google / alioth / 20385931445 / 1

26%

main: 26%

push

github

fix(hv): distinguish between VCPU index and identity

Alioth uses a VCPU index (0..num_cpus) to manage VCPUs internally.
However, the underlying hypervisor or the hardware uses an
architecture-dependent identity for each CPU, such as MPIDR on aarch64
and APIC ID on x86_64.

This commit introduces a clear distinction between the VCPU index and
the VCPU identity:

- The VCPU index is consistently represented as `u16`.
- A new method `encode_cpu_identity(index: u16) -> u64` is added to
  struct `Board` to translate an index into the corresponding identity.
- The `Vm::create_vcpu` method is updated to accept both the index and
  the identity.
- On aarch64, Alioth now generates and provides the MPIDR to the
  hypervisor, ensuring a consistent CPU topology.

Signed-off-by: Changyuan Lyu <changyuanl@google.com>

394 of 638 branches covered (61.76%)

Branch coverage included in aggregate %.

3403 of 13855 relevant lines covered (24.56%)

21.81 hits per line