Re: access shared_info?

[Chris Wright <chrisw@sous-sol.org>]

* Gerd Hoffmann (kraxel@suse.de) wrote:
> Keir Fraser wrote:
> > Oh, I see it's moved to a new function. I guess that's okay, although
> > couldn't you fake up an e820 map and call legacy_init_iomem_resource on
> > the domU path, rather than having to pull code out into a new function?
> > Does this patch change behaviour for dom0 at all? I think /proc/iomem
> > already looks like native there? Also the patch will need to include
> > x86/64 too.
> 
> new version attached.

Might want to double check against linux-2.6.tip-xen, as that code has
changed a bit since 2.6.16.

> diff -r c191c649cdb3 linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c
> --- a/linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c	Tue Jun  6 09:25:59 2006
> +++ b/linux-2.6-xen-sparse/arch/i386/kernel/setup-xen.c	Wed Jun  7 19:24:19 2006
> @@ -1378,7 +1378,6 @@
>  		res->end = res->start + e820[i].size - 1;
>  		res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
>  		request_resource(&iomem_resource, res);
> -#ifndef CONFIG_XEN
>  		if (e820[i].type == E820_RAM) {
>  			/*
>  			 *  We don't know which RAM region contains kernel data,
> @@ -1391,7 +1390,6 @@
>  			request_resource(res, &crashk_res);
>  #endif
>  		}
> -#endif
>  	}
>  }
>  
> @@ -1460,8 +1458,16 @@
>  	int	      i;
>  
>  	/* Nothing to do if not running in dom0. */
> -	if (!(xen_start_info->flags & SIF_INITDOMAIN))
> +	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
> +		struct e820entry domU_e820 = {
> +			.addr = 0,
> +			.size = max_pfn << PAGE_SHIFT,
> +			.type = E820_RAM,
> +		};

Or just do this during normal setup, then it is the base e820 map.  I
believe it's already done isn't it?

		memmap.nr_entries = 1;
		map[0].addr = 0ULL;
		map[0].size = xen_start_info->nr_pages << PAGE_SHIFT;
		/* 8MB slack (to balance backend allocations). */
		map[0].size += 8 << 20;
		map[0].type = E820_RAM;
...
	BUG_ON(copy_e820_map(map, (char)memmap.nr_entries) < 0);