Re: [PATCH v7 2/4] xen/riscv: fix A/D bits in Xen's page-table mappings

[Zhang Zheng <zhangzheng@xxxxxxxxxxx>]

On Fri, 16 Oct 2026 17:34:18 +0200, Baptiste Le Duc 
<baptiste.le-duc@xxxxxxxxxx> wrote:
> Xen does not handle page faults caused by clear A/D bits, so it presets
> them when creating PTEs. pt_update_entry() does so, but three places build
> leaf PTEs directly without going through it: setup_initial_mapping() (the
> boot page tables), check_pgtbl_mode_support() (the temporary root entry
> used to probe SATP mode support) and arch_pmap_map() (the fixmap).
> 
> On implementations that fault on clear A/D bits (Svade), all three fault
> on first access. For check_pgtbl_mode_support(), the fault is raised by the
> instruction fetch right after the SATP write, before any trap handler is
> set.
> 
> [...]

Tested-by: Zhang Zheng <zhangzheng@xxxxxxxxxxx>

-- 
Zhang Zheng <zhangzheng@xxxxxxxxxxx>