[libvirt] [PATCH v2 4/4] qemu: Allow use of iothreads for disk definitions

John Ferlan jferlan at redhat.com
Tue Aug 26 22:15:49 UTC 2014


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.

This code will check both the "start" and "hotplug" paths for the capability,
whether the iothreadsmap has been defined, and whether there's an available
iothread to be used for the disk.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/qemu/qemu_command.c                            | 51 ++++++++++++++++++++++
 src/qemu/qemu_hotplug.c                            |  6 +++
 .../qemuxml2argv-iothreads-disk.args               | 17 ++++++++
 .../qemuxml2argv-iothreads-disk.xml                | 40 +++++++++++++++++
 tests/qemuxml2argvtest.c                           |  2 +
 tests/qemuxml2xmltest.c                            |  1 +
 6 files changed, 117 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 ba0b977..763bb74 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3673,6 +3673,49 @@ qemuBuildDriveStr(virConnectPtr conn,
     return NULL;
 }
 
+
+static bool
+qemuCheckIothreads(virDomainDefPtr def,
+                   virQEMUCapsPtr qemuCaps,
+                   virDomainDiskDefPtr disk)
+{
+    bool inuse;
+
+    /* 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 not available for this 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;
+    }
+
+    /* Is the requested entry available */
+    if (virBitmapGetBit(def->iothreadmap, disk->iothread, &inuse) < 0 ||
+        inuse) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("IOThread '%u' is already in use"), disk->iothread);
+        return false;
+    }
+
+    return true;
+}
+
+
 char *
 qemuBuildDriveDevStr(virDomainDefPtr def,
                      virDomainDiskDefPtr disk,
@@ -3697,6 +3740,9 @@ 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) {
@@ -3874,6 +3920,8 @@ 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 &&
@@ -8288,6 +8336,9 @@ qemuBuildCommandLine(virConnectPtr conn,
                         goto error;
                     virCommandAddArg(cmd, optstr);
                     VIR_FREE(optstr);
+                    if (disk->iothread)
+                        ignore_value(virBitmapSetBit(def->iothreadmap,
+                                                     disk->iothread));
                 }
             }
         }
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index a364c52..71f47b2 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -379,6 +379,9 @@ qemuDomainAttachVirtioDiskDevice(virConnectPtr conn,
                     virFreeError(orig_err);
                 }
             }
+            if (ret == 0 && disk->iothread)
+                ignore_value(virBitmapSetBit(vm->def->iothreadmap,
+                                             disk->iothread));
         }
     } else if (!disk->info.type ||
                 disk->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) {
@@ -2539,6 +2542,9 @@ qemuDomainRemoveDiskDevice(virQEMUDriverPtr driver,
         }
     }
 
+    if (disk->iothread)
+        ignore_value(virBitmapClearBit(vm->def->iothreadmap, disk->iothread));
+
     qemuDomainReleaseDeviceAddress(vm, &disk->info, src);
 
     if (virSecurityManagerRestoreDiskLabel(driver->securityManager,
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.args b/tests/qemuxml2argvdata/qemuxml2argv-iothreads-disk.args
new file mode 100644
index 0000000..4d271ed
--- /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 0000000..72122fb
--- /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 64a4d3d..3feb2fe 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 796977b..b4ab671 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");
-- 
1.9.3




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