Re: [PATCH v7 3/5] virtio-iommu: Call iommu notifier for attach/detach

[Auger Eric <eric.auger@redhat.com>]

Hi Bharat

On 3/13/20 8:48 AM, Bharat Bhushan wrote:
> iommu-notifier are called when a device is attached
IOMMU notifiers
> or detached to as address-space.
> This is needed for VFIO.
and vhost for detach
> 
> Signed-off-by: Bharat Bhushan <bbhushan2@marvell.com>
> ---
>  hw/virtio/virtio-iommu.c | 47 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 47 insertions(+)
> 
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index e51344a53e..2006f72901 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -49,6 +49,7 @@ typedef struct VirtIOIOMMUEndpoint {
>      uint32_t id;
>      VirtIOIOMMUDomain *domain;
>      QLIST_ENTRY(VirtIOIOMMUEndpoint) next;
> +    VirtIOIOMMU *viommu;
This needs specal care on post-load. When migrating the EPs, only the id
is migrated. On post-load you need to set viommu as it is done for
domain. migration is allowed with vhost.
>  } VirtIOIOMMUEndpoint;
>  
>  typedef struct VirtIOIOMMUInterval {
> @@ -155,8 +156,44 @@ static void virtio_iommu_notify_unmap(IOMMUMemoryRegion *mr, hwaddr iova,
>      memory_region_notify_iommu(mr, 0, entry);
>  }
>  
> +static gboolean virtio_iommu_mapping_unmap(gpointer key, gpointer value,
> +                                           gpointer data)
> +{
> +    VirtIOIOMMUInterval *interval = (VirtIOIOMMUInterval *) key;
> +    IOMMUMemoryRegion *mr = (IOMMUMemoryRegion *) data;
> +
> +    virtio_iommu_notify_unmap(mr, interval->low,
> +                              interval->high - interval->low + 1);
> +
> +    return false;
> +}
> +
> +static gboolean virtio_iommu_mapping_map(gpointer key, gpointer value,
> +                                         gpointer data)
> +{
> +    VirtIOIOMMUMapping *mapping = (VirtIOIOMMUMapping *) value;
> +    VirtIOIOMMUInterval *interval = (VirtIOIOMMUInterval *) key;
> +    IOMMUMemoryRegion *mr = (IOMMUMemoryRegion *) data;
> +
> +    virtio_iommu_notify_map(mr, interval->low, mapping->phys_addr,
> +                            interval->high - interval->low + 1);
> +
> +    return false;
> +}
> +
>  static void virtio_iommu_detach_endpoint_from_domain(VirtIOIOMMUEndpoint *ep)
>  {
> +    VirtioIOMMUNotifierNode *node;
> +    VirtIOIOMMU *s = ep->viommu;
> +    VirtIOIOMMUDomain *domain = ep->domain;
> +
> +    QLIST_FOREACH(node, &s->notifiers_list, next) {
> +        if (ep->id == node->iommu_dev->devfn) {
> +            g_tree_foreach(domain->mappings, virtio_iommu_mapping_unmap,
> +                           &node->iommu_dev->iommu_mr);
I understand this should fo the job for domain removal
> +        }
> +    }
> +
>      if (!ep->domain) {
>          return;
>      }
> @@ -178,6 +215,7 @@ static VirtIOIOMMUEndpoint *virtio_iommu_get_endpoint(VirtIOIOMMU *s,
>      }
>      ep = g_malloc0(sizeof(*ep));
>      ep->id = ep_id;
> +    ep->viommu = s;
>      trace_virtio_iommu_get_endpoint(ep_id);
>      g_tree_insert(s->endpoints, GUINT_TO_POINTER(ep_id), ep);
>      return ep;
> @@ -272,6 +310,7 @@ static int virtio_iommu_attach(VirtIOIOMMU *s,
>  {
>      uint32_t domain_id = le32_to_cpu(req->domain);
>      uint32_t ep_id = le32_to_cpu(req->endpoint);
> +    VirtioIOMMUNotifierNode *node;
>      VirtIOIOMMUDomain *domain;
>      VirtIOIOMMUEndpoint *ep;
>  
> @@ -299,6 +338,14 @@ static int virtio_iommu_attach(VirtIOIOMMU *s,
>  
>      ep->domain = domain;
>  
> +    /* Replay existing address space mappings on the associated memory region */
maybe use the "domain" terminology here.
> +    QLIST_FOREACH(node, &s->notifiers_list, next) {
> +        if (ep_id == node->iommu_dev->devfn) {
> +            g_tree_foreach(domain->mappings, virtio_iommu_mapping_map,
> +                           &node->iommu_dev->iommu_mr);
> +        }
> +    }
> +
>      return VIRTIO_IOMMU_S_OK;
>  }
>  
> 
Thanks

Eric