Re: [PATCH 4/5] libxc: split p2m allocation in domain builder from other magic pages

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-09-11 at 14:32 +0200, Juergen Gross wrote:
> Add an own function to allocate the p2m list in the domain builder in

I'm not sure what you mean by "own" here. Perhaps "hook" or "callback"?

> order to prepare allocating the p2m list outside of the initial kernel
> mapping. This will be needed to support loading domains with huge
> memory (>512 GB).
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Other than the above it otherwise LGTM, so with that clarification:

Acked-by: Ian Campbell <ian.campbell@citrix.com>

> ---
>  tools/libxc/include/xc_dom.h |  1 +
>  tools/libxc/xc_dom_core.c    |  3 +++
>  tools/libxc/xc_dom_x86.c     | 11 ++++++++++-
>  3 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/libxc/include/xc_dom.h b/tools/libxc/include/xc_dom.h
> index a4ca8a4..43b1eab 100644
> --- a/tools/libxc/include/xc_dom.h
> +++ b/tools/libxc/include/xc_dom.h
> @@ -199,6 +199,7 @@ void xc_dom_register_loader(struct xc_dom_loader
> *loader);
>  struct xc_dom_arch {
>      /* pagetable setup */
>      int (*alloc_magic_pages) (struct xc_dom_image * dom);
> +    int (*alloc_p2m_list) (struct xc_dom_image * dom);
>      int (*count_pgtables) (struct xc_dom_image * dom);
>      int (*setup_pgtables) (struct xc_dom_image * dom);
>  
> diff --git a/tools/libxc/xc_dom_core.c b/tools/libxc/xc_dom_core.c
> index bb668b1..81b642e 100644
> --- a/tools/libxc/xc_dom_core.c
> +++ b/tools/libxc/xc_dom_core.c
> @@ -1048,6 +1048,9 @@ int xc_dom_build_image(struct xc_dom_image *dom)
>      }
>  
>      /* allocate other pages */
> +    if ( dom->arch_hooks->alloc_p2m_list &&
> +         dom->arch_hooks->alloc_p2m_list(dom) != 0 )
> +        goto err;
>      if ( dom->arch_hooks->alloc_magic_pages(dom) != 0 )
>          goto err;
>      if ( dom->arch_hooks->count_pgtables )
> diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c
> index 3d40fa4..91d4e49 100644
> --- a/tools/libxc/xc_dom_x86.c
> +++ b/tools/libxc/xc_dom_x86.c
> @@ -438,7 +438,7 @@ pfn_error:
>  
>  /* ---------------------------------------------------------------------
> --- */
>  
> -static int alloc_magic_pages(struct xc_dom_image *dom)
> +static int alloc_p2m_list(struct xc_dom_image *dom)
>  {
>      size_t p2m_alloc_size = dom->p2m_size * dom->arch_hooks->sizeof_pfn;
>  
> @@ -450,6 +450,13 @@ static int alloc_magic_pages(struct xc_dom_image
> *dom)
>      if ( dom->p2m_guest == NULL )
>          return -1;
>  
> +    return 0;
> +}
> +
> +/* ---------------------------------------------------------------------
> --- */
> +
> +static int alloc_magic_pages(struct xc_dom_image *dom)
> +{
>      /* allocate special pages */
>      dom->start_info_pfn = xc_dom_alloc_page(dom, "start info");
>      dom->xenstore_pfn = xc_dom_alloc_page(dom, "xenstore");
> @@ -676,6 +683,7 @@ static struct xc_dom_arch xc_dom_32_pae = {
>      .page_shift = PAGE_SHIFT_X86,
>      .sizeof_pfn = 4,
>      .alloc_magic_pages = alloc_magic_pages,
> +    .alloc_p2m_list = alloc_p2m_list,
>      .count_pgtables = count_pgtables_x86_32_pae,
>      .setup_pgtables = setup_pgtables_x86_32_pae,
>      .start_info = start_info_x86_32,
> @@ -689,6 +697,7 @@ static struct xc_dom_arch xc_dom_64 = {
>      .page_shift = PAGE_SHIFT_X86,
>      .sizeof_pfn = 8,
>      .alloc_magic_pages = alloc_magic_pages,
> +    .alloc_p2m_list = alloc_p2m_list,
>      .count_pgtables = count_pgtables_x86_64,
>      .setup_pgtables = setup_pgtables_x86_64,
>      .start_info = start_info_x86_64,