x86/mtrr: recalculate P2M type for domains with iocaps

This change reflects the logic in epte_get_entry_emt() and allows
changes in guest MTTRs to be reflected in EPT for domains having
direct access to certain hardware memory regions but without IOMMU
context assigned (e.g. XenGT).

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/hvm/mtrr.c

@@ -783,7 +783,7 @@ HVM_REGISTER_SAVE_RESTORE(MTRR, hvm_save_mtrr_msr, hvm_load_mtrr_msr, 1,
 
 void memory_type_changed(struct domain *d)
 {
-    if ( has_iommu_pt(d) && d->vcpu && d->vcpu[0] )
+    if ( (has_iommu_pt(d) || cache_flush_permitted(d)) && d->vcpu && d->vcpu[0] )
     {
         p2m_memory_type_changed(d);
         flush_all(FLUSH_CACHE);