From 819269c4f0aa8a3117d30cd12d01eb401bdf585a Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Wed, 21 Apr 2010 16:28:21 +0200
Subject: [PATCH] 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>
---
 src/qemu/qemu_command.c                       | 17 ++++++++++
 .../qemuxml2argv-disk-aio.args                |  1 +
 .../qemuxml2argv-disk-aio.xml                 | 33 +++++++++++++++++++
 tests/qemuxml2argvtest.c                      |  2 ++
 tests/qemuxml2xmltest.c                       |  1 +
 5 files changed, 54 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-aio.args
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-disk-aio.xml

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1ce894107f..c0ec00b782 100644
--- 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
index 0000000000..15d2a1b76d
--- /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
index 0000000000..d8937360ca
--- /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 0c0693b7be..0a39791d54 100644
--- 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 ab82d36520..dad91d4e77 100644
--- 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");