LoongArch: KVM: Implement kvm exception vectors

Implement kvm exception vectors, using kvm_fault_tables array to save
the handle function pointers and it is used when vcpu handle guest exit.

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: zhaotianrui-loongson

arch/loongarch/kvm/exit.c

@@ -658,3 +658,39 @@ static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcpu)
 
 	return RESUME_GUEST;
 }
+
+/*
+ * LoongArch KVM callback handling for unimplemented guest exiting
+ */
+static int kvm_fault_ni(struct kvm_vcpu *vcpu)
+{
+	unsigned int ecode, inst;
+	unsigned long estat, badv;
+
+	/* Fetch the instruction */
+	inst = vcpu->arch.badi;
+	badv = vcpu->arch.badv;
+	estat = vcpu->arch.host_estat;
+	ecode = (estat & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
+	kvm_err("ECode: %d PC=%#lx Inst=0x%08x BadVaddr=%#lx ESTAT=%#lx\n",
+			ecode, vcpu->arch.pc, inst, badv, read_gcsr_estat());
+	kvm_arch_vcpu_dump_regs(vcpu);
+	kvm_queue_exception(vcpu, EXCCODE_INE, 0);
+
+	return RESUME_GUEST;
+}
+
+static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = {
+	[0 ... EXCCODE_INT_START - 1]	= kvm_fault_ni,
+	[EXCCODE_TLBI]			= kvm_handle_read_fault,
+	[EXCCODE_TLBL]			= kvm_handle_read_fault,
+	[EXCCODE_TLBS]			= kvm_handle_write_fault,
+	[EXCCODE_TLBM]			= kvm_handle_write_fault,
+	[EXCCODE_FPDIS]			= kvm_handle_fpu_disabled,
+	[EXCCODE_GSPR]			= kvm_handle_gspr,
+};
+
+int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault)
+{
+	return kvm_fault_tables[fault](vcpu);
+}