From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: x86/msr: Free msr_vcpu_policy during vcpu destruction

c/s 4187f79dc7 "x86/msr: introduce struct msr_vcpu_policy" introduced a
per-vcpu memory allocation, but failed to free it in the clean vcpu
destruction case.

This is XSA-253

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index b17468c..0ae715d 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -382,6 +382,9 @@ void vcpu_destroy(struct vcpu *v)
 
     vcpu_destroy_fpu(v);
 
+    xfree(v->arch.msr);
+    v->arch.msr = NULL;
+
     if ( !is_idle_domain(v->domain) )
         vpmu_destroy(v);