[PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value

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* [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value
@ 2026-05-28 11:13 Juergen Gross
  2026-05-28 11:13 ` [PATCH v2 4/5] KVM/x86: Return -errno instead of "1" for VMX related MSR emulation Juergen Gross
  2026-05-28 11:35 ` [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value Juergen Gross
  0 siblings, 2 replies; 3+ messages in thread
From: Juergen Gross @ 2026-05-28 11:13 UTC (permalink / raw)
  To: linux-kernel, x86, kvm, linux-coco
  Cc: Juergen Gross, Sean Christopherson, Paolo Bonzini,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
	H. Peter Anvin, Vitaly Kuznetsov, Kiryl Shutsemau, Rick Edgecombe

Get rid of the literal "1" used as general error return value in KVM
MSR emulation. It can easily be replaced by negative errno values
instead.

This is meant to avoid confusion with the literal "1" used as return
value for "return to guest".

Changes in V2:
- series carved out from initial "KVM: Avoid literal numbers as return
  values" series
- don't use new KVM_MSR_RET_* defines, but 0 and -errno

Juergen Gross (5):
  KVM/x86: Change comment before KVM_MSR_RET_* defines
  KVM/x86: Return -errno instead of "1" for APIC related MSR emulation
  KVM/x86: Return -errno instead of "1" for Hyper-V related MSR
    emulation
  KVM/x86: Return -errno instead of "1" for VMX related MSR emulation
  KVM/x86: Return -errno instead of "1" for SVM related MSR emulation

 arch/x86/kvm/hyperv.c        | 72 +++++++++++++--------------
 arch/x86/kvm/lapic.c         | 39 +++++++--------
 arch/x86/kvm/svm/pmu.c       |  4 +-
 arch/x86/kvm/svm/svm.c       | 36 +++++++-------
 arch/x86/kvm/vmx/nested.c    |  2 +-
 arch/x86/kvm/vmx/pmu_intel.c | 16 +++---
 arch/x86/kvm/vmx/tdx.c       | 10 ++--
 arch/x86/kvm/vmx/vmx.c       | 96 ++++++++++++++++++------------------
 arch/x86/kvm/x86.h           |  4 +-
 9 files changed, 139 insertions(+), 140 deletions(-)

-- 
2.54.0


^ permalink raw reply	[flat|nested] 3+ messages in thread

* [PATCH v2 4/5] KVM/x86: Return -errno instead of "1" for VMX related MSR emulation
  2026-05-28 11:13 [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value Juergen Gross
@ 2026-05-28 11:13 ` Juergen Gross
  2026-05-28 11:35 ` [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value Juergen Gross
  1 sibling, 0 replies; 3+ messages in thread
From: Juergen Gross @ 2026-05-28 11:13 UTC (permalink / raw)
  To: linux-kernel, x86, kvm, linux-coco
  Cc: Juergen Gross, Sean Christopherson, Paolo Bonzini,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
	H. Peter Anvin, Kiryl Shutsemau, Rick Edgecombe

Instead of a literal "1" for signalling an error, use a negative errno
value in the emulation code of VMX related MSR registers.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- use -errno instead of KVM_MSR_RET_ERR
---
 arch/x86/kvm/vmx/nested.c    |  2 +-
 arch/x86/kvm/vmx/pmu_intel.c | 16 +++---
 arch/x86/kvm/vmx/tdx.c       | 10 ++--
 arch/x86/kvm/vmx/vmx.c       | 96 ++++++++++++++++++------------------
 4 files changed, 62 insertions(+), 62 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3fe88f29be7a..2236f15ffab2 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1611,7 +1611,7 @@ int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32 msr_index, u64 *pdata)
 		*pdata = msrs->vmfunc_controls;
 		break;
 	default:
-		return 1;
+		return -EINVAL;
 	}
 
 	return 0;
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 27eb76e6b6a0..4f7e354c4b50 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -362,7 +362,7 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		} else if (intel_pmu_handle_lbr_msrs_access(vcpu, msr_info, true)) {
 			break;
 		}
-		return 1;
+		return -EINVAL;
 	}
 
 	return 0;
@@ -379,14 +379,14 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	switch (msr) {
 	case MSR_CORE_PERF_FIXED_CTR_CTRL:
 		if (data & pmu->fixed_ctr_ctrl_rsvd)
-			return 1;
+			return -EINVAL;
 
 		if (pmu->fixed_ctr_ctrl != data)
 			reprogram_fixed_counters(pmu, data);
 		break;
 	case MSR_IA32_PEBS_ENABLE:
 		if (data & pmu->pebs_enable_rsvd)
-			return 1;
+			return -EINVAL;
 
 		if (pmu->pebs_enable != data) {
 			diff = pmu->pebs_enable ^ data;
@@ -396,13 +396,13 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_DS_AREA:
 		if (is_noncanonical_msr_address(data, vcpu))
-			return 1;
+			return -EINVAL;
 
 		pmu->ds_area = data;
 		break;
 	case MSR_PEBS_DATA_CFG:
 		if (data & pmu->pebs_data_cfg_rsvd)
-			return 1;
+			return -EINVAL;
 
 		pmu->pebs_data_cfg = data;
 		break;
@@ -411,7 +411,7 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		    (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {
 			if ((msr & MSR_PMC_FULL_WIDTH_BIT) &&
 			    (data & ~pmu->counter_bitmask[KVM_PMC_GP]))
-				return 1;
+				return -EINVAL;
 
 			if (!msr_info->host_initiated &&
 			    !(msr & MSR_PMC_FULL_WIDTH_BIT))
@@ -427,7 +427,7 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			    (pmu->raw_event_mask & HSW_IN_TX_CHECKPOINTED))
 				reserved_bits ^= HSW_IN_TX_CHECKPOINTED;
 			if (data & reserved_bits)
-				return 1;
+				return -EINVAL;
 
 			if (data != pmc->eventsel) {
 				pmc->eventsel = data;
@@ -439,7 +439,7 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			break;
 		}
 		/* Not a known PMU MSR. */
-		return 1;
+		return -EINVAL;
 	}
 
 	return 0;
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 04ce321ebdf3..acc3242af4f4 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -2158,12 +2158,12 @@ int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 		return 0;
 	case MSR_IA32_MCG_EXT_CTL:
 		if (!msr->host_initiated && !(vcpu->arch.mcg_cap & MCG_LMCE_P))
-			return 1;
+			return -EINVAL;
 		msr->data = vcpu->arch.mcg_ext_ctl;
 		return 0;
 	default:
 		if (!tdx_has_emulated_msr(msr->index))
-			return 1;
+			return -EACCES;
 
 		return kvm_get_msr_common(vcpu, msr);
 	}
@@ -2175,15 +2175,15 @@ int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 	case MSR_IA32_MCG_EXT_CTL:
 		if ((!msr->host_initiated && !(vcpu->arch.mcg_cap & MCG_LMCE_P)) ||
 		    (msr->data & ~MCG_EXT_CTL_LMCE_EN))
-			return 1;
+			return -EINVAL;
 		vcpu->arch.mcg_ext_ctl = msr->data;
 		return 0;
 	default:
 		if (tdx_is_read_only_msr(msr->index))
-			return 1;
+			return -EACCES;
 
 		if (!tdx_has_emulated_msr(msr->index))
-			return 1;
+			return -EACCES;
 
 		return kvm_set_msr_common(vcpu, msr);
 	}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b9103de01428..2eee599fca30 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2076,7 +2076,7 @@ int vmx_get_feature_msr(u32 msr, u64 *data)
 	switch (msr) {
 	case KVM_FIRST_EMULATED_VMX_MSR ... KVM_LAST_EMULATED_VMX_MSR:
 		if (!nested)
-			return 1;
+			return -EINVAL;
 		return vmx_get_vmx_msr(&vmcs_config.nested, msr, data);
 	default:
 		return KVM_MSR_RET_UNSUPPORTED;
@@ -2111,18 +2111,18 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_TSX_CTRL:
 		if (!msr_info->host_initiated &&
 		    !(vcpu->arch.arch_capabilities & ARCH_CAP_TSX_CTRL_MSR))
-			return 1;
+			return -EINVAL;
 		goto find_uret_msr;
 	case MSR_IA32_UMWAIT_CONTROL:
 		if (!msr_info->host_initiated && !vmx_has_waitpkg(vmx))
-			return 1;
+			return -EINVAL;
 
 		msr_info->data = vmx->msr_ia32_umwait_control;
 		break;
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr_info->host_initiated &&
 		    !guest_has_spec_ctrl_msr(vcpu))
-			return 1;
+			return -EINVAL;
 
 		msr_info->data = to_vmx(vcpu)->spec_ctrl;
 		break;
@@ -2139,14 +2139,14 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!kvm_mpx_supported() ||
 		    (!msr_info->host_initiated &&
 		     !guest_cpu_cap_has(vcpu, X86_FEATURE_MPX)))
-			return 1;
+			return -EINVAL;
 		msr_info->data = vmcs_read64(GUEST_BNDCFGS);
 		break;
 	case MSR_IA32_MCG_EXT_CTL:
 		if (!msr_info->host_initiated &&
 		    !(vmx->msr_ia32_feature_control &
 		      FEAT_CTL_LMCE_ENABLED))
-			return 1;
+			return -EINVAL;
 		msr_info->data = vcpu->arch.mcg_ext_ctl;
 		break;
 	case MSR_IA32_FEAT_CTL:
@@ -2155,16 +2155,16 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_SGXLEPUBKEYHASH0 ... MSR_IA32_SGXLEPUBKEYHASH3:
 		if (!msr_info->host_initiated &&
 		    !guest_cpu_cap_has(vcpu, X86_FEATURE_SGX_LC))
-			return 1;
+			return -EINVAL;
 		msr_info->data = to_vmx(vcpu)->msr_ia32_sgxlepubkeyhash
 			[msr_info->index - MSR_IA32_SGXLEPUBKEYHASH0];
 		break;
 	case KVM_FIRST_EMULATED_VMX_MSR ... KVM_LAST_EMULATED_VMX_MSR:
 		if (!guest_cpu_cap_has(vcpu, X86_FEATURE_VMX))
-			return 1;
+			return -EINVAL;
 		if (vmx_get_vmx_msr(&vmx->nested.msrs, msr_info->index,
 				    &msr_info->data))
-			return 1;
+			return -EINVAL;
 #ifdef CONFIG_KVM_HYPERV
 		/*
 		 * Enlightened VMCS v1 doesn't have certain VMCS fields but
@@ -2180,19 +2180,19 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_RTIT_CTL:
 		if (!vmx_pt_mode_is_host_guest())
-			return 1;
+			return -EINVAL;
 		msr_info->data = vmx->pt_desc.guest.ctl;
 		break;
 	case MSR_IA32_RTIT_STATUS:
 		if (!vmx_pt_mode_is_host_guest())
-			return 1;
+			return -EINVAL;
 		msr_info->data = vmx->pt_desc.guest.status;
 		break;
 	case MSR_IA32_RTIT_CR3_MATCH:
 		if (!vmx_pt_mode_is_host_guest() ||
 			!intel_pt_validate_cap(vmx->pt_desc.caps,
 						PT_CAP_cr3_filtering))
-			return 1;
+			return -EINVAL;
 		msr_info->data = vmx->pt_desc.guest.cr3_match;
 		break;
 	case MSR_IA32_RTIT_OUTPUT_BASE:
@@ -2201,7 +2201,7 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 					PT_CAP_topa_output) &&
 			 !intel_pt_validate_cap(vmx->pt_desc.caps,
 					PT_CAP_single_range_output)))
-			return 1;
+			return -EINVAL;
 		msr_info->data = vmx->pt_desc.guest.output_base;
 		break;
 	case MSR_IA32_RTIT_OUTPUT_MASK:
@@ -2210,14 +2210,14 @@ int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 					PT_CAP_topa_output) &&
 			 !intel_pt_validate_cap(vmx->pt_desc.caps,
 					PT_CAP_single_range_output)))
-			return 1;
+			return -EINVAL;
 		msr_info->data = vmx->pt_desc.guest.output_mask;
 		break;
 	case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
 		index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
 		if (!vmx_pt_mode_is_host_guest() ||
 		    (index >= 2 * vmx->pt_desc.num_address_ranges))
-			return 1;
+			return -EINVAL;
 		if (index % 2)
 			msr_info->data = vmx->pt_desc.guest.addr_b[index / 2];
 		else
@@ -2359,7 +2359,7 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_DEBUGCTLMSR:
 		if (!vmx_is_valid_debugctl(vcpu, data, msr_info->host_initiated))
-			return 1;
+			return -EINVAL;
 
 		data &= vmx_get_supported_debugctl(vcpu, msr_info->host_initiated);
 
@@ -2377,10 +2377,10 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!kvm_mpx_supported() ||
 		    (!msr_info->host_initiated &&
 		     !guest_cpu_cap_has(vcpu, X86_FEATURE_MPX)))
-			return 1;
+			return -EINVAL;
 		if (is_noncanonical_msr_address(data & PAGE_MASK, vcpu) ||
 		    (data & MSR_IA32_BNDCFGS_RSVD))
-			return 1;
+			return -EINVAL;
 
 		if (is_guest_mode(vcpu) &&
 		    ((vmx->nested.msrs.entry_ctls_high & VM_ENTRY_LOAD_BNDCFGS) ||
@@ -2391,21 +2391,21 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_IA32_UMWAIT_CONTROL:
 		if (!msr_info->host_initiated && !vmx_has_waitpkg(vmx))
-			return 1;
+			return -EINVAL;
 
 		/* The reserved bit 1 and non-32 bit [63:32] should be zero */
 		if (data & (BIT_ULL(1) | GENMASK_ULL(63, 32)))
-			return 1;
+			return -EINVAL;
 
 		vmx->msr_ia32_umwait_control = data;
 		break;
 	case MSR_IA32_SPEC_CTRL:
 		if (!msr_info->host_initiated &&
 		    !guest_has_spec_ctrl_msr(vcpu))
-			return 1;
+			return -EINVAL;
 
 		if (kvm_spec_ctrl_test_value(data))
-			return 1;
+			return -EINVAL;
 
 		vmx->spec_ctrl = data;
 		if (!data)
@@ -2430,9 +2430,9 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_IA32_TSX_CTRL:
 		if (!msr_info->host_initiated &&
 		    !(vcpu->arch.arch_capabilities & ARCH_CAP_TSX_CTRL_MSR))
-			return 1;
+			return -EINVAL;
 		if (data & ~(TSX_CTRL_RTM_DISABLE | TSX_CTRL_CPUID_CLEAR))
-			return 1;
+			return -EINVAL;
 		goto find_uret_msr;
 	case MSR_IA32_CR_PAT:
 		ret = kvm_set_msr_common(vcpu, msr_info);
@@ -2451,12 +2451,12 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		     !(to_vmx(vcpu)->msr_ia32_feature_control &
 		       FEAT_CTL_LMCE_ENABLED)) ||
 		    (data & ~MCG_EXT_CTL_LMCE_EN))
-			return 1;
+			return -EINVAL;
 		vcpu->arch.mcg_ext_ctl = data;
 		break;
 	case MSR_IA32_FEAT_CTL:
 		if (!is_vmx_feature_control_msr_valid(vmx, msr_info))
-			return 1;
+			return -EINVAL;
 
 		vmx->msr_ia32_feature_control = data;
 		if (msr_info->host_initiated && data == 0)
@@ -2481,70 +2481,70 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		    (!guest_cpu_cap_has(vcpu, X86_FEATURE_SGX_LC) ||
 		    ((vmx->msr_ia32_feature_control & FEAT_CTL_LOCKED) &&
 		    !(vmx->msr_ia32_feature_control & FEAT_CTL_SGX_LC_ENABLED))))
-			return 1;
+			return -EINVAL;
 		vmx->msr_ia32_sgxlepubkeyhash
 			[msr_index - MSR_IA32_SGXLEPUBKEYHASH0] = data;
 		break;
 	case KVM_FIRST_EMULATED_VMX_MSR ... KVM_LAST_EMULATED_VMX_MSR:
 		if (!msr_info->host_initiated)
-			return 1; /* they are read-only */
+			return -EINVAL; /* they are read-only */
 		if (!guest_cpu_cap_has(vcpu, X86_FEATURE_VMX))
-			return 1;
+			return -EINVAL;
 		return vmx_set_vmx_msr(vcpu, msr_index, data);
 	case MSR_IA32_RTIT_CTL:
 		if (!vmx_pt_mode_is_host_guest() ||
 			vmx_rtit_ctl_check(vcpu, data) ||
 			vmx->nested.vmxon)
-			return 1;
+			return -EINVAL;
 		vmcs_write64(GUEST_IA32_RTIT_CTL, data);
 		vmx->pt_desc.guest.ctl = data;
 		pt_update_intercept_for_msr(vcpu);
 		break;
 	case MSR_IA32_RTIT_STATUS:
 		if (!pt_can_write_msr(vmx))
-			return 1;
+			return -EINVAL;
 		if (data & MSR_IA32_RTIT_STATUS_MASK)
-			return 1;
+			return -EINVAL;
 		vmx->pt_desc.guest.status = data;
 		break;
 	case MSR_IA32_RTIT_CR3_MATCH:
 		if (!pt_can_write_msr(vmx))
-			return 1;
+			return -EINVAL;
 		if (!intel_pt_validate_cap(vmx->pt_desc.caps,
 					   PT_CAP_cr3_filtering))
-			return 1;
+			return -EINVAL;
 		vmx->pt_desc.guest.cr3_match = data;
 		break;
 	case MSR_IA32_RTIT_OUTPUT_BASE:
 		if (!pt_can_write_msr(vmx))
-			return 1;
+			return -EINVAL;
 		if (!intel_pt_validate_cap(vmx->pt_desc.caps,
 					   PT_CAP_topa_output) &&
 		    !intel_pt_validate_cap(vmx->pt_desc.caps,
 					   PT_CAP_single_range_output))
-			return 1;
+			return -EINVAL;
 		if (!pt_output_base_valid(vcpu, data))
-			return 1;
+			return -EINVAL;
 		vmx->pt_desc.guest.output_base = data;
 		break;
 	case MSR_IA32_RTIT_OUTPUT_MASK:
 		if (!pt_can_write_msr(vmx))
-			return 1;
+			return -EINVAL;
 		if (!intel_pt_validate_cap(vmx->pt_desc.caps,
 					   PT_CAP_topa_output) &&
 		    !intel_pt_validate_cap(vmx->pt_desc.caps,
 					   PT_CAP_single_range_output))
-			return 1;
+			return -EINVAL;
 		vmx->pt_desc.guest.output_mask = data;
 		break;
 	case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
 		if (!pt_can_write_msr(vmx))
-			return 1;
+			return -EINVAL;
 		index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
 		if (index >= 2 * vmx->pt_desc.num_address_ranges)
-			return 1;
+			return -EINVAL;
 		if (is_noncanonical_msr_address(data, vcpu))
-			return 1;
+			return -EINVAL;
 		if (index % 2)
 			vmx->pt_desc.guest.addr_b[index / 2] = data;
 		else
@@ -2563,20 +2563,20 @@ int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (data & PERF_CAP_LBR_FMT) {
 			if ((data & PERF_CAP_LBR_FMT) !=
 			    (kvm_caps.supported_perf_cap & PERF_CAP_LBR_FMT))
-				return 1;
+				return -EINVAL;
 			if (!cpuid_model_is_consistent(vcpu))
-				return 1;
+				return -EINVAL;
 		}
 		if (data & PERF_CAP_PEBS_FORMAT) {
 			if ((data & PERF_CAP_PEBS_MASK) !=
 			    (kvm_caps.supported_perf_cap & PERF_CAP_PEBS_MASK))
-				return 1;
+				return -EINVAL;
 			if (!guest_cpu_cap_has(vcpu, X86_FEATURE_DS))
-				return 1;
+				return -EINVAL;
 			if (!guest_cpu_cap_has(vcpu, X86_FEATURE_DTES64))
-				return 1;
+				return -EINVAL;
 			if (!cpuid_model_is_consistent(vcpu))
-				return 1;
+				return -EINVAL;
 		}
 		ret = kvm_set_msr_common(vcpu, msr_info);
 		break;
-- 
2.54.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value
  2026-05-28 11:13 [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value Juergen Gross
  2026-05-28 11:13 ` [PATCH v2 4/5] KVM/x86: Return -errno instead of "1" for VMX related MSR emulation Juergen Gross
@ 2026-05-28 11:35 ` Juergen Gross
  1 sibling, 0 replies; 3+ messages in thread
From: Juergen Gross @ 2026-05-28 11:35 UTC (permalink / raw)
  To: linux-kernel, x86, kvm, linux-coco
  Cc: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, Dave Hansen, H. Peter Anvin, Vitaly Kuznetsov,
	Kiryl Shutsemau, Rick Edgecombe


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On 28.05.26 13:13, Juergen Gross wrote:
> Get rid of the literal "1" used as general error return value in KVM
> MSR emulation. It can easily be replaced by negative errno values
> instead.
> 
> This is meant to avoid confusion with the literal "1" used as return
> value for "return to guest".
> 
> Changes in V2:
> - series carved out from initial "KVM: Avoid literal numbers as return
>    values" series
> - don't use new KVM_MSR_RET_* defines, but 0 and -errno
> 
> Juergen Gross (5):
>    KVM/x86: Change comment before KVM_MSR_RET_* defines
>    KVM/x86: Return -errno instead of "1" for APIC related MSR emulation
>    KVM/x86: Return -errno instead of "1" for Hyper-V related MSR
>      emulation
>    KVM/x86: Return -errno instead of "1" for VMX related MSR emulation
>    KVM/x86: Return -errno instead of "1" for SVM related MSR emulation
> 
>   arch/x86/kvm/hyperv.c        | 72 +++++++++++++--------------
>   arch/x86/kvm/lapic.c         | 39 +++++++--------
>   arch/x86/kvm/svm/pmu.c       |  4 +-
>   arch/x86/kvm/svm/svm.c       | 36 +++++++-------
>   arch/x86/kvm/vmx/nested.c    |  2 +-
>   arch/x86/kvm/vmx/pmu_intel.c | 16 +++---
>   arch/x86/kvm/vmx/tdx.c       | 10 ++--
>   arch/x86/kvm/vmx/vmx.c       | 96 ++++++++++++++++++------------------
>   arch/x86/kvm/x86.h           |  4 +-
>   9 files changed, 139 insertions(+), 140 deletions(-)
> 

Oh, sorry, there is another patch. Resending.


Juergen

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^ permalink raw reply	[flat|nested] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-28 11:13 [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value Juergen Gross
2026-05-28 11:13 ` [PATCH v2 4/5] KVM/x86: Return -errno instead of "1" for VMX related MSR emulation Juergen Gross
2026-05-28 11:35 ` [PATCH v2 0/5] KVM/x86: Drop "1" as MSR emulation return value Juergen Gross

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