diff options
| author | Chris J Arges <chris.j.arges@canonical.com> | 2014-11-12 21:00:39 -0600 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-11-13 11:56:11 +0100 |
| commit | d913b904355721e0aabb28dc8be2a3121de2e794 (patch) | |
| tree | 35312a4baa8932ed0522725c5d7a980fcc60b64f | |
| parent | 54b98bff8ef4ccfc6f638c5ed868d2d51cdde585 (diff) | |
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>
| -rw-r--r-- | arch/x86/kvm/svm.c | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
2 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index d4f3aaa2df7..6b411add23b 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1056,9 +1056,11 @@ static void svm_adjust_tsc_offset(struct kvm_vcpu *vcpu, s64 adjustment, bool ho { 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)) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index aae5969370d..a8f53a6960f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2143,7 +2143,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_TSC_ADJUST: if (guest_cpuid_has_tsc_adjust(vcpu)) { if (!msr_info->host_initiated) { - u64 adj = data - vcpu->arch.ia32_tsc_adjust_msr; + s64 adj = data - vcpu->arch.ia32_tsc_adjust_msr; kvm_x86_ops->adjust_tsc_offset(vcpu, adj, true); } vcpu->arch.ia32_tsc_adjust_msr = data; |