[PATCH v2 4/6] vfio-pci: Allow PCI IDs to be specified as module options

From: Alex Williamson
Date: Wed Mar 18 2015 - 16:13:41 EST


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@xxxxxxxxxx>
---
drivers/vfio/pci/vfio_pci.c | 49 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 25aef05..43517ce 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -11,6 +11,8 @@
* Author: Tom Lyon, pugs@xxxxxxxxx
*/

+#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@xxxxxxxxxx>"
#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:

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