virtualized guest use only 2 cores

[Gilboa Davara]

On Fri, Oct 18, 2013 at 2:54 PM, Frantisek Hanzlik <franta at hanzlici.cz> wrote:
>
> Gilboa Davara wrote:
> > On Fri, Oct 18, 2013 at 1:45 PM, Frantisek Hanzlik <franta at hanzlici.cz> wrote:
> >>
> >> Not sure if it is Fedora/KVM problem, but:
> >> I'm trying virtualize MS Win7 Pro 64 guest under Fedora 19 x86_64 host.
> >> In virt-manager I allocated 4 cores (host machine has Xeon E3-1230 CPU
> >> with 8 cores incl. hyperthreading) to guest. But after installation
> >> guest OS uses only two cores - as report its task manager and OS
> >> properties info page. But what is weird, its device manager report all
> >> cores (see attached picture - where I increased no. of cores to 6,
> >> again without increased number of used cores). Guest OS should support
> >> up to 4 cores, according to manufacturer:
> >> http://technet.microsoft.com/cs-CZ/library/cc794868.aspx
> >>
> >> But from this referenced URL it seems as they are considering hyper-v
> >> as virt. supervisor - maybe then this result be some KVM problem or
> >> nature?
> >>
> >> TIA, Franta Hanzlik
> >>
> >>
> >
> > Please post the output of:
> > $ for PID in $(pgrep qemu-system) ; do echo $PID ; cat
> > /proc/$PID/cmdline ; echo ; done
> >
> > - Gilboa
>
> This is output (there run only this one guest):
>
> 1447
> /usr/bin/qemu-system-x86_64-machineaccel=kvm-namew7-64-sql-jana-S-machinepc-i440fx-1.4,accel=kvm,usb=off-cpuSandyBridge,+erms,+smep,+fsgsbase,+rdrand,+f16c,+osxsave,+pcid,+pdcm,+xtpr,+tm2,+est,+smx,+vmx,+ds_cpl,+monitor,+dtes64,+pbe,+tm,+ht,+ss,+acpi,+ds,+vme-m4096-smp6,sockets=6,cores=1,threads=1-uuidba471904-759f-a14d-d6a9-c19874cc0904-no-user-config-nodefaults-chardevsocket,id=charmonitor,path=/var/lib/libvirt/qemu/w7-64-sql-jana.monitor,server,nowait-monchardev=charmonitor,id=monitor,mode=control-rtcbase=localtime-no-shutdown-devicepiix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2-devicevirtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5-drivefile=/mnt/virtualy/images/w7-64-sql-jana,if=none,id=drive-virtio-disk0,format=raw-devicevirtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1-driveif=none,id=drive-ide0-0-0,readonly=on,format=raw-deviceide-cd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0-netdevtap,fd=24,id=hostnet0,vhost=o!
>  n,vhostfd=
> 25-devicevirtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:21:e1:56,bus=pci.0,addr=0x3-chardevpty,id=charserial0-deviceisa-serial,chardev=charserial0,id=serial0-chardevspicevmc,id=charchannel0,name=vdagent-devicevirtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0-deviceusb-tablet,id=input0-spiceport=5900,addr=127.0.0.1,disable-ticketing,seamless-migration=on-vgaqxl-globalqxl-vga.ram_size=67108864-globalqxl-vga.vram_size=67108864-deviceintel-hda,id=sound0,bus=pci.0,addr=0x4-devicehda-duplex,id=sound0-codec0,bus=sound0.0,cad=0-devicevirtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6
>
> #------------------
> Or cutted one par/line:
>
> /usr/bin/qemu-system-x86_64
>  -machine accel=kvm -name w7-64-sql-jana -S
>  -machine pc-i440fx-1.4,accel=kvm,usb=off
>  -cpu SandyBridge,+erms,+smep,+fsgsbase,+rdrand,+f16c,+osxsave,+pcid,+pdcm,+xtpr,+tm2,+est,+smx,+vmx,+ds_cpl,+monitor,+dtes64,+pbe,+tm,+ht,+ss,+acpi,+ds,+vme -m 4096 -smp 6,sockets=6,cores=1,threads=1
>  -uuid ba471904-759f-a14d-d6a9-c19874cc0904
>  -no-user-config
>  -nodefaults
>  -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/w7-64-sql-jana.monitor,server,nowait
>  -mon chardev=charmonitor,id=monitor,mode=control
>  -rtc base=localtime
>  -no-shutdown
>  -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2
>  -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5
>  -drive file=/mnt/virtualy/images/w7-64-sql-jana,if=none,id=drive-virtio-disk0,format=raw
>  -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
>  -drive if=none,id=drive-ide0-0-0,readonly=on,format=raw -device ide-cd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0
>  -netdev tap,fd=24,id=hostnet0,vhost=on,vhostfd=25
>  -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:21:e1:56,bus=pci.0,addr=0x3
>  -chardev pty,id=charserial0
>  -device isa-serial,chardev=charserial0,id=serial0
>  -chardev spicevmc,id=charchannel0,name=vdagent
>  -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0
>  -device usb-tablet,id=input0
>  -spice port=5900,addr=127.0.0.1,disable-ticketing,seamless-migration=on
>  -vga qxl
>  -global qxl-vga.ram_size=67108864
>  -global qxl-vga.vram_size=67108864
>  -device intel-hda,id=sound0,bus=pci.0,addr=0x4
>  -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0
>  -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6

Your KVM SMP configuration is the source of the problem as its very
unlikely that your version of Windows (7 PRO?) supports a six socket
system. (This usually reserved for the Enterprise versions of Windows
Server 2K8 and 2K12)
You'll need to change the line from -smp 6,sockets=6,cores=1,threads=1
to -smp 6,sockets=1,cores=6,threads=1 (or cores=2,threads=2, if you
want to emulate a dual core / quad thread CPU).

- Gilboa