Remove the unstable_whp feature

[jstarks]

The WHP aarch64 support is no longer unstable—it is the only supported configuration. Remove the unstable_whp cargo feature and all associated cfg guards, making the previously-gated behavior unconditional.

This removes the feature from six Cargo.toml files (whp, virt_whp, openvmm, openvmm_entry, openvmm_resources, openvmm_core, tmk_vmm), simplifies cfg guards in whp's abi.rs and virt_whp's lib.rs, removes the UnstableWhp variant from the flowey build system, drops the --unstable-whp CLI flag from vmm-tests-run, and removes the related shell script logic from the cross-compilation guide.

[Copilot]

Pull request overview

This PR removes the unstable_whp Cargo feature and related conditional compilation/CLI/build-system plumbing, making the previously gated WHP aarch64 behavior unconditional now that it’s the only supported configuration.

Changes:

• Deletes the unstable_whp feature from relevant crates and removes associated cfg(feature = "unstable_whp") guards.
• Simplifies WHP aarch64 code paths to always compile/execute on guest_arch = "aarch64".
• Removes UnstableWhp handling from Flowey build/test pipelines, the vmm-tests-run CLI, and cross-compilation guide scripting.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
vmm_core/virt_whp/src/lib.rs	Makes previously unstable_whp-gated aarch64 WHP behavior unconditional under guest_arch = "aarch64".
vmm_core/virt_whp/Cargo.toml	Removes the unstable_whp feature definition from virt_whp.
vm/whp/src/abi.rs	Removes unstable_whp gating from an aarch64 ABI struct field.
vm/whp/Cargo.toml	Removes the unstable_whp feature definition from whp.
tmk/tmk_vmm/Cargo.toml	Drops forwarding of the removed unstable_whp feature to virt_whp.
openvmm/openvmm/Cargo.toml	Removes the top-level unstable_whp feature from openvmm.
openvmm/openvmm_resources/Cargo.toml	Removes unstable_whp feature wiring to openvmm_core.
openvmm/openvmm_entry/Cargo.toml	Removes unstable_whp feature wiring to virt_whp/whp.
openvmm/openvmm_core/Cargo.toml	Removes unstable_whp feature wiring to virt_whp.
Guide/src/dev_guide/getting_started/cross_compile.md	Removes shell-script logic that enabled --features unstable_whp.
flowey/flowey_lib_hvlite/src/build_tmk_vmm.rs	Removes unstable_whp request parameter and feature selection when building tmk_vmm.
flowey/flowey_lib_hvlite/src/build_openvmm.rs	Removes the UnstableWhp build feature variant from Flowey’s openvmm builder.
flowey/flowey_lib_hvlite/src/_jobs/local_build_and_run_nextest_vmm_tests.rs	Removes propagation of unstable_whp through the local VMM test job.
flowey/flowey_hvlite/src/pipelines/vmm_tests_run.rs	Drops the --unstable-whp CLI flag and pipeline wiring.
flowey/flowey_hvlite/src/pipelines/checkin_gates.rs	Removes CI/pipeline selection logic that previously enabled UnstableWhp for aarch64 runners.