Re: [PATCH v9 2/2] vhost-vdpa: add support for vIOMMU

[Cindy Lu <lulu@redhat.com>]

,


On Mon, 31 Oct 2022 at 15:04, Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Mon, Oct 31, 2022 at 11:10:20AM +0800, Cindy Lu wrote:
> > Add support for vIOMMU. add the new function to deal with iommu MR.
> > - during iommu_region_add register a specific IOMMU notifier,
> >  and store all notifiers in a list.
> > - during iommu_region_del, compare and delete the IOMMU notifier from the list
> >
> > Verified in vp_vdpa and vdpa_sim_net driver
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >  hw/virtio/vhost-vdpa.c         | 123 ++++++++++++++++++++++++++++++---
> >  include/hw/virtio/vhost-vdpa.h |  10 +++
> >  2 files changed, 122 insertions(+), 11 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> > index 3ff9ce3501..dcfaaccfa9 100644
> > --- a/hw/virtio/vhost-vdpa.c
> > +++ b/hw/virtio/vhost-vdpa.c
> > @@ -26,6 +26,7 @@
> >  #include "cpu.h"
> >  #include "trace.h"
> >  #include "qapi/error.h"
> > +#include "hw/virtio/virtio-access.h"
> >
> >  /*
> >   * Return one past the end of the end of section. Be careful with uint64_t
> > @@ -44,7 +45,6 @@ static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section,
> >                                                  uint64_t iova_min,
> >                                                  uint64_t iova_max)
> >  {
> > -    Int128 llend;
> >
> >      if ((!memory_region_is_ram(section->mr) &&
> >           !memory_region_is_iommu(section->mr)) ||
> > @@ -61,14 +61,6 @@ static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section,
> >          return true;
> >      }
> >
> > -    llend = vhost_vdpa_section_end(section);
> > -    if (int128_gt(llend, int128_make64(iova_max))) {
> > -        error_report("RAM section out of device range (max=0x%" PRIx64
> > -                     ", end addr=0x%" PRIx64 ")",
> > -                     iova_max, int128_get64(llend));
> > -        return true;
> > -    }
> > -
> >      return false;
> >  }
> >
>
> I couldn't figure out we are completely removing this.
> So this function is now checking iova_min but not iova_max?
> Seems asymmetrical.
>
this is because this is an asset for int128_get64，So I just not jump
this part of the check,
static inline uint64_t int128_get64(Int128 a)
{
    uint64_t r = a;
    assert(r == a);
    return r;
}


>
> > @@ -173,6 +165,106 @@ static void vhost_vdpa_listener_commit(MemoryListener *listener)
> >      v->iotlb_batch_begin_sent = false;
> >  }
> >
> > +static void vhost_vdpa_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
> > +{
> > +    struct vdpa_iommu *iommu = container_of(n, struct vdpa_iommu, n);
> > +
> > +    hwaddr iova = iotlb->iova + iommu->iommu_offset;
> > +    struct vhost_vdpa *v = iommu->dev;
> > +    void *vaddr;
> > +    int ret;
> > +
> > +    if (iotlb->target_as != &address_space_memory) {
> > +        error_report("Wrong target AS \"%s\", only system memory is allowed",
> > +                     iotlb->target_as->name ? iotlb->target_as->name : "none");
> > +        return;
> > +    }
> > +    RCU_READ_LOCK_GUARD();
> > +    vhost_vdpa_iotlb_batch_begin_once(v);
> > +
> > +    if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
> > +        bool read_only;
> > +
> > +        if (!memory_get_xlat_addr(iotlb, &vaddr, NULL, &read_only, NULL)) {
> > +            return;
> > +        }
> > +        ret =
> > +            vhost_vdpa_dma_map(v, iova, iotlb->addr_mask + 1, vaddr, read_only);
> > +        if (ret) {
> > +            error_report("vhost_vdpa_dma_map(%p, 0x%" HWADDR_PRIx ", "
> > +                         "0x%" HWADDR_PRIx ", %p) = %d (%m)",
> > +                         v, iova, iotlb->addr_mask + 1, vaddr, ret);
> > +        }
> > +    } else {
> > +        ret = vhost_vdpa_dma_unmap(v, iova, iotlb->addr_mask + 1);
> > +        if (ret) {
> > +            error_report("vhost_vdpa_dma_unmap(%p, 0x%" HWADDR_PRIx ", "
> > +                         "0x%" HWADDR_PRIx ") = %d (%m)",
> > +                         v, iova, iotlb->addr_mask + 1, ret);
> > +        }
> > +    }
> > +}
> > +
> > +static void vhost_vdpa_iommu_region_add(MemoryListener *listener,
> > +                                        MemoryRegionSection *section)
> > +{
> > +    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
> > +
> > +    struct vdpa_iommu *iommu;
> > +    Int128 end;
> > +    int iommu_idx;
> > +    IOMMUMemoryRegion *iommu_mr;
> > +    int ret;
> > +
> > +    iommu_mr = IOMMU_MEMORY_REGION(section->mr);
> > +
> > +    iommu = g_malloc0(sizeof(*iommu));
> > +    end =  int128_add(int128_make64(section->offset_within_region),
> > +            section->size);
> > +    end = int128_sub(end, int128_one());
> > +    iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr,
> > +            MEMTXATTRS_UNSPECIFIED);
> > +
> > +    iommu->iommu_mr = iommu_mr;
> > +
> > +    iommu_notifier_init(
> > +        &iommu->n, vhost_vdpa_iommu_map_notify, IOMMU_NOTIFIER_IOTLB_EVENTS,
> > +        section->offset_within_region, int128_get64(end), iommu_idx);
> > +    iommu->iommu_offset =
> > +        section->offset_within_address_space - section->offset_within_region;
> > +    iommu->dev = v;
> > +
> > +    ret = memory_region_register_iommu_notifier(section->mr, &iommu->n, NULL);
> > +    if (ret) {
> > +        g_free(iommu);
> > +        return;
> > +    }
> > +
> > +    QLIST_INSERT_HEAD(&v->iommu_list, iommu, iommu_next);
> > +    memory_region_iommu_replay(iommu->iommu_mr, &iommu->n);
> > +
> > +    return;
> > +}
> > +
> > +static void vhost_vdpa_iommu_region_del(MemoryListener *listener,
> > +                                        MemoryRegionSection *section)
> > +{
> > +    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
> > +
> > +    struct vdpa_iommu *iommu;
> > +
> > +    QLIST_FOREACH(iommu, &v->iommu_list, iommu_next)
> > +    {
> > +        if (MEMORY_REGION(iommu->iommu_mr) == section->mr &&
> > +            iommu->n.start == section->offset_within_region) {
> > +            memory_region_unregister_iommu_notifier(section->mr, &iommu->n);
> > +            QLIST_REMOVE(iommu, iommu_next);
> > +            g_free(iommu);
> > +            break;
> > +        }
> > +    }
> > +}
> > +
> >  static void vhost_vdpa_listener_region_add(MemoryListener *listener,
> >                                             MemoryRegionSection *section)
> >  {
> > @@ -186,6 +278,10 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
> >                                              v->iova_range.last)) {
> >          return;
> >      }
> > +    if (memory_region_is_iommu(section->mr)) {
> > +        vhost_vdpa_iommu_region_add(listener, section);
> > +        return;
> > +    }
> >
> >      if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> >                   (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> > @@ -260,6 +356,10 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
> >                                              v->iova_range.last)) {
> >          return;
> >      }
> > +    if (memory_region_is_iommu(section->mr)) {
> > +        vhost_vdpa_iommu_region_del(listener, section);
> > +        return;
> > +    }
> >
> >      if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
> >                   (section->offset_within_region & ~TARGET_PAGE_MASK))) {
> > @@ -312,6 +412,7 @@ static const MemoryListener vhost_vdpa_memory_listener = {
> >      .region_del = vhost_vdpa_listener_region_del,
> >  };
> >
> > +
> >  static int vhost_vdpa_call(struct vhost_dev *dev, unsigned long int request,
> >                               void *arg)
> >  {
>
>
> This change is not necessary.
>
will fix this
> > @@ -587,7 +688,6 @@ static int vhost_vdpa_cleanup(struct vhost_dev *dev)
> >      v = dev->opaque;
> >      trace_vhost_vdpa_cleanup(dev, v);
> >      vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
> > -    memory_listener_unregister(&v->listener);
> >      vhost_vdpa_svq_cleanup(dev);
> >
> >      dev->opaque = NULL;
> > @@ -1127,7 +1227,8 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> >      }
> >
> >      if (started) {
> > -        memory_listener_register(&v->listener, &address_space_memory);
> > +        memory_listener_register(&v->listener, dev->vdev->dma_as);
> > +
> >          return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> >      } else {
> >          vhost_vdpa_reset_device(dev);
> > diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> > index d10a89303e..64a46e37cb 100644
> > --- a/include/hw/virtio/vhost-vdpa.h
> > +++ b/include/hw/virtio/vhost-vdpa.h
> > @@ -41,8 +41,18 @@ typedef struct vhost_vdpa {
> >      void *shadow_vq_ops_opaque;
> >      struct vhost_dev *dev;
> >      VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
> > +    QLIST_HEAD(, vdpa_iommu) iommu_list;
> > +    IOMMUNotifier n;
> >  } VhostVDPA;
> >
> > +struct vdpa_iommu {
> > +    struct vhost_vdpa *dev;
> > +    IOMMUMemoryRegion *iommu_mr;
> > +    hwaddr iommu_offset;
> > +    IOMMUNotifier n;
> > +    QLIST_ENTRY(vdpa_iommu) iommu_next;
> > +};
> > +
>
> You need to add a typedef as per coding style.
>
will fix this
Thanks
Cindy
> >  int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
> >                         void *vaddr, bool readonly);
> >  int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova, hwaddr size);
> > --
> > 2.34.3
>