_ctrl_val;
+
+ /* Cache MSR TEST_CTRL */
+ rdmsrl(MSR_TEST_CTRL, test_ctrl_val);
+ this_cpu_write(msr_test_ctrl_cache, test_ctrl_val);
+
if (sld_state == sld_off)
return;
--
2.23.0
next prev parent reply other threads:[~2020-02-06 7:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 7:04 [PATCH v3 0/8] kvm/split_lock: Add feature split lock detection support in kvm Xiaoyao Li
2020-02-06 7:04 ` [PATCH v3 1/8] x86/split_lock: Export handle_user_split_lock() Xiaoyao Li
2020-03-03 18:42 ` Sean Christopherson
2020-02-06 7:04 ` [PATCH v3 2/8] x86/split_lock: Ensure X86_FEATURE_SPLIT_LOCK_DETECT means the existence of feature Xiaoyao Li
2020-03-03 18:55 ` Sean Christopherson
2020-03-03 19:41 ` Sean Christopherson
2020-03-04 1:49 ` Xiaoyao Li
2020-03-05 16:23 ` Sean Christopherson
2020-03-06 2:15 ` Xiaoyao Li
2020-03-04 2:20 ` Xiaoyao Li
2020-02-06 7:04 ` Xiaoyao Li [this message]
2020-02-06 20:23 ` [PATCH v3 3/8] x86/split_lock: Cache the value of MSR_TEST_CTRL in percpu data Arvind Sankar
2020-02-07 4:18 ` Xiaoyao Li
2020-03-03 19:18 ` Sean Christopherson
2020-03-05 6:48 ` Xiaoyao Li
2020-02-06 7:04 ` [PATCH v3 4/8] x86/split_lock: Add and export split_lock_detect_enabled() and split_lock_detect_fatal() Xiaoyao Li
2020-03-03 18:59 ` Sean Christopherson
2020-02-06 7:04 ` [PATCH v3 5/8] kvm: x86: Emulate split-lock access as a write Xiaoyao Li
2020-02-06 7:04 ` [PATCH v3 6/8] kvm: vmx: Extend VMX's #AC interceptor to handle split lock #AC happens in guest Xiaoyao Li
2020-03-03 19:08 ` Sean Christopherson
2020-02-06 7:04 ` [PATCH v3 7/8] kvm: x86: Emulate MSR IA32_CORE_CAPABILITIES Xiaoyao Li
2020-02-06 7:04 ` [PATCH v3 8/8] x86: vmx: virtualize split lock detection Xiaoyao Li
2020-02-07 18:27 ` Arvind Sankar
2020-02-08 4:51 ` Xiaoyao Li
2020-03-03 19:30 ` Sean Christopherson
2020-03-05 14:16 ` Xiaoyao Li
2020-03-05 16:49 ` Sean Christopherson
2020-03-06 0:29 ` Xiaoyao Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200206070412.17400-4-xiaoyao.li@intel.com \
--to=xiaoyao.li@intel.com \
--cc=bp@alien8.de \
--cc=fenghua.yu@intel.com \
--cc=hpa@zytor.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=sean.j.christopherson@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).