lkml.org 
[lkml]   [2011]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/6] KVM: X86: Let kvm-clock report the right tsc frequency
Date
This patch changes the kvm_guest_time_update function to use
TSC frequency the guest actually has for updating its clock.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/svm.c | 8 ++++++++
arch/x86/kvm/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 12 ++++++++++--
4 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ffd7f8d..9686950 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -592,6 +592,8 @@ struct kvm_x86_ops {

void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset);

+ bool (*use_virtual_tsc_khz)(struct kvm_vcpu *vcpu);
+
void (*get_exit_info)(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2);
const struct trace_print_flags *exit_reasons_str;
};
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c96c0a6..f51f757 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -905,6 +905,13 @@ static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment)
mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
}

+static bool svm_use_virtual_tsc_khz(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ return svm->tsc_scale.enabled;
+}
+
static void init_vmcb(struct vcpu_svm *svm)
{
struct vmcb_control_area *control = &svm->vmcb->control;
@@ -3976,6 +3983,7 @@ static struct kvm_x86_ops svm_x86_ops = {

.write_tsc_offset = svm_write_tsc_offset,
.adjust_tsc_offset = svm_adjust_tsc_offset,
+ .use_virtual_tsc_khz = svm_use_virtual_tsc_khz,

.set_tdp_cr3 = set_tdp_cr3,
};
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ae4f02d..c227a6b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1164,6 +1164,11 @@ static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment)
vmcs_write64(TSC_OFFSET, offset + adjustment);
}

+static bool vmx_use_virtual_tsc_khz(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
@@ -4443,6 +4448,7 @@ static struct kvm_x86_ops vmx_x86_ops = {

.write_tsc_offset = vmx_write_tsc_offset,
.adjust_tsc_offset = vmx_adjust_tsc_offset,
+ .use_virtual_tsc_khz = vmx_use_virtual_tsc_khz,

.set_tdp_cr3 = vmx_set_cr3,
};
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8575d85..597abc8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -979,6 +979,14 @@ static inline int kvm_tsc_changes_freq(void)
return ret;
}

+static u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
+{
+ if (kvm_x86_ops->use_virtual_tsc_khz(vcpu))
+ return vcpu->kvm->arch.virtual_tsc_khz;
+ else
+ return __this_cpu_read(cpu_tsc_khz);
+}
+
static inline u64 nsec_to_cycles(u64 nsec)
{
u64 ret;
@@ -1010,6 +1018,7 @@ static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
return tsc;
}

+
void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data)
{
struct kvm *kvm = vcpu->kvm;
@@ -1072,8 +1081,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
local_irq_save(flags);
kvm_get_msr(v, MSR_IA32_TSC, &tsc_timestamp);
kernel_ns = get_kernel_ns();
- this_tsc_khz = __this_cpu_read(cpu_tsc_khz);
-
+ this_tsc_khz = vcpu_tsc_khz(v);
if (unlikely(this_tsc_khz == 0)) {
local_irq_restore(flags);
kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
--
1.7.1



\
 
 \ /
  Last update: 2011-02-09 18:33    [from the cache]
©2003-2011 Jasper Spaans