qemu/hw/i386/xen/xen_pvdevice.c
Igor Druzhinin 1dd6af7395 xen-pvdevice: Introduce a simplistic xen-pvdevice save state
This should help to avoid problems with accessing the device after
migration/resume without PV drivers by migrating its PCI configuration
space state. Without an explicitly defined state record it resets
every time a VM migrates which confuses the OS and makes every
access to xen-pvdevice MMIO region to fail. PV tools enable some
logic to save and restore PCI configuration state from within the VM
every time it migrates which basically hides the issue.

Older systems will acquire the new record when migrated which should
not change their state for worse.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
2018-05-18 11:01:20 -07:00

153 lines
4.7 KiB
C

/* Copyright (c) Citrix Systems Inc.
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*
* Redistribution and use in source and binary forms,
* with or without modification, are permitted provided
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/hw.h"
#include "hw/pci/pci.h"
#include "trace.h"
#define TYPE_XEN_PV_DEVICE "xen-pvdevice"
#define XEN_PV_DEVICE(obj) \
OBJECT_CHECK(XenPVDevice, (obj), TYPE_XEN_PV_DEVICE)
typedef struct XenPVDevice {
/*< private >*/
PCIDevice parent_obj;
/*< public >*/
uint16_t vendor_id;
uint16_t device_id;
uint8_t revision;
uint32_t size;
MemoryRegion mmio;
} XenPVDevice;
static uint64_t xen_pv_mmio_read(void *opaque, hwaddr addr,
unsigned size)
{
trace_xen_pv_mmio_read(addr);
return ~(uint64_t)0;
}
static void xen_pv_mmio_write(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
trace_xen_pv_mmio_write(addr);
}
static const MemoryRegionOps xen_pv_mmio_ops = {
.read = &xen_pv_mmio_read,
.write = &xen_pv_mmio_write,
.endianness = DEVICE_LITTLE_ENDIAN,
};
static const VMStateDescription vmstate_xen_pvdevice = {
.name = "xen-pvdevice",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_PCI_DEVICE(parent_obj, XenPVDevice),
VMSTATE_END_OF_LIST()
}
};
static void xen_pv_realize(PCIDevice *pci_dev, Error **errp)
{
XenPVDevice *d = XEN_PV_DEVICE(pci_dev);
uint8_t *pci_conf;
/* device-id property must always be supplied */
if (d->device_id == 0xffff) {
error_setg(errp, "Device ID invalid, it must always be supplied");
return;
}
pci_conf = pci_dev->config;
pci_set_word(pci_conf + PCI_VENDOR_ID, d->vendor_id);
pci_set_word(pci_conf + PCI_SUBSYSTEM_VENDOR_ID, d->vendor_id);
pci_set_word(pci_conf + PCI_DEVICE_ID, d->device_id);
pci_set_word(pci_conf + PCI_SUBSYSTEM_ID, d->device_id);
pci_set_byte(pci_conf + PCI_REVISION_ID, d->revision);
pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_MEMORY);
pci_config_set_prog_interface(pci_conf, 0);
pci_conf[PCI_INTERRUPT_PIN] = 1;
memory_region_init_io(&d->mmio, NULL, &xen_pv_mmio_ops, d,
"mmio", d->size);
pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
&d->mmio);
}
static Property xen_pv_props[] = {
DEFINE_PROP_UINT16("vendor-id", XenPVDevice, vendor_id, PCI_VENDOR_ID_XEN),
DEFINE_PROP_UINT16("device-id", XenPVDevice, device_id, 0xffff),
DEFINE_PROP_UINT8("revision", XenPVDevice, revision, 0x01),
DEFINE_PROP_UINT32("size", XenPVDevice, size, 0x400000),
DEFINE_PROP_END_OF_LIST()
};
static void xen_pv_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
k->realize = xen_pv_realize;
k->class_id = PCI_CLASS_SYSTEM_OTHER;
dc->desc = "Xen PV Device";
dc->props = xen_pv_props;
dc->vmsd = &vmstate_xen_pvdevice;
}
static const TypeInfo xen_pv_type_info = {
.name = TYPE_XEN_PV_DEVICE,
.parent = TYPE_PCI_DEVICE,
.instance_size = sizeof(XenPVDevice),
.class_init = xen_pv_class_init,
.interfaces = (InterfaceInfo[]) {
{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
{ },
},
};
static void xen_pv_register_types(void)
{
type_register_static(&xen_pv_type_info);
}
type_init(xen_pv_register_types)