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[PATCH v2 01/12] KVM: x86: Collect information for setting TSC scaling ratio

From Haozhong Zhang <haozhong.zhang@intel.com>
Newsgroups linux.kernel
Subject [PATCH v2 01/12] KVM: x86: Collect information for setting TSC scaling ratio
Date 2015-10-20 10:00 +0200
Message-ID <qlzZV-5Mu-23@gated-at.bofh.it> (permalink)
References <qlzQe-5Bb-33@gated-at.bofh.it>
Organization linux.* mail to news gateway

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The number of bits of the fractional part of the 64-bit TSC scaling
ratio in VMX and SVM is different. This patch makes the architecture
code to collect the number of fractional bits and other related
information into variables that can be accessed in the common code.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
 arch/x86/include/asm/kvm_host.h | 6 ++++++
 arch/x86/kvm/svm.c              | 4 ++++
 arch/x86/kvm/x86.c              | 6 ++++++
 3 files changed, 16 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 53deb27..0540dc8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -990,6 +990,12 @@ extern bool kvm_has_tsc_control;
 extern u32  kvm_min_guest_tsc_khz;
 /* maximum supported tsc_khz for guests */
 extern u32  kvm_max_guest_tsc_khz;
+/* number of bits of the fractional part of the TSC scaling ratio */
+extern u8   kvm_tsc_scaling_ratio_frac_bits;
+/* default TSC scaling ratio (= 1.0) */
+extern u64  kvm_default_tsc_scaling_ratio;
+/* maximum allowed value of TSC scaling ratio */
+extern u64  kvm_max_tsc_scaling_ratio;
 
 enum emulation_result {
 	EMULATE_DONE,         /* no further processing */
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index cd8659c..55f5f49 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -908,7 +908,11 @@ static __init int svm_hardware_setup(void)
 		max = min(0x7fffffffULL, __scale_tsc(tsc_khz, TSC_RATIO_MAX));
 
 		kvm_max_guest_tsc_khz = max;
+
+		kvm_max_tsc_scaling_ratio = TSC_RATIO_MAX;
+		kvm_tsc_scaling_ratio_frac_bits = 32;
 	}
+	kvm_default_tsc_scaling_ratio = TSC_RATIO_DEFAULT;
 
 	if (nested) {
 		printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9e9c226..79cbbb5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -109,6 +109,12 @@ bool kvm_has_tsc_control;
 EXPORT_SYMBOL_GPL(kvm_has_tsc_control);
 u32  kvm_max_guest_tsc_khz;
 EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz);
+u8   kvm_tsc_scaling_ratio_frac_bits;
+EXPORT_SYMBOL_GPL(kvm_tsc_scaling_ratio_frac_bits);
+u64  kvm_default_tsc_scaling_ratio;
+EXPORT_SYMBOL_GPL(kvm_default_tsc_scaling_ratio);
+u64  kvm_max_tsc_scaling_ratio;
+EXPORT_SYMBOL_GPL(kvm_max_tsc_scaling_ratio);
 
 /* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
 static u32 tsc_tolerance_ppm = 250;
-- 
2.4.8

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Thread

[PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 09:50 +0200
  [PATCH v2 09/12] KVM: VMX: Enable and initialize VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 09:50 +0200
  [PATCH v2 03/12] KVM: x86: Add a common TSC scaling function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 09:50 +0200
  [PATCH v2 02/12] KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 09:50 +0200
  [PATCH v2 12/12] KVM: VMX: Dump TSC multiplier in dump_vmcs() Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 09:50 +0200
  [PATCH v2 06/12] KVM: x86: Move TSC scaling logic out of call-back adjust_tsc_offset() Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 09:50 +0200
  [PATCH v2 11/12] KVM: VMX: Use a scaled host TSC for guest readings of MSR_IA32_TSC Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 10:00 +0200
  [PATCH v2 01/12] KVM: x86: Collect information for setting TSC scaling ratio Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 10:00 +0200
  [PATCH v2 05/12] KVM: x86: Replace call-back compute_tsc_offset() with a common function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 10:00 +0200
  [PATCH v2 04/12] KVM: x86: Replace call-back set_tsc_khz() with a common function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-20 10:00 +0200
  Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Joerg Roedel <joro@8bytes.org> - 2015-10-23 12:10 +0200
    Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-23 14:40 +0200
      Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Joerg Roedel <joro@8bytes.org> - 2015-10-23 14:50 +0200
        Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Paolo Bonzini <pbonzini@redhat.com> - 2015-10-23 15:00 +0200
          Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-23 16:40 +0200
        Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-23 15:00 +0200
  Re: [PATCH v2 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-10-23 16:40 +0200

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