1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * KVM/MIPS: Hypercall handling. 7 * 8 * Copyright (C) 2015 Imagination Technologies Ltd. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/kvm_host.h> 13 #include <linux/kvm_para.h> 14 15 #define MAX_HYPCALL_ARGS 4 16 17 enum emulation_result kvm_mips_emul_hypcall(struct kvm_vcpu *vcpu, 18 union mips_instruction inst) 19 { 20 unsigned int code = (inst.co_format.code >> 5) & 0x3ff; 21 22 kvm_debug("[%#lx] HYPCALL %#03x\n", vcpu->arch.pc, code); 23 24 switch (code) { 25 case 0: 26 return EMULATE_HYPERCALL; 27 default: 28 return EMULATE_FAIL; 29 }; 30 } 31 32 static int kvm_mips_hypercall(struct kvm_vcpu *vcpu, unsigned long num, 33 const unsigned long *args, unsigned long *hret) 34 { 35 /* Report unimplemented hypercall to guest */ 36 *hret = -KVM_ENOSYS; 37 return RESUME_GUEST; 38 } 39 40 int kvm_mips_handle_hypcall(struct kvm_vcpu *vcpu) 41 { 42 unsigned long num, args[MAX_HYPCALL_ARGS]; 43 44 /* read hypcall number and arguments */ 45 num = vcpu->arch.gprs[2]; /* v0 */ 46 args[0] = vcpu->arch.gprs[4]; /* a0 */ 47 args[1] = vcpu->arch.gprs[5]; /* a1 */ 48 args[2] = vcpu->arch.gprs[6]; /* a2 */ 49 args[3] = vcpu->arch.gprs[7]; /* a3 */ 50 51 return kvm_mips_hypercall(vcpu, num, 52 args, &vcpu->arch.gprs[2] /* v0 */); 53 } 54