[PATCH] KVM: VMX: check match table

[Nick Desaulniers]

Fixes the warning:
arch/x86/kvm/vmx.c:64:32: warning: variable 'vmx_cpu_id' is not needed
and will not be emitted [-Wunneeded-internal-declaration]``

Other callers of MODULE_DEVICE_TABLE() seem to check their second
argument during driver init with the x86_match_cpu() function, if their
first argument to MODULE_DEVICE_TABLE() is x86cpu.  The documentation
for x86_match_cpu() seems to agree.

Suggested-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Signed-off-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx>
---
 arch/x86/kernel/cpu/match.c | 2 +-
 arch/x86/kvm/vmx.c          | 7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c
index e42117d5f4d7..fb1aeafa5cc7 100644
--- a/arch/x86/kernel/cpu/match.c
+++ b/arch/x86/kernel/cpu/match.c
@@ -5,7 +5,7 @@
 #include <linux/slab.h>
 
 /**
- * x86_match_cpu - match current CPU again an array of x86_cpu_ids
+ * x86_match_cpu - match current CPU against an array of x86_cpu_ids
  * @match: Pointer to array of x86_cpu_ids. Last entry terminated with
  *         {}.
  *
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6970249c09fc..e1a00b130935 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -12074,7 +12074,12 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 
 static int __init vmx_init(void)
 {
-	int r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx),
+	int r;
+
+	if (!x86_match_cpu(vmx_cpu_id))
+		return -ENODEV;
+
+	r = kvm_init(&vmx_x86_ops, sizeof(struct vcpu_vmx),
                      __alignof__(struct vcpu_vmx), THIS_MODULE);
 	if (r)
 		return r;
-- 
2.11.0