Re: [PATCH 14/16] x86/mm/legacy: Populate the user page-table with user pgd's

[Andy Lutomirski]

On Tue, Jan 16, 2018 at 8:36 AM, Joerg Roedel <joro@xxxxxxxxxx> wrote:
> From: Joerg Roedel <jroedel@xxxxxxx>
>
> Also populate the user-spage pgd's in the user page-table.
>
> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
> ---
>  arch/x86/include/asm/pgtable-2level.h | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h
> index 685ffe8a0eaf..d96486d23c58 100644
> --- a/arch/x86/include/asm/pgtable-2level.h
> +++ b/arch/x86/include/asm/pgtable-2level.h
> @@ -19,6 +19,9 @@ static inline void native_set_pte(pte_t *ptep , pte_t pte)
>
>  static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
>  {
> +#ifdef CONFIG_PAGE_TABLE_ISOLATION
> +       pmd.pud.p4d.pgd = pti_set_user_pgd(&pmdp->pud.p4d.pgd, pmd.pud.p4d.pgd);
> +#endif
>         *pmdp = pmd;
>  }
>

Nothing against your patch, but this seems like a perfectly fine place
to rant: I *hate* the way we deal with page table folding.  Grr.