4 files changed, 61 insertions, 0 deletions

diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
index 847429de780d..e56403c8a3f5 100644
--- a/arch/mips/kvm/Makefile
+++ b/arch/mips/kvm/Makefile
@@ -10,6 +10,7 @@ common-objs-$(CONFIG_CPU_HAS_MSA) += msa.o
 kvm-objs := $(common-objs-y) mips.o emulate.o entry.o \
 	    interrupt.o stats.o commpage.o \
 	    dyntrans.o trap_emul.o fpu.o
+kvm-objs += hypcall.o
 kvm-objs += mmu.o
 
 obj-$(CONFIG_KVM)	+= kvm.o
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index d40cfaad4529..637753ea0a00 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -1143,6 +1143,9 @@ enum emulation_result kvm_mips_emulate_CP0(union mips_instruction inst,
 		case wait_op:
 			er = kvm_mips_emul_wait(vcpu);
 			break;
+		case hypcall_op:
+			er = kvm_mips_emul_hypcall(vcpu, inst);
+			break;
 		}
 	} else {
 		rt = inst.c0r_format.rt;
diff --git a/arch/mips/kvm/hypcall.c b/arch/mips/kvm/hypcall.c
new file mode 100644
index 000000000000..83063435195f
--- /dev/null
+++ b/arch/mips/kvm/hypcall.c
@@ -0,0 +1,53 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * KVM/MIPS: Hypercall handling.
+ *
+ * Copyright (C) 2015  Imagination Technologies Ltd.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <linux/kvm_para.h>
+
+#define MAX_HYPCALL_ARGS	4
+
+enum emulation_result kvm_mips_emul_hypcall(struct kvm_vcpu *vcpu,
+					    union mips_instruction inst)
+{
+	unsigned int code = (inst.co_format.code >> 5) & 0x3ff;
+
+	kvm_debug("[%#lx] HYPCALL %#03x\n", vcpu->arch.pc, code);
+
+	switch (code) {
+	case 0:
+		return EMULATE_HYPERCALL;
+	default:
+		return EMULATE_FAIL;
+	};
+}
+
+static int kvm_mips_hypercall(struct kvm_vcpu *vcpu, unsigned long num,
+			      const unsigned long *args, unsigned long *hret)
+{
+	/* Report unimplemented hypercall to guest */
+	*hret = -KVM_ENOSYS;
+	return RESUME_GUEST;
+}
+
+int kvm_mips_handle_hypcall(struct kvm_vcpu *vcpu)
+{
+	unsigned long num, args[MAX_HYPCALL_ARGS];
+
+	/* read hypcall number and arguments */
+	num = vcpu->arch.gprs[2];	/* v0 */
+	args[0] = vcpu->arch.gprs[4];	/* a0 */
+	args[1] = vcpu->arch.gprs[5];	/* a1 */
+	args[2] = vcpu->arch.gprs[6];	/* a2 */
+	args[3] = vcpu->arch.gprs[7];	/* a3 */
+
+	return kvm_mips_hypercall(vcpu, num,
+				  args, &vcpu->arch.gprs[2] /* v0 */);
+}
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index b1fa53b252ea..3a854bb9e606 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -82,6 +82,10 @@ static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
 		ret = RESUME_HOST;
 		break;
 
+	case EMULATE_HYPERCALL:
+		ret = kvm_mips_handle_hypcall(vcpu);
+		break;
+
 	default:
 		BUG();
 	}