KVM: arm64: Add ICH_HCR_EL2 to the vcpu state

As we are about to describe the trap routing for ICH_HCR_EL2, add
the register to the vcpu state in its VNCR form, as well as reset
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-7-maz@kernel.orgSigned-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_host.h

@@ -530,6 +530,8 @@ enum vcpu_sysreg {
 	VNCR(CNTP_CVAL_EL0),
 	VNCR(CNTP_CTL_EL0),
 
+	VNCR(ICH_HCR_EL2),
+
 	NR_SYS_REGS	/* Nothing after this line! */
 };
 

arch/arm64/kvm/sys_regs.c

@@ -2797,6 +2797,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	EL2_REG(RVBAR_EL2, access_rw, reset_val, 0),
 	{ SYS_DESC(SYS_RMR_EL2), trap_undef },
 
+	EL2_REG_VNCR(ICH_HCR_EL2, reset_val, 0),
+
 	EL2_REG(CONTEXTIDR_EL2, access_rw, reset_val, 0),
 	EL2_REG(TPIDR_EL2, access_rw, reset_val, 0),