Hello everyone,
I am kind of new in the virtualization world; I am trying to benchmark the performance of VMs in a paravirtualized and a fully virtualized modes. I have installed Xen 4.2.1 and I have created different VMs through the VMM. I am trying to benchmark the disk performance using fio tool, and I was surprised when I found the results of the fully virtualized VMs are almost the same as the paravirtualized ones, and when I checked the configuration files (of the fully virtualized machines) I found the following:
(domain
(domid 53)
(vcpus_params ((cap 0) (weight 256)))
(PV_args ‘’)
(memory_static_min 0)
(HVM_boot_policy ‘BIOS order’)
(PV_bootloader ‘’)
(pool_name Pool-0)
(auto_power_on False)
(memory_static_max 2147483648)
(cpus (()))
(actions_after_shutdown destroy)
(memory_dynamic_max 2147483648)
(memory_sharing 0)
(superpages 0)
(is_a_template False)
(PV_bootloader_args ‘’)
(memory_dynamic_min 2147483648)
(VCPUs_live 1)
(target 0)
(actions_after_crash restart)
(uuid b34c0913-cb5d-62c8-6198-8515dd2d2eab)
(PV_ramdisk ‘’)
(other_config ())
(name_label winXP-FV)
(PV_kernel ‘’)
(actions_after_reboot restart)
(VCPUs_at_startup 1)
(HVM_boot_params ((order dc)))
(platform
((xenpaging_extra ())
(rtc_timeoffset 0)
(loader /usr/lib/xen/boot/hvmloader)
(serial pty)
(vncunused 1)
(soundhw es1370)
(timer_mode 1)
(hpet 0)
(boot dc)
(parallel none)
(xen_platform_pci 1)
(pci ())
(pae 1)
(vpt_align 1)
(viridian 0)
(acpi 1)
(localtime 1)
(smbios_firmware ‘’)
(vnc 1)
(actmem 0)
(apic 1)
(acpi_firmware ‘’)
(nomigrate 0)
(usb 1)
(tsc_mode 0)
(usbdevice tablet)
(device_model /usr/lib64/xen/bin/qemu-dm)
(xenpaging_file ‘’)
(keymap en-us)
)
)
(VCPUs_max 1)
(Description ‘’)
(pool_name Pool-0)
(bootloader ‘’)
(vcpus 1)
(cpus (()))
(on_poweroff destroy)
(description ‘’)
(on_crash restart)
(uuid b34c0913-cb5d-62c8-6198-8515dd2d2eab)
(bootloader_args ‘’)
(name winXP-FV)
(on_reboot restart)
(maxmem 2048)
(memory 2048)
(shadow_memory 17)
(vcpu_avail 1)
(features ‘’)
(on_xend_start ignore)
(on_xend_stop ignore)
(start_time 1398706105.87)
(image
(hvm
(kernel ‘’)
(superpages 0)
(hpet 0)
(loader /usr/lib/xen/boot/hvmloader)
(smbios_firmware ‘’)
(xen_platform_pci 1)
(rtc_timeoffset 0)
(parallel none)
(pci ())
(localtime 1)
(xenpaging_extra ())
(actmem 0)
(apic 1)
(acpi_firmware ‘’)
(usbdevice tablet)
(xenpaging_file ‘’)
(timer_mode 1)
(vpt_align 1)
(serial pty)
(vncunused 1)
(soundhw es1370)
(boot dc)
(pae 1)
(viridian 0)
(acpi 1)
(vnc 1)
(nomigrate 0)
(usb 1)
(tsc_mode 0)
(device_model /usr/lib64/xen/bin/qemu-dm)
(keymap en-us)
(notes (SUSPEND_CANCEL 1))
)
)
(status 1)
(state ------)
(store_mfn ‘1044476’)
(device
(vif
(bridge virbr0)
(mac 00:16:3e:db:2f:57)
(script /etc/xen/scripts/vif-bridge)
(uuid e9a3e492-cf05-5765-dc3f-5e0df9b42e90)
(backend 0)
)
)
(device
(vbd
(uuid d07bd05f-7f35-599f-55bb-b9dd9bdfa4ef)
(bootable 1)
(dev hda:disk)
(uname file:/var/lib/libvirt/images/winXP-FV.img)
(mode w)
(backend 0)
(VDI ‘’)
)
)
(device
(vbd
(uuid 79ca444a-0de1-2a24-e898-a1f95bbcde91)
(bootable 0)
(dev hdc:cdrom)
(uname phy:/dev/sr0)
(mode r)
(backend 0)
(VDI ‘’)
)
)
(device
(vfb
(vncunused 1)
(keymap en-us)
(vnc 1)
(uuid 3b33c676-4976-e3be-df2c-b5f0c82fab5d)
)
)
)
My question is…Are these configurations (especially the one that are marked in red) are the right configurations of a fully virtualized machine ?! And if they are the right configuration; why do I get such a high performance from a fully virtualized VM ?!
When I checked the configuration of Xen itself throught xm info… I got the following:
(XEN) Xen version 4.2.1_06-1.1.1 (abuild@) (gcc (SUSE Linux) 4.7.2 20130108 [gcc-4_7-branch revision 195012]) Mon Feb 25 21:26:36 UTC 2013
(XEN) Latest ChangeSet: 25952
(XEN) Bootloader: GRUB2 2.00
(XEN) Command line: dom0_max_vcpus=2 dom0_vcpus_pin dom0_mem=2048M
(XEN) Video information:
(XEN) VGA is text mode 80x25, font 8x16
(XEN) VBE/DDC methods: none; EDID transfer time: 0 seconds
(XEN) EDID info not retrieved because no DDC retrieval method detected
(XEN) Disc information:
(XEN) Found 2 MBR signatures
(XEN) Found 2 EDD information structures
(XEN) Xen-e820 RAM map:
(XEN) 0000000000000000 - 0000000000097c00 (usable)
(XEN) 0000000000097c00 - 00000000000a0000 (reserved)
(XEN) 00000000000e4000 - 0000000000100000 (reserved)
(XEN) 0000000000100000 - 00000000bf780000 (usable)
(XEN) 00000000bf780000 - 00000000bf798000 (ACPI data)
(XEN) 00000000bf798000 - 00000000bf7dc000 (ACPI NVS)
(XEN) 00000000bf7dc000 - 00000000c0000000 (reserved)
(XEN) 00000000fee00000 - 00000000fee01000 (reserved)
(XEN) 00000000ffe00000 - 0000000100000000 (reserved)
(XEN) 0000000100000000 - 0000000240000000 (usable)
(XEN) ACPI: RSDP 000FB0C0, 0024 (r2 ACPIAM)
(XEN) ACPI: XSDT BF780100, 0064 (r1 042010 XSDT2051 20100420 MSFT 97)
(XEN) ACPI: FACP BF780290, 00F4 (r3 042010 FACP2051 20100420 MSFT 97)
(XEN) ACPI: DSDT BF7804B0, D0DD (r1 A1234 A1234000 0 INTL 20060113)
(XEN) ACPI: FACS BF798000, 0040
(XEN) ACPI: APIC BF780390, 00D8 (r1 042010 APIC2051 20100420 MSFT 97)
(XEN) ACPI: MCFG BF780470, 003C (r1 042010 OEMMCFG 20100420 MSFT 97)
(XEN) ACPI: OEMB BF798040, 0072 (r1 042010 OEMB2051 20100420 MSFT 97)
(XEN) ACPI: HPET BF78F4B0, 0038 (r1 042010 OEMHPET 20100420 MSFT 97)
(XEN) ACPI: DMAR BF7980C0, 0138 (r1 AMI OEMDMAR 1 MSFT 97)
(XEN) ACPI: OSFR BF78F4F0, 00B0 (r1 042010 OEMOSFR 20100420 MSFT 97)
(XEN) ACPI: SSDT BF79A020, 0363 (r1 DpgPmm CpuPm 12 INTL 20060113)
(XEN) System RAM: 8183MB (8379484kB)
(XEN) Domain heap initialised
(XEN) Processor #0 7:10 APIC version 21
(XEN) Processor #2 7:10 APIC version 21
(XEN) Processor #4 7:10 APIC version 21
(XEN) Processor #6 7:10 APIC version 21
(XEN) Processor #1 7:10 APIC version 21
(XEN) Processor #3 7:10 APIC version 21
(XEN) Processor #5 7:10 APIC version 21
(XEN) Processor #7 7:10 APIC version 21
(XEN) IOAPIC[0]: apic_id 8, version 32, address 0xfec00000, GSI 0-23
(XEN) IOAPIC[1]: apic_id 9, version 32, address 0xfec8a000, GSI 24-47
(XEN) Enabling APIC mode: Flat. Using 2 I/O APICs
(XEN) [VT-D]dmar.c:535: RMRR address range not in reserved memory base = bf7dc000 end = bf7dbfff; iommu_inclusive_mapping=1 parameter may be needed.
(XEN) [VT-D]dmar.c:598: The RMRR (bf7dc000, bf7dbfff) is incorrect!
(XEN) Failed to parse ACPI DMAR. Disabling VT-d.
(XEN) Table is not found!
(XEN) Using scheduler: SMP Credit Scheduler (credit)
(XEN) Detected 2803.568 MHz processor.
(XEN) Initing memory sharing.
(XEN) PCI: Not using MCFG for segment 0000 bus 00-ff
(XEN) I/O virtualisation disabled
(XEN) ENABLING IO-APIC IRQs
(XEN) → Using new ACK method
(XEN) Platform timer is 14.318MHz HPET
(XEN) Allocated console ring of 16 KiB.
(XEN) VMX: Supported advanced features:
(XEN) - APIC MMIO access virtualisation
(XEN) - APIC TPR shadow
(XEN) - Extended Page Tables (EPT)
(XEN) - Virtual-Processor Identifiers (VPID)
(XEN) - Virtual NMI
(XEN) - MSR direct-access bitmap
(XEN) HVM: ASIDs enabled.
(XEN) HVM: VMX enabled
(XEN) HVM: Hardware Assisted Paging (HAP) detected
(XEN) HVM: HAP page sizes: 4kB, 2MB
(XEN) Brought up 8 CPUs
(XEN) *** LOADING DOMAIN 0 ***
(XEN) Xen kernel: 64-bit, lsb, compat32
(XEN) Dom0 kernel: 64-bit, lsb, paddr 0x2000 → 0xa65000
(XEN) PHYSICAL MEMORY ARRANGEMENT:
(XEN) Dom0 alloc.: 0000000234000000->0000000235000000 (505217 pages to be allocated)
(XEN) Init. ramdisk: 000000023c581000->000000023ffff400
(XEN) VIRTUAL MEMORY ARRANGEMENT:
(XEN) Loaded kernel: ffffffff80002000->ffffffff80a65000
(XEN) Init. ramdisk: 0000000000000000->0000000000000000
(XEN) Phys-Mach map: ffffea0000000000->ffffea0000400000
(XEN) Start info: ffffffff80a65000->ffffffff80a654b4
(XEN) Page tables: ffffffff80a66000->ffffffff80a6f000
(XEN) Boot stack: ffffffff80a6f000->ffffffff80a70000
(XEN) TOTAL: ffffffff80000000->ffffffff80c00000
(XEN) ENTRY ADDRESS: ffffffff80002000
(XEN) Dom0 has maximum 2 VCPUs
(XEN) Scrubbing Free RAM: …done.
(XEN) Initial low memory virq threshold set at 0x4000 pages.
(XEN) Std. Loglevel: Errors and warnings
(XEN) Guest Loglevel: Nothing (Rate-limited: Errors and warnings)
(XEN) Xen is relinquishing VGA console.
(XEN) *** Serial input → DOM0 (type ‘CTRL-a’ three times to switch input to Xen)
(XEN) Freed 264kB init memory.
(XEN) mtrr: type mismatch for d0000000,10000000 old: write-back new: write-combining
(XEN) sh error: sh_remove_all_mappings(): can’t find all mappings of mfn 17f4a2: c=c000000000000002 t=7400000000000001
(XEN) sh error: sh_remove_all_mappings(): can’t find all mappings of mfn 17f4a2: c=c000000000000002 t=7400000000000001
Does the parameters marked in red make any difference ?! As far as I understand I don’t need IOMMU/VT-D to be enabled !! I have Intel Virtualizatin Technology enabled in the kernel.
All my OS are 32bits…I am using MS OS (Win XP) as a fully virtualized VM and Linux (Ubuntu 12.04 LTS) as a paravitualized VM.
I apologize for the long post, any help would be appreciated 
Thanks.