Image format for an HVM domain

Image format for an HVM domain

[Jean-Yves Migeon (NetBSD)]

Hi list,

Is there a documentation somewhere where the image format for 
xc_domain_save/_restore is specified, or at least described?

I am looking for one regarding an HVM domU, but can't find any in the 
wiki -- Most notably, I am interested in knowing how the P2M translation 
tables are dumped, in case they are differences from the one for a PV 
domU. Purpose is to add its support to our NetBSD crash(8) program.

Cheers,

-- 
Jean-Yves Migeon
jym@NetBSD.org

Re: Image format for an HVM domain

[Mats Petersson]

On 14/11/12 14:31, Jean-Yves Migeon (NetBSD) wrote:
> Hi list,
>
> Is there a documentation somewhere where the image format for
> xc_domain_save/_restore is specified, or at least described?
I'm not aware of anything besides the source code itself.
libxc/xc_domain_restore, particularly apply_batch and pagebuf_get_one 
are fairly straight forward.

>
> I am looking for one regarding an HVM domU, but can't find any in the
> wiki -- Most notably, I am interested in knowing how the P2M translation
> tables are dumped, in case they are differences from the one for a PV
> domU. Purpose is to add its support to our NetBSD crash(8) program.
>
The main differences between pv and hvm can be found by searching for 
"hvm", such as:
      region_mfn[i] = hvm ? pfn : ctx->p2m[pfn];

Obviously, xc_domain_save is what produces the output, and will also 
contain the corresponding "if (hvm)" and "if (!hvm)" type of 
constructions to do things that only happen in PV or HVM guests.

The actual content format is the same, the difference is derived from 
"is this PV or HVM".

--
Mats
>
> Cheers,
>

Re: Image format for an HVM domain

[Ian Campbell]

On Wed, 2012-11-14 at 14:48 +0000, Mats Petersson wrote:
> On 14/11/12 14:31, Jean-Yves Migeon (NetBSD) wrote:
> > Hi list,
> >
> > Is there a documentation somewhere where the image format for
> > xc_domain_save/_restore is specified, or at least described?
> I'm not aware of anything besides the source code itself.

tools/libxc/xg_save_restore.h has something of a protocol doc at the
top.

Ian.