multicore virtual machine on fedora14

[dubi]

I am experiencing a multicpre problem with fedora14 / kernel 2.6.35.6-45.fc14.x86_64 #1 SMP. (standard from the distro). The host has a total of 2 cores .
yet a virtual machine started with 'smp 2' ( or xml : <vcpu>2</vcpu>) will not run on 2 pyhs cores . it will use just 1 core ('top' at the host shows 100%cpu while running an endless loop process on the VM) and libvirt 'virsh vcpuinfo <vm name>' shows only 1 physical
cpu used (although 2 vcpus are used : 0, 1)

The kernel seems to be an SMP one ( so says the uname -a . what does '#1 SMP' mean ?) . Am I missing something ?
same XML on a DEBIAN machine will run the VM with 2 phys cores as should although the host there has 4 cores
(>2)

Should I recompile the kernel src with some addtional flag ?
thanks

dubi

[Rubberman]

What virtual machine manager are you using to run this VM? Depending upon underlying hardware or the VMM in use, it may only simulate multiple cores. I run VirtualBox on an 8 core workstation, and I can categorically state that if I allocate 2 cores to a VM, then I get 2 cores for it, although they are still shared with other host applications, if necessary.

[dE_logics]

What virtual machine manager are you using to run this VM? Depending upon underlying hardware or the VMM in use, it may only simulate multiple cores. I run VirtualBox on an 8 core workstation, and I can categorically state that if I allocate 2 cores to a VM, then I get 2 cores for it, although they are still shared with other host applications, if necessary.

Yup, you need to have hardware visualization support for this. Post the output of

cat /proc/cpuinfo

Unfortunately, although my processor does have hardware virtulization, the virtualbox instance crashes if hardware virtulization is enabled.

[dubi]

I am starting the VM with libvirt : 'virsh create <domain.xml> . kernel is 2.6.35-6
The HW is some IBM desktop with 2 cores . If I run a 2 thread process (not a VM)
on that HW it does use the 2 cores so it seems to be a smp system.
But with a VM it does not use 2 cores since it has 2 vcpus but only 1 phys core as shown by 'top' at the host or by 'virsh vcpuinfo <domain>' at the host .

The same VM (same XML file) runs fine (invoked also by libvirt) -using 2 cores -on a nother (different Hw though !) distro OS : Debian 5 system with kernel 2.6.36trunk.

The qemu is the same on both fedora and Debian: version "0.13.0"

I recompiled the latest kernel from fedora (2.6.35-11 including kvm ) with CONFIG_X86_64_SMP=y in the .config file and now am using this kernel . Still I have the muticore problem when launching a VM
The fedora HW does have HW virtualization as seen below (cat /proc/cpuinfo)

Can there be any kernel config or HW issue with the fedora system ?

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 Duo CPU     E6550  @ 2.33GHz
stepping        : 11
cpu MHz         : 2333.000
cache size      : 4096 KB
physical id     : 0
siblings        : 2
core id         : 1
cpu cores       : 2
apicid          : 1
initial apicid  : 1
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm lahf_lm tpr_shadow vnmi flexpriority
bogomips        : 4654.99
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

(this is of processor 1 . similar for 0)

[dE_logics]

I think you should try virtualbox just to see if it works out.

[Rubberman]

You need to go into the BIOS and enable the hardware virtualization, otherwise VBox and other virtual machine managers will crash if you try to enable those features in a VM. I have done this on my workstation and laptop, and never had a problem.

[dE_logics]

You need to go into the BIOS and enable the hardware virtualization, otherwise VBox and other virtual machine managers will crash if you try to enable those features in a VM. I have done this on my workstation and laptop, and never had a problem.

Yup, I did that but still it crashes. I've to turn it off.

[Rubberman]

Yup, I did that but still it crashes. I've to turn it off.

Bummer! Sorry, but without system in hand, that's about where I get off...