[PATCH v2 20/36] KVM: VMX: Advertise tertiary controls to the user space
From: isaku . yamahata
Date: Thu Mar 05 2026 - 12:52:20 EST
From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Make KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST, KVM_GET_MSRS
to advertise MSR_IA32_VMX_PROCBASED_CTLS3 to the user space VMM like QEMU.
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 3 +++
arch/x86/kvm/x86.c | 1 +
2 files changed, 4 insertions(+)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index bac3f33f7d73..8c2ab0164714 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7214,6 +7214,9 @@ bool vmx_has_emulated_msr(struct kvm *kvm, u32 index)
*/
return enable_unrestricted_guest || emulate_invalid_guest_state;
case KVM_FIRST_EMULATED_VMX_MSR ... KVM_LAST_EMULATED_VMX_MSR:
+ if (index == MSR_IA32_VMX_PROCBASED_CTLS3 &&
+ !__nested_cpu_supports_tertiary_ctls(&vmcs_config.nested))
+ return false;
return nested;
case MSR_AMD64_VIRT_SPEC_CTRL:
case MSR_AMD64_TSC_RATIO:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1922e8699101..8a1ec0a39624 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -457,6 +457,7 @@ static const u32 emulated_msrs_all[] = {
MSR_IA32_VMX_PROCBASED_CTLS2,
MSR_IA32_VMX_EPT_VPID_CAP,
MSR_IA32_VMX_VMFUNC,
+ MSR_IA32_VMX_PROCBASED_CTLS3,
MSR_K7_HWCR,
MSR_KVM_POLL_CONTROL,
--
2.45.2