xref: /openbmc/qemu/hw/misc/vmcoreinfo.c (revision 500eb6db)
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 
13 #include "qemu/osdep.h"
14 #include "qapi/error.h"
15 #include "qemu/module.h"
16 #include "hw/nvram/fw_cfg.h"
17 #include "hw/misc/vmcoreinfo.h"
18 
19 static void fw_cfg_vmci_write(void *dev, off_t offset, size_t len)
20 {
21     VMCoreInfoState *s = VMCOREINFO(dev);
22 
23     s->has_vmcoreinfo = offset == 0 && len == sizeof(s->vmcoreinfo)
24         && s->vmcoreinfo.guest_format != FW_CFG_VMCOREINFO_FORMAT_NONE;
25 }
26 
27 static void vmcoreinfo_reset(void *dev)
28 {
29     VMCoreInfoState *s = VMCOREINFO(dev);
30 
31     s->has_vmcoreinfo = false;
32     memset(&s->vmcoreinfo, 0, sizeof(s->vmcoreinfo));
33     s->vmcoreinfo.host_format = cpu_to_le16(FW_CFG_VMCOREINFO_FORMAT_ELF);
34 }
35 
36 static void vmcoreinfo_realize(DeviceState *dev, Error **errp)
37 {
38     VMCoreInfoState *s = VMCOREINFO(dev);
39     FWCfgState *fw_cfg = fw_cfg_find();
40     /* for gdb script dump-guest-memory.py */
41     static VMCoreInfoState * volatile vmcoreinfo_state G_GNUC_UNUSED;
42 
43     /* Given that this function is executing, there is at least one VMCOREINFO
44      * device. Check if there are several.
45      */
46     if (!vmcoreinfo_find()) {
47         error_setg(errp, "at most one %s device is permitted",
48                    VMCOREINFO_DEVICE);
49         return;
50     }
51 
52     if (!fw_cfg || !fw_cfg->dma_enabled) {
53         error_setg(errp, "%s device requires fw_cfg with DMA",
54                    VMCOREINFO_DEVICE);
55         return;
56     }
57 
58     fw_cfg_add_file_callback(fw_cfg, FW_CFG_VMCOREINFO_FILENAME,
59                              NULL, fw_cfg_vmci_write, s,
60                              &s->vmcoreinfo, sizeof(s->vmcoreinfo), false);
61 
62     qemu_register_reset(vmcoreinfo_reset, dev);
63     vmcoreinfo_state = s;
64 }
65 
66 static const VMStateDescription vmstate_vmcoreinfo = {
67     .name = "vmcoreinfo",
68     .version_id = 1,
69     .minimum_version_id = 1,
70     .fields = (VMStateField[]) {
71         VMSTATE_BOOL(has_vmcoreinfo, VMCoreInfoState),
72         VMSTATE_UINT16(vmcoreinfo.host_format, VMCoreInfoState),
73         VMSTATE_UINT16(vmcoreinfo.guest_format, VMCoreInfoState),
74         VMSTATE_UINT32(vmcoreinfo.size, VMCoreInfoState),
75         VMSTATE_UINT64(vmcoreinfo.paddr, VMCoreInfoState),
76         VMSTATE_END_OF_LIST()
77     },
78 };
79 
80 static void vmcoreinfo_device_class_init(ObjectClass *klass, void *data)
81 {
82     DeviceClass *dc = DEVICE_CLASS(klass);
83 
84     dc->vmsd = &vmstate_vmcoreinfo;
85     dc->realize = vmcoreinfo_realize;
86     dc->hotpluggable = false;
87     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
88 }
89 
90 static const TypeInfo vmcoreinfo_device_info = {
91     .name          = VMCOREINFO_DEVICE,
92     .parent        = TYPE_DEVICE,
93     .instance_size = sizeof(VMCoreInfoState),
94     .class_init    = vmcoreinfo_device_class_init,
95 };
96 
97 static void vmcoreinfo_register_types(void)
98 {
99     type_register_static(&vmcoreinfo_device_info);
100 }
101 
102 type_init(vmcoreinfo_register_types)
103