Re: [PATCH v2 1/5] x86/shadow: tidy up fragmentary page lists in multi‑page shadows

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 02/02/15 11:18, Jan Beulich wrote:
> From: Tim Deegan <tim@xen.org>
>
> Multi-page shadows are linked together using the 'list' field.  When
> those shadows are in the pinned list, the list fragments are spliced
> into the pinned list; otherwise they have no associated list head.
>
> Rework the code that handles these fragments to use the page_list
> interface rather than manipulating the fields directly.  This makes
> the code cleaner, and allows the 'list' field to be either the
> compact pdx form or a normal list_entry.
>
> Signed-off-by: Tim Deegan <tim@xen.org>

I put v1 of the patch through XenRT over the weekend, and nothing
appeared to blow up spectacularly.

Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>

>
> Introduce sh_terminate_list() and make it use LIST_POISON*.
>
> Move helper array of shadow_size() into common.c.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>, with 1 small comment

>
> --- a/xen/arch/x86/mm/shadow/common.c
> +++ b/xen/arch/x86/mm/shadow/common.c
> @@ -1196,6 +1196,26 @@ int shadow_cmpxchg_guest_entry(struct vc
>   * the free pool.
>   */
>  
> +const u32 sh_type_to_size[] = {

u8 instead?  The maximum value held is 4.

~Andrew