Allow userspace to change the guest-visible value of the register with some severe limitation: - No changes to features not virtualized by KVM (MPAM_frac, RAS_frac) Also add the selftest for it. Changelog: ---------- v1 -> v2: * Tackling the full register instead of single field. * Changing the patch title and commit message. RFCv1 -> v1: * Fix the compilation error. * Delete the machine specific information and make the description more generable. RFCv1: https://lore.kernel.org/all/20240612023553.127813-1-shahuang@xxxxxxxxxx/ v1: https://lore.kernel.org/all/20240617075131.1006173-1-shahuang@xxxxxxxxxx/ Shaoqin Huang (2): KVM: arm64: Allow userspace to change ID_AA64PFR1_EL1 KVM: selftests: aarch64: Add writable test for ID_AA64PFR1_EL1 arch/arm64/kvm/sys_regs.c | 3 ++- tools/testing/selftests/kvm/aarch64/set_id_regs.c | 9 +++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) -- 2.40.1