vfio-pci: Allow PCI IDs to be specified as module options

This copies the same support from pci-stub for exactly the same
purpose, enabling a set of PCI IDs to be automatically added to the
driver's dynamic ID table at module load time.  The code here is
pretty simple and both vfio-pci and pci-stub are fairly unique in
being meta drivers, capable of attaching to any device, so there's no
attempt made to generalize the code into pci-core.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 25aef05b8692..43517ce930f2 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -11,6 +11,8 @@
  * Author: Tom Lyon, pugs@cisco.com
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/device.h>
 #include <linux/eventfd.h>
 #include <linux/file.h>
@@ -33,6 +35,10 @@
 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
 #define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
 
+static char ids[1024] __initdata;
+module_param_string(ids, ids, sizeof(ids), 0);
+MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified");
+
 static bool nointxmask;
 module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(nointxmask,
@@ -1105,6 +1111,47 @@ static void __exit vfio_pci_cleanup(void)
         vfio_pci_uninit_perm_bits();
 }
 
+static void __init vfio_pci_fill_ids(void)
+{
+        char *p, *id;
+        int rc;
+
+        /* no ids passed actually */
+        if (ids[0] == '\0')
+                return;
+
+        /* add ids specified in the module parameter */
+        p = ids;
+        while ((id = strsep(&p, ","))) {
+                unsigned int vendor, device, subvendor = PCI_ANY_ID,
+                        subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
+                int fields;
+
+                if (!strlen(id))
+                        continue;
+
+                fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
+                                &vendor, &device, &subvendor, &subdevice,
+                                &class, &class_mask);
+
+                if (fields < 2) {
+                        pr_warn("invalid id string \"%s\"\n", id);
+                        continue;
+                }
+
+                rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
+                                   subvendor, subdevice, class, class_mask, 0);
+                if (rc)
+                        pr_warn("failed to add dynamic id [%04hx:%04hx[%04hx:%04hx]] class %#08x/%08x (%d)\n",
+                                vendor, device, subvendor, subdevice,
+                                class, class_mask, rc);
+                else
+                        pr_info("add [%04hx:%04hx[%04hx:%04hx]] class %#08x/%08x\n",
+                                vendor, device, subvendor, subdevice,
+                                class, class_mask);
+        }
+}
+
 static int __init vfio_pci_init(void)
 {
         int ret;
@@ -1119,6 +1166,8 @@ static int __init vfio_pci_init(void)
         if (ret)
                 goto out_driver;
 
+        vfio_pci_fill_ids();
+
         return 0;
 
 out_driver: