From ca437d0603947a814a667c59928e8cf9c0756933 Mon Sep 17 00:00:00 2001
From: Pavel Mores <pmores@redhat.com>
Date: Mon, 30 Sep 2019 15:41:00 +0200
Subject: [PATCH] qemu: Refuse partitions in disk targets
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The way in which the qemu driver generates aliases for disks involves
ignoring the partition number part of a target dev name.  This means that
all partitions of a block device and the device itself all end up with the
same alias.  If multiple such disks are specified in XML, the resulting
name clash makes qemu invocation fail.

Since attaching partitions to qemu VMs doesn't seem to make much sense
anyway, disallow partitions in target specifications altogether.

https://bugzilla.redhat.com/show_bug.cgi?id=1346265

Signed-off-by: Pavel Mores <pmores@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/qemu/qemu_domain.c                        | 15 +++++++++++
 .../disk-attaching-partition-nosupport.xml    | 27 +++++++++++++++++++
 tests/qemuxml2argvtest.c                      |  1 +
 3 files changed, 43 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/disk-attaching-partition-nosupport.xml

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 28e5555b99..b4175a846e 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -5883,6 +5883,8 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk,
 {
     const char *driverName = virDomainDiskGetDriver(disk);
     virStorageSourcePtr n;
+    int idx;
+    int partition;
 
     if (disk->src->shared && !disk->src->readonly &&
         !qemuBlockStorageSourceSupportsConcurrentAccess(disk->src)) {
@@ -5951,6 +5953,19 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk,
         return -1;
     }
 
+    if (virDiskNameParse(disk->dst, &idx, &partition) < 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("invalid disk target '%s'"), disk->dst);
+        return -1;
+    }
+
+    if (partition != 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("invalid disk target '%s', partitions can't appear in disk targets"),
+                       disk->dst);
+        return -1;
+    }
+
     for (n = disk->src; virStorageSourceIsBacking(n); n = n->backingStore) {
         if (qemuDomainValidateStorageSource(n, qemuCaps) < 0)
             return -1;
diff --git a/tests/qemuxml2argvdata/disk-attaching-partition-nosupport.xml b/tests/qemuxml2argvdata/disk-attaching-partition-nosupport.xml
new file mode 100644
index 0000000000..591819fbb6
--- /dev/null
+++ b/tests/qemuxml2argvdata/disk-attaching-partition-nosupport.xml
@@ -0,0 +1,27 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-i686</emulator>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source file='/export/vmimages/1.raw'/>
+      <target dev='vdb1' bus='virtio'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 5f4e87aa6d..b7cb356d13 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1107,6 +1107,7 @@ mymain(void)
     DO_TEST("disk-no-boot", NONE);
     DO_TEST_PARSE_ERROR("disk-device-lun-type-invalid",
                         QEMU_CAPS_VIRTIO_SCSI);
+    DO_TEST_CAPS_LATEST_PARSE_ERROR("disk-attaching-partition-nosupport");
     DO_TEST_FAILURE("disk-usb-nosupport", NONE);
     DO_TEST("disk-usb-device",
             QEMU_CAPS_DEVICE_USB_STORAGE);
-- 
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