On 2/7/2020 4:23 AM, Arvind Sankar wrote:
On Thu, Feb 06, 2020 at 03:04:07PM +0800, Xiaoyao Li wrote:
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@xxxxxxxxx>
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
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);
+
Why does this depend on HOTPLUG_CPU?
Sorry, my bad,
It should be under CONFIG_CPU_SUP_INTEL
