[PATCH v4 12/25] KVM: arm64: Add infrastructure to create and track pKVM instances at EL2

[Quentin Perret]

On Monday 17 Oct 2022 at 12:51:56 (+0100), Will Deacon wrote:
> +struct pkvm_hyp_vm {
> +	struct kvm kvm;
> +
> +	/* Backpointer to the host's (untrusted) KVM instance. */
> +	struct kvm *host_kvm;
> +
> +	/*
> +	 * Total amount of memory donated by the host for maintaining
> +	 * this 'struct pkvm_hyp_vm' in the hypervisor.
> +	 */
> +	size_t donated_memory_size;

I think you could get rid of that member. IIUC, all you need to
re-compute it in the teardown path is the number of created vCPUs on
the host, which we should have safely stored in
pkvm_hyp_vm::kvm::created_vcpus.

> +	/* The guest's stage-2 page-table managed by the hypervisor. */
> +	struct kvm_pgtable pgt;
> +
> +	/*
> +	 * The number of vcpus initialized and ready to run.
> +	 * Modifying this is protected by 'vm_table_lock'.
> +	 */
> +	unsigned int nr_vcpus;
> +
> +	/* Array of the hyp vCPU structures for this VM. */
> +	struct pkvm_hyp_vcpu *vcpus[];
> +};

Cheers,
Quentin