Wrap read and write operations on consts::NCPU so users won't see unsafe anymore.

[FlowerBlackG]

Wrap read and write operations on consts::NCPU so users won't see unsafe anymore.

[Copilot]

Pull Request Overview

This PR wraps all direct accesses to the unsafe global NCPU with safe accessor functions to hide unsafety from users.

• Replace direct unsafe reads/writes on NCPU with consts::ncpu() and consts::set_ncpu().
• Update related call sites across zone, main, hypercall, irqchip, and other modules.
• Remove the now-unused MAX_CPUS constant from virtio_trampoline.

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/zone.rs	Updated Zone initialization to use consts::ncpu() instead of unsafe consts::NCPU.
src/main.rs	Replaced the unsafe block that assigned to consts::NCPU with a call to consts::set_ncpu(ncpu).
src/ivc.rs	Renamed the unused tuple field from is_new to _is_new in the ivc record insertion.
src/hypercall/mod.rs	Updated loops and conditionals to use consts::ncpu() instead of unsafe consts::NCPU.
src/device/virtio_trampoline.rs	Removed the unused MAX_CPUS constant to enforce dynamic CPU count.
src/device/irqchip/gicv3/vgic.rs	Replaced unsafe consts::NCPU calls with safe consts::ncpu() calls in loops/conditions.
src/device/irqchip/gicv3/mod.rs	Updated PendingIrqs initialization to use consts::ncpu().
src/device/irqchip/gicv3/gicr.rs	Replaced unsafe access to consts::NCPU with consts::ncpu() in iteration.
src/device/irqchip/gicv2/mod.rs	Updated PendingIrqs initialization to use consts::ncpu().
src/consts.rs	Added safe accessor functions (ncpu and set_ncpu) replacing direct unsafe access.
src/arch/aarch64/mm.rs	Updated setup_parange and assert conditions to use consts::ncpu() instead of unsafe consts::NCPU.

Comments suppressed due to low confidence (2)

src/ivc.rs:160

• [nitpick] The use of '_is_new' properly indicates that the variable is intentionally unused; consider adding a brief in-line comment if this placeholder might be revisited in future changes.

if let Ok((_is_new, start_paddr)) = insert_ivc_record(ivc_config, self.id as _)

src/device/virtio_trampoline.rs:43

• Since MAX_CPUS is removed in favor of a dynamic CPU count via consts::ncpu(), please ensure no residual references to this constant remain elsewhere in the codebase.

pub const MAX_CPUS: usize = 4;