Re: [PATCH v2] KVM: arm64: Restore the VM's feature bitmap when kvm_setup_vcpu() fails

[Lorenzo Stoakes (ARM)]

On Mon, Sep 21, 2026 at 08:24:56AM +0100, Fuad Tabba wrote:
> Hi Oliver,
>
> On Mon, 21 Sep 2026 00:09:17 -0700, Oliver Upton <oupton@xxxxxxxxxx> wrote:
> [...]
> > > Nothing in the tree loads a vCPU whose init failed, so this is latent.
> > > The upcoming series that enables KVM_PRE_FAULT_MEMORY for arm64 exposes
> > > it: the generic kvm_vcpu_pre_fault_memory() calls vcpu_load() whether
> > > or not the vCPU has been initialised.
> >
> > That's a bug, not a feature. We should require an initialized vcpu for
> > the ioctl.
>
> That one is for Lorenzo then :) I'll reword the message so the stale
> bitmap comes first and the pre-fault crash is just how it showed up.

Let me dig into this.

--
Cheers, Lorenzo