[PATCH 02/12] KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch

From: Haozhong Zhang
Date: Mon Sep 28 2015 - 01:43:01 EST


This patch moves the field of TSC scaling ratio from the architecture
struct vcpu_svm to the common struct kvm_vcpu_arch.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm.c | 23 +++++++++--------------
arch/x86/kvm/x86.c | 3 +++
3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5b9b86e..4f32c68 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -500,6 +500,7 @@ struct kvm_vcpu_arch {
u32 virtual_tsc_mult;
u32 virtual_tsc_khz;
s64 ia32_tsc_adjust_msr;
+ u64 tsc_scaling_ratio;

atomic_t nmi_queued; /* unprocessed asynchronous NMIs */
unsigned nmi_pending; /* NMI queued after currently running handler */
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index eff7db7..a3186e2 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -157,8 +157,6 @@ struct vcpu_svm {
unsigned int3_injected;
unsigned long int3_rip;
u32 apf_reason;
-
- u64 tsc_ratio;
};

static DEFINE_PER_CPU(u64, current_tsc_ratio);
@@ -1049,24 +1047,22 @@ static u64 __scale_tsc(u64 ratio, u64 tsc)

static u64 svm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc)
{
- struct vcpu_svm *svm = to_svm(vcpu);
u64 _tsc = tsc;

- if (svm->tsc_ratio != TSC_RATIO_DEFAULT)
- _tsc = __scale_tsc(svm->tsc_ratio, tsc);
+ if (vcpu->arch.tsc_scaling_ratio != TSC_RATIO_DEFAULT)
+ _tsc = __scale_tsc(vcpu->arch.tsc_scaling_ratio, tsc);

return _tsc;
}

static void svm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
{
- struct vcpu_svm *svm = to_svm(vcpu);
u64 ratio;
u64 khz;

/* Guest TSC same frequency as host TSC? */
if (!scale) {
- svm->tsc_ratio = TSC_RATIO_DEFAULT;
+ vcpu->arch.tsc_scaling_ratio = TSC_RATIO_DEFAULT;
return;
}

@@ -1091,7 +1087,7 @@ static void svm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
user_tsc_khz);
return;
}
- svm->tsc_ratio = ratio;
+ vcpu->arch.tsc_scaling_ratio = ratio;
}

static u64 svm_read_tsc_offset(struct kvm_vcpu *vcpu)
@@ -1125,7 +1121,7 @@ static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool ho
struct vcpu_svm *svm = to_svm(vcpu);

if (host) {
- if (svm->tsc_ratio != TSC_RATIO_DEFAULT)
+ if (vcpu->arch.tsc_scaling_ratio != TSC_RATIO_DEFAULT)
WARN_ON(adjustment < 0);
adjustment = svm_scale_tsc(vcpu, (u64)adjustment);
}
@@ -1335,8 +1331,6 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
goto out;
}

- svm->tsc_ratio = TSC_RATIO_DEFAULT;
-
err = kvm_vcpu_init(&svm->vcpu, kvm, id);
if (err)
goto free_svm;
@@ -1406,6 +1400,7 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
int i;
+ u64 tsc_ratio = vcpu->arch.tsc_scaling_ratio;

if (unlikely(cpu != vcpu->cpu)) {
svm->asid_generation = 0;
@@ -1423,9 +1418,9 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);

if (static_cpu_has(X86_FEATURE_TSCRATEMSR) &&
- svm->tsc_ratio != __this_cpu_read(current_tsc_ratio)) {
- __this_cpu_write(current_tsc_ratio, svm->tsc_ratio);
- wrmsrl(MSR_AMD64_TSC_RATIO, svm->tsc_ratio);
+ tsc_ratio != __this_cpu_read(current_tsc_ratio)) {
+ __this_cpu_write(current_tsc_ratio, tsc_ratio);
+ wrmsrl(MSR_AMD64_TSC_RATIO, tsc_ratio);
}
}

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f888225..4a521b4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7080,6 +7080,9 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,

vcpu = kvm_x86_ops->vcpu_create(kvm, id);

+ if (!IS_ERR(vcpu))
+ vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
+
return vcpu;
}

--
2.4.8

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