[libvirt] [PATCH 2/2] qemu: add support of optional 'deflate-on-oom' attribute

John Ferlan jferlan at redhat.com
Thu Dec 17 20:48:56 UTC 2015 


On 12/14/2015 06:35 AM, Dmitry Andreev wrote:
> xml:
> <devices>
>   <memballoon model='virtio' deflate-on-oom='on'/>
> </devices>
> 
> qemu:
> qemu -device virtio-balloon-pci,...,deflate-on-oom=on

Little light on the commit message

Next question to be asked - how about being able to enable/disable for
the running domain?!

If the memory period/seconds can be adjusted dynamically I begin to
wonder whether the feature is available for the running domain and
perhaps through something for a setmem option?

> ---
>  src/qemu/qemu_command.c                            |  4 ++++
>  .../qemuxml2argv-balloon-device-deflate-off.args   | 23 ++++++++++++++++++++
>  .../qemuxml2argv-balloon-device-deflate-off.xml    | 25 ++++++++++++++++++++++
>  .../qemuxml2argv-balloon-device-deflate.args       | 23 ++++++++++++++++++++
>  .../qemuxml2argv-balloon-device-deflate.xml        | 25 ++++++++++++++++++++++
>  tests/qemuxml2argvtest.c                           |  4 ++++
>  6 files changed, 104 insertions(+)
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.args
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.xml
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.args
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.xml
> 

Nice - tests. obvious updates as a result of comments in 1/2...

Just making sure - all the address types support in qemu_command.c can
support this feature, right? PCI, CCW, MMIO

Your tests only show PCI.

Of course I have to ask - since as you note in your cover this feature
was added to QEMU "a month ago" - why is there no capabilities check?

What happens when (and it will happen) this is run on a host that
doesn't have that capability for the balloon driver?

You'll need to add some sort of capabilities or version check. If qemu
didn't create one for this feature, then that really needs to be done.

John

> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index d2f37e4..227ba8a 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -5708,6 +5708,10 @@ qemuBuildMemballoonDevStr(virDomainDefPtr def,
>      if (qemuBuildDeviceAddressStr(&buf, def, &dev->info, qemuCaps) < 0)
>          goto error;
>  
> +    if (dev->deflate > 0)
> +        virBufferAsprintf(&buf, ",deflate-on-oom=%s",
> +                          virTristateSwitchTypeToString(dev->deflate));
> +
>      if (virBufferCheckError(&buf) < 0)
>          goto error;
>  
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.args b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.args
> new file mode 100644
> index 0000000..1e64c1a
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.args
> @@ -0,0 +1,23 @@
> +LC_ALL=C \
> +PATH=/bin \
> +HOME=/home/test \
> +USER=test \
> +LOGNAME=test \
> +QEMU_AUDIO_DRV=none \
> +/usr/bin/qemu \
> +-name QEMUGuest1 \
> +-S \
> +-M pc \
> +-m 214 \
> +-smp 1 \
> +-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
> +-nographic \
> +-nodefconfig \
> +-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,format=raw \
> +-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
> +-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x12,deflate-on-oom=off
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.xml b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.xml
> new file mode 100644
> index 0000000..5e536a1
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate-off.xml
> @@ -0,0 +1,25 @@
> +<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'>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'/>
> +    </disk>
> +    <memballoon model='virtio' deflate-on-oom='off'>
> +      <address type='pci' domain='0' bus='0' slot='18' function='0'/>
> +    </memballoon>
> +  </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.args b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.args
> new file mode 100644
> index 0000000..18a2df9
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.args
> @@ -0,0 +1,23 @@
> +LC_ALL=C \
> +PATH=/bin \
> +HOME=/home/test \
> +USER=test \
> +LOGNAME=test \
> +QEMU_AUDIO_DRV=none \
> +/usr/bin/qemu \
> +-name QEMUGuest1 \
> +-S \
> +-M pc \
> +-m 214 \
> +-smp 1 \
> +-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
> +-nographic \
> +-nodefconfig \
> +-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,format=raw \
> +-device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 \
> +-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x12,deflate-on-oom=on
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.xml b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.xml
> new file mode 100644
> index 0000000..efecbc6
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-balloon-device-deflate.xml
> @@ -0,0 +1,25 @@
> +<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'>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'/>
> +    </disk>
> +    <memballoon model='virtio' deflate-on-oom='on'>
> +      <address type='pci' domain='0' bus='0' slot='18' function='0'/>
> +    </memballoon>
> +  </devices>
> +</domain>
> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
> index 37f806e..42a6aed 100644
> --- a/tests/qemuxml2argvtest.c
> +++ b/tests/qemuxml2argvtest.c
> @@ -1194,6 +1194,10 @@ mymain(void)
>              QEMU_CAPS_DEVICE, QEMU_CAPS_CHARDEV, QEMU_CAPS_NODEFCONFIG,
>              QEMU_CAPS_BOOTINDEX, QEMU_CAPS_VIRTIO_S390);
>      DO_TEST("balloon-device", QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
> +    DO_TEST("balloon-device-deflate",
> +            QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
> +    DO_TEST("balloon-device-deflate-off",
> +            QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
>      DO_TEST("balloon-device-auto",
>              QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
>      DO_TEST("balloon-device-period", QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
>

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