[PATCH] x86/Xen: swap NX determination and GDT setup on BSP

[Jan Beulich]

xen_setup_gdt(), via xen_load_gdt_boot(), wants to adjust page tables.
For this to work when NX is not available, x86_configure_nx() needs to
be called first.

Reported-by: Olaf Hering <o...@aepfle.de>
Signed-off-by: Jan Beulich <jbeul...@suse.com>

--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1273,16 +1273,16 @@ asmlinkage __visible void __init xen_sta
        /* Get mfn list */
        xen_build_dynamic_phys_to_machine();
 
+       /* Work out if we support NX */
+       get_cpu_cap(&boot_cpu_data);
+       x86_configure_nx();
+
        /*
         * Set up kernel GDT and segment registers, mainly so that
         * -fstack-protector code can be executed.
         */
        xen_setup_gdt(0);
 
-       /* Work out if we support NX */
-       get_cpu_cap(&boot_cpu_data);
-       x86_configure_nx();
-
        /* Determine virtual and physical address sizes */
        get_cpu_address_sizes(&boot_cpu_data);