Re: [Xen-devel] [PATCH v2 02/16] xen/grant-table: Move xlated_setup_gnttab_pages to common place

[Stefano Stabellini]

On Fri, 15 Jan 2016, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
> 
> Move xlated_setup_gnttab_pages to common place, so it can be reused by
> ARM to setup grant table.
> 
> Rename it to xen_xlate_map_ballooned_pages.
> 
> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>

Reviewed-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


>  arch/x86/xen/grant-table.c | 57 +++++--------------------------------------
>  drivers/xen/xlate_mmu.c    | 61 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/xen/xen-ops.h      |  2 ++
>  3 files changed, 69 insertions(+), 51 deletions(-)
> 
> diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
> index e079500..de4144c 100644
> --- a/arch/x86/xen/grant-table.c
> +++ b/arch/x86/xen/grant-table.c
> @@ -111,63 +111,18 @@ int arch_gnttab_init(unsigned long nr_shared)
>  }
>  
>  #ifdef CONFIG_XEN_PVH
> -#include <xen/balloon.h>
>  #include <xen/events.h>
> -#include <linux/slab.h>
> -static int __init xlated_setup_gnttab_pages(void)
> -{
> -	struct page **pages;
> -	xen_pfn_t *pfns;
> -	void *vaddr;
> -	int rc;
> -	unsigned int i;
> -	unsigned long nr_grant_frames = gnttab_max_grant_frames();
> -
> -	BUG_ON(nr_grant_frames == 0);
> -	pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
> -	if (!pages)
> -		return -ENOMEM;
> -
> -	pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
> -	if (!pfns) {
> -		kfree(pages);
> -		return -ENOMEM;
> -	}
> -	rc = alloc_xenballooned_pages(nr_grant_frames, pages);
> -	if (rc) {
> -		pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
> -			nr_grant_frames, rc);
> -		kfree(pages);
> -		kfree(pfns);
> -		return rc;
> -	}
> -	for (i = 0; i < nr_grant_frames; i++)
> -		pfns[i] = page_to_pfn(pages[i]);
> -
> -	vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL);
> -	if (!vaddr) {
> -		pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
> -			nr_grant_frames, rc);
> -		free_xenballooned_pages(nr_grant_frames, pages);
> -		kfree(pages);
> -		kfree(pfns);
> -		return -ENOMEM;
> -	}
> -	kfree(pages);
> -
> -	xen_auto_xlat_grant_frames.pfn = pfns;
> -	xen_auto_xlat_grant_frames.count = nr_grant_frames;
> -	xen_auto_xlat_grant_frames.vaddr = vaddr;
> -
> -	return 0;
> -}
> -
> +#include <xen/xen-ops.h>
>  static int __init xen_pvh_gnttab_setup(void)
>  {
>  	if (!xen_pvh_domain())
>  		return -ENODEV;
>  
> -	return xlated_setup_gnttab_pages();
> +	xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
> +
> +	return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
> +					     &xen_auto_xlat_grant_frames.vaddr,
> +					     xen_auto_xlat_grant_frames.count);
>  }
>  /* Call it _before_ __gnttab_init as we need to initialize the
>   * xen_auto_xlat_grant_frames first. */
> diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c
> index 5063c5e..9692656 100644
> --- a/drivers/xen/xlate_mmu.c
> +++ b/drivers/xen/xlate_mmu.c
> @@ -29,6 +29,8 @@
>   */
>  #include <linux/kernel.h>
>  #include <linux/mm.h>
> +#include <linux/slab.h>
> +#include <linux/vmalloc.h>
>  
>  #include <asm/xen/hypercall.h>
>  #include <asm/xen/hypervisor.h>
> @@ -37,6 +39,7 @@
>  #include <xen/page.h>
>  #include <xen/interface/xen.h>
>  #include <xen/interface/memory.h>
> +#include <xen/balloon.h>
>  
>  typedef void (*xen_gfn_fn_t)(unsigned long gfn, void *data);
>  
> @@ -185,3 +188,61 @@ int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
> +
> +/**
> + * xen_xlate_map_ballooned_pages - map a new set of ballooned pages
> + * @gfns: returns the array of corresponding GFNs
> + * @virt: returns the virtual address of the mapped region
> + * @nr_grant_frames: number of GFNs
> + * @return 0 on success, error otherwise
> + *
> + * This allocates a set of ballooned pages and maps them into the
> + * kernel's address space.
> + */
> +int __init xen_xlate_map_ballooned_pages(xen_pfn_t **gfns, void **virt,
> +					 unsigned long nr_grant_frames)
> +{
> +	struct page **pages;
> +	xen_pfn_t *pfns;
> +	void *vaddr;
> +	int rc;
> +	unsigned int i;
> +
> +	BUG_ON(nr_grant_frames == 0);
> +	pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
> +	if (!pages)
> +		return -ENOMEM;
> +
> +	pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
> +	if (!pfns) {
> +		kfree(pages);
> +		return -ENOMEM;
> +	}
> +	rc = alloc_xenballooned_pages(nr_grant_frames, pages);
> +	if (rc) {
> +		pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
> +			nr_grant_frames, rc);
> +		kfree(pages);
> +		kfree(pfns);
> +		return rc;
> +	}
> +	for (i = 0; i < nr_grant_frames; i++)
> +		pfns[i] = page_to_pfn(pages[i]);
> +
> +	vaddr = vmap(pages, nr_grant_frames, 0, PAGE_KERNEL);
> +	if (!vaddr) {
> +		pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
> +			nr_grant_frames, rc);
> +		free_xenballooned_pages(nr_grant_frames, pages);
> +		kfree(pages);
> +		kfree(pfns);
> +		return -ENOMEM;
> +	}
> +	kfree(pages);
> +
> +	*gfns = pfns;
> +	*virt = vaddr;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(xen_xlate_map_ballooned_pages);
> diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
> index e4e214a..42be31a 100644
> --- a/include/xen/xen-ops.h
> +++ b/include/xen/xen-ops.h
> @@ -80,6 +80,8 @@ int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
>  			      struct page **pages);
>  int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
>  			      int nr, struct page **pages);
> +int xen_xlate_map_ballooned_pages(xen_pfn_t **pfns, void **vaddr,
> +				  unsigned long nr_grant_frames);
>  
>  bool xen_running_on_version_or_later(unsigned int major, unsigned int minor);
>  
> -- 
> 2.0.4
> 
> 
> 
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