| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * ucall support. A ucall is a "hypercall to userspace". |
| * |
| * Copyright (C) 2019 Red Hat, Inc. |
| */ |
| #include "kvm_util.h" |
| |
| void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) |
| { |
| } |
| |
| void ucall_arch_do_ucall(vm_vaddr_t uc) |
| { |
| /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */ |
| asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory"); |
| } |
| |
| void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_run *run = vcpu->run; |
| |
| if (run->exit_reason == KVM_EXIT_S390_SIEIC && |
| run->s390_sieic.icptcode == 4 && |
| (run->s390_sieic.ipa >> 8) == 0x83 && /* 0x83 means DIAGNOSE */ |
| (run->s390_sieic.ipb >> 16) == 0x501) { |
| int reg = run->s390_sieic.ipa & 0xf; |
| |
| return (void *)run->s.regs.gprs[reg]; |
| } |
| return NULL; |
| } |
