[PATCH] bus/fslmc: fix invalid use of default VFIO config

[PATCH] bus/fslmc: fix invalid use of default VFIO config

[Romain Delhomel]

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 uses 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 binding the group to it.

Fixes: a69f79300262 ("bus/fslmc: support multi VFIO group")
Cc: stable@dpdk.org

Signed-off-by: Romain Delhomel <romain.delhomel@6wind.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.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

Re: [PATCH] bus/fslmc: fix invalid use of default VFIO config

[Thomas Monjalon]

03/06/2022 17:18, Romain Delhomel:
> 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 uses 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 binding the group to it.
> 
> Fixes: a69f79300262 ("bus/fslmc: support multi VFIO group")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Romain Delhomel <romain.delhomel@6wind.com>
> Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>

Applied, thanks.