| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * ucall support. A ucall is a "hypercall to userspace". |
| * |
| * Copyright (C) 2021 Western Digital Corporation or its affiliates. |
| */ |
| |
| #include <linux/kvm.h> |
| |
| #include "kvm_util.h" |
| #include "processor.h" |
| |
| void ucall_init(struct kvm_vm *vm, void *arg) |
| { |
| } |
| |
| void ucall_uninit(struct kvm_vm *vm) |
| { |
| } |
| |
| struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0, |
| unsigned long arg1, unsigned long arg2, |
| unsigned long arg3, unsigned long arg4, |
| unsigned long arg5) |
| { |
| register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0); |
| register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1); |
| register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2); |
| register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3); |
| register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4); |
| register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5); |
| register uintptr_t a6 asm ("a6") = (uintptr_t)(fid); |
| register uintptr_t a7 asm ("a7") = (uintptr_t)(ext); |
| struct sbiret ret; |
| |
| asm volatile ( |
| "ecall" |
| : "+r" (a0), "+r" (a1) |
| : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7) |
| : "memory"); |
| ret.error = a0; |
| ret.value = a1; |
| |
| return ret; |
| } |
| |
| void ucall(uint64_t cmd, int nargs, ...) |
| { |
| struct ucall uc = { |
| .cmd = cmd, |
| }; |
| va_list va; |
| int i; |
| |
| nargs = min(nargs, UCALL_MAX_ARGS); |
| |
| va_start(va, nargs); |
| for (i = 0; i < nargs; ++i) |
| uc.args[i] = va_arg(va, uint64_t); |
| va_end(va); |
| |
| sbi_ecall(KVM_RISCV_SELFTESTS_SBI_EXT, |
| KVM_RISCV_SELFTESTS_SBI_UCALL, |
| (vm_vaddr_t)&uc, 0, 0, 0, 0, 0); |
| } |
| |
| uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc) |
| { |
| struct kvm_run *run = vcpu->run; |
| struct ucall ucall = {}; |
| |
| if (uc) |
| memset(uc, 0, sizeof(*uc)); |
| |
| if (run->exit_reason == KVM_EXIT_RISCV_SBI && |
| run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) { |
| switch (run->riscv_sbi.function_id) { |
| case KVM_RISCV_SELFTESTS_SBI_UCALL: |
| memcpy(&ucall, |
| addr_gva2hva(vcpu->vm, run->riscv_sbi.args[0]), |
| sizeof(ucall)); |
| |
| vcpu_run_complete_io(vcpu); |
| if (uc) |
| memcpy(uc, &ucall, sizeof(ucall)); |
| |
| break; |
| case KVM_RISCV_SELFTESTS_SBI_UNEXP: |
| vcpu_dump(stderr, vcpu, 2); |
| TEST_ASSERT(0, "Unexpected trap taken by guest"); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| return ucall.cmd; |
| } |