[PATCH v2 08/16] KVM: VMX: Check for full VMX support when verifying CPU compatibility

From: Sean Christopherson
Date: Mon Oct 21 2019 - 20:08:50 EST


Explicitly check the current CPU's VMX feature flag when verifying
compatibility across physical CPUs. This effectively adds a check on
IA32_FEATURE_CONTROL to ensure that VMX is fully enabled on all CPUs.

Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/vmx/vmx.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 510f8a778fca..a482949063f2 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -6837,6 +6837,11 @@ static int __init vmx_check_processor_compat(void)
struct vmcs_config vmcs_conf;
struct vmx_capability vmx_cap;

+ if (!this_cpu_has(X86_FEATURE_VMX)) {
+ pr_err("kvm: VMX is disabled on CPU %d\n", smp_processor_id());
+ return -EIO;
+ }
+
if (setup_vmcs_config(&vmcs_conf, &vmx_cap) < 0)
return -EIO;
if (nested)
--
2.22.0