Re: [Xen-devel] [BUGFIX] [PATCH] kexec/x86: Do map crash kernel area

[Don Slutz <dslutz@xxxxxxxxxxx>]

On 01/02/14 06:49, David Vrabel wrote:
> On 02/01/14 10:48, Andrew Cooper wrote:
> > On 02/01/14 10:46, David Vrabel wrote:
> > > On 01/01/14 16:51, Don Slutz wrote:
> > > > Revert of commit 7113a45451a9f656deeff070e47672043ed83664
> > > Since this commit introduced a regression, a revert is the best thing to
> > > do here.
> > >
> > > Acked-by: David Vrabel <david.vrabel@xxxxxxxxxx>
> > >
> > > > Using kexec commit 027413d822fd57dd39d2d2afab1484bc6b6b84f9
> > > >
> > > > With "crashkernel=256M@256M" ((XEN) Kdump: 256MB (262144kB) at 0x10000000)
> > > I guess Daniel tested a debug build without this crashkernel option.
> > > This would place the crash region above the direct mapping region and
> > > map_domain_page() would do the right thing.
> > >
> > >
> > > > +    map_pages_to_xen((unsigned long)__va(kexec_crash_area.start),
> > > > +                     kexec_crash_area.start >> PAGE_SHIFT,
> > > > +                     PFN_UP(kexec_crash_area.size), PAGE_HYPERVISOR);
> > > > +
> > > This should be made conditional on the location of the crash region --
> > > it is wrong to do this for portions of the crash region that are outside
> > > the crash region.
> > Presume you mean "outside the direct-map region"?
> Yes.
>
> David
I have no idea on how to even check for "outside the direct-map region" 
and how to test any additional changes.  Testing with "crashkernel=256M" 
((XEN) Kdump: 256MB (262144kB) at 0x82a1be000) does not work before or 
after this patch.  In both cases, I get an error out of kexec:
~/kexec/build/sbin/kexec -p '--command-line=placeholder 
root=/dev/mapper/vg_f17--xen-lv_root ro rd.md=0 rd.dm=0 
rd.lvm.lv=vg_f17-xen/lv_swap KEYTABLE=us SYSFONT=True rd.luks=0 
console=ttyS0,9600n8 rd.lvm.lv=vg_f17-xen/lv_root LANG=en_US.UTF-8 
earlyprintk=ttyS0 rd_NO_PLYMOUTH irqpoll nr_cpus=1 reset_devices 
cgroup_disable=memory mce=off' 
--initrd=/boot/initramfs-3.8.11-100.fc17.x86_64kdump.img 
/boot/vmlinuz-3.8.11-100.fc17.x86_64
Could not find a free area of memory of 0xa000 bytes...
locate_hole failed

I am currently busy with other tasks and so do not expect to get to 
learning about xen's direct-map region and/or finding out why kexec does 
not work in this case before xen 4.4.0 release date.
   -Don Slutz

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel