Re: [PATCH v23 13/14] KVM: arm64: Mandate VGIC v3 for pKVM VMs and Realms

[Suzuki K Poulose]

On 07/10/2026 14:45, Fuad Tabba wrote:
> Hi Suzuki,
>
> On Wed, 07 Oct 2026 08:35:36 +0100, Suzuki K Poulose
> <suzuki.poulose@xxxxxxx> wrote:
> > pKVM does not trust the host. Realm VMs follow a similar trust model, with
> > the Realm Management Monitor owning the protected state instead of the
> > host. Add a helper to identify VMs that run under a host-distrusting
> > hypervisor.
>
> When I reviewed this in v21, the Realm patches that use this came
> later in the same series. Without them, kvm_vm_hyp_is_distrusting() is
> true exactly when is_protected_kvm_enabled() is, and protected mode
> already doesn't register a GICv2, so this patch doesn't change
> anything on its own. Should it move to the series that adds Realms?

But the second part of the changes are required for pKVM today, right ?
and you requested that here. The check as such is useful, except that
it is using kvm_vm_hyp_is_distrusting() rather than 
is_protected_kvm_enabled(). I don't see this as a problem as this is
not a hotpath anyway.

https://lore.kernel.org/all/CA+EHjTzKjjEuAuoOuzGG0uKyVZE-r+CEreca2H2kEQYuRPpgUw@xxxxxxxxxxxxxx

Cheers
Suzuki>
> Cheers,
> /fuad