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>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index a39fde4f5fe8..8c4549bef4ed 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -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,