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, 6 insertions, 0 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e19c7a5473d5..aabe3334d064 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -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,