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KVM: x86: Unify TSC logic

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Move the TSC control logic from the vendor backends into x86.c
by adding adjust_tsc_offset to x86 ops.  Now all TSC decisions
can be done in one place.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Zachary Amsden 2010-08-19 22:07:23 -10:00 committed by Avi Kivity
parent 6755bae8e6
commit e48672fa25
4 changed files with 35 additions and 35 deletions
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5
arch/x86/include/asm/kvm_host.h
View File

@ -255,7 +255,6 @@ struct kvm_mmu {
};
struct kvm_vcpu_arch {
u64 host_tsc;
/*
* rip and regs accesses must go through
* kvm_{register,rip}_{read,write} functions.
@ -336,9 +335,10 @@ struct kvm_vcpu_arch {
gpa_t time;
struct pvclock_vcpu_time_info hv_clock;
unsigned int hv_clock_tsc_khz;
unsigned int hw_tsc_khz;
unsigned int time_offset;
struct page *time_page;
u64 last_host_tsc;
bool nmi_pending;
bool nmi_injected;
@ -520,6 +520,7 @@ struct kvm_x86_ops {
u64 (*get_mt_mask)(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio);
int (*get_lpage_level)(void);
bool (*rdtscp_supported)(void);
void (*adjust_tsc_offset)(struct kvm_vcpu *vcpu, s64 adjustment);
void (*set_supported_cpuid)(u32 func, struct kvm_cpuid_entry2 *entry);

26
arch/x86/kvm/svm.c
View File

@ -715,6 +715,15 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
svm->vmcb->control.tsc_offset = offset + g_tsc_offset;
}
static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment)
{
struct vcpu_svm *svm = to_svm(vcpu);
svm->vmcb->control.tsc_offset += adjustment;
if (is_nested(svm))
svm->nested.hsave->control.tsc_offset += adjustment;
}
static void init_vmcb(struct vcpu_svm *svm)
{
struct vmcb_control_area *control = &svm->vmcb->control;
@ -961,20 +970,6 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
int i;
if (unlikely(cpu != vcpu->cpu)) {
u64 delta;
if (check_tsc_unstable()) {
/*
* Make sure that the guest sees a monotonically
* increasing TSC.
*/
delta = vcpu->arch.host_tsc - native_read_tsc();
svm->vmcb->control.tsc_offset += delta;
if (is_nested(svm))
svm->nested.hsave->control.tsc_offset += delta;
}
vcpu->cpu = cpu;
kvm_migrate_timers(vcpu);
svm->asid_generation = 0;
}
@ -990,8 +985,6 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
++vcpu->stat.host_state_reload;
for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
vcpu->arch.host_tsc = native_read_tsc();
}
static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu)
@ -3553,6 +3546,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.has_wbinvd_exit = svm_has_wbinvd_exit,
.write_tsc_offset = svm_write_tsc_offset,
.adjust_tsc_offset = svm_adjust_tsc_offset,
};
static int __init svm_init(void)

22
arch/x86/kvm/vmx.c
View File

@ -505,7 +505,6 @@ static void __vcpu_clear(void *arg)
vmcs_clear(vmx->vmcs);
if (per_cpu(current_vmcs, cpu) == vmx->vmcs)
per_cpu(current_vmcs, cpu) = NULL;
rdtscll(vmx->vcpu.arch.host_tsc);
list_del(&vmx->local_vcpus_link);
vmx->vcpu.cpu = -1;
vmx->launched = 0;
@ -881,7 +880,6 @@ static void vmx_load_host_state(struct vcpu_vmx *vmx)
static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u64 tsc_this, delta, new_offset;
u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
if (!vmm_exclusive)
@ -898,14 +896,12 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
unsigned long sysenter_esp;
kvm_migrate_timers(vcpu);
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
local_irq_disable();
list_add(&vmx->local_vcpus_link,
&per_cpu(vcpus_on_cpu, cpu));
local_irq_enable();
vcpu->cpu = cpu;
/*
* Linux uses per-cpu TSS and GDT, so set these when switching
* processors.
@ -915,16 +911,6 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
/*
* Make sure the time stamp counter is monotonous.
*/
rdtscll(tsc_this);
if (tsc_this < vcpu->arch.host_tsc) {
delta = vcpu->arch.host_tsc - tsc_this;
new_offset = vmcs_read64(TSC_OFFSET) + delta;
vmcs_write64(TSC_OFFSET, new_offset);
}
}
}
@ -1153,6 +1139,12 @@ static void vmx_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
vmcs_write64(TSC_OFFSET, offset);
}
static void vmx_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment)
{
u64 offset = vmcs_read64(TSC_OFFSET);
vmcs_write64(TSC_OFFSET, offset + adjustment);
}
/*
* Reads an msr value (of 'msr_index') into 'pdata'.
* Returns 0 on success, non-0 otherwise.
@ -4108,6 +4100,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
cpu = get_cpu();
vmx_vcpu_load(&vmx->vcpu, cpu);
vmx->vcpu.cpu = cpu;
err = vmx_vcpu_setup(vmx);
vmx_vcpu_put(&vmx->vcpu);
put_cpu();
@ -4347,6 +4340,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,
.write_tsc_offset = vmx_write_tsc_offset,
.adjust_tsc_offset = vmx_adjust_tsc_offset,
};
static int __init vmx_init(void)

17
arch/x86/kvm/x86.c
View File

@ -973,9 +973,9 @@ static int kvm_write_guest_time(struct kvm_vcpu *v)
return 1;
}
if (unlikely(vcpu->hv_clock_tsc_khz != this_tsc_khz)) {
if (unlikely(vcpu->hw_tsc_khz != this_tsc_khz)) {
kvm_set_time_scale(this_tsc_khz, &vcpu->hv_clock);
vcpu->hv_clock_tsc_khz = this_tsc_khz;
vcpu->hw_tsc_khz = this_tsc_khz;
}
/* With all the info we got, fill in the values */
@ -1866,13 +1866,24 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
}
kvm_x86_ops->vcpu_load(vcpu, cpu);
kvm_request_guest_time_update(vcpu);
if (unlikely(vcpu->cpu != cpu)) {
/* Make sure TSC doesn't go backwards */
s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
native_read_tsc() - vcpu->arch.last_host_tsc;
if (tsc_delta < 0)
mark_tsc_unstable("KVM discovered backwards TSC");
if (check_tsc_unstable())
kvm_x86_ops->adjust_tsc_offset(vcpu, -tsc_delta);
kvm_migrate_timers(vcpu);
vcpu->cpu = cpu;
}
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->vcpu_put(vcpu);
kvm_put_guest_fpu(vcpu);
vcpu->arch.last_host_tsc = native_read_tsc();
}
static int is_efer_nx(void)