On Fri, Nov 03, 2017 at 08:01:52PM +0800, Liu, Yi L wrote: > From: Peter Xu <pet...@redhat.com> > > AddressSpaceOps is similar to MemoryRegionOps, it's just for address > spaces to store arch-specific hooks. > > The first hook I would like to introduce is iommu_get(). Return an > IOMMUObject behind the AddressSpace. > > For systems that have IOMMUs, we will create a special address > space per device which is different from system default address > space for it (please refer to pci_device_iommu_address_space()). > Normally when that happens, there will be one specific IOMMU (or > say, translation unit) stands right behind that new address space. > > This iommu_get() fetches that guy behind the address space. Here, > the guy is defined as IOMMUObject, which includes a notifier_list > so far, may extend in future. Along with IOMMUObject, a new iommu > notifier mechanism is introduced. It would be used for virt-svm. > Also IOMMUObject can further have a IOMMUObjectOps which is similar > to MemoryRegionOps. The difference is IOMMUObjectOps is not relied > on MemoryRegion. > > Signed-off-by: Peter Xu <pet...@redhat.com> > Signed-off-by: Liu, Yi L <yi.l....@linux.intel.com>
Hi, sorry I didn't reply to the earlier postings of this after our discussion in China. I've been sick several times and very busy. I still don't feel like there's an adequate explanation of exactly what an IOMMUObject represents. Obviously it can represent more than a single translation window - since that's represented by the IOMMUMR. But what exactly do all the MRs - or whatever else - that are represented by the IOMMUObject have in common, from a functional point of view. Even understanding the SVM stuff better than I did, I don't really see why an AddressSpace is an obvious unit to have an IOMMUObject associated with it. > --- > hw/core/Makefile.objs | 1 + > hw/core/iommu.c | 58 +++++++++++++++++++++++++++++++++++++++ > include/exec/memory.h | 22 +++++++++++++++ > include/hw/core/iommu.h | 73 > +++++++++++++++++++++++++++++++++++++++++++++++++ > memory.c | 10 +++++-- > 5 files changed, 162 insertions(+), 2 deletions(-) > create mode 100644 hw/core/iommu.c > create mode 100644 include/hw/core/iommu.h > > diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs > index f8d7a4a..d688412 100644 > --- a/hw/core/Makefile.objs > +++ b/hw/core/Makefile.objs > @@ -5,6 +5,7 @@ common-obj-y += fw-path-provider.o > # irq.o needed for qdev GPIO handling: > common-obj-y += irq.o > common-obj-y += hotplug.o > +common-obj-y += iommu.o > common-obj-y += nmi.o > > common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o > diff --git a/hw/core/iommu.c b/hw/core/iommu.c > new file mode 100644 > index 0000000..7c4fcfe > --- /dev/null > +++ b/hw/core/iommu.c > @@ -0,0 +1,58 @@ > +/* > + * QEMU emulation of IOMMU logic > + * > + * Copyright (C) 2017 Red Hat Inc. > + * > + * Authors: Peter Xu <pet...@redhat.com>, > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + > + * You should have received a copy of the GNU General Public License along > + * with this program; if not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include "qemu/osdep.h" > +#include "hw/core/iommu.h" > + > +void iommu_notifier_register(IOMMUObject *iommu, > + IOMMUNotifier *n, > + IOMMUNotifyFn fn, > + IOMMUEvent event) > +{ > + n->event = event; > + n->iommu_notify = fn; > + QLIST_INSERT_HEAD(&iommu->iommu_notifiers, n, node); > + return; > +} > + > +void iommu_notifier_unregister(IOMMUObject *iommu, > + IOMMUNotifier *notifier) > +{ > + IOMMUNotifier *cur, *next; > + > + QLIST_FOREACH_SAFE(cur, &iommu->iommu_notifiers, node, next) { > + if (cur == notifier) { > + QLIST_REMOVE(cur, node); > + break; > + } > + } > +} > + > +void iommu_notify(IOMMUObject *iommu, IOMMUEventData *event_data) > +{ > + IOMMUNotifier *cur; > + > + QLIST_FOREACH(cur, &iommu->iommu_notifiers, node) { > + if ((cur->event == event_data->event) && cur->iommu_notify) { > + cur->iommu_notify(cur, event_data); > + } > + } > +} > diff --git a/include/exec/memory.h b/include/exec/memory.h > index 03595e3..8350973 100644 > --- a/include/exec/memory.h > +++ b/include/exec/memory.h > @@ -26,6 +26,7 @@ > #include "qom/object.h" > #include "qemu/rcu.h" > #include "hw/qdev-core.h" > +#include "hw/core/iommu.h" > > #define RAM_ADDR_INVALID (~(ram_addr_t)0) > > @@ -301,6 +302,19 @@ struct MemoryListener { > }; > > /** > + * AddressSpaceOps: callbacks structure for address space specific operations > + * > + * @iommu_get: returns an IOMMU object that backs the address space. > + * Normally this should be NULL for generic address > + * spaces, and it's only used when there is one > + * translation unit behind this address space. > + */ > +struct AddressSpaceOps { > + IOMMUObject *(*iommu_get)(AddressSpace *as); > +}; > +typedef struct AddressSpaceOps AddressSpaceOps; > + > +/** > * AddressSpace: describes a mapping of addresses to #MemoryRegion objects > */ > struct AddressSpace { > @@ -316,6 +330,7 @@ struct AddressSpace { > struct MemoryRegionIoeventfd *ioeventfds; > QTAILQ_HEAD(memory_listeners_as, MemoryListener) listeners; > QTAILQ_ENTRY(AddressSpace) address_spaces_link; > + AddressSpaceOps as_ops; > }; > > FlatView *address_space_to_flatview(AddressSpace *as); > @@ -1988,6 +2003,13 @@ address_space_write_cached(MemoryRegionCache *cache, > hwaddr addr, > address_space_write(cache->as, cache->xlat + addr, > MEMTXATTRS_UNSPECIFIED, buf, len); > } > > +/** > + * address_space_iommu_get: Get the backend IOMMU for the address space > + * > + * @as: the address space to fetch IOMMU from > + */ > +IOMMUObject *address_space_iommu_get(AddressSpace *as); > + > #endif > > #endif > diff --git a/include/hw/core/iommu.h b/include/hw/core/iommu.h > new file mode 100644 > index 0000000..34387c0 > --- /dev/null > +++ b/include/hw/core/iommu.h > @@ -0,0 +1,73 @@ > +/* > + * QEMU emulation of IOMMU logic > + * > + * Copyright (C) 2017 Red Hat Inc. > + * > + * Authors: Peter Xu <pet...@redhat.com>, > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + > + * You should have received a copy of the GNU General Public License along > + * with this program; if not, see <http://www.gnu.org/licenses/>. > + */ > + > +#ifndef HW_CORE_IOMMU_H > +#define HW_CORE_IOMMU_H > + > +#include "qemu/queue.h" > + > +enum IOMMUEvent { > + IOMMU_EVENT_BIND_PASIDT, > +}; > +typedef enum IOMMUEvent IOMMUEvent; > + > +struct IOMMUEventData { > + IOMMUEvent event; > + uint64_t length; > + void *data; > +}; > +typedef struct IOMMUEventData IOMMUEventData; > + > +typedef struct IOMMUNotifier IOMMUNotifier; > + > +typedef void (*IOMMUNotifyFn)(IOMMUNotifier *notifier, > + IOMMUEventData *event_data); > + > +struct IOMMUNotifier { > + IOMMUNotifyFn iommu_notify; > + /* > + * What events we are listening to. Let's allow multiple event > + * registrations from beginning. > + */ > + IOMMUEvent event; > + QLIST_ENTRY(IOMMUNotifier) node; > +}; > + > +typedef struct IOMMUObject IOMMUObject; > + > +/* > + * This stands for an IOMMU unit. Any translation device should have > + * this struct inside its own structure to make sure it can leverage > + * common IOMMU functionalities. > + */ > +struct IOMMUObject { > + QLIST_HEAD(, IOMMUNotifier) iommu_notifiers; > +}; > + > +void iommu_notifier_register(IOMMUObject *iommu, > + IOMMUNotifier *n, > + IOMMUNotifyFn fn, > + IOMMUEvent event); > +void iommu_notifier_unregister(IOMMUObject *iommu, > + IOMMUNotifier *notifier); > +void iommu_notify(IOMMUObject *iommu, IOMMUEventData *event_data); > + > +#endif > diff --git a/memory.c b/memory.c > index 77fb3ef..307f665 100644 > --- a/memory.c > +++ b/memory.c > @@ -235,8 +235,6 @@ struct FlatView { > MemoryRegion *root; > }; > > -typedef struct AddressSpaceOps AddressSpaceOps; > - > #define FOR_EACH_FLAT_RANGE(var, view) \ > for (var = (view)->ranges; var < (view)->ranges + (view)->nr; ++var) > > @@ -2793,6 +2791,14 @@ static void do_address_space_destroy(AddressSpace *as) > memory_region_unref(as->root); > } > > +IOMMUObject *address_space_iommu_get(AddressSpace *as) > +{ > + if (!as->as_ops.iommu_get) { > + return NULL; > + } > + return as->as_ops.iommu_get(as); > +} > + > void address_space_destroy(AddressSpace *as) > { > MemoryRegion *root = as->root; -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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