[libvirt] [PATCH 5/5] tests: add qemuxml2argv memfd-memory-numa test

John Ferlan jferlan at redhat.com
Wed Sep 12 00:01:08 UTC 2018



On 09/11/2018 04:48 AM, Marc-André Lureau wrote:
> Hi
> 
> On Tue, Sep 11, 2018 at 2:57 AM, John Ferlan <jferlan at redhat.com> wrote:
>>
>>
>> On 09/07/2018 07:32 AM, marcandre.lureau at redhat.com wrote:
>>> From: Marc-André Lureau <marcandre.lureau at redhat.com>
>>>
>>> Check anonymous memory is backed by memfd if qemu is capable.
>>>
>>> Signed-off-by: Marc-André Lureau <marcandre.lureau at redhat.com>
>>> ---
>>>  tests/qemuxml2argvdata/memfd-memory-numa.args | 28 +++++++++++++++
>>>  tests/qemuxml2argvdata/memfd-memory-numa.xml  | 36 +++++++++++++++++++
>>>  tests/qemuxml2argvtest.c                      |  5 +++
>>>  3 files changed, 69 insertions(+)
>>>  create mode 100644 tests/qemuxml2argvdata/memfd-memory-numa.args
>>>  create mode 100644 tests/qemuxml2argvdata/memfd-memory-numa.xml
>>>
>>> diff --git a/tests/qemuxml2argvdata/memfd-memory-numa.args b/tests/qemuxml2argvdata/memfd-memory-numa.args
>>> new file mode 100644
>>> index 0000000000..b26c476196
>>> --- /dev/null
>>> +++ b/tests/qemuxml2argvdata/memfd-memory-numa.args
>>> @@ -0,0 +1,28 @@
>>> +LC_ALL=C \
>>> +PATH=/bin \
>>> +HOME=/home/test \
>>> +USER=test \
>>> +LOGNAME=test \
>>> +QEMU_AUDIO_DRV=none \
>>> +/usr/bin/qemu-system-x86_64 \
>>> +-name instance-00000092 \
>>> +-S \
>>> +-machine pc-i440fx-wily,accel=kvm,usb=off,dump-guest-core=off \
>>> +-m 14336 \
>>> +-mem-prealloc \
>>> +-smp 20,sockets=1,cores=8,threads=1 \
>>> +-object memory-backend-memfd,id=ram-node0,hugetlb=yes,hugetlbsize=2097152,share=yes,\
>>> +size=15032385536,host-nodes=3,policy=preferred \
>>
>> Another syntax-check error here, needed to move the "share=yes," to the
>> subsequent line.
>>
> 
> ok
> 
>>> +-numa node,nodeid=0,cpus=0-7,memdev=ram-node0 \
>>> +-uuid 126f2720-6f8e-45ab-a886-ec9277079a67 \
>>> +-display none \
>>> +-no-user-config \
>>> +-nodefaults \
>>> +-chardev socket,id=charmonitor,\
>>> +path=/tmp/lib/domain--1-instance-00000092/monitor.sock,server,nowait \
>>> +-mon chardev=charmonitor,id=monitor,mode=control \
>>> +-rtc base=utc \
>>> +-no-shutdown \
>>> +-no-acpi \
>>> +-usb \
>>> +-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
>>> diff --git a/tests/qemuxml2argvdata/memfd-memory-numa.xml b/tests/qemuxml2argvdata/memfd-memory-numa.xml
>>> new file mode 100644
>>> index 0000000000..abe93e8c4b
>>> --- /dev/null
>>> +++ b/tests/qemuxml2argvdata/memfd-memory-numa.xml
>>> @@ -0,0 +1,36 @@
>>> +  <domain type='kvm' id='56'>
>>> +    <name>instance-00000092</name>
>>> +    <uuid>126f2720-6f8e-45ab-a886-ec9277079a67</uuid>
>>> +    <memory unit='KiB'>14680064</memory>
>>> +    <currentMemory unit='KiB'>14680064</currentMemory>
>>> +    <memoryBacking>
>>> +      <hugepages>
>>> +          <page size="2" unit="M"/>
>>> +      </hugepages>
>>> +      <source type='anonymous'/>
>>> +      <access mode='shared'/>
>>> +      <allocation mode='immediate'/>
>>> +    </memoryBacking>
>>> +    <numatune>
>>> +        <memnode cellid='0' mode='preferred' nodeset='3'/>
>>> +    </numatune>
>>> +    <vcpu placement='static'>20</vcpu>
>>> +    <os>
>>> +      <type arch='x86_64' machine='pc-i440fx-wily'>hvm</type>>> +      <boot dev='hd'/>
>>> +    </os>
>>> +    <cpu>
>>> +      <topology sockets='1' cores='8' threads='1'/>
>>> +      <numa>
>>> +        <cell id='0' cpus='0-7' memory='14680064' unit='KiB'/>
>>> +      </numa>
>>> +    </cpu>
>>> +    <clock offset='utc'/>
>>> +    <on_poweroff>destroy</on_poweroff>
>>> +    <on_reboot>restart</on_reboot>
>>> +    <on_crash>destroy</on_crash>
>>> +    <devices>
>>> +      <emulator>/usr/bin/qemu-system-x86_64</emulator>
>>> +      <memballoon model='virtio'/>
>>> +    </devices>
>>> +  </domain>
>>> diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
>>> index 35df63b2ac..76008a8d07 100644
>>> --- a/tests/qemuxml2argvtest.c
>>> +++ b/tests/qemuxml2argvtest.c
>>> @@ -2928,6 +2928,11 @@ mymain(void)
>>>      DO_TEST("fd-memory-no-numa-topology", QEMU_CAPS_OBJECT_MEMORY_FILE,
>>>              QEMU_CAPS_KVM);
>>>
>>> +    DO_TEST("memfd-memory-numa",
>>> +            QEMU_CAPS_OBJECT_MEMORY_MEMFD,
>>> +            QEMU_CAPS_OBJECT_MEMORY_MEMFD_HUGETLB,
>>> +            QEMU_CAPS_KVM);
>>> +
>>
>> Theoretically, if we have 3.1 capabilties to test against, then this
>> would use a DO_TEST_CAPS_LATEST, while a "pre-3.1" would still be using
>> -ramfd, right?  That is, using DO_TEST_CAPS_VER w/ "3.0.0" would
>> generate different results.
>>
>> I'm conflicted if we should wait for someone to generate the 3.1 caps or
>> not. For whatever reason, when I post them they're not quite right for
>> someone else's tastes...
>>
>> Let's see if anyone else has strong feelings one way or another.
>>
> 
> -memfd is available since 2.12. After patch 1 & 2 are applied, we
> should probably switch to use DO_TEST_CAPS_LATEST.
> 

hrmph - tried using CAPS_LATEST, and got the error

"CPU topology doesn't match maximum vcpu count"

well *that's* helpful /-|...

The only libvirt test that cares about it currently is
cpu-hotplug-startup and yes, the maxvcpus matches the cpu topology
calculation...

So, as long as I change vcpu count from 20 to 8, rename the
tests/qemuxml2argvdata/memfd-memory-numa.args to
memfd-memory-numa.x86_64-latest.args, and regenerate the output to:

LC_ALL=C \
PATH=/bin \
HOME=/home/test \
USER=test \
LOGNAME=test \
QEMU_AUDIO_DRV=none \
/usr/bin/qemu-system-x86_64 \
-name guest=instance-00000092,debug-threads=on \
-S \
-object secret,id=masterKey0,format=raw,\
file=/tmp/lib/domain--1-instance-00000092/master-key.aes \
-machine pc-i440fx-wily,accel=kvm,usb=off,dump-guest-core=off \
-m 14336 \
-mem-prealloc \
-realtime mlock=off \
-smp 8,sockets=1,cores=8,threads=1 \
-object memory-backend-memfd,id=ram-node0,hugetlb=yes,hugetlbsize=2097152,\
share=yes,size=15032385536,host-nodes=3,policy=preferred \
-numa node,nodeid=0,cpus=0-7,memdev=ram-node0 \
-uuid 126f2720-6f8e-45ab-a886-ec9277079a67 \
-display none \
-no-user-config \
-nodefaults \
-chardev socket,id=charmonitor,fd=1729,server,nowait \
-mon chardev=charmonitor,id=monitor,mode=control \
-rtc base=utc \
-no-shutdown \
-no-acpi \
-boot strict=on \
-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 \
-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
resourcecontrol=deny \
-msg timestamp=on

Then, the test is happy. The memory-backend-memfd object doesn't change.

So all that's "left":

 1. "Add" a check in qemuDomainABIStabilityCheck to ensure we're not
changing from memory-backend-ram to memory-backend-memfd.  We already
check that "(src->mem.source != dst->mem.source)" - so we know we're
already anonymous or not.

Any suggestions?  If source is anonymous, then what?  I think we can use
the qemuDomainObjPrivatePtr in some way to determine that we were
started with -memfd (or not started that way).

 2. Get the patches I posted today to cleanup/move the memory backing
checks from domain_conf to qemu_domain:

   https://www.redhat.com/archives/libvir-list/2018-September/msg00463.html

reviewed and pushed so that patch4 can use the qemu_domain API to alter
it's hugepages check.

John

> Before 2.12 (or if the capabilities are not exposed by the host qemu)
> the argv will use -file. This is already covered by existing tests,
> like hugepages-shared.
> 
> thanks
> 
>> John
>>
>>>      DO_TEST("cpu-check-none", QEMU_CAPS_KVM);
>>>      DO_TEST("cpu-check-partial", QEMU_CAPS_KVM);
>>>      DO_TEST("cpu-check-full", QEMU_CAPS_KVM);
>>>




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