Если вы сами писали конфиг, то должны знать, в каком режиме грузится гостевая система. Откуда вопрос?
По-любому, внутри системы можно сделать dmesg|grep Xen и увидеть:
[ 0.000000] Booting paravirtualized kernel on Xen
[ 0.000000] Xen version: 4.0.1 (preserve-AD)
[ 0.000000] Xen: using vcpu_info placement
[ 0.000000] Xen: using vcpuop timer interface
На HVM же выдаёт:
[ 0.000000] ACPI: RSDP 000ea020 00024 (v02 Xen)
[ 0.000000] ACPI: XSDT fc012cb0 00034 (v01 Xen HVM 00000000 HVML 00000000)
[ 0.000000] ACPI: FACP fc012ad0 000F4 (v04 Xen HVM 00000000 HVML 00000000)
[ 0.000000] ACPI: DSDT fc002c40 0FE0B (v02 Xen HVM 00000000 INTL 20100528)
[ 0.000000] ACPI: APIC fc012bd0 000D8 (v02 Xen HVM 00000000 HVML 00000000)
[ 0.000000] Xen version 4.0.
[ 0.000000] Xen Platform PCI: I/O protocol version 1
[ 0.000000] Netfront and the Xen platform PCI driver have been compiled for this kernel: unplug emulated NICs.
[ 0.000000] Blkfront and the Xen platform PCI driver have been compiled for this kernel: unplug emulated disks.
[ 0.000000] Booting paravirtualized kernel on Xen
[ 0.000000] Xen HVM callback vector for event delivery is enabled