// 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 "../kvm_util_internal.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 = nargs <= UCALL_MAX_ARGS ? 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, 0, (vm_vaddr_t)&uc, 0, 0, 0, 0, 0); } uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc) { struct kvm_run *run = vcpu_state(vm, vcpu_id); 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 && run->riscv_sbi.function_id == 0) { memcpy(&ucall, addr_gva2hva(vm, run->riscv_sbi.args[0]), sizeof(ucall)); vcpu_run_complete_io(vm, vcpu_id); if (uc) memcpy(uc, &ucall, sizeof(ucall)); } return ucall.cmd; }