[Qemu-devel] [PATCH for 2.9] vhost: generalize iommu memory region

Jason Wang posted 1 patch 7 years ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/1490760604-9756-1-git-send-email-jasowang@redhat.com
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hw/virtio/vhost.c         | 84 ++++++++++++++++++++++++++++++++++++-----------
include/hw/virtio/vhost.h | 11 +++++++
2 files changed, 75 insertions(+), 20 deletions(-)
[Qemu-devel] [PATCH for 2.9] vhost: generalize iommu memory region
Posted by Jason Wang 7 years ago
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 3716d5902d74 ("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: Maxime Coquelin <maxime.coquelin@redhat.com>
Fixes: 3716d5902d74 ("pci: introduce a bus master container")
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost.c         | 84 ++++++++++++++++++++++++++++++++++++-----------
 include/hw/virtio/vhost.h | 11 +++++++
 2 files changed, 75 insertions(+), 20 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index febe519..613494d 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -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;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 52f633e..a450321 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -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;
 };
 
-- 
2.7.4


Re: [Qemu-devel] [PATCH for 2.9] vhost: generalize iommu memory region
Posted by Peter Xu 7 years ago
On Wed, Mar 29, 2017 at 12:10:04PM +0800, Jason Wang wrote:
> 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 3716d5902d74 ("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.

I guess I'll need to tune vtd-vfio series as well for this - now vhost
would have the same dup-flush issue just like vfio, and in that series
we need to settle both.

I'm thinking maybe I should post a new version for that series as well
even before 2.9 release for some early review comments.

> 
> Reported-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> Fixes: 3716d5902d74 ("pci: introduce a bus master container")
> Cc: Peter Xu <peterx@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

If this patch will make it for 2.9, I'll drop the corresponding one in
my series, but only keep the other one ("intel_iommu: use the correct
memory region for device IOTLB notification"). Thanks,

> ---
>  hw/virtio/vhost.c         | 84 ++++++++++++++++++++++++++++++++++++-----------
>  include/hw/virtio/vhost.h | 11 +++++++
>  2 files changed, 75 insertions(+), 20 deletions(-)
> 
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index febe519..613494d 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -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;
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 52f633e..a450321 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -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;
>  };
>  
> -- 
> 2.7.4
> 

-- peterx

Re: [Qemu-devel] [PATCH for 2.9] vhost: generalize iommu memory region
Posted by Maxime Coquelin 7 years ago

On 03/29/2017 06:10 AM, Jason Wang wrote:
> 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 3716d5902d74 ("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: Maxime Coquelin <maxime.coquelin@redhat.com>
> Fixes: 3716d5902d74 ("pci: introduce a bus master container")
> Cc: Peter Xu <peterx@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  hw/virtio/vhost.c         | 84 ++++++++++++++++++++++++++++++++++++-----------
>  include/hw/virtio/vhost.h | 11 +++++++
>  2 files changed, 75 insertions(+), 20 deletions(-)

Tested-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks!
Maxime