qemu aio: enable support

qemu allows the user to choose what io storage api should be used,
either the default (threads) or native (linux aio) which in the latter
case can result in better performance.

Based on a patch originally by Matthias Dahl.

Red Hat Bugzilla #591703
Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1ce894107fc91afb10f2c7e510537ef34962014f..c0ec00b782ee8e0a91dd0477f7afefe6785241c7 100644 (file)
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1328,6 +1328,18 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk,
         }
     }
 
+    if (disk->iomode) {
+        if (qemuCmdFlags & QEMUD_CMD_FLAG_DRIVE_AIO) {
+            virBufferVSprintf(&opt, ",aio=%s",
+                              virDomainDiskIoTypeToString(disk->iomode));
+        } else {
+            qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                            _("disk aio mode not supported with this "
+                              "QEMU binary"));
+            goto error;
+        }
+    }
+
     if (virBufferError(&opt)) {
         virReportOOMError();
         goto error;
@@ -4545,6 +4557,11 @@ qemuParseCommandLineDisk(virCapsPtr caps,
         } else if (STREQ(keywords[i], "readonly")) {
             if ((values[i] == NULL) || STREQ(values[i], "on"))
                 def->readonly = 1;
+        } else if (STREQ(keywords[i], "aio")) {
+            if ((def->iomode = virDomainDiskIoTypeFromString(values[i])) < 0) {
+                qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                                _("cannot parse io mode '%s'"), values[i]);
+            }
         }
     }
 

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-aio.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-aio.args
new file mode 100644 (file)
index 0000000..15d2a1b
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-aio.args
@@ -0,0 +1 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -drive file=/dev/HostVG/QEMUGuest1,if=ide,bus=0,unit=0,format=qcow2,cache=none,aio=native -drive file=/dev/HostVG/QEMUGuest2,if=ide,media=cdrom,bus=1,unit=0,format=raw,aio=threads -net none -serial none -parallel none -usb

diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-aio.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-aio.xml
new file mode 100644 (file)
index 0000000..d893736
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-aio.xml
@@ -0,0 +1,33 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory>219200</memory>
+  <currentMemory>219200</currentMemory>
+  <vcpu>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</emulator>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none' io='native'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' unit='0'/>
+    </disk>
+    <disk type='block' device='cdrom'>
+      <driver name='qemu' type='raw' io='threads'/>
+      <source dev='/dev/HostVG/QEMUGuest2'/>
+      <target dev='hdc' bus='ide'/>
+      <readonly/>
+      <address type='drive' controller='0' bus='1' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 0c0693b7be63e56c0e3703bc9f5d6c895d99fa03..0a39791d54fd29b0a7dd2f36dfb0a13ab8c4dcd3 100644 (file)
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -320,6 +320,8 @@ mymain(int argc, char **argv)
             QEMUD_CMD_FLAG_DEVICE | QEMUD_CMD_FLAG_NODEFCONFIG, false);
     DO_TEST("disk-scsi-device-auto", QEMUD_CMD_FLAG_DRIVE |
             QEMUD_CMD_FLAG_DEVICE | QEMUD_CMD_FLAG_NODEFCONFIG, false);
+    DO_TEST("disk-aio", QEMUD_CMD_FLAG_DRIVE | QEMUD_CMD_FLAG_DRIVE_AIO |
+            QEMUD_CMD_FLAG_DRIVE_CACHE_V2 | QEMUD_CMD_FLAG_DRIVE_FORMAT, false);
     DO_TEST("graphics-vnc", 0, false);
     DO_TEST("graphics-vnc-socket", 0, false);
 

diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index ab82d3652023ed3bbed1b6f0d4f04dda06ab698b..dad91d4e772bcf1360a34fccafa5e34f05998bbf 100644 (file)
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -132,6 +132,7 @@ mymain(int argc, char **argv)
     DO_TEST("clock-utc");
     DO_TEST("clock-localtime");
     DO_TEST("hugepages");
+    DO_TEST("disk-aio");
     DO_TEST("disk-cdrom");
     DO_TEST("disk-floppy");
     DO_TEST("disk-many");