Re: [PATCH v2 1/4] xl: Add support for ignore_msrs option

[Julien Grall <julien@xxxxxxx>]

On 22/01/2021 18:28, Boris Ostrovsky wrote:
> On 1/22/21 4:52 AM, Julien Grall wrote:
> > Hi Boris,
> >
> > On 20/01/2021 22:49, Boris Ostrovsky wrote:
> > > This option allows guest administrator specify what should happen when
> > > guest accesses an MSR which is not explicitly emulated by the hypervisor.
> > >
> > > Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> > > ---
> > >    docs/man/xl.cfg.5.pod.in         | 20 +++++++++++++++++++-
> > >    tools/libs/light/libxl_types.idl |  7 +++++++
> > >    tools/xl/xl_parse.c              |  7 +++++++
> > >    3 files changed, 33 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> > > index c8e017f950de..96ce97c42cab 100644
> > > --- a/docs/man/xl.cfg.5.pod.in
> > > +++ b/docs/man/xl.cfg.5.pod.in
> > > @@ -2044,7 +2044,25 @@ Do not provide a VM generation ID.
> > >    See also "Virtual Machine Generation ID" by Microsoft:
> > >    
> > > L<https://docs.microsoft.com/en-us/windows/win32/hyperv_v2/virtual-machine-generation-identifier>
> > >    -=back
> > > +=over
> > > +
> > > +=item B<ignore_msrs="STRING">
> > > +
> > > +Determine hypervisor behavior on accesses to MSRs that are not emulated by the 
> > > hypervisor.
> > The description of the feature looks very x86 focus. Yet, it seems to be 
> > defined as a generic one.
> >
> > Could you clarify whether this is intended to be re-usable by other 
> > architectures?
>
> x86 only. I'll add appropriate note.
Thanks. In which case, I would suggest to move the definition of 
ignore_msrs in the idle to an x86 specific structure. Maybe "arch_x86"?
I noticed that none exists today, but we could duplicate that "arch_arm" 
one.
Wei, Ian, what do you think?

Cheers,

--
Julien Grall