| Message ID | 20201105153932.24316-1-pankaj.gupta.linux@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: handle MSR_IA32_DEBUGCTLMSR with report_ignored_msrs | expand |
On 05/11/20 16:39, Pankaj Gupta wrote: > From: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> > > Guest tries to enable LBR (last branch/interrupt/exception) repeatedly, > thus spamming the host kernel logs. As MSR_IA32_DEBUGCTLMSR is not emulated by > KVM, its better to add the error log only with "report_ignored_msrs". > > Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> > --- > arch/x86/kvm/x86.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index f5ede41bf9e6..99c69ae43c69 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3063,9 +3063,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > /* Values other than LBR and BTF are vendor-specific, > thus reserved and should throw a #GP */ > return 1; > - } > - vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", > - __func__, data); > + } else if (report_ignored_msrs) > + vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", > + __func__, data); > break; > case 0x200 ... 0x2ff: > return kvm_mtrr_set_msr(vcpu, msr, data); > Which guest it is? (Patch queued, but I'd like to have a better description). Paolo
> > Guest tries to enable LBR (last branch/interrupt/exception) repeatedly, > > thus spamming the host kernel logs. As MSR_IA32_DEBUGCTLMSR is not emulated by > > KVM, its better to add the error log only with "report_ignored_msrs". > > > > Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> > > --- > > arch/x86/kvm/x86.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index f5ede41bf9e6..99c69ae43c69 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -3063,9 +3063,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > > /* Values other than LBR and BTF are vendor-specific, > > thus reserved and should throw a #GP */ > > return 1; > > - } > > - vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", > > - __func__, data); > > + } else if (report_ignored_msrs) > > + vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", > > + __func__, data); > > break; > > case 0x200 ... 0x2ff: > > return kvm_mtrr_set_msr(vcpu, msr, data); > > > > Which guest it is? (Patch queued, but I'd like to have a better > description). How about this? Windows2016 guest tries to enable LBR (last branch/interrupt/exception) by setting MSR_IA32_DEBUGCTLMSR. KVM does not emulate MSR_IA32_DEBUGCTLMSR and spams the host kernel logs with the below error messages.This patch fixes this by enabling error logging only with 'report_ignored_msrs'. "kvm []: vcpu1, guest rIP: 0xfffff800a8b687d3 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop" Thanks, Pankaj > > Paolo >
On 05/11/20 19:58, Pankaj Gupta wrote: > Windows2016 guest tries to enable LBR (last > branch/interrupt/exception) by setting > MSR_IA32_DEBUGCTLMSR. KVM does not emulate MSR_IA32_DEBUGCTLMSR and > spams the host kernel logs with the below error messages.This patch > fixes this by enabling > error logging only with 'report_ignored_msrs'. > > "kvm []: vcpu1, guest rIP: 0xfffff800a8b687d3 kvm_set_msr_common: > MSR_IA32_DEBUGCTLMSR 0x1, nop" Sounds good, thanks. Paolo
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f5ede41bf9e6..99c69ae43c69 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3063,9 +3063,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) /* Values other than LBR and BTF are vendor-specific, thus reserved and should throw a #GP */ return 1; - } - vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", - __func__, data); + } else if (report_ignored_msrs) + vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", + __func__, data); break; case 0x200 ... 0x2ff: return kvm_mtrr_set_msr(vcpu, msr, data);