qemu/hw/misc/vmcoreinfo.c
Philippe Mathieu-Daudé 88552b16f2 hw/misc/vmcoreinfo: Add comment about reset handler
The VM coreinfo device does not sit on a bus, so it won't be
reset automatically. This is why it calls qemu_register_reset().

Add a comment about it, so we don't convert its reset handler
to a DeviceReset method.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191010131527.32513-9-philmd@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2019-10-15 18:18:08 -03:00

108 lines
3.2 KiB
C

/*
* Virtual Machine coreinfo device
*
* Copyright (C) 2017 Red Hat, Inc.
*
* Authors: Marc-André Lureau <marcandre.lureau@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/module.h"
#include "sysemu/reset.h"
#include "hw/nvram/fw_cfg.h"
#include "migration/vmstate.h"
#include "hw/misc/vmcoreinfo.h"
static void fw_cfg_vmci_write(void *dev, off_t offset, size_t len)
{
VMCoreInfoState *s = VMCOREINFO(dev);
s->has_vmcoreinfo = offset == 0 && len == sizeof(s->vmcoreinfo)
&& s->vmcoreinfo.guest_format != FW_CFG_VMCOREINFO_FORMAT_NONE;
}
static void vmcoreinfo_reset(void *dev)
{
VMCoreInfoState *s = VMCOREINFO(dev);
s->has_vmcoreinfo = false;
memset(&s->vmcoreinfo, 0, sizeof(s->vmcoreinfo));
s->vmcoreinfo.host_format = cpu_to_le16(FW_CFG_VMCOREINFO_FORMAT_ELF);
}
static void vmcoreinfo_realize(DeviceState *dev, Error **errp)
{
VMCoreInfoState *s = VMCOREINFO(dev);
FWCfgState *fw_cfg = fw_cfg_find();
/* for gdb script dump-guest-memory.py */
static VMCoreInfoState * volatile vmcoreinfo_state G_GNUC_UNUSED;
/* Given that this function is executing, there is at least one VMCOREINFO
* device. Check if there are several.
*/
if (!vmcoreinfo_find()) {
error_setg(errp, "at most one %s device is permitted",
VMCOREINFO_DEVICE);
return;
}
if (!fw_cfg || !fw_cfg->dma_enabled) {
error_setg(errp, "%s device requires fw_cfg with DMA",
VMCOREINFO_DEVICE);
return;
}
fw_cfg_add_file_callback(fw_cfg, FW_CFG_VMCOREINFO_FILENAME,
NULL, fw_cfg_vmci_write, s,
&s->vmcoreinfo, sizeof(s->vmcoreinfo), false);
/*
* This device requires to register a global reset because it is
* not plugged to a bus (which, as its QOM parent, would reset it).
*/
qemu_register_reset(vmcoreinfo_reset, dev);
vmcoreinfo_state = s;
}
static const VMStateDescription vmstate_vmcoreinfo = {
.name = "vmcoreinfo",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_BOOL(has_vmcoreinfo, VMCoreInfoState),
VMSTATE_UINT16(vmcoreinfo.host_format, VMCoreInfoState),
VMSTATE_UINT16(vmcoreinfo.guest_format, VMCoreInfoState),
VMSTATE_UINT32(vmcoreinfo.size, VMCoreInfoState),
VMSTATE_UINT64(vmcoreinfo.paddr, VMCoreInfoState),
VMSTATE_END_OF_LIST()
},
};
static void vmcoreinfo_device_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &vmstate_vmcoreinfo;
dc->realize = vmcoreinfo_realize;
dc->hotpluggable = false;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
}
static const TypeInfo vmcoreinfo_device_info = {
.name = VMCOREINFO_DEVICE,
.parent = TYPE_DEVICE,
.instance_size = sizeof(VMCoreInfoState),
.class_init = vmcoreinfo_device_class_init,
};
static void vmcoreinfo_register_types(void)
{
type_register_static(&vmcoreinfo_device_info);
}
type_init(vmcoreinfo_register_types)