Re: update_va_mapping failing on recent core i7 980X

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

On 17.12.2010 11:47, Jean-Yves Migeon wrote:
> Hi list,
>
> I am currently trying to boot an amd64 dom0 kernel (5.0, 5.1, current)
> with Xen 3.3 on a recent core i7 980X host (with 6GiB RAM).
>
> Thing is, boot fails very early, in pmap_prealloc_lowmem_ptps(). At
> level == 4 (first iteration in the loop), the:
>
> ...
> avail_start += PAGE_SIZE;
> HYPERVISOR_update_va_mapping ((vaddr_t)early_zerop,
>                     xpmap_ptom_masked(newp) | PG_u | PG_V | PG_RW,
> UVMF_INVLPG);
> ...
>
> code seems to cause some sort of fault at hypervisor level, leading to a
> reboot.

Conclusion: the hypervisor does not seem to like to be chainloaded from
grub. GRUB => NetBSD /boot => xen.gz fails, but with the exact same
commands directly from GRUB, it works fine.

So... I am not sure what happens at memory level with all these
chainloaded bootloaders, but as x86 is so lovely to debug in real mode,
I assume the issue "solved." Sorry for the noise.

-- 
Jean-Yves Migeon
jeanyves.migeon%free.fr@localhost