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