From 8d46386bfe01b84982e25e915ad9cfbae5cf4cb1 Mon Sep 17 00:00:00 2001
From: John Ferlan <jferlan@redhat.com>
Date: Wed, 12 Aug 2015 15:30:45 -0400
Subject: [PATCH] conf: Add SCSI hostdev check for disk drive address already
 in use

https://bugzilla.redhat.com/show_bug.cgi?id=1210587  (partial)

If a SCSI subsystem <hostdev> element address is provided, we need to
make sure the address provided doesn't conflict with an existing or
libvirt generated address for a SCSI <disk> element. We can handle
this condition in device post processing since we're not generating an
address based on some target name - rather it's either generated based
on space or provided from the user. If the user provides one that conflicts,
then we need to disallow the change.

This will fix the issue where the domain XML provided an <address> for
the <hostdev>, but not the <disk> element where the address provided
ends up being the same address used for the <disk>. A <disk> address
is generated using it's assigned <target> 'dev' name prior to the
check/validation of the <hostdev> address value.
---
 src/conf/domain_conf.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index f1e02e3391..7e5a11d589 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -4141,12 +4141,33 @@ virDomainDeviceDefPostParseInternal(virDomainDeviceDefPtr dev,
         virDomainHostdevDefPtr hdev = dev->data.hostdev;
 
         if (hdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-            hdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI &&
-            hdev->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE &&
-            virDomainHostdevAssignAddress(xmlopt, def, hdev) < 0) {
+            hdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI) {
+
+            if (hdev->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE &&
+                virDomainHostdevAssignAddress(xmlopt, def, hdev) < 0) {
                 virReportError(VIR_ERR_XML_ERROR, "%s",
                                _("Cannot assign SCSI host device address"));
                 return -1;
+            } else {
+                /* Ensure provided address doesn't conflict with existing
+                 * scsi disk drive address
+                 */
+                virDomainDeviceDriveAddressPtr addr = &hdev->info->addr.drive;
+                if (virDomainDriveAddressIsUsedByDisk(def,
+                                                      VIR_DOMAIN_DISK_BUS_SCSI,
+                                                      addr->controller,
+                                                      addr->bus,
+                                                      addr->target,
+                                                      addr->unit)) {
+                    virReportError(VIR_ERR_XML_ERROR,
+                                   _("SCSI host address controller='%u' "
+                                     "bus='%u' target='%u' unit='%u' in "
+                                     "use by a SCSI disk"),
+                                   addr->controller, addr->bus,
+                                   addr->target, addr->unit);
+                    return -1;
+                }
+            }
         }
     }
     return 0;
-- 
2.39.5