1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ucall support. A ucall is a "hypercall to userspace". 4 * 5 * Copyright (C) 2021 Western Digital Corporation or its affiliates. 6 */ 7 8 #include <linux/kvm.h> 9 10 #include "kvm_util.h" 11 #include "processor.h" 12 13 struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0, 14 unsigned long arg1, unsigned long arg2, 15 unsigned long arg3, unsigned long arg4, 16 unsigned long arg5) 17 { 18 register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0); 19 register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1); 20 register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2); 21 register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3); 22 register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4); 23 register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5); 24 register uintptr_t a6 asm ("a6") = (uintptr_t)(fid); 25 register uintptr_t a7 asm ("a7") = (uintptr_t)(ext); 26 struct sbiret ret; 27 28 asm volatile ( 29 "ecall" 30 : "+r" (a0), "+r" (a1) 31 : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7) 32 : "memory"); 33 ret.error = a0; 34 ret.value = a1; 35 36 return ret; 37 } 38 39 void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) 40 { 41 struct kvm_run *run = vcpu->run; 42 43 if (run->exit_reason == KVM_EXIT_RISCV_SBI && 44 run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) { 45 switch (run->riscv_sbi.function_id) { 46 case KVM_RISCV_SELFTESTS_SBI_UCALL: 47 return (void *)run->riscv_sbi.args[0]; 48 case KVM_RISCV_SELFTESTS_SBI_UNEXP: 49 vcpu_dump(stderr, vcpu, 2); 50 TEST_ASSERT(0, "Unexpected trap taken by guest"); 51 break; 52 default: 53 break; 54 } 55 } 56 return NULL; 57 } 58