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[PATCH 05/12] KVM: x86: Replace call-back compute_tsc_offset() with a common function

From Haozhong Zhang <haozhong.zhang@intel.com>
Newsgroups linux.kernel
Subject [PATCH 05/12] KVM: x86: Replace call-back compute_tsc_offset() with a common function
Date 2015-09-28 07:50 +0200
Message-ID <qdzu2-52B-7@gated-at.bofh.it> (permalink)
References <qdzkm-4Rn-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Both VMX and SVM calculate the tsc-offset in the same way, so this
patch removes the call-back compute_tsc_offset() and replaces it with a
common function kvm_compute_tsc_offset().

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
 arch/x86/include/asm/kvm_host.h |  1 -
 arch/x86/kvm/svm.c              | 10 ----------
 arch/x86/kvm/vmx.c              |  6 ------
 arch/x86/kvm/x86.c              | 15 ++++++++++++---
 4 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5a0c435..0bbb2a7 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -845,7 +845,6 @@ struct kvm_x86_ops {
 	u64 (*read_tsc_offset)(struct kvm_vcpu *vcpu);
 	void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset);
 
-	u64 (*compute_tsc_offset)(struct kvm_vcpu *vcpu, u64 target_tsc);
 	u64 (*read_l1_tsc)(struct kvm_vcpu *vcpu, u64 host_tsc);
 
 	void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d46dcf3..c49cd28 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1062,15 +1062,6 @@ static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool ho
 	mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
 }
 
-static u64 svm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
-{
-	u64 tsc;
-
-	tsc = kvm_scale_tsc(vcpu, rdtsc());
-
-	return target_tsc - tsc;
-}
-
 static void svm_set_guest_pat(struct vcpu_svm *svm, u64 *g_pat)
 {
 	struct kvm_vcpu *vcpu = &svm->vcpu;
@@ -4475,7 +4466,6 @@ static struct kvm_x86_ops svm_x86_ops = {
 	.read_tsc_offset = svm_read_tsc_offset,
 	.write_tsc_offset = svm_write_tsc_offset,
 	.adjust_tsc_offset = svm_adjust_tsc_offset,
-	.compute_tsc_offset = svm_compute_tsc_offset,
 	.read_l1_tsc = svm_read_l1_tsc,
 
 	.set_tdp_cr3 = set_tdp_cr3,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1751537..7a71191 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2299,11 +2299,6 @@ static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool ho
 					   offset + adjustment);
 }
 
-static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
-{
-	return target_tsc - rdtsc();
-}
-
 static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best = kvm_find_cpuid_entry(vcpu, 1, 0);
@@ -10367,7 +10362,6 @@ static struct kvm_x86_ops vmx_x86_ops = {
 	.read_tsc_offset = vmx_read_tsc_offset,
 	.write_tsc_offset = vmx_write_tsc_offset,
 	.adjust_tsc_offset = vmx_adjust_tsc_offset,
-	.compute_tsc_offset = vmx_compute_tsc_offset,
 	.read_l1_tsc = vmx_read_l1_tsc,
 
 	.set_tdp_cr3 = vmx_set_cr3,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e2e1fdb..7c372ad 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1418,6 +1418,15 @@ u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc)
 }
 EXPORT_SYMBOL_GPL(kvm_scale_tsc);
 
+static u64 kvm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
+{
+	u64 tsc;
+
+	tsc = kvm_scale_tsc(vcpu, rdtsc());
+
+	return target_tsc - tsc;
+}
+
 void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
 {
 	struct kvm *kvm = vcpu->kvm;
@@ -1429,7 +1438,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
 	u64 data = msr->data;
 
 	raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
-	offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
+	offset = kvm_compute_tsc_offset(vcpu, data);
 	ns = get_kernel_ns();
 	elapsed = ns - kvm->arch.last_tsc_nsec;
 
@@ -1486,7 +1495,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		} else {
 			u64 delta = nsec_to_cycles(vcpu, elapsed);
 			data += delta;
-			offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
+			offset = kvm_compute_tsc_offset(vcpu, data);
 			pr_debug("kvm: adjusted tsc offset by %llu\n", delta);
 		}
 		matched = true;
@@ -2720,7 +2729,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 		if (tsc_delta < 0)
 			mark_tsc_unstable("KVM discovered backwards TSC");
 		if (check_tsc_unstable()) {
-			u64 offset = kvm_x86_ops->compute_tsc_offset(vcpu,
+			u64 offset = kvm_compute_tsc_offset(vcpu,
 						vcpu->arch.last_guest_tsc);
 			kvm_x86_ops->write_tsc_offset(vcpu, offset);
 			vcpu->arch.tsc_catchup = 1;
-- 
2.4.8

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Thread

[PATCH 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:40 +0200
  [PATCH 07/12] KVM: x86: Move TSC scaling logic out of call-back read_l1_tsc() Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:40 +0200
  [PATCH 11/12] KVM: VMX: Use a scaled host TSC for guest readings of MSR_IA32_TSC Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:40 +0200
  [PATCH 06/12] KVM: x86: Move TSC scaling logic out of call-back adjust_tsc_offset() Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:40 +0200
    Re: [PATCH 06/12] KVM: x86: Move TSC scaling logic out of call-back  adjust_tsc_offset() Paolo Bonzini <pbonzini@redhat.com> - 2015-09-28 22:20 +0200
      Re: [PATCH 06/12] KVM: x86: Move TSC scaling logic out of call-back  adjust_tsc_offset() Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-29 03:50 +0200
  [PATCH 01/12] KVM: x86: Collect information for setting TSC scaling ratio Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:40 +0200
    Re: [PATCH 01/12] KVM: x86: Collect information for setting TSC  scaling ratio Eric Northup <digitaleric@google.com> - 2015-09-29 05:30 +0200
      Re: [PATCH 01/12] KVM: x86: Collect information for setting TSC  scaling ratio Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-29 06:10 +0200
  [PATCH 02/12] KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:50 +0200
    Re: [PATCH 02/12] KVM: x86: Add a common TSC scaling ratio field in  kvm_vcpu_arch Radim Krčmář <rkrcmar@redhat.com> - 2015-10-05 21:30 +0200
  [PATCH 08/12] KVM: x86: Use the correct vcpu's TSC rate to compute time scale Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:50 +0200
    Re: [PATCH 08/12] KVM: x86: Use the correct vcpu's TSC rate to  compute time scale Radim Krčmář <rkrcmar@redhat.com> - 2015-10-05 22:20 +0200
  [PATCH 05/12] KVM: x86: Replace call-back compute_tsc_offset() with a common function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:50 +0200
  [PATCH 03/12] KVM: x86: Add a common TSC scaling function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:50 +0200
    Re: [PATCH 03/12] KVM: x86: Add a common TSC scaling function Paolo Bonzini <pbonzini@redhat.com> - 2015-09-28 22:20 +0200
      Re: [PATCH 03/12] KVM: x86: Add a common TSC scaling function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-29 04:00 +0200
  [PATCH 10/12] KVM: VMX: Setup TSC scaling ratio when a vcpu is loaded Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:50 +0200
  [PATCH 04/12] KVM: x86: Replace call-back set_tsc_khz() with a common function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-28 07:50 +0200
    Re: [PATCH 04/12] KVM: x86: Replace call-back set_tsc_khz() with a  common function Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-29 05:50 +0200
    Re: [PATCH 04/12] KVM: x86: Replace call-back set_tsc_khz() with a  common function Radim Krčmář <rkrcmar@redhat.com> - 2015-10-05 22:00 +0200
      Re: [PATCH 04/12] KVM: x86: Replace call-back set_tsc_khz() with a  common function David Matlack <dmatlack@google.com> - 2015-10-05 22:50 +0200
  Re: [PATCH 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang <haozhong.zhang@intel.com> - 2015-09-29 06:10 +0200
  Re: [PATCH 00/12] KVM: x86: add support for VMX TSC scaling Eric Northup <digitaleric@google.com> - 2015-09-29 06:10 +0200

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