1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * ucall support. A ucall is a "hypercall to userspace".
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2019 Red Hat, Inc.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun #include "kvm_util.h"
8*4882a593Smuzhiyun
ucall_init(struct kvm_vm * vm,void * arg)9*4882a593Smuzhiyun void ucall_init(struct kvm_vm *vm, void *arg)
10*4882a593Smuzhiyun {
11*4882a593Smuzhiyun }
12*4882a593Smuzhiyun
ucall_uninit(struct kvm_vm * vm)13*4882a593Smuzhiyun void ucall_uninit(struct kvm_vm *vm)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun }
16*4882a593Smuzhiyun
ucall(uint64_t cmd,int nargs,...)17*4882a593Smuzhiyun void ucall(uint64_t cmd, int nargs, ...)
18*4882a593Smuzhiyun {
19*4882a593Smuzhiyun struct ucall uc = {
20*4882a593Smuzhiyun .cmd = cmd,
21*4882a593Smuzhiyun };
22*4882a593Smuzhiyun va_list va;
23*4882a593Smuzhiyun int i;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun va_start(va, nargs);
28*4882a593Smuzhiyun for (i = 0; i < nargs; ++i)
29*4882a593Smuzhiyun uc.args[i] = va_arg(va, uint64_t);
30*4882a593Smuzhiyun va_end(va);
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun /* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
33*4882a593Smuzhiyun asm volatile ("diag 0,%0,0x501" : : "a"(&uc) : "memory");
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun
get_ucall(struct kvm_vm * vm,uint32_t vcpu_id,struct ucall * uc)36*4882a593Smuzhiyun uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun struct kvm_run *run = vcpu_state(vm, vcpu_id);
39*4882a593Smuzhiyun struct ucall ucall = {};
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun if (uc)
42*4882a593Smuzhiyun memset(uc, 0, sizeof(*uc));
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun if (run->exit_reason == KVM_EXIT_S390_SIEIC &&
45*4882a593Smuzhiyun run->s390_sieic.icptcode == 4 &&
46*4882a593Smuzhiyun (run->s390_sieic.ipa >> 8) == 0x83 && /* 0x83 means DIAGNOSE */
47*4882a593Smuzhiyun (run->s390_sieic.ipb >> 16) == 0x501) {
48*4882a593Smuzhiyun int reg = run->s390_sieic.ipa & 0xf;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun memcpy(&ucall, addr_gva2hva(vm, run->s.regs.gprs[reg]),
51*4882a593Smuzhiyun sizeof(ucall));
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun vcpu_run_complete_io(vm, vcpu_id);
54*4882a593Smuzhiyun if (uc)
55*4882a593Smuzhiyun memcpy(uc, &ucall, sizeof(ucall));
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun return ucall.cmd;
59*4882a593Smuzhiyun }
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