[RFC,v2] bus/fslmc: fix invalid use of default VFIO config
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Commit Message
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")
Signed-off-by: Romain Delhomel <romain.delhomel@6wind.com>
---
v2:
* Fix wrong indentation
drivers/bus/fslmc/fslmc_vfio.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
Comments
Tested ok
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
On 5/31/2022 2:57 PM, Romain Delhomel wrote:
> 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")
> Signed-off-by: Romain Delhomel <romain.delhomel@6wind.com>
> ---
> v2:
> * Fix wrong indentation
>
> 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;
@@ -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;