Bug 1015689

We must match the existing documentation.  Consistency with all other memory-related parameters, which are also output in k, says that the bug is in treating the value as bytes when it should be handled in k.  The first attempt at a patch:
https://www.redhat.com/archives/libvir-list/2013-October/msg00361.html
doesn't seem right to me, as it tries to reject XML that was previously output by older libvirt, which is not backwards-compatible.

Another upstream patch attempted:
https://www.redhat.com/archives/libvir-list/2013-October/msg00415.html

Missing units default to KiB, and XML generated by older libvirt is parsed correctly.

Both of them also fix the bug of libvirt not being able to parse the units in its own generated XML correctly.

The third version of the patch has been pushed upstream:
https://www.redhat.com/archives/libvir-list/2013-October/msg00435.html

commit 3f029fb5319b9dc9cc2fbf8d1ba4505ee9e4b1e3
Author:     Ján Tomko <jtomko>
AuthorDate: 2013-10-09 14:17:13 +0200
Commit:     Ján Tomko <jtomko>
CommitDate: 2013-10-09 17:44:45 +0200

    LXC: Fix handling of RAM filesystem size units
    
    Since 76b644c when the support for RAM filesystems was introduced,
    libvirt accepted the following XML:
    <source usage='1024' unit='KiB'/>
    
    This was parsed correctly and internally stored in bytes, but it
    was formatted as (with an extra 's'):
    <source usage='1024' units='KiB'/>
    When read again, this was treated as if the units were missing,
    meaning libvirt was unable to parse its own XML correctly.
    
    The usage attribute was documented as being in KiB, but it was not
    scaled if the unit was missing. Transient domains still worked,
    because this was balanced by an extra 'k' in the mount options.
    
    This patch:
    Changes the parser to use 'units' instead of 'unit', as the latter
    was never documented (fixing persistent domains) and some programs
    (libvirt-glib, libvirt-sandbox) already parse the 'units' attribute.
    
    Removes the extra 'k' from the tmpfs mount options, which is needed
    because now we parse our own XML correctly.
    
    Changes the default input unit to KiB to match documentation, fixing:
    https://bugzilla.redhat.com/show_bug.cgi?id=1015689

git describe: v1.1.3-77-g3f029fb

Verify with
libvirt-1.1.1-9.el7.x86_64

1.Prepare the lxc xml

<domain type='lxc'>
  <name>test</name>
  <uuid>3c77a62e-b868-4351-b837-c225c0a87592</uuid>
  <memory unit='KiB'>1048576</memory>
  <currentMemory unit='KiB'>1048576</currentMemory>
  <vcpu placement='static'>1</vcpu>
  <resource>
    <partition>/machine</partition>
  </resource>
  <os>
    <type arch='x86_64'>exe</type>
    <init>/bin/sh</init>
  </os>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/libexec/libvirt_lxc</emulator>
    <filesystem type='ram' accessmode='passthrough'>
      <source usage='10240' units='KiB'/>
      <target dir='/mnt/mississippi'/>
    </filesystem>
    <filesystem type='ram' accessmode='passthrough'>
      <source usage='1024' units='KiB'/>
      <target dir='/mnt/antananarivo'/>
    </filesystem>
    <filesystem type='ram' accessmode='passthrough'>
      <source usage='4' units='KiB'/>
      <target dir='/mnt/ouagadougou'/>
    </filesystem>
    <filesystem type='ram' accessmode='passthrough'>
      <source usage='393216' units='KiB'/>
      <target dir='/dev/shm'/>
    </filesystem>
    <interface type='network'>
      <mac address='00:16:3e:87:67:8c'/>
      <source network='default'/>
    </interface>
    <console type='pty'>
      <target type='lxc' port='0'/>
    </console>
  </devices>
</domain>

2.
#virsh -c lxc:/// start test

3.
#virt-sandbox-service connect test
sh-4.2# df
Filesystem     1K-blocks    Used Available Use% Mounted on
/dev/sda1       41153856 2131960  36908360   6% /
tmpfs              10240       0     10240   0% /mnt/mississippi
tmpfs               1024       0      1024   0% /mnt/antananarivo
tmpfs                  4       0         4   0% /mnt/ouagadougou
tmpfs             393216       0    393216   0% /dev/shm

4.
If omits the units attribute , or change the unit to B , MiB , it will auto-complete and scaler properly , so Set VERIFIED

This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.

> The third version of the patch has been pushed upstream:
> https://www.redhat.com/archives/libvir-list/2013-October/msg00435.html
> 
> commit 3f029fb5319b9dc9cc2fbf8d1ba4505ee9e4b1e3
> Author:     Ján Tomko <jtomko>
> AuthorDate: 2013-10-09 14:17:13 +0200
> Commit:     Ján Tomko <jtomko>
> CommitDate: 2013-10-09 17:44:45 +0200
> 
>     LXC: Fix handling of RAM filesystem size units
>     
>     Since 76b644c when the support for RAM filesystems was introduced,
>     libvirt accepted the following XML: https://www.dubaiescortsgirls.me/
>     <source usage='1024' unit='KiB'/>
>     
>     This was parsed correctly and internally stored in bytes, but it
>     was formatted as (with an extra 's'):
>     <source usage='1024' units='KiB'/>
>     When read again, this was treated as if the units were missing,
>     meaning libvirt was unable to parse its own XML correctly.
>     
>     The usage attribute was documented as being in KiB, but it was not
>     scaled if the unit was missing. Transient domains still worked,
>     because this was balanced by an extra 'k' in the mount options.
>     
>     This patch:
>     Changes the parser to use 'units' instead of 'unit', as the latter
>     was never documented (fixing persistent domains) and some programs
>     (libvirt-glib, libvirt-sandbox) already parse the 'units' attribute.
>     
>     Removes the extra 'k' from the tmpfs mount options, which is needed
>     because now we parse our own XML correctly.
>     
>     Changes the default input unit to KiB to match documentation, fixing:
>     https://bugzilla.redhat.com/show_bug.cgi?id=1015689
> 
> git describe: v1.1.3-77-g3f029fb

Another upstream patch attempted:
https://www.redhat.com/archives/libvir-list/2013-October/msg00415.html

Missing units default to KiB, and XML generated by older libvirt is parsed correctly.

Both of them also fix the bug of libvirt not being able to parse the units in its own generated XML correctly.