KVM: MIPS: Let indexed cacheops cause guest exit on Loongson-3

Loongson-3's indexed cache operations need a node-id in the address,
but in KVM guest the node-id may be incorrect. So, let indexed cache
operations cause guest exit on Loongson-3.
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <1590220602-3547-9-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/mips/kvm/vz.c

@@ -2853,8 +2853,12 @@ static int kvm_vz_hardware_enable(void)
 	write_c0_guestctl0(MIPS_GCTL0_CP0 |
 			   (MIPS_GCTL0_AT_GUEST << MIPS_GCTL0_AT_SHIFT) |
 			   MIPS_GCTL0_CG | MIPS_GCTL0_CF);
-	if (cpu_has_guestctl0ext)
-		set_c0_guestctl0ext(MIPS_GCTL0EXT_CGI);
+	if (cpu_has_guestctl0ext) {
+		if (current_cpu_type() != CPU_LOONGSON64)
+			set_c0_guestctl0ext(MIPS_GCTL0EXT_CGI);
+		else
+			clear_c0_guestctl0ext(MIPS_GCTL0EXT_CGI);
+	}
 
 	if (cpu_has_guestid) {
 		write_c0_guestctl1(0);