[Qemu-devel] Qemu the right way.

[Qemu-devel] Qemu the right way.

[liebrecht]

I have been using Qemu in the past about 8 years ago or so to run legacy 
windows software.

I installed the latest qemu and noticed a lot changed and cant find 
conclusive answers online.

I am writing this post to find what is the right way to start to set up 
qemu with a windows 7 pro guest. I want to try and eliminate the 
iterations and find out what is really possible for the guest.

Hardware used"
24 Core AMD rackserver.
Host OS Debian 9 Stretch
Guest Windows 7 Pro 32 bit

Requirements:
1) I need to be able to run at least 4 processors in the guest. Is this 
possible with qemu as hosts ?
2) I need to at least have sound working from applications in the guest 
with pulseaudio on the Debian host. Is it  possible ?
3) USB, what is the level of support 2.0 3.0 ?
( However windo$ 7 cannot really do USB3. so usb-3 is moot anyway)
4) What kind of devices can be run through usb ?

The answers to 1-4 will be really helpful to decide if I should even be 
using it. The documentation is schetchy about all this.
I tried Virtualbox, but it is just a nice looking empty promisebox 
yielding nothing. Since Qemu helped me a lot in the past I will have 
better chances here.

5) I am currently installing win7pro guest with command
$] qemu-system-x86_64 -boot c -cdrom /dev/cdrom -m 2048M

and left out all the network card and sound driver switches as I have no 
clue what I should choose.
Can they be configured afterwards ?

Thanks

Re: [Qemu-devel] Qemu the right way.

[Thomas Huth]

On 2018-12-25 23:46, liebrecht@grossmann-venter.com wrote:
> I have been using Qemu in the past about 8 years ago or so to run legacy
> windows software.
> 
> I installed the latest qemu and noticed a lot changed and cant find
> conclusive answers online.
> 
> I am writing this post to find what is the right way to start to set up
> qemu with a windows 7 pro guest. I want to try and eliminate the
> iterations and find out what is really possible for the guest.
> 
> Hardware used"
> 24 Core AMD rackserver.
> Host OS Debian 9 Stretch
> Guest Windows 7 Pro 32 bit
> 
> Requirements:
> 1) I need to be able to run at least 4 processors in the guest. Is this
> possible with qemu as hosts ?

Try to run QEMU with "-smp 4".

> 2) I need to at least have sound working from applications in the guest
> with pulseaudio on the Debian host. Is it  possible ?

Should be possible. Run the configure script before compiling with

 --audio-drv-list=pa

and then make sure to give a soundcard to the guest (e.g. with the
-soundhw option).

> 3) USB, what is the level of support 2.0 3.0 ?
> ( However windo$ 7 cannot really do USB3. so usb-3 is moot anyway)

QEMU supports both, e.g. with "-device usb-ehci" for a USB 2.0
controller or with "-device nec-usb-xhci" for a USB 3.0 controller.

> 4) What kind of devices can be run through usb ?

Do you mean emulated devices? You can get a list with:

 qemu-system-x86_64 -device help | grep usb

Or do you want to pass-through a real device from the host?

> The answers to 1-4 will be really helpful to decide if I should even be
> using it. The documentation is schetchy about all this.
> I tried Virtualbox, but it is just a nice looking empty promisebox
> yielding nothing. Since Qemu helped me a lot in the past I will have
> better chances here.
> 
> 5) I am currently installing win7pro guest with command
> $] qemu-system-x86_64 -boot c -cdrom /dev/cdrom -m 2048M
> 
> and left out all the network card and sound driver switches as I have no
> clue what I should choose.
> Can they be configured afterwards ?

I don't have much clue about Windows, but I think you can change it
afterwards - it's like you're changing PCI cards of a real system in
that case.

 HTH,
  Thomas

Re: [Qemu-devel] Qemu the right way.

[liebrecht]

> 
> Try to run QEMU with "-smp 4".
> 

Thomas thank you for your reply.
I will try each of your suggestions in turn.

-smp 4 did help and this time i could configure 2 cpus in windows.

Now for a very important question.
If hardware virtualization was not switched on in bios will qemu refuse 
to create more cpus? I just want to know if there are not bogus software 
cpus or cores created by qemu and that it actually checks it can get 
real cores from the machine and make it available to the host.

Second question. In the past qemu was lightning fast. However with this 
newer qemu windows 7 is very slow. It takes about 1 minute to open an 
application. What can slow it dow so much ? This happens with or without 
the smp switch. It seems there is some polling botlleneck if i move the 
mouse in circles in the windows guest, it would freeze for four seconds 
and then work for about 6 seconds then freeze again etc. What is that 
about.?

What is the official posting rules in this forum, top post or bottom 
post ? Thanks

Re: [Qemu-devel] Qemu the right way.

[liebrecht]

I now move on to sound.

I could get sound working as you instructed. I chose to load all sound 
cards and see if I can find one that works.

Sound does work but it ios very intermittent, seemingly the same as what 
happens to the mouse as if there is a timeshare going on.

Any idea what that can be.

Please not that I am running AVLinux which has a real time kernel as I 
can remember. Maybe qemu has trouble with realtime kernels ? Or what can 
the reason be for the intermittent sound. Sound on for 2 seconds off for 
a seconds etc,
Note that I did not compile a new version yet and just used the deb 
version. I will do that now

Is the sound problems due to not following your advice below ? What does
--audio-drv-list=pa actually do  ???


For reference
My string now looks as follows.

qemu-system-x86_64 -soundhw all  -smp 4 -m 2048M -boot d -cdrom 
/dev/cdrom -drive format=raw,file=hd.img




On 2018-12-26 02:14, Thomas Huth wrote:

> 
>> 2) I need to at least have sound working from applications in the 
>> guest
>> with pulseaudio on the Debian host. Is it  possible ?
> 
> Should be possible. Run the configure script before compiling with
> 
>  --audio-drv-list=pa
> 
> and then make sure to give a soundcard to the guest (e.g. with the
> -soundhw option).
> 

Re: [Qemu-devel] Qemu the right way.

[liebrecht]

> 
> Try to run QEMU with "-smp 4".
> 

Thomas thank you for your reply.
I will try each of your suggestions in turn.

-smp 4 did help and this time i could configure 2 cpus in windows.

Now for a very important question.
If hardware virtualization was not switched on in bios will qemu refuse 
to create more cpus? I just want to know if there are not bogus software 
cpus or cores created by qemu and that it actually checks it can get 
real cores from the machine and make it available to the host.

Second question. In the past qemu was lightning fast. However with this 
newer qemu windows 7 is very slow. It takes about 1 minute to open an 
application. What can slow it dow so much ? This happens with or without 
the smp switch. It seems there is some polling botlleneck if i move the 
mouse in circles in the windows guest, it would freeze for four seconds 
and then work for about 6 seconds then freeze again etc. What is that 
about.?

What is the official posting rules in this forum, top post or bottom 
post ? Thanks

Re: [Qemu-devel] Qemu the right way.

[liebrecht]

On 2018-12-26 02:14, Thomas Huth wrote:

> 
>> 2) I need to at least have sound working from applications in the 
>> guest
>> with pulseaudio on the Debian host. Is it  possible ?
> 
> Should be possible. Run the configure script before compiling with
> 
>  --audio-drv-list=pa
> 
> and then make sure to give a soundcard to the guest (e.g. with the
> -soundhw option).
> 


I now move on to sound.

I could get sound working as you instructed. I chose to load all sound 
cards and see if I can find one that works.

Sound does work but it ios very intermittent, seemingly the same as what 
happens to the mouse as if there is a timeshare going on.

Any idea what that can be.

Please not that I am running AVLinux which has a real time kernel as I 
can remember. Maybe qemu has trouble with realtime kernels ? Or what can 
the reason be for the intermittent sound. Sound on for 2 seconds off for 
a seconds etc,
Note that I did not compile a new version yet and just used the deb 
version. I will do that now

Is the sound problems due to not following your advice below ? What does
--audio-drv-list=pa actually do  ???


For reference
My string now looks as follows.

qemu-system-x86_64 -soundhw all  -smp 4 -m 2048M -boot d -cdrom 
/dev/cdrom -drive format=raw,file=hd.img

Re: [Qemu-devel] Qemu the right way.

[liebrecht]

Sound is rickety but at least I can see that it is possible as in my 
previous post which is already way better than virtualbox.

Turning to networking;
I can configure windows tcp/ip very well, but for some reason qemu fails 
at a network connection.
Windows report the qemu provided network card as Intel 1000.
However it fails when configured.
The dns and gateway is assigned correctly and known to route correctly 
from the other machines on the network.

So, I then try to explicitly add a switch to see if there is maybe a 
misreported mac or something and explicitly add the -nic network switch 
in the startup command

I work from this manual.
https://qemu.weilnetz.de/doc/qemu-doc.html

The string used is

qemu-system-x86_64 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 
-soundhw all  -smp 4 -m 2048M -boot d -cdrom /dev/cdrom -drive 
format=raw,file=hd.img


The network switch used above fails with
qemu-system-x86_64: -nic: invalid option

Cant figure out why as it is what is used in the manual as is!

[Qemu-devel] Usb device disappears from linux after Qemu starts

[liebrecht]

Below is the string I use:

I use lsb to search for the the hostaddr of the usb device i want to 
connect to qemu.
Qemu when it starts with this hostaddr then removes the device from the 
acticve usb list.
Running lsusb after qemu starts shows the device disappeared.

Is this a bug ? as I cannot see a device just disappearing when qemu 
starts.


sudo qemu-system-x86_64 -usb -device usb-host,hostbus=1,hostaddr=42 
-device piix3-usb-uhci  -enable-kvm -soundhw all  -smp 4 -m 2048M -boot 
d -cdrom /dev/cdrom -drive format=raw,file=hd.img

[Qemu-devel] Qemu the right way.

[liebrecht]

I have been using Qemu in the past about 8 years ago or so to run legacy 
windows software.

I installed the latest qemu and noticed a lot changed and cant find 
conclusive answers online.

I am writing this post to find what is the right way to start to set up 
qemu with a windows 7 pro guest. I want to try and eliminate the 
iterations and find out what is really possible for the guest.

Hardware used"
24 Core AMD rackserver.
Host OS Debian 9 Stretch
Guest Windows 7 Pro 32 bit

Requirements:
1) I need to be able to run at least 4 processors in the guest. Is this 
possible with qemu as hosts ?
2) I need to at least have sound working from applications in the guest 
with pulseaudio on the Debian host. Is it  possible ?
3) USB, what is the level of support 2.0 3.0 ?
( However windo$ 7 cannot really do USB3. so usb-3 is moot anyway)
4) What kind of devices can be run through usb ?

The answers to 1-4 will be really helpful to decide if I should even be 
using it. The documentation is schetchy about all this.
I tried Virtualbox, but it is just a nice looking empty promisebox 
yielding nothing. Since Qemu helped me a lot in the past I will have 
better chances here.

5) I am currently installing win7pro guest with command
$] qemu-system-x86_64 -boot c -cdrom /dev/cdrom -m 2048M

and left out all the network card and sound driver switches as I have no 
clue what I should choose.
Can they be configured afterwards ?

Thanks

Re: [Qemu-devel] Qemu the right way.

[Stefan Hajnoczi]

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On Tue, Dec 25, 2018 at 05:48:50PM -0500, liebrecht@grossmann-venter.com wrote:
> I have been using Qemu in the past about 8 years ago or so to run legacy
> windows software.
> 
> I installed the latest qemu and noticed a lot changed and cant find
> conclusive answers online.
> 
> I am writing this post to find what is the right way to start to set up qemu
> with a windows 7 pro guest. I want to try and eliminate the iterations and
> find out what is really possible for the guest.
> 
> Hardware used"
> 24 Core AMD rackserver.
> Host OS Debian 9 Stretch
> Guest Windows 7 Pro 32 bit
> 
> Requirements:
> 1) I need to be able to run at least 4 processors in the guest. Is this
> possible with qemu as hosts ?
> 2) I need to at least have sound working from applications in the guest with
> pulseaudio on the Debian host. Is it  possible ?
> 3) USB, what is the level of support 2.0 3.0 ?
> ( However windo$ 7 cannot really do USB3. so usb-3 is moot anyway)
> 4) What kind of devices can be run through usb ?
> 
> The answers to 1-4 will be really helpful to decide if I should even be
> using it. The documentation is schetchy about all this.
> I tried Virtualbox, but it is just a nice looking empty promisebox yielding
> nothing. Since Qemu helped me a lot in the past I will have better chances
> here.
> 
> 5) I am currently installing win7pro guest with command
> $] qemu-system-x86_64 -boot c -cdrom /dev/cdrom -m 2048M
> 
> and left out all the network card and sound driver switches as I have no
> clue what I should choose.
> Can they be configured afterwards ?

Running QEMU manually is pretty complex.  It's often used as a component
underneath libvirt - with nicer GUIs on top.

Have you tried virt-manager (https://virt-manager.org/) or GNOME Boxes
(https://wiki.gnome.org/Apps/Boxes)?

That way you don't need to learn all the details of QEMU command-line
options (and there are many!).

Stefan

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Re: [Qemu-devel] Qemu the right way.

[liebrecht]

I resolved it by removing the nic driver detected  by windows and 
rebooted.
It seems llike the first thing to do after the startup string is 
complete is to remove all drivers and then let windows find them again 
according to what is available from the startup string switches.

The nic problem is solved.
Thanks all for the kind help

On 2018-12-26 22:13, Andrew Randrianasulu wrote:
> re:
> 
> The network switch used above fails with
> qemu-system-x86_64: -nic: invalid option
> 
> Cant figure out why as it is what is used in the manual as is!
> 
> ----------------
> 
> May be because your qemu is not as new as documentation (documentation 
> describe
> current stable qemu - v 3.1.0) ?
> 
> I tried this line
> 
> qemu-system-x86_64 -nic user,ipv6=off,model=e1000,mac=52:54:98:76:54:32 
> -cdrom
> ~/Downloads/ISO/slax-English-US-7.0.8-x86_64.iso -m 1999 -enable-kvm 
> -cpu
> host -smp 4
> 
> and it worked for me (obviosly with Linux guest), browser in this 
> specific
> live-cd was too old for youtube, but at least it showed previews and 
> error
> messages.
> 
> My qemu is self-compiled and sort-of behind the times:
> 
> qemu-system-x86_64 --version
> QEMU emulator version 3.0.50 (v3.0.0-1559-g179f9ac887-dirty)
> Copyright (c) 2003-2018 Fabrice Bellard and the QEMU Project developers