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qemu/hw/remote/iommu.c

136 lines
3.5 KiB
C

/**
* IOMMU for remote device
*
* Copyright © 2022 Oracle and/or its affiliates.
*
* 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 "hw/remote/iommu.h"
#include "hw/pci/pci_bus.h"
#include "hw/pci/pci.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "trace.h"
/**
* IOMMU for TYPE_REMOTE_MACHINE - manages DMA address space isolation
* for remote machine. It is used by TYPE_VFIO_USER_SERVER.
*
* - Each TYPE_VFIO_USER_SERVER instance handles one PCIDevice on a PCIBus.
* There is one RemoteIommu per PCIBus, so the RemoteIommu tracks multiple
* PCIDevices by maintaining a ->elem_by_devfn mapping.
*
* - memory_region_init_iommu() is not used because vfio-user MemoryRegions
* will be added to the elem->mr container instead. This is more natural
* than implementing the IOMMUMemoryRegionClass APIs since vfio-user
* provides something that is close to a full-fledged MemoryRegion and
* not like an IOMMU mapping.
*
* - When a device is hot unplugged, the elem->mr reference is dropped so
* all vfio-user MemoryRegions associated with this vfio-user server are
* destroyed.
*/
static AddressSpace *remote_iommu_find_add_as(PCIBus *pci_bus,
void *opaque, int devfn)
{
RemoteIommu *iommu = opaque;
RemoteIommuElem *elem = NULL;
qemu_mutex_lock(&iommu->lock);
elem = g_hash_table_lookup(iommu->elem_by_devfn, INT2VOIDP(devfn));
if (!elem) {
elem = g_new0(RemoteIommuElem, 1);
g_hash_table_insert(iommu->elem_by_devfn, INT2VOIDP(devfn), elem);
}
if (!elem->mr) {
elem->mr = MEMORY_REGION(object_new(TYPE_MEMORY_REGION));
memory_region_set_size(elem->mr, UINT64_MAX);
address_space_init(&elem->as, elem->mr, NULL);
}
qemu_mutex_unlock(&iommu->lock);
return &elem->as;
}
void remote_iommu_unplug_dev(PCIDevice *pci_dev)
{
AddressSpace *as = pci_device_iommu_address_space(pci_dev);
RemoteIommuElem *elem = NULL;
if (as == &address_space_memory) {
return;
}
elem = container_of(as, RemoteIommuElem, as);
address_space_destroy(&elem->as);
object_unref(elem->mr);
elem->mr = NULL;
}
static void remote_iommu_init(Object *obj)
{
RemoteIommu *iommu = REMOTE_IOMMU(obj);
iommu->elem_by_devfn = g_hash_table_new_full(NULL, NULL, NULL, g_free);
qemu_mutex_init(&iommu->lock);
}
static void remote_iommu_finalize(Object *obj)
{
RemoteIommu *iommu = REMOTE_IOMMU(obj);
qemu_mutex_destroy(&iommu->lock);
g_hash_table_destroy(iommu->elem_by_devfn);
iommu->elem_by_devfn = NULL;
}
static const PCIIOMMUOps remote_iommu_ops = {
.get_address_space = remote_iommu_find_add_as,
};
void remote_iommu_setup(PCIBus *pci_bus)
{
RemoteIommu *iommu = NULL;
g_assert(pci_bus);
iommu = REMOTE_IOMMU(object_new(TYPE_REMOTE_IOMMU));
pci_setup_iommu(pci_bus, &remote_iommu_ops, iommu);
object_property_add_child(OBJECT(pci_bus), "remote-iommu", OBJECT(iommu));
object_unref(OBJECT(iommu));
}
static const TypeInfo remote_iommu_info = {
.name = TYPE_REMOTE_IOMMU,
.parent = TYPE_OBJECT,
.instance_size = sizeof(RemoteIommu),
.instance_init = remote_iommu_init,
.instance_finalize = remote_iommu_finalize,
};
static void remote_iommu_register_types(void)
{
type_register_static(&remote_iommu_info);
}
type_init(remote_iommu_register_types)