On Centos 5.7 with the a recent vz 2.6.18 kernel, all the containers with VSWAP (created with vswap-256 for example) are showing the whole memory from de server. The vswap size is correct.
Example (memory server is 3GB):
Container
free
total used free shared buffers cached
Mem: 3079328 376840 2702488 0 0 0
-/+ buffers/cache: 376840 2702488
Swap: 524288 0 524288
conf:
PHYSPAGES="0:256M"
SWAPPAGES="0:512M"
KMEMSIZE="233M:256M"
DCACHESIZE="116M:128M"
LOCKEDPAGES="256M"
PRIVVMPAGES="unlimited"
SHMPAGES="unlimited"
NUMPROC="unlimited"
VMGUARPAGES="0:unlimited"
OOMGUARPAGES="0:unlimited"
NUMTCPSOCK="unlimited"
NUMFLOCK="unlimited"
NUMPTY="unlimited"
NUMSIGINFO="unlimited"
TCPSNDBUF="unlimited"
TCPRCVBUF="unlimited"
OTHERSOCKBUF="unlimited"
DGRAMRCVBUF="unlimited"
NUMOTHERSOCK="unlimited"
NUMFILE="unlimited"
NUMIPTENT="unlimited"
# Disk quota parameters (in form of softlimit:hardlimit)
DISKSPACE="10485760:11534336"
DISKINODES="200000:220000"
QUOTATIME="0"