x86/ucode: don't crash during AP bringup on non-Intel, non-AMD CPUs

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>

diff --git a/xen/arch/x86/microcode.c b/xen/arch/x86/microcode.c
index bdda3f5f4db51f1bf2afae45b48052af9d7a3e72..fe51034426312db7ed8750951331ea98adbf727a 100644 (file)
--- a/xen/arch/x86/microcode.c
+++ b/xen/arch/x86/microcode.c
@@ -109,6 +109,9 @@ int microcode_resume_cpu(int cpu)
     struct cpu_signature nsig;
     unsigned int cpu2;
 
+    if ( !microcode_ops )
+        return 0;
+
     spin_lock(&microcode_mutex);
 
     err = microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);