[Devel] [PATCH RHEL7 COMMIT] ms/KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Nov 16 04:45:54 PST 2016
The commit is pushed to "branch-rh7-3.10.0-327.36.1.vz7.19.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.36.1.vz7.19.9
------>
commit ee1d42e13b1bbef0b338e62e9539d118bc16921a
Author: Haozhong Zhang <haozhong.zhang at intel.com>
Date: Wed Nov 16 16:45:54 2016 +0400
ms/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 at intel.com>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
(cherry-picked from commit ad721883e9c5f46cc5fa9496bc12c097c6238b4a)
Signed-off-by: Denis Plotnikov <dplotnikov at virtuozzo.com>
Signed-off-by: Roman Kagan <rkagan at virtuozzo.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm.c | 27 +++++++++++++--------------
arch/x86/kvm/x86.c | 18 ++++++++++++++++--
3 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e4cff52..44ff862 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -496,6 +496,7 @@ 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 71b7c57..c613f6e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -158,7 +158,8 @@ struct vcpu_svm {
unsigned long int3_rip;
u32 apf_reason;
- u64 tsc_ratio;
+ /* cached guest cpuid flags for faster access */
+ bool nrips_enabled : 1;
};
static DEFINE_PER_CPU(u64, current_tsc_ratio);
@@ -987,24 +988,22 @@ 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;
}
@@ -1029,7 +1028,7 @@ 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)
@@ -1063,7 +1062,7 @@ 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);
}
@@ -1231,8 +1230,6 @@ 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;
@@ -1323,10 +1320,12 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
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 != __get_cpu_var(current_tsc_ratio)) {
- __get_cpu_var(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 e911037..e348b4f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -112,6 +112,7 @@ u8 __read_mostly kvm_tsc_scaling_ratio_frac_bits;
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;
@@ -1236,8 +1237,11 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz)
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,
@@ -7466,7 +7470,17 @@ void kvm_arch_hardware_disable(void)
int kvm_arch_hardware_setup(void)
{
- return kvm_x86_ops->hardware_setup();
+ int r;
+
+ r = kvm_x86_ops->hardware_setup();
+ 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;
}
void kvm_arch_hardware_unsetup(void)
More information about the Devel
mailing list