LXR qemu/hw/misc/vmcoreinfo.c

   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 "sysemu/reset.h"
  17#include "hw/nvram/fw_cfg.h"
  18#include "migration/vmstate.h"
  19#include "hw/misc/vmcoreinfo.h"
  20
  21static void fw_cfg_vmci_write(void *dev, off_t offset, size_t len)
  22{
  23    VMCoreInfoState *s = VMCOREINFO(dev);
  24
  25    s->has_vmcoreinfo = offset == 0 && len == sizeof(s->vmcoreinfo)
  26        && s->vmcoreinfo.guest_format != FW_CFG_VMCOREINFO_FORMAT_NONE;
  27}
  28
  29static void vmcoreinfo_reset(void *dev)
  30{
  31    VMCoreInfoState *s = VMCOREINFO(dev);
  32
  33    s->has_vmcoreinfo = false;
  34    memset(&s->vmcoreinfo, 0, sizeof(s->vmcoreinfo));
  35    s->vmcoreinfo.host_format = cpu_to_le16(FW_CFG_VMCOREINFO_FORMAT_ELF);
  36}
  37
  38static void vmcoreinfo_realize(DeviceState *dev, Error **errp)
  39{
  40    VMCoreInfoState *s = VMCOREINFO(dev);
  41    FWCfgState *fw_cfg = fw_cfg_find();
  42    /* for gdb script dump-guest-memory.py */
  43    static VMCoreInfoState * volatile vmcoreinfo_state G_GNUC_UNUSED;
  44
  45    /* Given that this function is executing, there is at least one VMCOREINFO
  46     * device. Check if there are several.
  47     */
  48    if (!vmcoreinfo_find()) {
  49        error_setg(errp, "at most one %s device is permitted",
  50                   VMCOREINFO_DEVICE);
  51        return;
  52    }
  53
  54    if (!fw_cfg || !fw_cfg->dma_enabled) {
  55        error_setg(errp, "%s device requires fw_cfg with DMA",
  56                   VMCOREINFO_DEVICE);
  57        return;
  58    }
  59
  60    fw_cfg_add_file_callback(fw_cfg, FW_CFG_VMCOREINFO_FILENAME,
  61                             NULL, fw_cfg_vmci_write, s,
  62                             &s->vmcoreinfo, sizeof(s->vmcoreinfo), false);
  63
  64    /*
  65     * This device requires to register a global reset because it is
  66     * not plugged to a bus (which, as its QOM parent, would reset it).
  67     */
  68    qemu_register_reset(vmcoreinfo_reset, dev);
  69    vmcoreinfo_state = s;
  70}
  71
  72static const VMStateDescription vmstate_vmcoreinfo = {
  73    .name = "vmcoreinfo",
  74    .version_id = 1,
  75    .minimum_version_id = 1,
  76    .fields = (VMStateField[]) {
  77        VMSTATE_BOOL(has_vmcoreinfo, VMCoreInfoState),
  78        VMSTATE_UINT16(vmcoreinfo.host_format, VMCoreInfoState),
  79        VMSTATE_UINT16(vmcoreinfo.guest_format, VMCoreInfoState),
  80        VMSTATE_UINT32(vmcoreinfo.size, VMCoreInfoState),
  81        VMSTATE_UINT64(vmcoreinfo.paddr, VMCoreInfoState),
  82        VMSTATE_END_OF_LIST()
  83    },
  84};
  85
  86static void vmcoreinfo_device_class_init(ObjectClass *klass, void *data)
  87{
  88    DeviceClass *dc = DEVICE_CLASS(klass);
  89
  90    dc->vmsd = &vmstate_vmcoreinfo;
  91    dc->realize = vmcoreinfo_realize;
  92    dc->hotpluggable = false;
  93    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
  94}
  95
  96static const TypeInfo vmcoreinfo_device_info = {
  97    .name          = VMCOREINFO_DEVICE,
  98    .parent        = TYPE_DEVICE,
  99    .instance_size = sizeof(VMCoreInfoState),
 100    .class_init    = vmcoreinfo_device_class_init,
 101};
 102
 103static void vmcoreinfo_register_types(void)
 104{
 105    type_register_static(&vmcoreinfo_device_info);
 106}
 107
 108type_init(vmcoreinfo_register_types)
 109