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KVM: X86: Delegate tsc-offset calculation to architecture code 

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@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
hifive-unleashed-5.1
Joerg Roedel 2011-03-25 09:44:50 +01:00 committed by Avi Kivity
parent 4051b18801
commit 857e40999e
4 changed files with 23 additions and 5 deletions
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2
arch/x86/include/asm/kvm_host.h
View File

@ -609,6 +609,8 @@ 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);
int (*check_intercept)(struct kvm_vcpu *vcpu,

10
arch/x86/kvm/svm.c
View File

@ -943,6 +943,15 @@ 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;
@ -4194,6 +4203,7 @@ 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,

6
arch/x86/kvm/vmx.c
View File

@ -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.
@ -4510,6 +4515,7 @@ 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,

10
arch/x86/kvm/x86.c
View File

@ -977,7 +977,7 @@ 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;
@ -985,7 +985,7 @@ 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;
}
@ -1015,7 +1015,7 @@ 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;
@ -1031,13 +1031,13 @@ 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);
}