[RFC] bus/fslmc: fix invalid use of default vfio config

[Romain Delhomel <romain.delhomel@6wind.com>]

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At device probe, the fslmc bus driver calls rte_vfio_get_group_fd() to
get a fd associated to a vfio group. This function first checks if the
group is already opened, else it opens /dev/vfio/%u, and increases the
number of active groups in default_vfio_cfg (which references the
default vfio container).

When adding the first group to a vfio_cfg, the caller is supposed to
pick an IOMMU type and set up DMA mappings for container, as it's done
by pci bus, but it is not done here. Instead, a new container is created
and used.

This prevents the pci bus driver, which use the default_vfio_cfg
container, to configure the container because
default_vfio_cfg->active_group > 1.

This patch fixes the issue by always creating a new container (and its
associated vfio_cfg) and bind the group to it.

Fixes: a69f79300262 ("bus/fslmc: support multi VFIO group")
Signed-off-by: Romain Delhomel <romain.delhomel@6wind.com>
---
 drivers/bus/fslmc/fslmc_vfio.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/fslmc/fslmc_vfio.c b/drivers/bus/fslmc/fslmc_vfio.c
index b4704eeae4e2..abe1cab2ee20 100644
--- a/drivers/bus/fslmc/fslmc_vfio.c
+++ b/drivers/bus/fslmc/fslmc_vfio.c
@@ -979,6 +979,7 @@ fslmc_vfio_setup_group(void)
 {
  int groupid;
  int ret;
+ int vfio_container_fd;
  struct vfio_group_status status = { .argsz = sizeof(status) };

  /* if already done once */
@@ -997,8 +998,15 @@ fslmc_vfio_setup_group(void)
  return 0;
  }

+ ret = rte_vfio_container_create();
+ if (ret < 0) {
+ DPAA2_BUS_ERR("Failed to open VFIO container");
+ return ret;
+ }
+ vfio_container_fd = ret;
+
  /* Get the actual group fd */
- ret = rte_vfio_get_group_fd(groupid);
+ ret = rte_vfio_container_group_bind(vfio_container_fd, groupid);
  if (ret < 0)
  return ret;
  vfio_group.fd = ret;
-- 
2.30.2

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