Re: [libvirt] PATCH: Include OS driver name in device information

3 Jun 2009

Hey,

Looks fine to me, but if you're looking for comments ... :-)

On Fri, 2009-05-29 at 14:39 +0100, Daniel P. Berrange wrote:
...
To, also include the operating system driver name.
$ virsh nodedev-dumpxml pci_8086_27d6
<device>
  <name>pci_8086_27d6</name>
  <parent>computer</parent>
  <driver>
    <name>pcieport-driver</name>
  </driver>
  <capability type='pci'>
    <domain>0</domain>
    <bus>0</bus>
    <slot>28</slot>
    <function>3</function>
    <product id='0x27d6'>82801G (ICH7 Family) PCI Express Port 4</product>
    <vendor id='0x8086'>Intel Corporation</vendor>
  </capability>
</device>
We're not defining any particular semantics for the driver name, it is
just a opaque string following rules of the OS in question.
The obvious question is "what's this for?"

If this is just an opaque string, what should people use it for?
...
diff -r ec78a5d6c00c src/node_device.c

--- a/src/node_device.c	Thu May 28 14:42:24 2009 +0100
+++ b/src/node_device.c	Thu May 28 16:00:12 2009 +0100
@@ -46,6 +46,60 @@ static int dev_has_cap(const virNodeDevi
     return 0;
 }
+#ifdef __linux__
+static int update_driver_name(virConnectPtr conn,
+                              virNodeDeviceObjPtr dev)
+{
+    char *driver_link = NULL;
+    char devpath[PATH_MAX];
+    char *p;
+    int ret = -1;
+    int n;
+
+    VIR_FREE(dev->def->driver);
+
+    if (virAsprintf(&driver_link, "%s/driver", dev->devicePath) < 0) {
+        virReportOOMError(conn);
+        goto cleanup;
+    }
+
+    /* Some devices don't have an explicit driver, so just return
+       without a name */
+    if (access(driver_link, R_OK) < 0) {
+        ret = 0;
+        goto cleanup;
+    }
+
+    if ((n = readlink(driver_link, devpath, sizeof devpath)) < 0) {
+        virReportSystemError(conn, errno,
+                             _("cannot resolve driver link %s"), driver_link);
Do we really want dumpxml to fail for this?
...
+        goto cleanup;
+    }
+    devpath[n] = '\0';
+
+    p = strrchr(devpath, '/');
+    if (p) {
+        dev->def->driver = strdup(p+1);
basename() ?

(you already use basename() in storage_backend_disk.c)
...
diff -r ec78a5d6c00c src/node_device_hal.c
--- a/src/node_device_hal.c	Thu May 28 14:42:24 2009 +0100
+++ b/src/node_device_hal.c	Thu May 28 16:00:12 2009 +0100
Probably should add a FIXME in node_device_devkit.c about adding support
for this.

Cheers,
Mark.

    

Re: [libvirt] PATCH: Include OS driver name in device information

Mark McLoughlin