[PATCH v3 1/4] KVM: nVMX: Setup VMX MSRs on loading CPU during nested_vmx_hardware_setup()

From: Sean Christopherson
Date: Thu Jan 08 2026 - 23:15:37 EST


Move the call to nested_vmx_setup_ctls_msrs() from vmx_hardware_setup() to
nested_vmx_hardware_setup() so that the nested code can deal with ordering
dependencies without having to straddle vmx_hardware_setup() and
nested_vmx_hardware_setup(). Specifically, an upcoming change will
sanitize the vmcs12 fields based on hardware support, and that code needs
to run _before_ the MSRs are configured, because the lovely vmcs_enum MSR
depends on the max support vmcs12 field.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 2 ++
arch/x86/kvm/vmx/vmx.c | 2 --
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 6137e5307d0f..61113ead3d7b 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -7407,6 +7407,8 @@ __init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *))
{
int i;

+ nested_vmx_setup_ctls_msrs(&vmcs_config, vmx_capability.ept);
+
if (!cpu_has_vmx_shadow_vmcs())
enable_shadow_vmcs = 0;
if (enable_shadow_vmcs) {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6b96f7aea20b..5bb67566e43a 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -8670,8 +8670,6 @@ __init int vmx_hardware_setup(void)
* can hide/show features based on kvm_cpu_cap_has().
*/
if (nested) {
- nested_vmx_setup_ctls_msrs(&vmcs_config, vmx_capability.ept);
-
r = nested_vmx_hardware_setup(kvm_vmx_exit_handlers);
if (r)
return r;
--
2.52.0.457.g6b5491de43-goog