xref: /openbmc/qemu/hw/misc/vmcoreinfo.c (revision c39f95dc)
1 /*
2  * Virtual Machine coreinfo device
3  *
4  * Copyright (C) 2017 Red Hat, Inc.
5  *
6  * Authors: Marc-André Lureau <marcandre.lureau@redhat.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or later.
9  * See the COPYING file in the top-level directory.
10  *
11  */
12 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "hw/nvram/fw_cfg.h"
15 #include "hw/misc/vmcoreinfo.h"
16 
17 static void fw_cfg_vmci_write(void *dev, off_t offset, size_t len)
18 {
19     VMCoreInfoState *s = VMCOREINFO(dev);
20 
21     s->has_vmcoreinfo = offset == 0 && len == sizeof(s->vmcoreinfo)
22         && s->vmcoreinfo.guest_format != VMCOREINFO_FORMAT_NONE;
23 }
24 
25 static void vmcoreinfo_reset(void *dev)
26 {
27     VMCoreInfoState *s = VMCOREINFO(dev);
28 
29     s->has_vmcoreinfo = false;
30     memset(&s->vmcoreinfo, 0, sizeof(s->vmcoreinfo));
31     s->vmcoreinfo.host_format = cpu_to_le16(VMCOREINFO_FORMAT_ELF);
32 }
33 
34 static void vmcoreinfo_realize(DeviceState *dev, Error **errp)
35 {
36     VMCoreInfoState *s = VMCOREINFO(dev);
37     FWCfgState *fw_cfg = fw_cfg_find();
38 
39     /* Given that this function is executing, there is at least one VMCOREINFO
40      * device. Check if there are several.
41      */
42     if (!vmcoreinfo_find()) {
43         error_setg(errp, "at most one %s device is permitted",
44                    VMCOREINFO_DEVICE);
45         return;
46     }
47 
48     if (!fw_cfg || !fw_cfg->dma_enabled) {
49         error_setg(errp, "%s device requires fw_cfg with DMA",
50                    VMCOREINFO_DEVICE);
51         return;
52     }
53 
54     fw_cfg_add_file_callback(fw_cfg, "etc/vmcoreinfo",
55                              NULL, fw_cfg_vmci_write, s,
56                              &s->vmcoreinfo, sizeof(s->vmcoreinfo), false);
57 
58     qemu_register_reset(vmcoreinfo_reset, dev);
59 }
60 
61 static const VMStateDescription vmstate_vmcoreinfo = {
62     .name = "vmcoreinfo",
63     .version_id = 1,
64     .minimum_version_id = 1,
65     .fields = (VMStateField[]) {
66         VMSTATE_BOOL(has_vmcoreinfo, VMCoreInfoState),
67         VMSTATE_UINT16(vmcoreinfo.host_format, VMCoreInfoState),
68         VMSTATE_UINT16(vmcoreinfo.guest_format, VMCoreInfoState),
69         VMSTATE_UINT32(vmcoreinfo.size, VMCoreInfoState),
70         VMSTATE_UINT64(vmcoreinfo.paddr, VMCoreInfoState),
71         VMSTATE_END_OF_LIST()
72     },
73 };
74 
75 static void vmcoreinfo_device_class_init(ObjectClass *klass, void *data)
76 {
77     DeviceClass *dc = DEVICE_CLASS(klass);
78 
79     dc->vmsd = &vmstate_vmcoreinfo;
80     dc->realize = vmcoreinfo_realize;
81     dc->hotpluggable = false;
82 }
83 
84 static const TypeInfo vmcoreinfo_device_info = {
85     .name          = VMCOREINFO_DEVICE,
86     .parent        = TYPE_DEVICE,
87     .instance_size = sizeof(VMCoreInfoState),
88     .class_init    = vmcoreinfo_device_class_init,
89 };
90 
91 static void vmcoreinfo_register_types(void)
92 {
93     type_register_static(&vmcoreinfo_device_info);
94 }
95 
96 type_init(vmcoreinfo_register_types)
97