Re: [PATCH v2 04/26] xen: consolidate CONFIG_VM_EVENT

[Tamas K Lengyel <tamas@xxxxxxxxxxxxx>]

> > @@ -99,10 +98,40 @@ long p2m_set_mem_access_multi(struct domain *d,
> >  int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t 
> > *access,
> >                         unsigned int altp2m_idx);
> >
> > -#ifdef CONFIG_VM_EVENT
> >  int mem_access_memop(unsigned long cmd,
> >                       XEN_GUEST_HANDLE_PARAM(xen_mem_access_op_t) arg);
> >  #else
> > +static inline bool xenmem_access_to_p2m_access(const struct p2m_domain 
> > *p2m,
> > +                                               xenmem_access_t xaccess,
> > +                                               p2m_access_t *paccess)
> > +{
> > +    return false;
> > +}
>
> So this is needed when VM_EVENT=n and ALTP2M=y. Tamas, is this a configuration
> which makes sense?

Yes, altp2m should be functional without vm_event being enabled. There
could very well be in-guest only use of altp2m via #VE. This function
is used in p2m_init_next_altp2m which means it being stubbed out like
this when vm_event is disabled breaks altp2m.

Tamas