From ef8da2ad11827109bd255dd060a14d89286af2a9 Mon Sep 17 00:00:00 2001
From: John Ferlan <jferlan@redhat.com>
Date: Mon, 25 Aug 2014 15:59:32 -0400
Subject: [PATCH] qemu: Allow use of iothreads for disk definitions

For virtio-blk-pci disks with the disk iothread attribute that are
running the correct emulator, add the "iothread=iothread#" to the
-device command line in order to enable iothreads for the disk as
long as the command is available, the disk iothread value provided is
valid, and is supported for the disk device being added
---
 src/qemu/qemu_command.c                       | 38 ++++++++++++++++++
 .../qemuxml2argv-iothreads-disk.args          | 17 ++++++++
 .../qemuxml2argv-iothreads-disk.xml           | 40 +++++++++++++++++++
 tests/qemuxml2argvtest.c                      |  2 +
 tests/qemuxml2xmltest.c                       |  1 +
 5 files changed, 98 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.args
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.xml

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 13acb8ec82..2184caa9da 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3674,6 +3674,39 @@ qemuBuildDriveStr(virConnectPtr conn,
     return NULL;
 }
 
+
+static bool
+qemuCheckIothreads(virDomainDefPtr def,
+                   virQEMUCapsPtr qemuCaps,
+                   virDomainDiskDefPtr disk)
+{
+    /* Have capability */
+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_OBJECT_IOTHREAD)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("IOThreads not supported for this QEMU"));
+        return false;
+    }
+
+    /* Right "type" of disk" */
+    if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO &&
+        disk->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("IOThreads only available for virtio pci disk"));
+        return false;
+    }
+
+    /* Value larger than iothreads available? */
+    if (disk->iothread > def->iothreads) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("Disk iothread '%u' invalid only %u IOThreads"),
+                       disk->iothread, def->iothreads);
+        return false;
+    }
+
+    return true;
+}
+
+
 char *
 qemuBuildDriveDevStr(virDomainDefPtr def,
                      virDomainDiskDefPtr disk,
@@ -3698,6 +3731,9 @@ qemuBuildDriveDevStr(virDomainDefPtr def,
         }
     }
 
+    if (disk->iothread && !qemuCheckIothreads(def, qemuCaps, disk))
+        goto error;
+
     switch (disk->bus) {
     case VIR_DOMAIN_DISK_BUS_IDE:
         if (disk->info.addr.drive.target != 0) {
@@ -3875,6 +3911,8 @@ qemuBuildDriveDevStr(virDomainDefPtr def,
             virBufferAddLit(&opt, "virtio-blk-device");
         } else {
             virBufferAddLit(&opt, "virtio-blk-pci");
+            if (disk->iothread)
+                virBufferAsprintf(&opt, ",iothread=iothread%u", disk->iothread);
         }
         qemuBuildIoEventFdStr(&opt, disk->ioeventfd, qemuCaps);
         if (disk->event_idx &&
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.args b/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.args
new file mode 100644
index 0000000000..4d271ed1ba
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.args
@@ -0,0 +1,17 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu -S -M \
+pc -m 214 -smp 2 \
+-object iothread,id=iothread1 \
+-object iothread,id=iothread2 \
+-nographic -nodefaults -monitor \
+unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -usb \
+-drive file=/dev/HostVG/QEMUGuest1,if=none,id=drive-ide0-0-0 \
+-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
+-drive file=/var/lib/libvirt/images/iothrtest1.img,if=none,\
+id=drive-virtio-disk1 \
+-device virtio-blk-pci,iothread=iothread1,bus=pci.0,addr=0x4,\
+drive=drive-virtio-disk1,id=virtio-disk1 \
+-drive file=/var/lib/libvirt/images/iothrtest2.img,if=none,\
+id=drive-virtio-disk2 \
+-device virtio-blk-pci,iothread=iothread2,bus=pci.0,addr=0x3,\
+drive=drive-virtio-disk2,id=virtio-disk2
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.xml b/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.xml
new file mode 100644
index 0000000000..72122fb103
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.xml
@@ -0,0 +1,40 @@
+<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'>2</vcpu>
+  <iothreads>2</iothreads>
+  <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</emulator>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='raw' iothread='1'/>
+      <source file='/var/lib/libvirt/images/iothrtest1.img'/>
+      <target dev='vdb' bus='virtio'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+    </disk>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='raw' iothread='2'/>
+      <source file='/var/lib/libvirt/images/iothrtest2.img'/>
+      <target dev='vdc' bus='virtio'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 64a4d3d752..3feb2fe259 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1186,6 +1186,8 @@ mymain(void)
     DO_TEST("smp", QEMU_CAPS_SMP_TOPOLOGY);
 
     DO_TEST("iothreads", QEMU_CAPS_OBJECT_IOTHREAD);
+    DO_TEST("iothreads-disk", QEMU_CAPS_OBJECT_IOTHREAD, QEMU_CAPS_DEVICE,
+            QEMU_CAPS_DRIVE);
 
     DO_TEST("cpu-topology1", QEMU_CAPS_SMP_TOPOLOGY);
     DO_TEST("cpu-topology2", QEMU_CAPS_SMP_TOPOLOGY);
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 796977b1aa..b4ab67149b 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -302,6 +302,7 @@ mymain(void)
 
     DO_TEST("smp");
     DO_TEST("iothreads");
+    DO_TEST("iothreads-disk");
     DO_TEST("lease");
     DO_TEST("event_idx");
     DO_TEST("vhost_queues");