[xen staging] xen/riscv: fix level_map_mask truncation on load_start

[patchbot@xxxxxxx]

commit 08a898b93d214a38965fbc4cd9b7a36e5c715691
Author:     Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>
AuthorDate: Wed Sep 23 09:04:16 2026 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Sep 23 10:01:38 2026 +0200

    xen/riscv: fix level_map_mask truncation on load_start
    
    check_pgtbl_mode_support() declares level_map_mask as bare `unsigned`, i.e.
    a 32-bit type while it derives from a paddr_t which is in both RV32/RV64 a
    64-bit type. Storing that value into a 32-bit local silently drops any set
    bits above bit 31.
    
    The mask is then used as:
    
        aligned_load_start = load_start & level_map_mask;
    
    load_start is `unsigned long` (64-bit on riscv64) and if it requires more
    than 32 bits to represent, because load_start zero-extend to 64 bits, we
    would drop some load_start's bits during the AND.
    
    Widen level_map_mask to `unsigned long`, matching the width of the physical
    address.
    
    Fixes: e66003e7be19 ("xen/riscv: introduce setup_initial_pages")
    Reported-by: Zheng Zhang <zhangzheng@xxxxxxxxxxx>
    Signed-off-by: Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>
    Tested-by: Zheng Zhang <zhangzheng@xxxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
 xen/arch/riscv/mm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/riscv/mm.c b/xen/arch/riscv/mm.c
index 4d3b8c2204..610d111945 100644
--- a/xen/arch/riscv/mm.c
+++ b/xen/arch/riscv/mm.c
@@ -181,7 +181,7 @@ static bool __init check_pgtbl_mode_support(struct mmu_desc 
*mmu_desc,
     bool is_mode_supported = false;
     unsigned int index;
     unsigned int page_table_level = (mmu_desc->num_levels - 1);
-    unsigned level_map_mask = XEN_PT_LEVEL_MAP_MASK(page_table_level);
+    unsigned long level_map_mask = XEN_PT_LEVEL_MAP_MASK(page_table_level);
 
     unsigned long aligned_load_start = load_start & level_map_mask;
     unsigned long aligned_page_size = XEN_PT_LEVEL_SIZE(page_table_level);
--
generated by git-patchbot for /home/xen/git/xen.git#staging