Re: [PATCH 7/9] xen/x86: hook up xen_banner() also for PVH

[Juergen Gross <jgross@xxxxxxxx>]

On 23.09.21 17:19, Jan Beulich wrote:
> On 23.09.2021 17:15, Juergen Gross wrote:
> > On 23.09.21 17:10, Jan Beulich wrote:
> > > On 23.09.2021 16:59, Juergen Gross wrote:
> > > > On 07.09.21 12:11, Jan Beulich wrote:
> > > > > This was effectively lost while dropping PVHv1 code. Move the function
> > > > > and arrange for it to be called the same way as done in PV mode. Clearly
> > > > > this then needs re-introducing the XENFEAT_mmu_pt_update_preserve_ad
> > > > > check that was recently removed, as that's a PV-only feature.
> > > > >
> > > > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> > > > >
> > > > > --- a/arch/x86/xen/enlighten.c
> > > > > +++ b/arch/x86/xen/enlighten.c
> > > > > @@ -261,6 +261,18 @@ int xen_vcpu_setup(int cpu)
> > > > >         return ((per_cpu(xen_vcpu, cpu) == NULL) ? -ENODEV : 0);
> > > > >     }
> > > > >     
> > > > > +void __init xen_banner(void)
> > > > > +{
> > > > > +       unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
> > > > > +       struct xen_extraversion extra;
> > > > Please add a blank line here.
> > > Oops.
> > >
> > > > > +       HYPERVISOR_xen_version(XENVER_extraversion, &extra);
> > > > > +
> > > > > +       pr_info("Booting paravirtualized kernel on %s\n", pv_info.name);
> > > > Is this correct? I don't think the kernel needs to be paravirtualized
> > > > with PVH (at least not to the same extend as for PV).
> > > What else do you suggest the message to say? Simply drop
> > > "paravirtualized"? To some extent it is applicable imo, further
> > > qualified by pv_info.name. And that's how it apparently was with
> > > PVHv1.
> > The string could be selected depending on CONFIG_XEN_PV.
> Hmm, now I'm confused: Doesn't this setting control whether the kernel
> can run in PV mode? If so, that functionality being present should have
> no effect on the functionality of the kernel when running in PVH mode.
> So what you suggest would end up in misleading information imo.
Hmm, yes, I mixed "paravirtualized" with "capable to run
paravirtualized".

So the string should depend on xen_pv_domain().


Juergen

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