libvirt users - Sep 2015 - Re: hvm on x86_64 on binutils i386

Hi,

 I have this setup


kernel: x86_64 version 4.2.0
operating system (rootfs binutils etc.,) :  i386 (ELF-32-bit)
qemu-system : version 2.4.0  qemu-system-x86_64 (i386 binary)
libvirt: 1.2.19 (i386 )

When I run the qemu-system-x86_64 binary with --enable-kvm, the guest
machine is working properly as hvm. So
QEMU can run x86_64 OS as hvm

when I install using virt-install
virt-install   --name debian --cdrom
./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
--ram 1024 --graphics vnc

I expect the 64-bit kernel to load and start install in the guest but
i get a complaint that the guest cannot boot since the cpu is not
64-bit capable (please use a kernel appropriate for your CPU)

I tried adding the machine option to virt-install
virt-install   --name debian --cdrom
./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
--ram 1024 --graphics vnc  --machine pc-i440fx-2.0

No joy

Tried changing the machine as hvm and also added --arch x86_64
none of them help !

Can someone tell me how to do this ?
Just because the binutils and the OS is 32-bit I think libvirt must
not refuse to hvm a x86_64 guest  since the kernel is still x86_64
kernel and so so the kvm (module)

I am guessing I am missing some option passed to virt-install or this
is a limitation purely on libvirt (not qemu or kvm)

Moreover QEMU is able to run a hvm guest x86_64 and manually running
qemu does bootup the 64-bit kernel guests.

Using virt-manager and copying host CPU can still boot the guest OS (64-bit)
virt-install however still is not doing the job.

On 9/6/15, Bhasker C V <bhasker@unixindia.com>
wrote:
> Hi,
>
>  I have this setup
>
>
> kernel: x86_64 version 4.2.0
> operating system (rootfs binutils etc.,) :  i386 (ELF-32-bit)
> qemu-system : version 2.4.0  qemu-system-x86_64 (i386 binary)
> libvirt: 1.2.19 (i386 )
>
> When I run the qemu-system-x86_64 binary with --enable-kvm, the guest
> machine is working properly as hvm. So
> QEMU can run x86_64 OS as hvm
>
> when I install using virt-install
> virt-install   --name debian --cdrom
> ./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
> --ram 1024 --graphics vnc
>
> I expect the 64-bit kernel to load and start install in the guest but
> i get a complaint that the guest cannot boot since the cpu is not
> 64-bit capable (please use a kernel appropriate for your CPU)
>
> I tried adding the machine option to virt-install
> virt-install   --name debian --cdrom
> ./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
> --ram 1024 --graphics vnc  --machine pc-i440fx-2.0
>
> No joy
>
> Tried changing the machine as hvm and also added --arch x86_64
> none of them help !
>
> Can someone tell me how to do this ?
> Just because the binutils and the OS is 32-bit I think libvirt must
> not refuse to hvm a x86_64 guest  since the kernel is still x86_64
> kernel and so so the kvm (module)
>
> I am guessing I am missing some option passed to virt-install or this
> is a limitation purely on libvirt (not qemu or kvm)
>
> Moreover QEMU is able to run a hvm guest x86_64 and manually running
> qemu does bootup the 64-bit kernel guests.
>

On Sun, Sep 06, 2015 at 01:47:47PM +0100, Bhasker C V
wrote:
>Hi,
>
> I have this setup
>
>
>kernel: x86_64 version 4.2.0
>operating system (rootfs binutils etc.,) :  i386 (ELF-32-bit)
>qemu-system : version 2.4.0  qemu-system-x86_64 (i386 binary)
>libvirt: 1.2.19 (i386 )
>
>When I run the qemu-system-x86_64 binary with --enable-kvm, the guest
>machine is working properly as hvm. So
>QEMU can run x86_64 OS as hvm
>
>when I install using virt-install
>virt-install   --name debian --cdrom
>./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
>--ram 1024 --graphics vnc
>
>I expect the 64-bit kernel to load and start install in the guest but
>i get a complaint that the guest cannot boot since the cpu is not
>64-bit capable (please use a kernel appropriate for your CPU)
>
>I tried adding the machine option to virt-install
>virt-install   --name debian --cdrom
>./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
>--ram 1024 --graphics vnc  --machine pc-i440fx-2.0
>
>No joy
>
>Tried changing the machine as hvm and also added --arch x86_64
>none of them help !
>
>Can someone tell me how to do this ?
>Just because the binutils and the OS is 32-bit I think libvirt must
>not refuse to hvm a x86_64 guest  since the kernel is still x86_64
>kernel and so so the kvm (module)
>
>I am guessing I am missing some option passed to virt-install or this
>is a limitation purely on libvirt (not qemu or kvm)
>
>Moreover QEMU is able to run a hvm guest x86_64 and manually running
>qemu does bootup the 64-bit kernel guests.
>
If the qemu you have installed is able to do that, and virt-manager as
well, then the best thing you can do is start comparing the XMLs (or
command lines) from virt-install and virt-manager.  I would try
adding '--arch x86_64 --cpu host-model-only --virt-type kvm', but the
XML differentiation is your best bet.

To see why the difference is there, you might ask on virt-tools-list
for detailed answers.
>_______________________________________________
>libvirt-users mailing list
>libvirt-users@redhat.com
>https://www.redhat.com/mailman/listinfo/libvirt-users

Adding switch  --cpu mode=host-model along with --arch x86_64 fixes
this issue. However I am not able to boot with "any other" CPU type
like I used to be able to give --cpu core2duo and things would work !


On 9/6/15, Bhasker C V <bhasker@unixindia.com>
wrote:
> Using virt-manager and copying host CPU can still boot the guest OS
> (64-bit)
> virt-install however still is not doing the job.
>
> On 9/6/15, Bhasker C V <bhasker@unixindia.com> wrote:
>> Hi,
>>
>>  I have this setup
>>
>>
>> kernel: x86_64 version 4.2.0
>> operating system (rootfs binutils etc.,) :  i386 (ELF-32-bit)
>> qemu-system : version 2.4.0  qemu-system-x86_64 (i386 binary)
>> libvirt: 1.2.19 (i386 )
>>
>> When I run the qemu-system-x86_64 binary with --enable-kvm, the guest
>> machine is working properly as hvm. So
>> QEMU can run x86_64 OS as hvm
>>
>> when I install using virt-install
>> virt-install   --name debian --cdrom
>> ./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
>> --ram 1024 --graphics vnc
>>
>> I expect the 64-bit kernel to load and start install in the guest but
>> i get a complaint that the guest cannot boot since the cpu is not
>> 64-bit capable (please use a kernel appropriate for your CPU)
>>
>> I tried adding the machine option to virt-install
>> virt-install   --name debian --cdrom
>> ./debian-stretch-DI-a1-amd64-netinst.iso --disk /STOR/DEBIAN,bus=sata
>> --ram 1024 --graphics vnc  --machine pc-i440fx-2.0
>>
>> No joy
>>
>> Tried changing the machine as hvm and also added --arch x86_64
>> none of them help !
>>
>> Can someone tell me how to do this ?
>> Just because the binutils and the OS is 32-bit I think libvirt must
>> not refuse to hvm a x86_64 guest  since the kernel is still x86_64
>> kernel and so so the kvm (module)
>>
>> I am guessing I am missing some option passed to virt-install or this
>> is a limitation purely on libvirt (not qemu or kvm)
>>
>> Moreover QEMU is able to run a hvm guest x86_64 and manually running
>> qemu does bootup the 64-bit kernel guests.
>>
>