KVM: x86: Convert TSC writes to TSC offset writes

Change svm / vmx to be the same internally and write TSC offset
instead of bare TSC in helper functions.  Isolated as a single
patch to contain code movement.

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 22:07:16 -10:00 committed by Avi Kivity
parent ae38436b78
commit f4e1b3c8bd
2 changed files with 22 additions and 20 deletions

View file

@ -701,6 +701,20 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type)
seg->base = 0;
}
static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
{
struct vcpu_svm *svm = to_svm(vcpu);
u64 g_tsc_offset = 0;
if (is_nested(svm)) {
g_tsc_offset = svm->vmcb->control.tsc_offset -
svm->nested.hsave->control.tsc_offset;
svm->nested.hsave->control.tsc_offset = offset;
}
svm->vmcb->control.tsc_offset = offset + g_tsc_offset;
}
static void init_vmcb(struct vcpu_svm *svm)
{
struct vmcb_control_area *control = &svm->vmcb->control;
@ -901,7 +915,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
svm->asid_generation = 0;
init_vmcb(svm);
svm->vmcb->control.tsc_offset = 0-native_read_tsc();
svm_write_tsc_offset(&svm->vcpu, 0-native_read_tsc());
err = fx_init(&svm->vcpu);
if (err)
@ -2566,20 +2580,9 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
struct vcpu_svm *svm = to_svm(vcpu);
switch (ecx) {
case MSR_IA32_TSC: {
u64 tsc_offset = data - native_read_tsc();
u64 g_tsc_offset = 0;
if (is_nested(svm)) {
g_tsc_offset = svm->vmcb->control.tsc_offset -
svm->nested.hsave->control.tsc_offset;
svm->nested.hsave->control.tsc_offset = tsc_offset;
}
svm->vmcb->control.tsc_offset = tsc_offset + g_tsc_offset;
case MSR_IA32_TSC:
svm_write_tsc_offset(vcpu, data - native_read_tsc());
break;
}
case MSR_STAR:
svm->vmcb->save.star = data;
break;

View file

@ -1149,9 +1149,9 @@ static u64 guest_read_tsc(void)
* writes 'guest_tsc' into guest's timestamp counter "register"
* guest_tsc = host_tsc + tsc_offset ==> tsc_offset = guest_tsc - host_tsc
*/
static void guest_write_tsc(u64 guest_tsc, u64 host_tsc)
static void vmx_write_tsc_offset(u64 offset)
{
vmcs_write64(TSC_OFFSET, guest_tsc - host_tsc);
vmcs_write64(TSC_OFFSET, offset);
}
/*
@ -1255,7 +1255,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
break;
case MSR_IA32_TSC:
rdtscll(host_tsc);
guest_write_tsc(data, host_tsc);
vmx_write_tsc_offset(data - host_tsc);
break;
case MSR_IA32_CR_PAT:
if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
@ -2512,7 +2512,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
{
u32 host_sysenter_cs, msr_low, msr_high;
u32 junk;
u64 host_pat, tsc_this;
u64 host_pat;
unsigned long a;
struct desc_ptr dt;
int i;
@ -2653,8 +2653,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
vmx->vcpu.arch.cr4_guest_owned_bits |= X86_CR4_PGE;
vmcs_writel(CR4_GUEST_HOST_MASK, ~vmx->vcpu.arch.cr4_guest_owned_bits);
tsc_this = native_read_tsc();
guest_write_tsc(0, tsc_this);
vmx_write_tsc_offset(0-native_read_tsc());
return 0;
}