[xen staging] x86/mm: Move base_disallow_mask into __ro_after_init

[patchbot@xxxxxxx]

commit c2770e51b402d25fa1bdc9b9e3a12d23bbc11935
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Thu Apr 28 18:00:41 2022 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Jul 22 18:18:00 2024 +0100

    x86/mm: Move base_disallow_mask into __ro_after_init
    
    base_disallow_mask is calculated once in arch_init_memory() and doesn't 
change
    thereafter.  Write-protect it at runtime.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/mm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 0ecea0f707..95795567f2 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -150,7 +150,8 @@ bool __read_mostly machine_to_phys_mapping_valid;
 
 struct rangeset *__read_mostly mmio_ro_ranges;
 
-static uint32_t base_disallow_mask;
+static uint32_t __ro_after_init base_disallow_mask;
+
 /* Global bit is allowed to be set on L1 PTEs. Intended for user mappings. */
 #define L1_DISALLOW_MASK ((base_disallow_mask | _PAGE_GNTTAB) & ~_PAGE_GLOBAL)
 
--
generated by git-patchbot for /home/xen/git/xen.git#staging