Commit 375f74f4 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

vhost: generalize iommu memory region 



We assumes the iommu_ops were attached to the root region of address
space. This may not be true for all kinds of IOMMU implementation and
especially after commit 3716d590 ("pci: introduce a bus master
container"). So fix this by not assuming as->root has iommu_ops,
instead depending on the regions reported by memory listener through:

- register a memory listener to dma_as
- during region_add, if it's a region of IOMMU, register a specific
  IOMMU notifier, and store all notifiers in a list.
- during region_del, compare and delete the IOMMU notifier from the list

This is also a must for making vhost device IOTLB works for all types
of IOMMUs. Note, since we register one notifier during each
.region_add, the IOTLB may be flushed more than one times, this is
suboptimal and could be optimized in the future.

Reported-by: default avatarMaxime Coquelin <maxime.coquelin@redhat.com>
Fixes: 3716d590 ("pci: introduce a bus master container")
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Tested-by: default avatarMaxime Coquelin <maxime.coquelin@redhat.com>
parent e839001d

hw/virtio/vhost.c

+64 −20
Original line number Diff line number Diff line
@@ -425,10 +425,8 @@ static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size) 
static int vhost_dev_has_iommu(struct vhost_dev *dev)

{

    VirtIODevice *vdev = dev->vdev;

    AddressSpace *dma_as = vdev->dma_as;



    return memory_region_is_iommu(dma_as->root) &&

           virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);

    return virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);

}



static void *vhost_memory_map(struct vhost_dev *dev, hwaddr addr,
@@ -720,6 +718,63 @@ static void vhost_region_del(MemoryListener *listener, 
    }

}



static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)

{

    struct vhost_iommu *iommu = container_of(n, struct vhost_iommu, n);

    struct vhost_dev *hdev = iommu->hdev;

    hwaddr iova = iotlb->iova + iommu->iommu_offset;



    if (hdev->vhost_ops->vhost_invalidate_device_iotlb(hdev, iova,

                                                       iotlb->addr_mask + 1)) {

        error_report("Fail to invalidate device iotlb");

    }

}



static void vhost_iommu_region_add(MemoryListener *listener,

                                   MemoryRegionSection *section)

{

    struct vhost_dev *dev = container_of(listener, struct vhost_dev,

                                         iommu_listener);

    struct vhost_iommu *iommu;



    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;

    iommu->mr = section->mr;

    iommu->iommu_offset = section->offset_within_address_space -

                          section->offset_within_region;

    iommu->hdev = dev;

    memory_region_register_iommu_notifier(section->mr, &iommu->n);

    QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next);

    /* TODO: can replay help performance here? */

}



static void vhost_iommu_region_del(MemoryListener *listener,

                                   MemoryRegionSection *section)

{

    struct vhost_dev *dev = container_of(listener, struct vhost_dev,

                                         iommu_listener);

    struct vhost_iommu *iommu;



    if (!memory_region_is_iommu(section->mr)) {

        return;

    }



    QLIST_FOREACH(iommu, &dev->iommu_list, iommu_next) {

        if (iommu->mr == section->mr) {

            memory_region_unregister_iommu_notifier(iommu->mr,

                                                    &iommu->n);

            QLIST_REMOVE(iommu, iommu_next);

            g_free(iommu);

            break;

        }

    }

}



static void vhost_region_nop(MemoryListener *listener,

                             MemoryRegionSection *section)

{
@@ -1161,17 +1216,6 @@ static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq) 
    event_notifier_cleanup(&vq->masked_notifier);

}



static void vhost_iommu_unmap_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)

{

    struct vhost_dev *hdev = container_of(n, struct vhost_dev, n);



    if (hdev->vhost_ops->vhost_invalidate_device_iotlb(hdev,

                                                       iotlb->iova,

                                                       iotlb->addr_mask + 1)) {

        error_report("Fail to invalidate device iotlb");

    }

}



int vhost_dev_init(struct vhost_dev *hdev, void *opaque,

                   VhostBackendType backend_type, uint32_t busyloop_timeout)

{
@@ -1244,8 +1288,10 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, 
        .priority = 10

    };



    hdev->n.notify = vhost_iommu_unmap_notify;

    hdev->n.notifier_flags = IOMMU_NOTIFIER_UNMAP;

    hdev->iommu_listener = (MemoryListener) {

        .region_add = vhost_iommu_region_add,

        .region_del = vhost_iommu_region_del,

    };



    if (hdev->migration_blocker == NULL) {

        if (!(hdev->features & (0x1ULL << VHOST_F_LOG_ALL))) {
@@ -1455,8 +1501,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev) 
    }



    if (vhost_dev_has_iommu(hdev)) {

        memory_region_register_iommu_notifier(vdev->dma_as->root,

                                              &hdev->n);

        memory_listener_register(&hdev->iommu_listener, vdev->dma_as);

    }



    r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem);
@@ -1538,8 +1583,7 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) 


    if (vhost_dev_has_iommu(hdev)) {

        hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false);

        memory_region_unregister_iommu_notifier(vdev->dma_as->root,

                                                &hdev->n);

        memory_listener_unregister(&hdev->iommu_listener);

    }

    vhost_log_put(hdev, true);

    hdev->started = false;

include/hw/virtio/vhost.h

+11 −0
Original line number Diff line number Diff line
@@ -37,10 +37,20 @@ struct vhost_log { 
    vhost_log_chunk_t *log;

};



struct vhost_dev;

struct vhost_iommu {

    struct vhost_dev *hdev;

    MemoryRegion *mr;

    hwaddr iommu_offset;

    IOMMUNotifier n;

    QLIST_ENTRY(vhost_iommu) iommu_next;

};



struct vhost_memory;

struct vhost_dev {

    VirtIODevice *vdev;

    MemoryListener memory_listener;

    MemoryListener iommu_listener;

    struct vhost_memory *mem;

    int n_mem_sections;

    MemoryRegionSection *mem_sections;
@@ -64,6 +74,7 @@ struct vhost_dev { 
    void *opaque;

    struct vhost_log *log;

    QLIST_ENTRY(vhost_dev) entry;

    QLIST_HEAD(, vhost_iommu) iommu_list;

    IOMMUNotifier n;

};