[PATCH v3 0/7] Rework device probing

[David Marchand]

On Fri, 10 Apr 2026 at 16:35, Morten Brørup <mb at smartsharesystems.com> wrote:
>
> Is there a workaround until this patch is added, if I don't want rte_eal_init() to probe any devices, but I want my application to probe devices later by calling rte_bus_scan() followed by rte_bus_probe()?
>
> It's not something we really need, so if you don't know it off the top of your head, don't spend time trying to figure it out.

Well, starting from the well known -a pci:0000:00:00.0 trick, I wrote
an incomplete workaround implemented for OVS.
https://patchwork.ozlabs.org/project/openvswitch/patch/20260226172429.212034-3-david.marchand@redhat.com/

Incomplete, because some buses make life harder with some additional
parsing restraints (bus/dpaa is the first one that comes to mind) or
requiring a driver handling the device exists (bus/platform which has
*no* in-tree driver, though this is a different story..).

+    if (!args_contains(&args, "-a") && !args_contains(&args, "-b")
+        && !smap_get_bool(ovs_other_config, "dpdk-probe-at-init", false)) {
+#ifdef RTE_BUS_AUXILIARY
+        svec_add(&args, "-a");
+        svec_add(&args, "auxiliary:");
+#endif
+#ifdef RTE_BUS_CDX
+        svec_add(&args, "-a");
+        svec_add(&args, "cdx:cdx-");
+#endif
+#ifdef RTE_BUS_FSLMC
+        svec_add(&args, "-a");
+        svec_add(&args, "fslmc:dpni.65535");
+#endif
+#ifdef RTE_BUS_PCI
+        svec_add(&args, "-a");
+        svec_add(&args, "pci:0000:00:00.0");
+#endif
+#ifdef RTE_BUS_UACCE
+        svec_add(&args, "-a");
+        svec_add(&args, "uacce:");
+#endif
+#ifdef RTE_BUS_VMBUS
+        svec_add(&args, "-a");
+        svec_add(&args, "vmbus:00000000-0000-0000-0000-000000000000");
+#endif
+    }
+


-- 
David Marchand