From: Alexey Makhalov <amakhalov@vmware.com>
To: <linux-kernel@vger.kernel.org>,
<virtualization@lists.linux-foundation.org>, <hpa@zytor.com>,
<bp@alien8.de>, <mingo@redhat.com>, <tglx@linutronix.de>,
<pv-drivers@vmware.com>, <sdeep@vmware.com>
Cc: Alexey Makhalov <amakhalov@vmware.com>
Subject: [PATCH] x86/vmware: avoid TSC recalibration
Date: Mon, 4 Jan 2021 16:47:52 -0800 [thread overview]
Message-ID: <20210105004752.131069-1-amakhalov@vmware.com> (raw)
When TSC frequency is known (retrieved from hypervisor), we should skip
TSC refined calibration by setting X86_FEATURE_TSC_KNOWN_FREQ.
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
---
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 c6ede3b3d302..83164110ccc5 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)
--
2.11.0
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next reply other threads:[~2021-01-05 1:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 0:47 Alexey Makhalov [this message]
2021-01-05 13:06 ` [PATCH] x86/vmware: avoid TSC recalibration Vitaly Kuznetsov
2021-03-15 22:24 ` Alexey Makhalov
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