XEN VPS memória errada?

Question

Eu pedi um VPS na plataforma XEN com 1 GB de memória. CentOS 6.6

uname -a

Linux vps 2.6.32-504.23.4.el6.x86_64 #1 SMP Tue Jun 9 20:57:37 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Eu verifiquei a quantidade de memória:

cat /proc/meminfo 
MemTotal:         667536 kB
MemFree:          211084 kB
Buffers:           12880 kB
Cached:           304484 kB
SwapCached:            0 kB
Active:           135240 kB
Inactive:         192692 kB
Active(anon):      10572 kB
Inactive(anon):      124 kB
Active(file):     124668 kB
Inactive(file):   192568 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:       1048572 kB
SwapFree:        1048572 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:         10588 kB
Mapped:             8408 kB
Shmem:               132 kB
Slab:              39156 kB
SReclaimable:      20188 kB
SUnreclaim:        18968 kB
KernelStack:         736 kB
PageTables:         1804 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     1382340 kB
Committed_AS:      63000 kB
VmallocTotal:   34359738367 kB
VmallocUsed:       43944 kB
VmallocChunk:   34359693268 kB
HardwareCorrupted:     0 kB
AnonHugePages:         0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:    10485760 kB
DirectMap2M:           0 kB

Parece com 512MB de memória. Superior:

Mem:    667536k total,   456708k used,   210828k free,    12888k buffers

Eu perguntei ao suporte técnico e fui informado:

This is normal. this is due to us using the latest Xen 4.x.x Versions for performance enhancements which unfortunately can cause this anomaly
You can verify you have the correct memory information with the following command:
cat /proc/meminfo
This will produce something that looks like this:
...
...
At the bottom you will see ‘DirectMap4k’ this is the actual amount of RAM your VPS has allocated and can use.
Using the above example, take ‘DirectMap4k: 524288 kB’ divide the 524288 > kB by 1024 to convert it to megabytes and you get 512, yet the old free > -m command takes its info from the MemTotal line near the top which is not actually what you system is able to use.

Por favor, me diga que está certo? Posso usar 1 GB de memória?