With TSC scaling in SVM the tsc-offset needs to be
calculated differently. This patch propagates this
calculation into the architecture specific modules so that
this complexity can be handled there.
Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/svm.c | 10 ++++++++++
arch/x86/kvm/vmx.c | 6 ++++++
arch/x86/kvm/x86.c | 10 +++++-----
4 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9958dd8..7f48528 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -591,6 +591,8 @@ struct kvm_x86_ops {
void (*set_tsc_khz)(struct kvm_vcpu *vcpu, u32 user_tsc_khz);
void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset);
+ u64 (*compute_tsc_offset)(struct kvm_vcpu *vcpu, u64 target_tsc);
+
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 f6d66c2..38a4bcc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -954,6 +954,15 @@ static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment)
mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
}
+static u64 svm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
+{
+ u64 tsc;
+
+ tsc = svm_scale_tsc(vcpu, native_read_tsc());
+
+ return target_tsc - tsc;
+}
+
static void init_vmcb(struct vcpu_svm *svm)
{
struct vmcb_control_area *control = &svm->vmcb->control;
@@ -4039,6 +4048,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.set_tsc_khz = svm_set_tsc_khz,
.write_tsc_offset = svm_write_tsc_offset,
.adjust_tsc_offset = svm_adjust_tsc_offset,
+ .compute_tsc_offset = svm_compute_tsc_offset,
.set_tdp_cr3 = set_tdp_cr3,
};
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0e5dfc6..c4f077a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1184,6 +1184,11 @@ static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment)
vmcs_write64(TSC_OFFSET, offset + adjustment);
}
+static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
+{
+ return target_tsc - native_read_tsc();
+}
+
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
@@ -4509,6 +4514,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.set_tsc_khz = vmx_set_tsc_khz,
.write_tsc_offset = vmx_write_tsc_offset,
.adjust_tsc_offset = vmx_adjust_tsc_offset,
+ .compute_tsc_offset = vmx_compute_tsc_offset,
.set_tdp_cr3 = vmx_set_cr3,
};
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 47dd6ed..2f0b552 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -990,7 +990,7 @@ static u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
return __this_cpu_read(cpu_tsc_khz);
}
-static inline u64 nsec_to_cycles(u64 nsec)
+static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
{
u64 ret;
@@ -998,7 +998,7 @@ static inline u64 nsec_to_cycles(u64 nsec)
if (kvm_tsc_changes_freq())
printk_once(KERN_WARNING
"kvm: unreliable cycle conversion on adjustable rate TSC\n");
- ret = nsec * __this_cpu_read(cpu_tsc_khz);
+ ret = nsec * vcpu_tsc_khz(vcpu);
do_div(ret, USEC_PER_SEC);
return ret;
}
@@ -1028,7 +1028,7 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data)
s64 sdiff;
raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
- offset = data - native_read_tsc();
+ offset = kvm_x86_ops->compute_tsc_offset(vcpu, data);
ns = get_kernel_ns();
elapsed = ns - kvm->arch.last_tsc_nsec;
sdiff = data - kvm->arch.last_tsc_write;
@@ -1044,13 +1044,13 @@ void kvm_write_tsc(struct kvm_vcpu *vcpu, u64 data)
* In that case, for a reliable TSC, we can match TSC offsets,
* or make a best guest using elapsed value.
*/
- if (sdiff < nsec_to_cycles(5ULL * NSEC_PER_SEC) &&
+ if (sdiff < nsec_to_cycles(vcpu, 5ULL * NSEC_PER_SEC) &&
elapsed < 5ULL * NSEC_PER_SEC) {
if (!check_tsc_unstable()) {
offset = kvm->arch.last_tsc_offset;
pr_debug("kvm: matched tsc offset for %llu\n", data);
} else {
- u64 delta = nsec_to_cycles(elapsed);
+ u64 delta = nsec_to_cycles(vcpu, elapsed);
offset += delta;
pr_debug("kvm: adjusted tsc offset by %llu\n", delta);
}
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
