[libvirt] [PATCH 09/11] storage_scsi: Allow the direct PCI address for 'parent'

[Osier Yang]

To be more flexible, except allowing to specify 'parent' with name
produced by node device udev/HAL backends, this supports to specify
'parent' with PCI address directly (e.g.  0000:00:1f:2). The specified
address will be padded if it's not consistent with what sysfs exposed.
(e.g 0:0:2:2 will be padded to 0000:00:02:2).
---
 src/storage/storage_backend_scsi.c | 117 +++++++++++++++++++++++++++++--------
 1 file changed, 93 insertions(+), 24 deletions(-)

diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
index a77b9ae..5635f73 100644
--- a/src/storage/storage_backend_scsi.c
+++ b/src/storage/storage_backend_scsi.c
@@ -604,51 +604,120 @@ out:
 static char *
 getScsiHostParentAddress(const char *parent)
 {
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
     char **tokens = NULL;
     char *vendor = NULL;
     char *product = NULL;
     char *ret = NULL;
-    int len;
+    int length;
+    int i;
 
-    if (!strchr(parent, '_')) {
+    if (!strchr(parent, '_') &&
+        !strchr(parent, ':')) {
         virReportError(VIR_ERR_XML_ERROR, "%s",
-                       _("'parent' of scsi_host adapter must "
-                         "be consistent with name of node device"));
+                       _("'parent' of scsi_host adapter must be "
+                         "either consistent with name of mode "
+                         "device, or in domain:bus:slot:function "
+                         "format"));
         return NULL;
     }
 
-    if (!(tokens = virStringSplit(parent, "_", 0)))
-        return NULL;
+    if (strchr(parent, '_')) {
+        if (!(tokens = virStringSplit(parent, "_", 0)))
+            return NULL;
 
-    len = virStringListLength(tokens);
+        length = virStringListLength(tokens);
+
+        switch (length) {
+        case 4:
+            if (!(ret = virStringJoin((const char **)(&tokens[1]), ":")))
+                goto cleanup;
+            break;
 
-    switch (len) {
-    case 4:
-        if (!(ret = virStringJoin((const char **)(&tokens[1]), ":")))
+        case 2:
+            vendor = tokens[1];
+            product = tokens[2];
+            if (!(ret = virFindPCIDeviceByVPD(NULL, vendor, product))) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("Unable to find PCI device with vendor '%s' "
+                                 "product '%s'"), vendor, product);
+                goto cleanup;
+            }
+
+            break;
+        default:
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                       _("'parent' of scsi_host adapter must be "
+                         "either consistent with name of mode "
+                         "device, or in domain:bus:slot:function "
+                         "format"));
             goto cleanup;
-        break;
+        }
+    } else if (strchr(parent, ':')) {
+        char *padstr = NULL;
+
+        if (!(tokens = virStringSplit(parent, ":", 0)))
+            return NULL;
 
-    case 2:
-        vendor = tokens[1];
-        product = tokens[2];
-        if (!(ret = virFindPCIDeviceByVPD(NULL, vendor, product))) {
-            virReportError(VIR_ERR_INTERNAL_ERROR,
-                           _("Unable to find PCI device with vendor '%s' "
-                             "product '%s'"), vendor, product);
+        length = virStringListLength(tokens);
+
+        if (length != 4) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("invalid PCI address for scsi_host "
+                             "'parent' '%s'"), parent);
             goto cleanup;
         }
 
-        break;
-    default:
-        virReportError(VIR_ERR_XML_ERROR, "%s",
-                       _("'parent' of scsi_host adapter must "
-                         "be consistent with name of node device"));
-        goto cleanup;
+        for (i = 0; i < length; i++) {
+            if (strlen(tokens[i]) == 0) {
+                virReportError(VIR_ERR_XML_ERROR,
+                               _("invalid PCI address for scsi_host "
+                                 "'parent' '%s'"), parent);
+                goto cleanup;
+            }
+        }
+
+        /* sysfs always exposes the PCI address like "0000:00:1f:2",
+         * this do the padding if the address prodived by user is
+         * not padded (e.g. 0:0:2:0).
+         */
+        if (strlen(tokens[0]) != 4) {
+            if (!(padstr = virStringPad(tokens[0], '0', 4, false)))
+                goto cleanup;
+
+            virBufferAsprintf(&buf, "%s", padstr);
+            VIR_FREE(padstr);
+        } else {
+            virBufferAsprintf(&buf, "%s", tokens[0]);
+        }
+
+        for (i = 1; i < 3; i++) {
+            if (strlen(tokens[i]) != 2) {
+                if (!(padstr = virStringPad(tokens[i], '0', 2, false)))
+                    goto error;
+                virBufferAsprintf(&buf, "%s", padstr);
+                VIR_FREE(padstr);
+            } else {
+                virBufferAsprintf(&buf, "%s", tokens[i]);
+            }
+        }
+
+        if (virBufferError(&buf)) {
+            virBufferFreeAndReset(&buf);
+            virReportOOMError();
+            goto cleanup;
+        }
+
+        ret = virBufferContentAndReset(&buf);
     }
 
 cleanup:
     virStringFreeList(tokens);
     return ret;
+
+error:
+    virBufferFreeAndReset(&buf);
+    goto cleanup;
 }
 
 static int
-- 
1.8.1.4