[PATCH 2/3] x86: fix resource leaks on arch_vcpu_create() error path

[Jan Beulich <jbeulich@xxxxxxxx>]

{hvm,pv}_vcpu_initialise() have always been meant to be the final
possible source of errors in arch_vcpu_create(), hence not requiring
any unrolling of what they've done on the error path. (Of course this
may change once the various involved paths all have become idempotent.)

But even beyond this aspect I think it is more logical to do policy
initialization ahead of the calling of these two functions, as they may
in principle want to access it.

Fixes: 4187f79dc718 ("x86/msr: introduce struct msr_vcpu_policy")
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -569,6 +569,9 @@ int arch_vcpu_create(struct vcpu *v)
         vmce_init_vcpu(v);
 
         arch_vcpu_regs_init(v);
+
+        if ( (rc = init_vcpu_msr_policy(v)) )
+            goto fail;
     }
     else if ( (rc = xstate_alloc_save_area(v)) != 0 )
         return rc;
@@ -594,9 +597,6 @@ int arch_vcpu_create(struct vcpu *v)
     {
         vpmu_initialise(v);
 
-        if ( (rc = init_vcpu_msr_policy(v)) )
-            goto fail;
-
         cpuid_policy_updated(v);
     }