Re: [Draft C] Boot ABI for HVM guests without a device-model

[Ian Campbell <ian.campbell@citrix.com>]

On Fri, 2015-09-04 at 10:01 -0600, Jan Beulich wrote:
> > 
> > > > On 04.09.15 at 17:26, <ian.campbell@citrix.com> wrote:
> > On Fri, 2015-09-04 at 09:21 -0600, Jan Beulich wrote:
> > > > > > On 04.09.15 at 16:31, <roger.pau@citrix.com> wrote:
> > > > El 04/09/15 a les 16.08, Jan Beulich ha escrit:
> > > > > > > > On 04.09.15 at 14:11, <roger.pau@citrix.com> wrote:
> > > > > > AP startup
> > > > > > ==========
> > > > > > 
> > > > > > AP startup is performed using hypercalls. The following VCPU 
> > > > > > operations
> > > > > > are used in order to bring up secondary vCPUs:
> > > > > > 
> > > > > >  * VCPUOP_initialise is used to set the initial state of the 
> > > > > > vCPU. 
> > > > > > The
> > > > > >    argument passed to the hypercall must be of the type > > > > 
> > > > > > 
> > vcpu_hvm_context.
> > > > > 
> > > > > VCPUOP_initialise takes a struct vcpu_guest_context; I don't 
> > > > > think
> > > > > we can or should change that.
> > > > 
> > > > Didn't we agree that vcpu_guest_context was not suitable for 
> > > > HVM/PVH 
> > > > guests?
> > > 
> > > Yes we did.
> > > 
> > > > Patch 24 of my HVM-without-dm series already introduces this new
> > > > structure and the necessary helpers.
> > > 
> > > I didn't look at most of the series yet (despite it already being at 
> > > v6;
> > > I'm sorry, I just didn't get around so far). But I think you agree 
> > > that
> > > we can't just change an existing hypercall. Iirc along with agreeing
> > > on vcpu_guest_context not being suitable we also agreed that this
> > > will need to be a new sub-op, and I wondered whether calling it
> > > VCPUOP_initialize would be too subtle.
> > 
> > You mean literally only s/s/z/?
> 
> Indeed ;-)
> 
> > In which case, yes, far far to subtle.
> 
> I was afraid I would get feedback like this (and I was surprised I
> didn't already when I first suggested this).

I think even if I'd have seen it the first time I'd have thought you were
joking...

Ian.