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

[Bharat Bhushan <bharatb.linux@gmail.com>]

Hi Eric,

On Fri, Mar 13, 2020 at 8:11 PM Auger Eric <eric.auger@redhat.com> wrote:
>
> 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.

ok, I have not tried vhost/migration. Below change set viommu when
reconstructing endpoint.

@@ -984,6 +973,7 @@ static gboolean reconstruct_endpoints(gpointer
key, gpointer value,

     QLIST_FOREACH(iter, &d->endpoint_list, next) {
         iter->domain = d;
+       iter->viommu = s;
         g_tree_insert(s->endpoints, GUINT_TO_POINTER(iter->id), iter);
     }
     return false; /* continue the domain traversal */

> >  } 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

did not get the comment, are you saying we should do this on 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.

ok,

Thanks
-Bharat

> > +    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
>