[CENNSO-1969] fix: avoid scan of PCI devices (#46)

Disable scan of PCI devices if no supported driver is registered.

Scanning of all PCI devices can sometimes lead to kernel issues. Since only legacy drivers use this infra, and currently no driver is build with this infra, scanning is basically disabled.

vpp-patches/0034-CENNSO-1969-fix-avoid-scan-of-PCI-devices.patch

@@ -0,0 +1,29 @@
+From b55e9b395d854a39d3ad5317883158e476576623 Mon Sep 17 00:00:00 2001
+From: Vladimir Zhigulin <[email protected]>
+Date: Wed, 17 Apr 2024 15:30:40 +0200
+Subject: [PATCH] [CENNSO-1969] fix: avoid scan of PCI devices
+
+Only if no pci drivers registered, what usually
+the case
+---
+ src/vlib/linux/pci.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/vlib/linux/pci.c b/src/vlib/linux/pci.c
+index 9f0629f46..8442bf984 100644
+--- a/src/vlib/linux/pci.c
++++ b/src/vlib/linux/pci.c
+@@ -1545,6 +1545,10 @@ linux_pci_init (vlib_main_t * vm)
+
+   ASSERT (sizeof (vlib_pci_addr_t) == sizeof (u32));
+
++  // avoid iterating over devices if we don't have registration
++  if (!pm->pci_device_registrations)
++    return 0;
++
+   addrs = vlib_pci_get_all_dev_addrs ();
+   /* *INDENT-OFF* */
+   vec_foreach (addr, addrs)
+-- 
+2.44.0
+