kvm: svm: move WARN_ON in svm_adjust_tsc_offset
When running the tsc_adjust kvm-unit-test on an AMD processor with the
IA32_TSC_ADJUST feature enabled, the WARN_ON in svm_adjust_tsc_offset can be
triggered. This WARN_ON checks for a negative adjustment in case __scale_tsc
is called; however it may trigger unnecessary warnings.
This patch moves the WARN_ON to trigger only if __scale_tsc will actually be
called from svm_adjust_tsc_offset. In addition make adj in kvm_set_msr_common
s64 since this can have signed values.
Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d4f3aaa..6b411ad 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1056,9 +1056,11 @@
{
struct vcpu_svm *svm = to_svm(vcpu);
- WARN_ON(adjustment < 0);
- if (host)
- adjustment = svm_scale_tsc(vcpu, adjustment);
+ if (host) {
+ if (svm->tsc_ratio != TSC_RATIO_DEFAULT)
+ WARN_ON(adjustment < 0);
+ adjustment = svm_scale_tsc(vcpu, (u64)adjustment);
+ }
svm->vmcb->control.tsc_offset += adjustment;
if (is_guest_mode(vcpu))