Re: [PATCHv4 28/33] x86/mm: add support of additional page table level during early boot

[Boris Ostrovsky]

> diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
> index 9991224f6238..c9e41f1599dd 100644
> --- a/arch/x86/include/asm/pgtable_64.h
> +++ b/arch/x86/include/asm/pgtable_64.h
> @@ -14,15 +14,17 @@
>  #include <linux/bitops.h>
>  #include <linux/threads.h>
>  
> +extern p4d_t level4_kernel_pgt[512];
> +extern p4d_t level4_ident_pgt[512];
>  extern pud_t level3_kernel_pgt[512];
>  extern pud_t level3_ident_pgt[512];
>  extern pmd_t level2_kernel_pgt[512];
>  extern pmd_t level2_fixmap_pgt[512];
>  extern pmd_t level2_ident_pgt[512];
>  extern pte_t level1_fixmap_pgt[512];
> -extern pgd_t init_level4_pgt[];
> +extern pgd_t init_top_pgt[];
>  
> -#define swapper_pg_dir init_level4_pgt
> +#define swapper_pg_dir init_top_pgt
>  
>  extern void paging_init(void);
>  


This means you also need


diff --git a/arch/x86/xen/xen-pvh.S b/arch/x86/xen/xen-pvh.S
index 5e24671..e1a5fbe 100644
--- a/arch/x86/xen/xen-pvh.S
+++ b/arch/x86/xen/xen-pvh.S
@@ -87,7 +87,7 @@ ENTRY(pvh_start_xen)
        wrmsr
 
        /* Enable pre-constructed page tables. */
-       mov $_pa(init_level4_pgt), %eax
+       mov $_pa(init_top_pgt), %eax
        mov %eax, %cr3
        mov $(X86_CR0_PG | X86_CR0_PE), %eax
        mov %eax, %cr0


-boris