KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch
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@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5333767..f3354bd 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -505,6 +505,7 @@
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 74712ea..9c92e6f 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -158,8 +158,6 @@
unsigned long int3_rip;
u32 apf_reason;
- u64 tsc_ratio;
-
/* cached guest cpuid flags for faster access */
bool nrips_enabled : 1;
};
@@ -991,24 +989,22 @@
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;
}
@@ -1033,7 +1029,7 @@
user_tsc_khz);
return;
}
- svm->tsc_ratio = ratio;
+ vcpu->arch.tsc_scaling_ratio = ratio;
}
static u64 svm_read_tsc_offset(struct kvm_vcpu *vcpu)
@@ -1067,7 +1063,7 @@
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);
}
@@ -1238,8 +1234,6 @@
goto out;
}
- svm->tsc_ratio = TSC_RATIO_DEFAULT;
-
err = kvm_vcpu_init(&svm->vcpu, kvm, id);
if (err)
goto free_svm;
@@ -1325,10 +1319,12 @@
for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
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);
+ if (static_cpu_has(X86_FEATURE_TSCRATEMSR)) {
+ u64 tsc_ratio = vcpu->arch.tsc_scaling_ratio;
+ if (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 e728c53..ef5b9d6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -113,6 +113,7 @@
EXPORT_SYMBOL_GPL(kvm_tsc_scaling_ratio_frac_bits);
u64 __read_mostly kvm_max_tsc_scaling_ratio;
EXPORT_SYMBOL_GPL(kvm_max_tsc_scaling_ratio);
+static u64 __read_mostly kvm_default_tsc_scaling_ratio;
/* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
static u32 __read_mostly tsc_tolerance_ppm = 250;
@@ -1258,8 +1259,11 @@
int use_scaling = 0;
/* tsc_khz can be zero if TSC calibration fails */
- if (this_tsc_khz == 0)
+ if (this_tsc_khz == 0) {
+ /* set tsc_scaling_ratio to a safe value */
+ vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
return;
+ }
/* Compute a scale to convert nanoseconds in TSC cycles */
kvm_get_time_scale(this_tsc_khz, NSEC_PER_SEC / 1000,
@@ -7367,6 +7371,9 @@
if (r != 0)
return r;
+ if (kvm_has_tsc_control)
+ kvm_default_tsc_scaling_ratio = 1ULL << kvm_tsc_scaling_ratio_frac_bits;
+
kvm_init_msr_list();
return 0;
}