[libvirt] [PATCH v2 11/11] qemu: command: Mark <shared/> disks as such in qemu

[Peter Krempa]

Qemu has now an internal mechanism for locking images to fix specific
cases of disk corruption. This requires libvirt to mark the image as
shared so that qemu lifts certain restrictions.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1378242
---
 src/qemu/qemu_command.c                            |  4 +++
 .../qemuxml2argv-disk-drive-shared-locking.args    | 32 +++++++++++++++++
 .../qemuxml2argv-disk-drive-shared-locking.xml     | 42 ++++++++++++++++++++++
 tests/qemuxml2argvtest.c                           |  2 ++
 4 files changed, 80 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.args
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.xml

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 216a4bdfe0..f009b28254 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2126,6 +2126,10 @@ qemuBuildDriveDevStr(const virDomainDef *def,
         goto error;
     }

+    if (disk->src->shared &&
+        virQEMUCapsGet(qemuCaps, QEMU_CAPS_DISK_SHARE_RW))
+        virBufferAddLit(&opt, ",share-rw=on");
+
     if (!(drivealias = qemuAliasFromDisk(disk)))
         goto error;
     virBufferAsprintf(&opt, ",drive=%s,id=%s", drivealias, disk->info.alias);
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.args
new file mode 100644
index 0000000000..cdf17f26d1
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.args
@@ -0,0 +1,32 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-i686 \
+-name QEMUGuest1 \
+-S \
+-M pc \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-nographic \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-QEMUGuest1/monitor.sock,\
+server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=readline \
+-no-acpi \
+-boot c \
+-device virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x3 \
+-usb \
+-drive file=/dev/ide,format=raw,if=none,id=drive-ide0-0-0,cache=none \
+-device ide-drive,bus=ide.0,unit=0,share-rw=on,drive=drive-ide0-0-0,\
+id=ide0-0-0 \
+-drive file=/dev/scsi,format=raw,if=none,id=drive-scsi0-0-0-0,cache=none \
+-device scsi-disk,bus=scsi0.0,channel=0,scsi-id=0,lun=0,share-rw=on,\
+drive=drive-scsi0-0-0-0,id=scsi0-0-0-0 \
+-drive file=/dev/virtio,format=raw,if=none,id=drive-virtio-disk0,cache=none \
+-device virtio-blk-pci,bus=pci.0,addr=0x4,share-rw=on,drive=drive-virtio-disk0,\
+id=virtio-disk0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.xml
new file mode 100644
index 0000000000..dd48857a30
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared-locking.xml
@@ -0,0 +1,42 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</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='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/ide'/>
+      <target dev='hda' bus='ide'/>
+      <shareable/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/scsi'/>
+      <target dev='sda' bus='scsi'/>
+      <shareable/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/virtio'/>
+      <target dev='vda' bus='virtio'/>
+      <shareable/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='scsi' index='0' model='virtio-scsi'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index fdfc3c0b5e..fc6f2f10e1 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -909,6 +909,8 @@ mymain(void)
     DO_TEST("disk-drive-shared",
             QEMU_CAPS_DRIVE_SERIAL);
     DO_TEST_PARSE_ERROR("disk-drive-shared-qcow", NONE);
+    DO_TEST("disk-drive-shared-locking",
+            QEMU_CAPS_VIRTIO_SCSI, QEMU_CAPS_DISK_SHARE_RW);
     DO_TEST("disk-drive-error-policy-stop",
             QEMU_CAPS_MONITOR_JSON);
     DO_TEST("disk-drive-error-policy-enospace",
-- 
2.14.3