We move the setting of write_cr3 from the early bootup variant
(see git commit 
0cc9129d75ef8993702d97ab0e49542c15ac6ab9
"x86-64, xen, mmu: Provide an early version of write_cr3.")
to a more appropiate location.
This new location sets all of the other non-early variants
of pvops calls - and most importantly is before the
alternative_asm mechanism kicks in.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
        __xen_write_cr3(true, cr3);
 
        xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
-
-       pv_mmu_ops.write_cr3 = &xen_write_cr3;
 }
 #endif
 
 #endif
 
 #ifdef CONFIG_X86_64
+       pv_mmu_ops.write_cr3 = &xen_write_cr3;
        SetPagePinned(virt_to_page(level3_user_vsyscall));
 #endif
        xen_mark_init_mm_pinned();