[Patch][RFC] makedumpfile: fix for xen-3.1.2

[Akio Takebe]

Hi, Ohmichi-san

Thank you very much for you report.

>Akio Takebe wrote:
>> This patch fixes makedumpfile for xen-3.1.
>> xen-3.1.2+ hypervisor doesn't have idle_pg_table_l3,
>> we need to find a symbole of idle_pg_table.
>
>Thank you for the patch !
>I tested your patch with RHEL5.2-beta, and it worked fine on i386 machine.
>But it doesn't work on x86_64 machine. makedumpfile went to the loop in
>kvtop_xen_x86_64(), and it failed with a segmentation fault:
>
>makedumpfile/x86_64.c
> 196         if ((dirp = kvtop_xen_x86_64(SYMBOL(pgd_l4))) == NOT_PADDR) <- 
>*HERE*
> 197                 return NOT_PADDR;
>
>
>If you know, please teach me. Should this patch fix the problem for
>not only the upstream but also RHEL5.2 ?
>Unfortunately I don't know the detail of xen, and I haven't used the
>upstream xen yet. 
Sorry for that. 
Yes, this patch will fix also RHEL5.2 because the base is 3.1.2.
https://www.redhat.com/archives/rhelv5-list/2008-March/msg00111.html

The bug may be occurred by changing __XEN_VIRT_START.
http://xenbits.xensource.com/xen-3.1-testing.hg?rev/a06a28ebad5d

So we may be able to fix it by changing DIRECTMAP_VIRT_START.

I didn't have x86_64 system.
I'll setup x86_64 system, and try to investigate it next week.

Best Regards,

Akio Takebe