qemu-e2k/hw/virtio/virtio-mem-pci.c
David Hildenbrand 339a8bbdfe virtio-mem-pci: Device unplug support
Let's support device unplug by forwarding the unplug_request_check()
callback to the virtio-mem device.

Further, disallow changing the requested-size once an unplug request is
pending.

Disallowing requested-size changes handles corner cases such as
(1) pausing the VM (2) requesting device unplug and (3) adjusting the
requested size. If the VM would plug memory (due to the requested size
change) before processing the unplug request, we would be in trouble.

Message-ID: <20230711153445.514112-8-david@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
2023-07-12 09:27:32 +02:00

200 lines
6.7 KiB
C

/*
* Virtio MEM PCI device
*
* Copyright (C) 2020 Red Hat, Inc.
*
* Authors:
* David Hildenbrand <david@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "virtio-mem-pci.h"
#include "hw/mem/memory-device.h"
#include "qapi/error.h"
#include "qapi/qapi-events-machine.h"
#include "qapi/qapi-events-misc.h"
static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
{
VirtIOMEMPCI *mem_pci = VIRTIO_MEM_PCI(vpci_dev);
DeviceState *vdev = DEVICE(&mem_pci->vdev);
virtio_pci_force_virtio_1(vpci_dev);
qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
}
static void virtio_mem_pci_set_addr(MemoryDeviceState *md, uint64_t addr,
Error **errp)
{
object_property_set_uint(OBJECT(md), VIRTIO_MEM_ADDR_PROP, addr, errp);
}
static uint64_t virtio_mem_pci_get_addr(const MemoryDeviceState *md)
{
return object_property_get_uint(OBJECT(md), VIRTIO_MEM_ADDR_PROP,
&error_abort);
}
static MemoryRegion *virtio_mem_pci_get_memory_region(MemoryDeviceState *md,
Error **errp)
{
VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(md);
VirtIOMEM *vmem = &pci_mem->vdev;
VirtIOMEMClass *vmc = VIRTIO_MEM_GET_CLASS(vmem);
return vmc->get_memory_region(vmem, errp);
}
static uint64_t virtio_mem_pci_get_plugged_size(const MemoryDeviceState *md,
Error **errp)
{
return object_property_get_uint(OBJECT(md), VIRTIO_MEM_SIZE_PROP,
errp);
}
static void virtio_mem_pci_fill_device_info(const MemoryDeviceState *md,
MemoryDeviceInfo *info)
{
VirtioMEMDeviceInfo *vi = g_new0(VirtioMEMDeviceInfo, 1);
VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(md);
VirtIOMEM *vmem = &pci_mem->vdev;
VirtIOMEMClass *vpc = VIRTIO_MEM_GET_CLASS(vmem);
DeviceState *dev = DEVICE(md);
if (dev->id) {
vi->id = g_strdup(dev->id);
}
/* let the real device handle everything else */
vpc->fill_device_info(vmem, vi);
info->u.virtio_mem.data = vi;
info->type = MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM;
}
static uint64_t virtio_mem_pci_get_min_alignment(const MemoryDeviceState *md)
{
return object_property_get_uint(OBJECT(md), VIRTIO_MEM_BLOCK_SIZE_PROP,
&error_abort);
}
static void virtio_mem_pci_size_change_notify(Notifier *notifier, void *data)
{
VirtIOMEMPCI *pci_mem = container_of(notifier, VirtIOMEMPCI,
size_change_notifier);
DeviceState *dev = DEVICE(pci_mem);
char *qom_path = object_get_canonical_path(OBJECT(dev));
const uint64_t * const size_p = data;
qapi_event_send_memory_device_size_change(dev->id, *size_p, qom_path);
g_free(qom_path);
}
static void virtio_mem_pci_unplug_request_check(VirtIOMDPCI *vmd, Error **errp)
{
VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(vmd);
VirtIOMEM *vmem = &pci_mem->vdev;
VirtIOMEMClass *vpc = VIRTIO_MEM_GET_CLASS(vmem);
vpc->unplug_request_check(vmem, errp);
}
static void virtio_mem_pci_get_requested_size(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(obj);
object_property_get(OBJECT(&pci_mem->vdev), name, v, errp);
}
static void virtio_mem_pci_set_requested_size(Object *obj, Visitor *v,
const char *name, void *opaque,
Error **errp)
{
VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(obj);
DeviceState *dev = DEVICE(obj);
/*
* If we passed virtio_mem_pci_unplug_request_check(), making sure that
* the requested size is 0, don't allow modifying the requested size
* anymore, otherwise the VM might end up hotplugging memory before
* handling the unplug request.
*/
if (dev->pending_deleted_event) {
error_setg(errp, "'%s' cannot be changed if the device is in the"
" process of unplug", name);
return;
}
object_property_set(OBJECT(&pci_mem->vdev), name, v, errp);
}
static void virtio_mem_pci_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
MemoryDeviceClass *mdc = MEMORY_DEVICE_CLASS(klass);
VirtIOMDPCIClass *vmdc = VIRTIO_MD_PCI_CLASS(klass);
k->realize = virtio_mem_pci_realize;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
pcidev_k->class_id = PCI_CLASS_OTHERS;
mdc->get_addr = virtio_mem_pci_get_addr;
mdc->set_addr = virtio_mem_pci_set_addr;
mdc->get_plugged_size = virtio_mem_pci_get_plugged_size;
mdc->get_memory_region = virtio_mem_pci_get_memory_region;
mdc->fill_device_info = virtio_mem_pci_fill_device_info;
mdc->get_min_alignment = virtio_mem_pci_get_min_alignment;
vmdc->unplug_request_check = virtio_mem_pci_unplug_request_check;
}
static void virtio_mem_pci_instance_init(Object *obj)
{
VirtIOMEMPCI *dev = VIRTIO_MEM_PCI(obj);
VirtIOMEMClass *vmc;
VirtIOMEM *vmem;
virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
TYPE_VIRTIO_MEM);
dev->size_change_notifier.notify = virtio_mem_pci_size_change_notify;
vmem = &dev->vdev;
vmc = VIRTIO_MEM_GET_CLASS(vmem);
/*
* We never remove the notifier again, as we expect both devices to
* disappear at the same time.
*/
vmc->add_size_change_notifier(vmem, &dev->size_change_notifier);
object_property_add_alias(obj, VIRTIO_MEM_BLOCK_SIZE_PROP,
OBJECT(&dev->vdev), VIRTIO_MEM_BLOCK_SIZE_PROP);
object_property_add_alias(obj, VIRTIO_MEM_SIZE_PROP, OBJECT(&dev->vdev),
VIRTIO_MEM_SIZE_PROP);
object_property_add(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP, "size",
virtio_mem_pci_get_requested_size,
virtio_mem_pci_set_requested_size, NULL, NULL);
}
static const VirtioPCIDeviceTypeInfo virtio_mem_pci_info = {
.base_name = TYPE_VIRTIO_MEM_PCI,
.parent = TYPE_VIRTIO_MD_PCI,
.generic_name = "virtio-mem-pci",
.instance_size = sizeof(VirtIOMEMPCI),
.instance_init = virtio_mem_pci_instance_init,
.class_init = virtio_mem_pci_class_init,
};
static void virtio_mem_pci_register_types(void)
{
virtio_pci_types_register(&virtio_mem_pci_info);
}
type_init(virtio_mem_pci_register_types)