[PATCH v2 5/5] KVM/x86: Return -errno instead of "1" for SVM related MSR emulation
From: Juergen Gross
Date: Thu May 28 2026 - 07:21:22 EST
Instead of a literal "1" for signalling an error, use a negative errno
value in the emulation code of SVM related MSR registers.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V2:
- use -errno instead of KVM_MSR_RET_ERR
---
arch/x86/kvm/svm/pmu.c | 4 ++--
arch/x86/kvm/svm/svm.c | 36 ++++++++++++++++++------------------
2 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 7aa298eeb072..1c325d602baa 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -144,7 +144,7 @@ static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 0;
}
- return 1;
+ return -EINVAL;
}
static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
@@ -173,7 +173,7 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 0;
}
- return 1;
+ return -EINVAL;
}
static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index e02a38da5296..f8d9df822ab3 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2791,7 +2791,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_AMD64_TSC_RATIO:
if (!msr_info->host_initiated &&
!guest_cpu_cap_has(vcpu, X86_FEATURE_TSCRATEMSR))
- return 1;
+ return -EINVAL;
msr_info->data = svm->tsc_ratio_msr;
break;
case MSR_STAR:
@@ -2860,7 +2860,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_SPEC_CTRL:
if (!msr_info->host_initiated &&
!guest_has_spec_ctrl_msr(vcpu))
- return 1;
+ return -EINVAL;
if (boot_cpu_has(X86_FEATURE_V_SPEC_CTRL))
msr_info->data = svm->vmcb->save.spec_ctrl;
@@ -2870,7 +2870,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_AMD64_VIRT_SPEC_CTRL:
if (!msr_info->host_initiated &&
!guest_cpu_cap_has(vcpu, X86_FEATURE_VIRT_SSBD))
- return 1;
+ return -EINVAL;
msr_info->data = svm->virt_spec_ctrl;
break;
@@ -2907,7 +2907,7 @@ static int svm_complete_emulated_msr(struct kvm_vcpu *vcpu, int err)
return kvm_complete_insn_gp(vcpu, err);
svm_vmgexit_inject_exception(svm, X86_TRAP_GP);
- return 1;
+ return -EINVAL;
}
static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data)
@@ -2916,7 +2916,7 @@ static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data)
int svm_dis, chg_mask;
if (data & ~SVM_VM_CR_VALID_MASK)
- return 1;
+ return -EINVAL;
chg_mask = SVM_VM_CR_VALID_MASK;
@@ -2930,7 +2930,7 @@ static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data)
/* check for svm_disable while efer.svme is set */
if (svm_dis && (vcpu->arch.efer & EFER_SVME))
- return 1;
+ return -EINVAL;
return 0;
}
@@ -2952,7 +2952,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
if (!guest_cpu_cap_has(vcpu, X86_FEATURE_TSCRATEMSR)) {
if (!msr->host_initiated)
- return 1;
+ return -EINVAL;
/*
* In case TSC scaling is not enabled, always
* leave this MSR at the default value.
@@ -2962,12 +2962,12 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
* Ignore this value as well.
*/
if (data != 0 && data != svm->tsc_ratio_msr)
- return 1;
+ return -EINVAL;
break;
}
if (data & SVM_TSC_RATIO_RSVD)
- return 1;
+ return -EINVAL;
svm->tsc_ratio_msr = data;
@@ -2989,10 +2989,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
case MSR_IA32_SPEC_CTRL:
if (!msr->host_initiated &&
!guest_has_spec_ctrl_msr(vcpu))
- return 1;
+ return -EINVAL;
if (kvm_spec_ctrl_test_value(data))
- return 1;
+ return -EINVAL;
if (boot_cpu_has(X86_FEATURE_V_SPEC_CTRL))
svm->vmcb->save.spec_ctrl = data;
@@ -3017,10 +3017,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
case MSR_AMD64_VIRT_SPEC_CTRL:
if (!msr->host_initiated &&
!guest_cpu_cap_has(vcpu, X86_FEATURE_VIRT_SSBD))
- return 1;
+ return -EINVAL;
if (data & ~SPEC_CTRL_SSBD)
- return 1;
+ return -EINVAL;
svm->virt_spec_ctrl = data;
break;
@@ -3115,7 +3115,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
}
if (data & DEBUGCTL_RESERVED_BITS)
- return 1;
+ return -EINVAL;
if (svm->vmcb->save.dbgctl == data)
break;
@@ -3131,7 +3131,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
if (!lbrv)
return KVM_MSR_RET_UNSUPPORTED;
if (!msr->host_initiated)
- return 1;
+ return -EINVAL;
*svm_vmcb_lbr(svm, ecx) = data;
vmcb_mark_dirty(svm->vmcb, VMCB_LBR);
break;
@@ -3143,7 +3143,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
* originating from those kernels.
*/
if (!msr->host_initiated && !page_address_valid(vcpu, data))
- return 1;
+ return -EINVAL;
svm->nested.hsave_msr = data & PAGE_MASK;
break;
@@ -3156,10 +3156,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
u64 supported_de_cfg;
if (svm_get_feature_msr(ecx, &supported_de_cfg))
- return 1;
+ return -EINVAL;
if (data & ~supported_de_cfg)
- return 1;
+ return -EINVAL;
svm->msr_decfg = data;
break;
--
2.54.0