| Message ID | 20180622095101.32587-4-bp@alien8.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2018-06-22 11:51+0200, Borislav Petkov: > From: Borislav Petkov <bp@suse.de> > > Extend the range of MCA banks which get passed to set/get_msr_mce() to > include all the MSRs of the last bank too. > > Signed-off-by: Borislav Petkov <bp@suse.de> > --- > arch/x86/kvm/x86.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 80452b0f0e8c..a7d344823356 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -2466,7 +2466,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > > case MSR_IA32_MCG_CTL: > case MSR_IA32_MCG_STATUS: > - case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: > + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1: It was correct before. We have 32 banks (KVM_MAX_MCE_BANKS), so the last useable has index 31 and the "- 1" is going to roll over from first MSR of bank 32 to the last MSR of the last bank. Another way of writing it would be: case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS - 1): > return set_msr_mce(vcpu, msr_info); > > case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3: > @@ -2588,9 +2588,10 @@ static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) > case MSR_IA32_MCG_STATUS: > data = vcpu->arch.mcg_status; > break; > + > default: > if (msr >= MSR_IA32_MC0_CTL && > - msr < MSR_IA32_MCx_CTL(bank_num)) { > + msr < MSR_IA32_MCx_MISC(bank_num)) { Similar logic here. I think it would be best just to keep the current code, thanks.
On Fri, Jun 22, 2018 at 08:16:04PM +0200, Radim Krčmář wrote: > 2018-06-22 11:51+0200, Borislav Petkov: > > From: Borislav Petkov <bp@suse.de> > > > > Extend the range of MCA banks which get passed to set/get_msr_mce() to > > include all the MSRs of the last bank too. > > > > Signed-off-by: Borislav Petkov <bp@suse.de> > > --- > > arch/x86/kvm/x86.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 80452b0f0e8c..a7d344823356 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -2466,7 +2466,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > > > > case MSR_IA32_MCG_CTL: > > case MSR_IA32_MCG_STATUS: > > - case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: > > + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1: > > It was correct before. We have 32 banks (KVM_MAX_MCE_BANKS), so the > last useable has index 31 and the "- 1" is going to roll over from first > MSR of bank 32 to the last MSR of the last bank. > > Another way of writing it would be: > > case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS - 1): Huh? This is what I did: + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1: It needs to be MISC because it is the last MSR in the MCA bank and thus the highest.
2018-06-22 20:24+0200, Borislav Petkov: > On Fri, Jun 22, 2018 at 08:16:04PM +0200, Radim Krčmář wrote: > > 2018-06-22 11:51+0200, Borislav Petkov: > > > From: Borislav Petkov <bp@suse.de> > > > > > > Extend the range of MCA banks which get passed to set/get_msr_mce() to > > > include all the MSRs of the last bank too. > > > > > > Signed-off-by: Borislav Petkov <bp@suse.de> > > > --- > > > arch/x86/kvm/x86.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > > index 80452b0f0e8c..a7d344823356 100644 > > > --- a/arch/x86/kvm/x86.c > > > +++ b/arch/x86/kvm/x86.c > > > @@ -2466,7 +2466,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > > > > > > case MSR_IA32_MCG_CTL: > > > case MSR_IA32_MCG_STATUS: > > > - case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: > > > + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1: > > > > It was correct before. We have 32 banks (KVM_MAX_MCE_BANKS), so the > > last useable has index 31 and the "- 1" is going to roll over from first > > MSR of bank 32 to the last MSR of the last bank. > > > > Another way of writing it would be: > > > > case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS - 1): > > Huh? > > This is what I did: > > + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1: > > It needs to be MISC because it is the last MSR in the MCA bank and thus > the highest. The last MSR is the original "MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1". "MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1" also covers MSR_IA32_MC32_CTL, MSR_IA32_MC32_STATUS, and MSR_IA32_MC32_ADDR but the maximal valid MSR is MSR_IA32_MC31_MISC.
On Fri, Jun 22, 2018 at 08:47:48PM +0200, Radim Krčmář wrote: > The last MSR is the original "MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1". > > "MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1" also covers > > MSR_IA32_MC32_CTL, MSR_IA32_MC32_STATUS, and MSR_IA32_MC32_ADDR > > but the maximal valid MSR is MSR_IA32_MC31_MISC. Bah, right you are, MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1 *is* the last MSR of bank 31, yes. Pls ignore this patch.
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 80452b0f0e8c..a7d344823356 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2466,7 +2466,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) case MSR_IA32_MCG_CTL: case MSR_IA32_MCG_STATUS: - case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_MISC(KVM_MAX_MCE_BANKS) - 1: return set_msr_mce(vcpu, msr_info); case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3: @@ -2588,9 +2588,10 @@ static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) case MSR_IA32_MCG_STATUS: data = vcpu->arch.mcg_status; break; + default: if (msr >= MSR_IA32_MC0_CTL && - msr < MSR_IA32_MCx_CTL(bank_num)) { + msr < MSR_IA32_MCx_MISC(bank_num)) { u32 offset = msr - MSR_IA32_MC0_CTL; data = vcpu->arch.mce_banks[offset]; break;