Re: [PATCH for-4.5 v6 05/16] tools: Add vmware_port support

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 22/09/14 14:41, Ian Campbell wrote:
> On Sat, 2014-09-20 at 14:07 -0400, Don Slutz wrote:
>> This new libxl_domain_create_info field is used to set
>> XEN_DOMCTL_CDF_vmware_port for the xc_domain_create() routine.
> Does this really need to be a CDF, rather than a domctl/hvm param?

I have made the argument that many things which are currently HVM Params
should be CDF, as they absolutely should be set and immutable for the
entire lifetime of the domain.

>From recollection, we have had several XSAs in the past which are
directly attributable to the toolstack or guest being able to play with
an (insufficiently locked down) HVM param after boot.

Using a CDF avoids potential issues along these lines.

>
> The latter would allow moving to buildinfo.u.hvm, which would be nicer
> from the libxl PoV, I think.
>

Whatever the decision regarding CDF/hvmparam/other is, getting it right
in the hypervisor is a much higher priority than being nice in libxl.

It is unfortunate that libxl exposes the internal implementation details
of createinfo vs buildinfo in its API.  With hindsight, it was a poor
design decision.

~Andrew