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>
This commit is contained in:
Eric Blake 2010-04-21 16:28:21 +02:00
parent f19357ce37
commit 819269c4f0
5 changed files with 54 additions and 0 deletions

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@ -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]);
}
}
}

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@ -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

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@ -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>

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@ -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);

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@ -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");