Re: [PATCH v6 09/10] vdpa: Add listener_shadow_vq to vhost_vdpa

[Eugenio Perez Martin <eperezma@redhat.com>]

On Thu, Nov 10, 2022 at 7:01 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Wed, Nov 9, 2022 at 1:08 AM Eugenio Pérez <eperezma@redhat.com> wrote:
> >
> > The memory listener that thells the device how to convert GPA to qemu's
> > va is registered against CVQ vhost_vdpa. This series try to map the
> > memory listener translations to ASID 0, while it maps the CVQ ones to
> > ASID 1.
> >
> > Let's tell the listener if it needs to register them on iova tree or
> > not.
> >
> > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > ---
> > v5: Solve conflict about vhost_iova_tree_remove accepting mem_region by
> >     value.
> > ---
> >  include/hw/virtio/vhost-vdpa.h | 2 ++
> >  hw/virtio/vhost-vdpa.c         | 6 +++---
> >  net/vhost-vdpa.c               | 1 +
> >  3 files changed, 6 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> > index 6560bb9d78..0c3ed2d69b 100644
> > --- a/include/hw/virtio/vhost-vdpa.h
> > +++ b/include/hw/virtio/vhost-vdpa.h
> > @@ -34,6 +34,8 @@ typedef struct vhost_vdpa {
> >      struct vhost_vdpa_iova_range iova_range;
> >      uint64_t acked_features;
> >      bool shadow_vqs_enabled;
> > +    /* The listener must send iova tree addresses, not GPA */
> > +    bool listener_shadow_vq;
> >      /* IOVA mapping used by the Shadow Virtqueue */
> >      VhostIOVATree *iova_tree;
> >      GPtrArray *shadow_vqs;
> > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> > index 8fd32ba32b..e3914fa40e 100644
> > --- a/hw/virtio/vhost-vdpa.c
> > +++ b/hw/virtio/vhost-vdpa.c
> > @@ -220,7 +220,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
> >                                           vaddr, section->readonly);
> >
> >      llsize = int128_sub(llend, int128_make64(iova));
> > -    if (v->shadow_vqs_enabled) {
> > +    if (v->listener_shadow_vq) {
> >          int r;
> >
> >          mem_region.translated_addr = (hwaddr)(uintptr_t)vaddr,
> > @@ -247,7 +247,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
> >      return;
> >
> >  fail_map:
> > -    if (v->shadow_vqs_enabled) {
> > +    if (v->listener_shadow_vq) {
> >          vhost_iova_tree_remove(v->iova_tree, mem_region);
> >      }
> >
> > @@ -292,7 +292,7 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
> >
> >      llsize = int128_sub(llend, int128_make64(iova));
> >
> > -    if (v->shadow_vqs_enabled) {
> > +    if (v->listener_shadow_vq) {
> >          const DMAMap *result;
> >          const void *vaddr = memory_region_get_ram_ptr(section->mr) +
> >              section->offset_within_region +
> > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > index 85a318faca..02780ee37b 100644
> > --- a/net/vhost-vdpa.c
> > +++ b/net/vhost-vdpa.c
> > @@ -570,6 +570,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
> >      s->vhost_vdpa.index = queue_pair_index;
> >      s->always_svq = svq;
> >      s->vhost_vdpa.shadow_vqs_enabled = svq;
> > +    s->vhost_vdpa.listener_shadow_vq = svq;
>
> Any chance those above two can differ?
>

If CVQ is shadowed but data VQs are not, shadow_vqs_enabled is true
but listener_shadow_vq is not.

It is more clear in the next commit, where only shadow_vqs_enabled is
set to true at vhost_vdpa_net_cvq_start.

Thanks!

> Thanks
>
> >      s->vhost_vdpa.iova_tree = iova_tree;
> >      if (!is_datapath) {
> >          s->cvq_cmd_out_buffer = qemu_memalign(qemu_real_host_page_size(),
> > --
> > 2.31.1
> >
>