[tip: x86/vmware] x86/vmware: Avoid TSC recalibration when frequency is known

From: tip-bot2 for Alexey Makhalov
Date: Sun Mar 28 2021 - 15:23:46 EST


The following commit has been merged into the x86/vmware branch of tip:

Commit-ID: 0b4a285e2c65c2c9449c6eccb87298e385213e7b
Gitweb: https://git.kernel.org/tip/0b4a285e2c65c2c9449c6eccb87298e385213e7b
Author: Alexey Makhalov <amakhalov@xxxxxxxxxx>
AuthorDate: Mon, 04 Jan 2021 16:47:52 -08:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Sun, 28 Mar 2021 21:11:43 +02:00

x86/vmware: Avoid TSC recalibration when frequency is known

When the TSC frequency is known because it is retrieved from the
hypervisor, skip TSC refined calibration by setting X86_FEATURE_TSC_KNOWN_FREQ.

Signed-off-by: Alexey Makhalov <amakhalov@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210105004752.131069-1-amakhalov@xxxxxxxxxx

---
arch/x86/kernel/cpu/vmware.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index c6ede3b..8316411 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -378,6 +378,8 @@ static void __init vmware_set_capabilities(void)
{
setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+ if (vmware_tsc_khz)
+ setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL)
setup_force_cpu_cap(X86_FEATURE_VMCALL);
else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL)