Re: [PATCH v6 03/19] xen/riscv: introduce VMID allocation and manegement

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 12/9/25 8:51 AM, Jan Beulich wrote:
> On 08.12.2025 18:28, Teddy Astie wrote:
> > Le 24/11/2025 à 13:36, Oleksii Kurochko a écrit :
> > > diff --git a/docs/misc/xen-command-line.pandoc 
> > > b/docs/misc/xen-command-line.pandoc
> > > index 34004ce282..6c4bfa3603 100644
> > > --- a/docs/misc/xen-command-line.pandoc
> > > +++ b/docs/misc/xen-command-line.pandoc
> > > @@ -3096,3 +3096,12 @@ the hypervisor was compiled with `CONFIG_XSM` enabled.
> > >    * `silo`: this will deny any unmediated communication channels between
> > >      unprivileged VMs.  To choose this, the separated option in kconfig must 
> > > also
> > >      be enabled.
> > > +
> > > +### vmid (RISC-V)
> > > +> `= <boolean>`
> > > +
> > > +> Default: `true`
> > > +
> > > +Permit Xen to use Virtual Machine Identifiers. This is an optimisation which
> > > +tags the TLB entries with an ID per vcpu. This allows for guest TLB flushes
> > > +to be performed without the overhead of a complete TLB flush.
> > Should we regroup all asid/vpid/vmid (which are pretty much the same
> > thing with different names and for different arch) under a single
> > command-line option ?
> How would you name such an option, without losing it being recognized by people
> knowing the respective arch?
Teddy,

I would also like to note that, for RISC-V, both the terms ASID and VMID are 
used.
Therefore, I prefer to have separate command-line options and not overcomplicate
things. Furthermore, these options are used only in architecture-specific code,
so it would be best to follow the relevant architecture-specific documentation
and specifications.

~ Oleksii