From: Peter Krempa <pkrempa@redhat.com>
Date: Wed, 15 Nov 2017 15:21:14 +0100
Subject: [PATCH] qemu: command: Mark <shared/> disks as such in qemu

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
(cherry picked from commit 28907b0043fbf71085a798372ab9c816ba043b93)
---
 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 ae78cd17e..883525752 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2075,6 +2075,10 @@ 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 000000000..cdf17f26d
--- /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 000000000..dd48857a3
--- /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 93f892229..9585fdb70 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -896,6 +896,8 @@ 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",