2022-09-16 14:13:04

by Vitaly Kuznetsov

[permalink] [raw]
Subject: [PATCH v3 1/6] x86/hyperv: Add HV_INVARIANT_TSC_EXPOSED define

Avoid open coding BIT(0) of HV_X64_MSR_TSC_INVARIANT_CONTROL by adding
a dedicated define. While there's only one user at this moment, the
upcoming KVM implementation of Hyper-V Invariant TSC feature will need
to use it as well.

Signed-off-by: Vitaly Kuznetsov <[email protected]>
---
arch/x86/include/asm/hyperv-tlfs.h | 3 +++
arch/x86/kernel/cpu/mshyperv.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 0a9407dc0859..251d88c06210 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -250,6 +250,9 @@ enum hv_isolation_type {
/* TSC invariant control */
#define HV_X64_MSR_TSC_INVARIANT_CONTROL 0x40000118

+/* HV_X64_MSR_TSC_INVARIANT_CONTROL bits */
+#define HV_INVARIANT_TSC_EXPOSED BIT_ULL(0)
+
/* Register name aliases for temporary compatibility */
#define HV_X64_MSR_STIMER0_COUNT HV_REGISTER_STIMER0_COUNT
#define HV_X64_MSR_STIMER0_CONFIG HV_REGISTER_STIMER0_CONFIG
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 831613959a92..3716c358da98 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -388,7 +388,7 @@ static void __init ms_hyperv_init_platform(void)
* setting of this MSR bit should happen before init_intel()
* is called.
*/
- wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1);
+ wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, HV_INVARIANT_TSC_EXPOSED);
setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
}

--
2.37.2