KVM: x86: Move TSC offset writes to common code

Also, ensure that the storing of the offset and the reading of the TSC
are never preempted by taking a spinlock.  While the lock is overkill
now, it is useful later in this patch series.

Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e06f00d1f15c..ea41c551fa44 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -915,7 +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_write_tsc_offset(&svm->vcpu, 0-native_read_tsc());
+        kvm_write_tsc(&svm->vcpu, 0);
 
         err = fx_init(&svm->vcpu);
         if (err)
@@ -2581,7 +2581,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
 
         switch (ecx) {
         case MSR_IA32_TSC:
-                svm_write_tsc_offset(vcpu, data - native_read_tsc());
+                kvm_write_tsc(vcpu, data);
                 break;
         case MSR_STAR:
                 svm->vmcb->save.star = data;
@@ -3551,6 +3551,8 @@ static struct kvm_x86_ops svm_x86_ops = {
         .set_supported_cpuid = svm_set_supported_cpuid,
 
         .has_wbinvd_exit = svm_has_wbinvd_exit,
+
+        .write_tsc_offset = svm_write_tsc_offset,
 };
 
 static int __init svm_init(void)