[PATCH v2 1/7] xen: Improve calculation of beginning of virtual address space

[Atsushi Kumagai]

On Tue, 16 Jul 2013 14:32:03 +0200
Daniel Kiper <daniel.kiper at oracle.com> wrote:

> Xen commit 4b28bf6ae90bd83fd1113d8bdc53c3266ffeb328 (x86: re-introduce
> map_domain_page() et al) once again altered virtual address space.
> Current algorithm calculating its start could not cope with that change.
> New version establishes this value on the base of domain_list placement
> and is more generic.
> 
> Similar patch was applied to crash tool.
> 
> Signed-off-by: Daniel Kiper <daniel.kiper at oracle.com>

OK, I'll merge this patch into v1.5.5.


Thanks
Atsushi Kumagai

> ---
>  arch/x86_64.c  |   16 +++++++++++-----
>  makedumpfile.h |    2 --
>  2 files changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86_64.c b/arch/x86_64.c
> index 8e61b20..d864a06 100644
> --- a/arch/x86_64.c
> +++ b/arch/x86_64.c
> @@ -372,14 +372,20 @@ int get_xen_basic_info_x86_64(void)
>  		info->xen_phys_start = info->xen_crash_info.v2->xen_phys_start;
>  	}
>  
> +	info->xen_virt_start = SYMBOL(domain_list);
> +
> +	/*
> +	 * Xen virtual mapping is aligned to 1 GiB boundary.
> +	 * domain_list lives in bss which sits no more than
> +	 * 1 GiB below beginning of virtual address space.
> +	 */
> +	info->xen_virt_start &= 0xffffffffc0000000;
> +
>  	if (info->xen_crash_info.com &&
> -	    info->xen_crash_info.com->xen_major_version >= 4) {
> -		info->xen_virt_start = XEN_VIRT_START_V4;
> +	    info->xen_crash_info.com->xen_major_version >= 4)
>  		info->directmap_virt_end = DIRECTMAP_VIRT_END_V4;
> -	} else {
> -		info->xen_virt_start = XEN_VIRT_START_V3;
> +	else
>  		info->directmap_virt_end = DIRECTMAP_VIRT_END_V3;
> -	}
>  
>  	if (SYMBOL(pgd_l4) == NOT_FOUND_SYMBOL) {
>  		ERRMSG("Can't get pml4.\n");
> diff --git a/makedumpfile.h b/makedumpfile.h
> index a5826e0..1a87500 100644
> --- a/makedumpfile.h
> +++ b/makedumpfile.h
> @@ -1473,8 +1473,6 @@ int get_xen_info_x86(void);
>  #define DIRECTMAP_VIRT_END_V3 (0xffff840000000000)
>  #define DIRECTMAP_VIRT_END_V4 (0xffff880000000000)
>  #define DIRECTMAP_VIRT_END    (info->directmap_virt_end)
> -#define XEN_VIRT_START_V3     (0xffff828c80000000)
> -#define XEN_VIRT_START_V4     (0xffff82c480000000)
>  #define XEN_VIRT_START        (info->xen_virt_start)
>  #define XEN_VIRT_END          (XEN_VIRT_START + (1UL << 30))
>  #define FRAMETABLE_VIRT_START 0xffff82f600000000
> -- 
> 1.7.10.4