| Message ID | 1415847657-22178-1-git-send-email-chris.j.arges@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 13/11/2014 04:00, Chris J Arges wrote: > 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> > --- > arch/x86/kvm/svm.c | 8 +++++--- > 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 d4f3aaa..6b411ad 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 f85da5c..1cd1376 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2141,7 +2141,7 @@ 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; > Applied, thanks! Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 @@ 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 f85da5c..1cd1376 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2141,7 +2141,7 @@ 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;
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> --- arch/x86/kvm/svm.c | 8 +++++--- arch/x86/kvm/x86.c | 2 +- 2 files changed, 6 insertions(+), 4 deletions(-)