hvm guest direct kernel boot

hvm guest direct kernel boot

[William Dauchy]

Hi,

I'm trying to boot a hvm guest directly on a linux kernel.
Here is my config file:

name='test'
builder='hvm'
memory = 512
vcpus=1
cpus = ['1']
disk = ['phy:/dev/iscsi/hosting-2253:0,hda,w']
device_model = '/usr/lib/xen/bin/qemu-dm'
loader='/usr/lib/xen/boot/hvmloader'
kernel='/boot/bzImage'
serial='pty'
apic=0
acpi=1
pae=0
videoram=4
stdvga=0
nographic=1
sdl=0
isa=0
display=0
vncdisplay=0

I'm using Xen 4.1.1 with an upstream linux 3.1-rc1 for the dom0.

The console is not working and the qemu-dm process is dying after a while
Here are the qemu-dm log:

# cat /var/log/xen/qemu-dm-test.log
domid: 58
-videoram option does not work with cirrus vga device model. Videoram set to 4M.
Using file /dev/iscsi/hosting-2253:0 in read-write mode
Watching /local/domain/0/device-model/58/logdirty/cmd
Watching /local/domain/0/device-model/58/command
Watching /local/domain/58/cpu
char device redirected to /dev/pts/1
qemu_map_cache_init nr_buckets = 10000 size 4194304
shared page at pfn feffd
buffered io page at pfn feffb
Guest uuid = fa5d2eb8-d026-9f66-8ccc-3f89f1545517
Time offset set 0
populating video RAM at ff000000
mapping video RAM from ff000000
Register xen platform.
Done register platform.
platform_fixed_ioport: changed ro/rw state of ROM memory area. now is rw state.
xs_read(/local/domain/0/device-model/58/xen_extended_power_mgmt): read error
Log-dirty: no command yet.
I/O request not ready: 0, ptr: 0, port: 0, data: 0, count: 0, size: 0
(qemu) vcpu-set: watch node error.
char device redirected to /dev/pts/2
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xs_read(/local/domain/58/log-throttling): read error
qemu: ignoring not-understood drive `/local/domain/58/log-throttling'
medium change watch on `/local/domain/58/log-throttling' - unknown
device, ignored
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
xen be: console-0: xen be: console-0: initialise() failed
initialise() failed
cirrus vga map change while on lfb mode
mapping vram to f0000000 - f0400000
platform_fixed_ioport: changed ro/rw state of ROM memory area. now is rw state.
platform_fixed_ioport: changed ro/rw state of ROM memory area. now is ro state.

I was wondering how could I fix the following errors:
xs_read(/local/domain/0/device-model/58/xen_extended_power_mgmt): read error
qemu: ignoring not-understood drive `/local/domain/58/log-throttling'
xen be: console-0: xen be: console-0: initialise() failed

I can't see what I forgot to make it boot on the kernel and make the
console working.

Regards,

-- 
William

Re: hvm guest direct kernel boot

[William Dauchy]

Hi,

On Thu, Aug 11, 2011 at 2:56 PM, William Dauchy <wdauchy@gmail.com> wrote:
> I'm trying to boot a hvm guest directly on a linux kernel.

I finally figured out that the direct kernel boot is broken since at
least xen 4.x (both with qemu-dm and upstream qemu)

-- 
William

Re: hvm guest direct kernel boot

[Stefano Stabellini]

On Thu, 11 Aug 2011, William Dauchy wrote:
> Hi,
> 
> I'm trying to boot a hvm guest directly on a linux kernel.

That has never been supported AFAIK.
Of course we could accept patches to make it work.

Re: hvm guest direct kernel boot

[William Dauchy]

Hi Stefani,

Thank you for your reply.

On Tue, Aug 23, 2011 at 7:02 PM, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> That has never been supported AFAIK.
> Of course we could accept patches to make it work.

Probably but there was config options to support this (loader +
kernel) and code in both xend and qemu-dm.

In upstream qemu, the code is present to support direct boot but the
xen implementation is quite different from the usual "qemu way", at
least for grabbing ram at start; see `pc_memory_init` which is
bypassed by `xen_enabled`.
I will see if I find time to patch the upstream qemu version.
-- 
William

Re: hvm guest direct kernel boot

[Stefano Stabellini]

On Tue, 23 Aug 2011, William Dauchy wrote:
> Hi Stefani,
> 
> Thank you for your reply.
> 
> On Tue, Aug 23, 2011 at 7:02 PM, Stefano Stabellini
> <stefano.stabellini@eu.citrix.com> wrote:
> > That has never been supported AFAIK.
> > Of course we could accept patches to make it work.
> 
> Probably but there was config options to support this (loader +
> kernel) and code in both xend and qemu-dm.
> 

It is still present for PV guests (remove builder=hvm), you can use
kernel and ramdisk.


> In upstream qemu, the code is present to support direct boot but the
> xen implementation is quite different from the usual "qemu way", at
> least for grabbing ram at start; see `pc_memory_init` which is
> bypassed by `xen_enabled`.
> I will see if I find time to patch the upstream qemu version.
 
Unfortuntely it is not just a matter of editing qemu, you need to start
from libxc and libxenlight: the linux kernel image should probably be
passed by libxenlight to xc_hvm_build_target_mem, that should be able to
read it and map it in the guest.

Re: hvm guest direct kernel boot

[William Dauchy]

Hi Stefano,

On Wed, Aug 24, 2011 at 1:07 PM, Stefano Stabellini
<stefano.stabellini@eu.citrix.com> wrote:
> It is still present for PV guests (remove builder=hvm), you can use
> kernel and ramdisk.

Yes I know that.

> Unfortuntely it is not just a matter of editing qemu, you need to start
> from libxc and libxenlight: the linux kernel image should probably be
> passed by libxenlight to xc_hvm_build_target_mem, that should be able to
> read it and map it in the guest.

Thanks for the details. I will dig into it if I find time to.
-- 
William

Re: hvm guest direct kernel boot

[Pasi Kärkkäinen]

On Wed, Aug 24, 2011 at 02:08:44PM +0200, William Dauchy wrote:
> Hi Stefano,
> 
> On Wed, Aug 24, 2011 at 1:07 PM, Stefano Stabellini
> <stefano.stabellini@eu.citrix.com> wrote:
> > It is still present for PV guests (remove builder=hvm), you can use
> > kernel and ramdisk.
> 
> Yes I know that.
> 
> > Unfortuntely it is not just a matter of editing qemu, you need to start
> > from libxc and libxenlight: the linux kernel image should probably be
> > passed by libxenlight to xc_hvm_build_target_mem, that should be able to
> > read it and map it in the guest.
> 
> Thanks for the details. I will dig into it if I find time to.
>

Hello,

Some user on ##xen was asking for this feature.. did you have time to try it? 

-- Pasi