xen/arm: domain_build: Use copy_to_guest_phys_flush_dcache in dtb_load

The function dtb_load is dealing with IPA but uses gvirt_to_maddr to do
the translation. This is currently working fine because the stage-1 MMU
is disabled.

Rather than relying on such assumption, use the new
copy_to_guest_phys_flush_dcache. This also result to a slightly more
comprehensible code.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/arch/arm/domain_build.c

@@ -1950,14 +1950,15 @@ static int prepare_acpi(struct domain *d, struct kernel_info *kinfo)
 #endif
 static void dtb_load(struct kernel_info *kinfo)
 {
-    void * __user dtb_virt = (void * __user)(register_t)kinfo->dtb_paddr;
     unsigned long left;
 
     printk("Loading dom0 DTB to 0x%"PRIpaddr"-0x%"PRIpaddr"\n",
            kinfo->dtb_paddr, kinfo->dtb_paddr + fdt_totalsize(kinfo->fdt));
 
-    left = raw_copy_to_guest_flush_dcache(dtb_virt, kinfo->fdt,
-                                        fdt_totalsize(kinfo->fdt));
+    left = copy_to_guest_phys_flush_dcache(kinfo->d, kinfo->dtb_paddr,
+                                           kinfo->fdt,
+                                           fdt_totalsize(kinfo->fdt));
+
     if ( left != 0 )
         panic("Unable to copy the DTB to dom0 memory (left = %lu bytes)", left);
     xfree(kinfo->fdt);