It appears the WS3520 chip does support hardware virtualization.
The following tables list Intel and AMD CPUs that support hardware virtualization:
Intel® Xeon® Processor
E5405 / E5410 / E5420 / E5430 / E5440 / E5450 / E5462 / E5472 / L5408 / L5410 / L5420 / L5430 / X5450 / X5460 / X5470 / X5472 / X5482 / X5492 E5502 / E5504 / E5506 / E5520 / E5530 / E5540 / L5506 / L5508 / L5518 / L5520 / L5530 / W5580 / X5550 / X5560 / X5570 E7210 / E7220 E7310 / E7320 / E7330 / E7340 / L7345 / X7350 E7420 / E7430 / E7440 / E7450 / L7445 / L7455 / X7460 L3360 / X3320 / X3330 / X3350 / X3360 / X3370 / X3380 W3520 / W3540 / W3550 / W3570 / W3580 X3210 / X3220 / X3230
So....... I've been in the bios and I've turnd on virtualization but still hvm appears not to work.
The following is the solution to this issue. Although xen was installed on the initial system when the host system was being built, apparently some
necessary items/packages were omitted.
After doing the following on the host system:
572 yum install libvir*
573 yum groupinstall xen
I rebooted the system and checked the cpu info again.
[root@atoz ~]# cat /proc/cpuinfo |grep svm
[root@atoz ~]# cat /proc/cpuinfo |grep vmx
flags : fpu tsc msr pae cx8 apic mtrr cmov pat clflush acpi mmx fxsr sse sse2 ss ht nx constant_tsc ida nonstop_tsc pni vmx est ssse3 sse4_1 sse4_2 popcnt 
It seems hardware virtualization (vmx) is now available.