ICC_IGRPEN0_EL1_MASK
vmcr.grpen0 = FIELD_GET(ICC_IGRPEN0_EL1_MASK, val);
*val = FIELD_PREP(ICC_IGRPEN0_EL1_MASK, vmcr.grpen0);
write_sysreg_s(ICC_IGRPEN0_EL1_MASK, SYS_ICC_IGRPEN1_EL1);