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 "../kvm_util_internal.h" 12 #include "processor.h" 13 14 void ucall_init(struct kvm_vm *vm, void *arg) 15 { 16 } 17 18 void ucall_uninit(struct kvm_vm *vm) 19 { 20 } 21 22 struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0, 23 unsigned long arg1, unsigned long arg2, 24 unsigned long arg3, unsigned long arg4, 25 unsigned long arg5) 26 { 27 register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0); 28 register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1); 29 register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2); 30 register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3); 31 register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4); 32 register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5); 33 register uintptr_t a6 asm ("a6") = (uintptr_t)(fid); 34 register uintptr_t a7 asm ("a7") = (uintptr_t)(ext); 35 struct sbiret ret; 36 37 asm volatile ( 38 "ecall" 39 : "+r" (a0), "+r" (a1) 40 : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7) 41 : "memory"); 42 ret.error = a0; 43 ret.value = a1; 44 45 return ret; 46 } 47 48 void ucall(uint64_t cmd, int nargs, ...) 49 { 50 struct ucall uc = { 51 .cmd = cmd, 52 }; 53 va_list va; 54 int i; 55 56 nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS; 57 58 va_start(va, nargs); 59 for (i = 0; i < nargs; ++i) 60 uc.args[i] = va_arg(va, uint64_t); 61 va_end(va); 62 63 sbi_ecall(KVM_RISCV_SELFTESTS_SBI_EXT, 0, (vm_vaddr_t)&uc, 64 0, 0, 0, 0, 0); 65 } 66 67 uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc) 68 { 69 struct kvm_run *run = vcpu_state(vm, vcpu_id); 70 struct ucall ucall = {}; 71 72 if (uc) 73 memset(uc, 0, sizeof(*uc)); 74 75 if (run->exit_reason == KVM_EXIT_RISCV_SBI && 76 run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT && 77 run->riscv_sbi.function_id == 0) { 78 memcpy(&ucall, addr_gva2hva(vm, run->riscv_sbi.args[0]), 79 sizeof(ucall)); 80 81 vcpu_run_complete_io(vm, vcpu_id); 82 if (uc) 83 memcpy(uc, &ucall, sizeof(ucall)); 84 } 85 86 return ucall.cmd; 87 } 88