Re: FreeBSD PVH guest support

On 09/11/13 13:04, Roger Pau Monné wrote:
> On 07/11/13 19:10, Roger Pau Monné wrote:
>> On 28/10/13 14:35, Roger Pau Monné wrote:
>>> Hello,
>>>
>>> The Xen community is working on a new virtualization mode (or maybe I 
>>> should say an extension of HVM) to be able to run PV guests inside HVM 
>>> containers without requiring a device-model (Qemu). One of the 
>>> advantages of this new virtualization mode is that now it is much more 
>>> easier to port guests to run under it (as compared to pure PV guests).
>>>
>>> Given that FreeBSD already supports PVHVM, adding PVH support is quite 
>>> easy, we only need some glue for the PV entry point and then support 
>>> for diverging some early init functions (like fetching the e820 map or 
>>> starting the APs).
>>>
>>> The attached patch contains all this changes, and allows a SMP FreeBSD 
>>> guest to fully boot (and AFAIK work) under this new PVH mode. The patch 
>>> can also be found on my git repo:
>>>
>>> git://xenbits.xen.org/people/royger/freebsd.git pvh_v2
>>>
>>> The patch touches quite a lot of the early init, so I've Cced the 
>>> persons that maintain those areas, so they can review it.
>>>
>>> In order to test it, and since the PVH changes are not yet merged into 
>>> upstream Xen, the use of a patched Xen is necessary. I've collected the 
>>> patches for PVH guest support from George Dunlap (v13) and fixed some 
>>> bugs on top of them, the tree can be found at:
>>>
>>> git://xenbits.xen.org/people/royger/xen.git fix_pvh

PVH DomU support has been committed to upstream Xen, and I've updated
the patch to match the interface. The main change is that cr4 is not set
to ctrlreg[4] by Xen, and the AP is launched without the PSE flag set,
so we have to set it on init_secondary.

Patch can be found here:

http://xenbits.xen.org/gitweb/?p=people/royger/freebsd.git;a=commit;h=8db6aa8cbc5b7a2a88f4e4fb51f99a166c128cec

And attached on this email.

Thanks for the review, Roger.