tree de3adbc8d296c4f788f7bf35f3825ce91ea1afb7
parent 6c7f31dd7ba77bfd432e1b5c369fff798091f5d9
author Marc Zyngier <maz@kernel.org> 1709024603 +0000
committer Marc Zyngier <maz@kernel.org> 1714570321 +0100

KVM: arm64: vgic: Allocate private interrupts on demand

Private interrupts are currently part of the CPU interface structure
that is part of each and every vcpu we create.

Currently, we have 32 of them per vcpu, resulting in a per-vcpu array
that is just shy of 4kB. On its own, that's no big deal, but it gets
in the way of other things:

- each vcpu gets mapped at EL2 on nVHE/hVHE configurations. This
  requires memory that is physically contiguous. However, the EL2
  code has no purpose looking that the interrupt structures and
  could do without them being mapped.

- supporting features such as EPPIs, which extend the number of
  privrate interrupts past the 32 limit would make the array
  even larger, even for VMs that do not use the EPPI feature.

Address these issues by moving the private interrupt array outside
of the vcpu, and replace it with a simple pointer. We take this
opportunity to make it obvious what gets initialised when, as
that path was remarkably opaque, and tighten the locking.

Signed-off-by: Marc Zyngier <maz@kernel.org>