On Thu, Apr 06, 2017 at 03:08:36PM +0800, Peter Xu wrote: > In this patch, IOMMUNotifier.{start|end} are introduced to store section > information for a specific notifier. When notification occurs, we not > only check the notification type (MAP|UNMAP), but also check whether the > notified iova range overlaps with the range of specific IOMMU notifier, > and skip those notifiers if not in the listened range. > > When removing an region, we need to make sure we removed the correct > VFIOGuestIOMMU by checking the IOMMUNotifier.start address as well. > > This patch is solving the problem that vfio-pci devices receive > duplicated UNMAP notification on x86 platform when vIOMMU is there. The > issue is that x86 IOMMU has a (0, 2^64-1) IOMMU region, which is > splitted by the (0xfee00000, 0xfeefffff) IRQ region. AFAIK > this (splitted IOMMU region) is only happening on x86. > > This patch also helps vhost to leverage the new interface as well, so > that vhost won't get duplicated cache flushes. In that sense, it's an > slight performance improvement. > > Suggested-by: David Gibson <da...@gibson.dropbear.id.au> > Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com> > --- > v7->v8: > - let vhost dmar leverage the new interface as well > - add some more comments in commit message, mentioning what issue this > patch has solved > - since touched up, removing Alex's a-b and DavidG's r-b > --- > hw/vfio/common.c | 12 +++++++++--- > hw/virtio/vhost.c | 10 ++++++++-- > include/exec/memory.h | 19 ++++++++++++++++++- > memory.c | 9 +++++++++ > 4 files changed, 44 insertions(+), 6 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index f3ba9b9..6b33b9f 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -478,8 +478,13 @@ static void vfio_listener_region_add(MemoryListener > *listener, > giommu->iommu_offset = section->offset_within_address_space - > section->offset_within_region; > giommu->container = container; > - giommu->n.notify = vfio_iommu_map_notify; > - giommu->n.notifier_flags = IOMMU_NOTIFIER_ALL; > + llend = int128_add(int128_make64(section->offset_within_region), > + section->size); > + llend = int128_sub(llend, int128_one()); > + iommu_notifier_init(&giommu->n, vfio_iommu_map_notify, > + IOMMU_NOTIFIER_ALL, > + section->offset_within_region, > + int128_get64(llend)); > QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next); > > memory_region_register_iommu_notifier(giommu->iommu, &giommu->n); > @@ -550,7 +555,8 @@ static void vfio_listener_region_del(MemoryListener > *listener, > VFIOGuestIOMMU *giommu; > > QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) { > - if (giommu->iommu == section->mr) { > + if (giommu->iommu == section->mr && > + giommu->n.start == section->offset_within_region) { > memory_region_unregister_iommu_notifier(giommu->iommu, > &giommu->n); > QLIST_REMOVE(giommu, giommu_next); > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 613494d..185b95b 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -736,14 +736,20 @@ static void vhost_iommu_region_add(MemoryListener > *listener, > struct vhost_dev *dev = container_of(listener, struct vhost_dev, > iommu_listener); > struct vhost_iommu *iommu; > + Int128 end; > > if (!memory_region_is_iommu(section->mr)) { > return; > } > > iommu = g_malloc0(sizeof(*iommu)); > - iommu->n.notify = vhost_iommu_unmap_notify; > - iommu->n.notifier_flags = IOMMU_NOTIFIER_UNMAP; > + end = int128_add(int128_make64(section->offset_within_region), > + section->size); > + end = int128_sub(end, int128_one()); > + iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify, > + IOMMU_NOTIFIER_UNMAP, > + section->offset_within_region, > + int128_get64(end)); > iommu->mr = section->mr; > iommu->iommu_offset = section->offset_within_address_space - > section->offset_within_region; > diff --git a/include/exec/memory.h b/include/exec/memory.h > index f20b191..0840c89 100644 > --- a/include/exec/memory.h > +++ b/include/exec/memory.h > @@ -77,13 +77,30 @@ typedef enum { > > #define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP) > > +struct IOMMUNotifier; > +typedef void (*IOMMUNotify)(struct IOMMUNotifier *notifier, > + IOMMUTLBEntry *data); > + > struct IOMMUNotifier { > - void (*notify)(struct IOMMUNotifier *notifier, IOMMUTLBEntry *data); > + IOMMUNotify notify; > IOMMUNotifierFlag notifier_flags; > + /* Notify for address space range start <= addr <= end */ > + hwaddr start; > + hwaddr end; > QLIST_ENTRY(IOMMUNotifier) node; > }; > typedef struct IOMMUNotifier IOMMUNotifier; > > +static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn, > + IOMMUNotifierFlag flags, > + hwaddr start, hwaddr end) > +{ > + n->notify = fn; > + n->notifier_flags = flags; > + n->start = start; > + n->end = end; > +} > + > /* New-style MMIO accessors can indicate that the transaction failed. > * A zero (MEMTX_OK) response means success; anything else is a failure > * of some kind. The memory subsystem will bitwise-OR together results > diff --git a/memory.c b/memory.c > index 4c95aaf..75ac595 100644 > --- a/memory.c > +++ b/memory.c > @@ -1606,6 +1606,7 @@ void memory_region_register_iommu_notifier(MemoryRegion > *mr, > > /* We need to register for at least one bitfield */ > assert(n->notifier_flags != IOMMU_NOTIFIER_NONE); > + assert(n->start <= n->end); > QLIST_INSERT_HEAD(&mr->iommu_notify, n, node); > memory_region_update_iommu_notify_flags(mr); > } > @@ -1667,6 +1668,14 @@ void memory_region_notify_iommu(MemoryRegion *mr, > } > > QLIST_FOREACH(iommu_notifier, &mr->iommu_notify, node) { > + /* > + * Skip the notification if the notification does not overlap > + * with registered range. > + */ > + if (iommu_notifier->start > entry.iova + entry.addr_mask + 1 || > + iommu_notifier->end < entry.iova) { > + continue; > + } > if (iommu_notifier->notifier_flags & request_flags) { > iommu_notifier->notify(iommu_notifier, &entry); > } > -- > 2.7.4