1 files changed, 91 insertions, 0 deletions
diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
index 37bc8a4209bd..7e729dd9e915 100644
--- a/arch/loongarch/kvm/exit.c
+++ b/arch/loongarch/kvm/exit.c
@@ -103,3 +103,94 @@ static int kvm_handle_csr(struct kvm_vcpu *vcpu, larch_inst inst)
 
 	return EMULATE_DONE;
 }
+
+int kvm_emu_iocsr(larch_inst inst, struct kvm_run *run, struct kvm_vcpu *vcpu)
+{
+	int ret;
+	unsigned long val;
+	u32 addr, rd, rj, opcode;
+
+	/*
+	 * Each IOCSR with different opcode
+	 */
+	rd = inst.reg2_format.rd;
+	rj = inst.reg2_format.rj;
+	opcode = inst.reg2_format.opcode;
+	addr = vcpu->arch.gprs[rj];
+	ret = EMULATE_DO_IOCSR;
+	run->iocsr_io.phys_addr = addr;
+	run->iocsr_io.is_write = 0;
+
+	/* LoongArch is Little endian */
+	switch (opcode) {
+	case iocsrrdb_op:
+		run->iocsr_io.len = 1;
+		break;
+	case iocsrrdh_op:
+		run->iocsr_io.len = 2;
+		break;
+	case iocsrrdw_op:
+		run->iocsr_io.len = 4;
+		break;
+	case iocsrrdd_op:
+		run->iocsr_io.len = 8;
+		break;
+	case iocsrwrb_op:
+		run->iocsr_io.len = 1;
+		run->iocsr_io.is_write = 1;
+		break;
+	case iocsrwrh_op:
+		run->iocsr_io.len = 2;
+		run->iocsr_io.is_write = 1;
+		break;
+	case iocsrwrw_op:
+		run->iocsr_io.len = 4;
+		run->iocsr_io.is_write = 1;
+		break;
+	case iocsrwrd_op:
+		run->iocsr_io.len = 8;
+		run->iocsr_io.is_write = 1;
+		break;
+	default:
+		ret = EMULATE_FAIL;
+		break;
+	}
+
+	if (ret == EMULATE_DO_IOCSR) {
+		if (run->iocsr_io.is_write) {
+			val = vcpu->arch.gprs[rd];
+			memcpy(run->iocsr_io.data, &val, run->iocsr_io.len);
+		}
+		vcpu->arch.io_gpr = rd;
+	}
+
+	return ret;
+}
+
+int kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	enum emulation_result er = EMULATE_DONE;
+	unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
+
+	switch (run->iocsr_io.len) {
+	case 1:
+		*gpr = *(s8 *)run->iocsr_io.data;
+		break;
+	case 2:
+		*gpr = *(s16 *)run->iocsr_io.data;
+		break;
+	case 4:
+		*gpr = *(s32 *)run->iocsr_io.data;
+		break;
+	case 8:
+		*gpr = *(s64 *)run->iocsr_io.data;
+		break;
+	default:
+		kvm_err("Bad IOCSR length: %d, addr is 0x%lx\n",
+				run->iocsr_io.len, vcpu->arch.badv);
+		er = EMULATE_FAIL;
+		break;
+	}
+
+	return er;
+}