libvirt/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-device.xml

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<domain type='qemu'>
<name>QEMUGuest1</name>
<uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
xml: output memory unit for clarity Make it obvious to 'dumpxml' readers what unit we are using, since our default of KiB for memory (1024) differs from qemu's default of MiB; and differs from our use of bytes for storage. Tests were updated via: $ find tests/*data tests/*out -name '*.xml' | \ xargs sed -i 's/<\(memory\|currentMemory\|hard_limit\|soft_limit\|min_guarantee\|swap_hard_limit\)>/<\1 unit='"'KiB'>/" $ find tests/*data tests/*out -name '*.xml' | \ xargs sed -i 's/<\(capacity\|allocation\|available\)>/<\1 unit='"'bytes'>/" followed by a few fixes for the stragglers. Note that with this patch, the RNG for <memory> still forbids validation of anything except unit='KiB', since the code silently ignores the attribute; a later patch will expand <memory> to allow scaled input in the code and update the RNG to match. * docs/schemas/basictypes.rng (unit): Add 'bytes'. (scaledInteger): New define. * docs/schemas/storagevol.rng (sizing): Use it. * docs/schemas/storagepool.rng (sizing): Likewise. * docs/schemas/domaincommon.rng (memoryKBElement): New define; use for memory elements. * src/conf/storage_conf.c (virStoragePoolDefFormat) (virStorageVolDefFormat): Likewise. * src/conf/domain_conf.h (_virDomainDef): Document unit used internally. * src/conf/storage_conf.h (_virStoragePoolDef, _virStorageVolDef): Likewise. * tests/*data/*.xml: Update all tests. * tests/*out/*.xml: Likewise. * tests/define-dev-segfault: Likewise. * tests/openvzutilstest.c (testReadNetworkConf): Likewise. * tests/qemuargv2xmltest.c (blankProblemElements): Likewise.
2012-02-23 00:48:38 +00:00
<memory unit='KiB'>219136</memory>
<currentMemory unit='KiB'>219136</currentMemory>
<vcpu placement='static'>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'>
<source dev='/dev/HostVG/QEMUGuest1'/>
<target dev='hda' bus='ide'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
<controller type='usb' index='0'/>
Add txmode attribute to interface XML for virtio backend This is in response to: https://bugzilla.redhat.com/show_bug.cgi?id=629662 Explanation qemu's virtio-net-pci driver allows setting the algorithm used for tx packets to either "bh" or "timer". This is done by adding ",tx=bh" or ",tx=timer" to the "-device virtio-net-pci" commandline option. 'bh' stands for 'bottom half'; when this is set, packet tx is all done in an iothread in the bottom half of the driver. (In libvirt, this option is called the more descriptive "iothread".) 'timer' means that tx work is done in qemu, and if there is more tx data than can be sent at the present time, a timer is set before qemu moves on to do other things; when the timer fires, another attempt is made to send more data. (libvirt retains the name "timer" for this option.) The resulting difference, according to the qemu developer who added the option is: bh makes tx more asynchronous and reduces latency, but potentially causes more processor bandwidth contention since the cpu doing the tx isn't necessarily the cpu where the guest generated the packets. Solution This patch provides a libvirt domain xml knob to change the option on the qemu commandline, by adding a new attribute "txmode" to the <driver> element that can be placed inside any <interface> element in a domain definition. It's use would be something like this: <interface ...> ... <model type='virtio'/> <driver txmode='iothread'/> ... </interface> I chose to put this setting as an attribute to <driver> rather than as a sub-element to <tune> because it is specific to the virtio-net driver, not something that is generally usable by all network drivers. (note that this is the same placement as the "driver name=..." attribute used to choose kernel vs. userland backend for the virtio-net driver.) Actually adding the tx=xxx option to the qemu commandline is only done if the version of qemu being used advertises it in the output of qemu -device virtio-net-pci,? If a particular txmode is requested in the XML, and the option isn't listed in that help output, an UNSUPPORTED_CONFIG error is logged, and the domain fails to start.
2011-02-03 20:20:01 +00:00
<controller type='ide' index='0'/>
<controller type='pci' index='0' model='pci-root'/>
<interface type='user'>
<mac address='00:11:22:33:44:55'/>
<model type='virtio'/>
Add txmode attribute to interface XML for virtio backend This is in response to: https://bugzilla.redhat.com/show_bug.cgi?id=629662 Explanation qemu's virtio-net-pci driver allows setting the algorithm used for tx packets to either "bh" or "timer". This is done by adding ",tx=bh" or ",tx=timer" to the "-device virtio-net-pci" commandline option. 'bh' stands for 'bottom half'; when this is set, packet tx is all done in an iothread in the bottom half of the driver. (In libvirt, this option is called the more descriptive "iothread".) 'timer' means that tx work is done in qemu, and if there is more tx data than can be sent at the present time, a timer is set before qemu moves on to do other things; when the timer fires, another attempt is made to send more data. (libvirt retains the name "timer" for this option.) The resulting difference, according to the qemu developer who added the option is: bh makes tx more asynchronous and reduces latency, but potentially causes more processor bandwidth contention since the cpu doing the tx isn't necessarily the cpu where the guest generated the packets. Solution This patch provides a libvirt domain xml knob to change the option on the qemu commandline, by adding a new attribute "txmode" to the <driver> element that can be placed inside any <interface> element in a domain definition. It's use would be something like this: <interface ...> ... <model type='virtio'/> <driver txmode='iothread'/> ... </interface> I chose to put this setting as an attribute to <driver> rather than as a sub-element to <tune> because it is specific to the virtio-net driver, not something that is generally usable by all network drivers. (note that this is the same placement as the "driver name=..." attribute used to choose kernel vs. userland backend for the virtio-net driver.) Actually adding the tx=xxx option to the qemu commandline is only done if the version of qemu being used advertises it in the output of qemu -device virtio-net-pci,? If a particular txmode is requested in the XML, and the option isn't listed in that help output, an UNSUPPORTED_CONFIG error is logged, and the domain fails to start.
2011-02-03 20:20:01 +00:00
<driver txmode='iothread'/>
</interface>
<memballoon model='virtio'/>
</devices>
</domain>