kvm-85 won't boot guests with virtio block device

kvm-85 won't boot guests with virtio block device

[Darius Drozdowski]

Hello!

After an upgrade from kvm-84 to kvm-85 all my guests won't start because 
no boot device could be found.
The kvm host is an 2xDual-Opteron 2212 with 8 GB RAM installed on debian 
lenny 2.6.26-2-amd64.
All the guests are debian etch 2.6.26-1-amd64 or debian lenny 
2.6.26-2-amd64 with 1 CPU and 1 GB mem.

A rollback to kvm-84 OR changing the hdd from vda to ide for the guests 
and everything is OK again (grub entrys have to be changed also from 
vda1 to hda1).

It seems that kvm-85 has a Problem detecting guest configured to use 
virtio block device.
I would like to habe virtio block device support because the performance 
of the guest is much better with it.

Can You help?

Greetings

Darius

Re: kvm-85 won't boot guests with virtio block device

[Gerd v. Egidy]

Hi Darius,

> After an upgrade from kvm-84 to kvm-85 all my guests won't start because
> no boot device could be found.
[...]
> A rollback to kvm-84 OR changing the hdd from vda to ide for the guests
> and everything is OK again

I'm having the same problem and repored it to the list just some hours ago.

Do you use the kvm kernel modules that came with your host kernel or the ones 
that came with kvm-85? I used the ones that came with my 2.6.29.1 host kernel.

Kind regards,

Gerd

Re: kvm-85 won't boot guests with virtio block device

[Bernhard Held]

>> After an upgrade from kvm-84 to kvm-85 all my guests won't start because
>> no boot device could be found.
> [...]
>> A rollback to kvm-84 OR changing the hdd from vda to ide for the guests
>> and everything is OK again
> 
> I'm having the same problem and repored it to the list just some hours ago.
No problem here, my guests run fine with kvm-85 and 2.6.29.1:
	-drive file="$IMG",format=raw,cache=none

> Do you use the kvm kernel modules that came with your host kernel or the ones 
> that came with kvm-85? I used the ones that came with my 2.6.29.1 host kernel.
I use the modules from kvm-85.

Bernhard

Re: kvm-85 won't boot guests with virtio block device

[Alexey Eremenko]

On Thu, Apr 23, 2009 at 3:40 PM, Bernhard Held <bheld@mgpi.de> wrote:
>>> After an upgrade from kvm-84 to kvm-85 all my guests won't start because
>>> no boot device could be found.
>>
>> [...]
>>>
>>> A rollback to kvm-84 OR changing the hdd from vda to ide for the guests
>>> and everything is OK again
>>
>> I'm having the same problem and repored it to the list just some hours
>> ago.
>
> No problem here, my guests run fine with kvm-85 and 2.6.29.1:
>        -drive file="$IMG",format=raw,cache=none

That's a bit strange - because other guests - such as RHEL-5.3 guests
work fine on RHEL-5.3 hosts with virtio block device.
So KVM-85 works here.

-- 
-Alexey Eromenko "Technologov"

Re: kvm-85 won't boot guests with virtio block device

[Gerd v. Egidy]

Hi Bernhard,

> >> After an upgrade from kvm-84 to kvm-85 all my guests won't start because
> >> no boot device could be found.
>
> No problem here, my guests run fine with kvm-85 and 2.6.29.1:
> 	-drive file="$IMG",format=raw,cache=none

Are you sure you are using a virtio blockdevice and not a regular ide one? 
IIRC, you need to add if=virtio to the -drive parameter to get virtio. Or 
became virtio the default these days?

Kind regards,

Gerd

Re: kvm-85 won't boot guests with virtio block device

[Bernhard Held]

>>>> After an upgrade from kvm-84 to kvm-85 all my guests won't start because
>>>> no boot device could be found.
>> No problem here, my guests run fine with kvm-85 and 2.6.29.1:
>> 	-drive file="$IMG",format=raw,cache=none
> 
> Are you sure you are using a virtio blockdevice and not a regular ide one? 
> IIRC, you need to add if=virtio to the -drive parameter to get virtio. Or 
> became virtio the default these days?
Oh, sorry, I picked the wrong one :-(

This is the right example:
	-drive file="$IMAGE1",if=virtio,format=raw,cache=none,boot=on

I'm running 32 bit guest on 32 bit host and 32 bit guest on 64 bit host.
Both "big floppies" and images with partition tables work.

Sorry for the noise,
Bernhard

Re: kvm-85 won't boot guests with virtio block device

[Gerd v. Egidy]

Hi Bernhard,

> >>>> After an upgrade from kvm-84 to kvm-85 all my guests won't start
> >>>> because no boot device could be found.
> >>
> >> No problem here, my guests run fine with kvm-85 and 2.6.29.1:
> >> 	-drive file="$IMG",format=raw,cache=none
>
> This is the right example:
> 	-drive file="$IMAGE1",if=virtio,format=raw,cache=none,boot=on

Hmm, ok. Now we've got to find out whats different between yours and Alexeys 
systems where it works and mine and Darius' where it doesnt.

> I'm running 32 bit guest on 32 bit host and 32 bit guest on 64 bit host.
> Both "big floppies" and images with partition tables work.

I tried 32 bit and 64 bit guest on a 64 bit host.

So bitness doesn't seem to be the issue. The kvm-modules seem not to be the 
issue too because Darius wrote he's using the modules from kvm-85 (seems he 
forgot to cc the list).

Any other ideas?

Kind regards,

Gerd

kvm-85 won't boot guests with virtio block device

[Pauline Middelink]

[-- Attachment #1: Type: text/plain, Size: 727 bytes --]

Hi,

To follow up on the issues with kvm-85 and libvirt I discovered the following
issue: libvirt detects from the help of qemu which options it can give to
qemu. (in this case obviously /usr/kvm/bin/qemu-system-x86_64 -help)

If you look carefully to the output of the -help of qemu from kvm-84 and
kvm-85, you will notice the boot flag to the -drive option has disappeared!
Hence letting libvirt believe it isnt allowed to use it, hence the unable
to boot error.

A small patch which fixes the problem for me, is attached.

    Met vriendelijke groet,
        Pauline Middelink
-- 
GPG Key fingerprint = 2D5B 87A7 DDA6 0378 5DEA  BD3B 9A50 B416 E2D0 C3C2
For more details look at my website http://www.polyware.nl/~middelink

[-- Attachment #2: kvm-85-virtio-boot.patch --]
[-- Type: text/plain, Size: 602 bytes --]

diff -ur kvm-85/qemu/qemu-options.hx kvm-85a/qemu/qemu-options.hx
--- kvm-85/qemu/qemu-options.hx 2009-04-21 11:57:31.000000000 +0200
+++ kvm-85a/qemu/qemu-options.hx        2009-04-24 19:04:50.000000000 +0200
@@ -77,6 +77,7 @@
     "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
     "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
     "       [,cache=writethrough|writeback|none][,format=f][,serial=s]\n"
+    "       [,boot=on|off]\n"
     "                use 'file' as a drive image\n")
 STEXI
 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]

Re: kvm-85 won't boot guests with virtio block device

[Marcelo Tosatti]

Pauline,

Good catch.

Anthony, what is the reason for extboot not being upstream?

On Fri, Apr 24, 2009 at 07:18:53PM +0200, Pauline Middelink wrote:
> Hi,
> 
> To follow up on the issues with kvm-85 and libvirt I discovered the following
> issue: libvirt detects from the help of qemu which options it can give to
> qemu. (in this case obviously /usr/kvm/bin/qemu-system-x86_64 -help)
> 
> If you look carefully to the output of the -help of qemu from kvm-84 and
> kvm-85, you will notice the boot flag to the -drive option has disappeared!
> Hence letting libvirt believe it isnt allowed to use it, hence the unable
> to boot error.
> 
> A small patch which fixes the problem for me, is attached.
> 
>     Met vriendelijke groet,
>         Pauline Middelink

Can you add a Signed-off-by: line so we can apply?

> -- 
> GPG Key fingerprint = 2D5B 87A7 DDA6 0378 5DEA  BD3B 9A50 B416 E2D0 C3C2
> For more details look at my website http://www.polyware.nl/~middelink

> diff -ur kvm-85/qemu/qemu-options.hx kvm-85a/qemu/qemu-options.hx
> --- kvm-85/qemu/qemu-options.hx 2009-04-21 11:57:31.000000000 +0200
> +++ kvm-85a/qemu/qemu-options.hx        2009-04-24 19:04:50.000000000 +0200
> @@ -77,6 +77,7 @@
>      "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
>      "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
>      "       [,cache=writethrough|writeback|none][,format=f][,serial=s]\n"
> +    "       [,boot=on|off]\n"
>      "                use 'file' as a drive image\n")
>  STEXI
>  @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]

Re: kvm-85 won't boot guests with virtio block device

[Anthony Liguori]

Marcelo Tosatti wrote:
> Pauline,
>
> Good catch.
>
> Anthony, what is the reason for extboot not being upstream?
>   

Paul Brook nacked it. 

He didn't like that it was so x86 specific.  I think a better approach 
that would be mergable is something based on the FW config interface 
with the driver code living as a patch to the Bochs BIOS.

-- 
Regards,

Anthony Liguori

Re: kvm-85 won't boot guests with virtio block device

[Anthony Liguori]

Anthony Liguori wrote:
> Marcelo Tosatti wrote:
>> Pauline,
>>
>> Good catch.
>>
>> Anthony, what is the reason for extboot not being upstream?
>>   
>
> Paul Brook nacked it.
> He didn't like that it was so x86 specific.  I think a better approach 
> that would be mergable is something based on the FW config interface 
> with the driver code living as a patch to the Bochs BIOS.

By hooking the int13 code in the Bochs BIOS directly, we'd probably 
avoid 99% of the bugs we've encountered with extboot implementing int13 
functionality too so I think it's a good idea.

-- 
Regards,

Anthony Liguori

Re: kvm-85 won't boot guests with virtio block device

[Gerd v. Egidy]

Hi Pauline,

> To follow up on the issues with kvm-85 and libvirt I discovered the
> following issue: libvirt detects from the help of qemu which options it can
> give to qemu. (in this case obviously /usr/kvm/bin/qemu-system-x86_64
> -help)
>
> If you look carefully to the output of the -help of qemu from kvm-84 and
> kvm-85, you will notice the boot flag to the -drive option has disappeared!
> Hence letting libvirt believe it isnt allowed to use it, hence the unable
> to boot error.
>
> A small patch which fixes the problem for me, is attached.

thank you very much for discovering this, your patch solved my problems 
starting kvm-85 with virtio-blk from libvirt.

Kind regards,

Gerd

Re: kvm-85 won't boot guests with virtio block device

[Avi Kivity]

Pauline Middelink wrote:
> Hi,
>
> To follow up on the issues with kvm-85 and libvirt I discovered the following
> issue: libvirt detects from the help of qemu which options it can give to
> qemu. (in this case obviously /usr/kvm/bin/qemu-system-x86_64 -help)
>
> If you look carefully to the output of the -help of qemu from kvm-84 and
> kvm-85, you will notice the boot flag to the -drive option has disappeared!
> Hence letting libvirt believe it isnt allowed to use it, hence the unable
> to boot error.
>
> A small patch which fixes the problem for me, is attached.
>
>   

It's missing the sacred signoff, can you add it please?

-- 
error compiling committee.c: too many arguments to function

Re: kvm-85 won't boot guests with virtio block device

[Avi Kivity]

Anthony Liguori wrote:
> Marcelo Tosatti wrote:
>> Pauline,
>>
>> Good catch.
>>
>> Anthony, what is the reason for extboot not being upstream?
>>   
>
> Paul Brook nacked it.
> He didn't like that it was so x86 specific.  
Which part?  The guest/host interface, or the option rom part?

> I think a better approach that would be mergable is something based on 
> the FW config interface with the driver code living as a patch to the 
> Bochs BIOS.

The firmware interface is for reading configuration information.  It's 
an idempotent, zero-latency interface.  Let's not mix it with disk 
sector read/writes which is a completely different thing.

-- 
error compiling committee.c: too many arguments to function

kvm-85 won't boot guests with virtio block device

[Pauline Middelink]

[-- Attachment #1: Type: text/plain, Size: 251 bytes --]

Added the sacred signoff at numerious request :)

    Met vriendelijke groet,
        Pauline Middelink
-- 
GPG Key fingerprint = 2D5B 87A7 DDA6 0378 5DEA  BD3B 9A50 B416 E2D0 C3C2
For more details look at my website http://www.polyware.nl/~middelink

[-- Attachment #2: kvm-85-virtio-boot.patch --]
[-- Type: text/plain, Size: 815 bytes --]

Small regression. libvirt determines the use of the boot= flag by looking
at the helptext. This flag is required for booting off virtio-blk devices.

Signed-off-by: Pauline Middelink <middelink <at> polyware.nl>

diff -ur kvm-85/qemu/qemu-options.hx kvm-85a/qemu/qemu-options.hx
--- kvm-85/qemu/qemu-options.hx 2009-04-21 11:57:31.000000000 +0200
+++ kvm-85a/qemu/qemu-options.hx        2009-04-24 19:04:50.000000000 +0200
@@ -77,6 +77,7 @@
     "-drive [file=file][,if=type][,bus=n][,unit=m][,media=d][,index=i]\n"
     "       [,cyls=c,heads=h,secs=s[,trans=t]][,snapshot=on|off]\n"
     "       [,cache=writethrough|writeback|none][,format=f][,serial=s]\n"
+    "       [,boot=on|off]\n"
     "                use 'file' as a drive image\n")
 STEXI
 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]

Re: kvm-85 won't boot guests with virtio block device

[Avi Kivity]

Pauline Middelink wrote:
> Added the sacred signoff at numerious request :)
>
>     Met vriendelijke groet,
>         Pauline Middelink
>   

Applied, thanks.

-- 
error compiling committee.c: too many arguments to function