Subject: x86/early_ioremap: don't assume we're using swapper_pg_dir At the early stages of boot, before the kernel pagetable has been fully initialized, a Xen kernel will still be running off the Xen-provided pagetables rather than swapper_pg_dir[]. Therefore, readback cr3 to determine the base of the pagetable rather than assuming swapper_pg_dir[]. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/mm/ioremap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) =================================================================== --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -265,7 +265,9 @@ static inline pmd_t * __init early_ioremap_pmd(unsigned long addr) { - pgd_t *pgd = &swapper_pg_dir[pgd_index(addr)]; + /* Don't assume we're using swapper_pg_dir at this point */ + pgd_t *base = __va(read_cr3()); + pgd_t *pgd = &base[pgd_index(addr)]; pud_t *pud = pud_offset(pgd, addr); pmd_t *pmd = pmd_offset(pud, addr);