Re: [PATCH 2/2] KVM: arm64: Ensure TLBs and I-cache are private to each vCPU in pKVM

[Vincent Donnefort <vdonnefort@google.com>]

On Mon, Oct 19, 2026 at 12:43:57PM +0100, Fuad Tabba wrote:
> Hi Vincent,
> 
> On Mon, 19 Oct 2026 11:00:15 +0100, Vincent Donnefort <vdonnefort@google.com> wrote:
> [...]
> > > diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
> [...]
> > > @@ -54,6 +54,9 @@ struct pkvm_hyp_vm {
> > >          unsigned short refcount;
> > >          hyp_spinlock_t lock;
> > >  
> > > +        /* Per physical CPU, the vcpu_idx of the last vCPU of this VM loaded there. */
> > > +        int *last_vcpu_ran;
> > 
> > Unlikely to be a problem in pratice, but vcpu_idx is "unsigned int". I wonder if
> > this shouldn't be unsigned int here too and initialised to UINT_MAX?
> 
> I'd copied int and -1 from the host's mmu->last_vcpu_ran, but the
> vcpu_idx it's comparing against here is unsigned int, so I'll switch to
> unsigned int and UINT_MAX in v2.
> 
> Thanks,
> /fuad

Also,

as it is always allocated when pkvm_hyp_vm is, Would it make sense to add this
to pkvm_get_hyp_vm_size() instead of allocating separately?

-- 
Vincent