Re: [Qemu-discuss] quick start help after build

[Mike Lovell]

On 07/30/2014 12:21 PM, graff zeltner wrote:
> Hi,
>
> I've built version 2.0.95 with the following sequence of steps:
> 'git clone git://git.qemu-project.org/qemu.git'
> './configure' halted on missing libfdt, so used
> 'git submodule update --init dtc' to fix missing dependency
> './configure --prefix=/home/graf/test/qemu --target-list="i386-linux-user 
> x86_64-linux-user"'
> 'make all' && 'make install'

you probably wanted --target-list to be "i386-softmmu x86_64-softmmu" 
and not the linux-user ones. the softmmu targets are the ones that build 
the qemu-system-i386 and qemu-system-x86_64 programs. those will match 
what you were doing before. qemu-i386 and qemu-x86_64 are for an very 
different use case and have a different method of invoking them.

> Now in ~/test/qemu directory I have bin/ etc/ libexec/ share/ and var/ 
> directories with bin/ showing
> qemu-ga
> qemu-i386
> qemu-img
> qemu-io
> qemu-nbd
> qemu-x86_64
> At this point I would have installed in the /usr/local where all these files 
> belong, except I could not
> run the program. Tried quick start document section to no avail.
> The old command sequence did not work.
> 'qemu-system_x86_64 -L . -m 1024 -boot c -hda harddisk.img' -> no such 
> file 'qemu-system-x86_64'
> 'qemu-x86_64 -L . -m 1024 -boot c -hda harddisk.img' -> usage 
> 'qemu-86_64 [options] program [arguments]'
>
> The options section (usage help) does not show any "useful" help for 
> setting even the basic parameters. Was that the intended
> design decision? Instead we are faced with environment options 
> variables which, I am sorry if you did not realize yet, they for the 
> most part are gibberish. Viz. there is not a section in the 
> documentation that covers them, and the documentation still has 
> 'qemu-system-x86_64' where the 'system' keyword has been dropped. You 
> have to weed through the entire documentation and examine every 
> option, and even then you are not yet ready to set the environment 
> options.
>
> I've tried both qemu-i386 and qemu-x86_64 adding file-descriptor options
> 'qemu-i386 -add-fd fd=3,set=2,opaque="rdwr:/home/graff/harddisk.img"
>
> or even boot order
> qemu-system-i386 -boot order=nc harddisk.img
>
> The 'usage options' for example do not echo 'invalid or unrecognized option'. 
> Every attempt brings you back to the same
> useless options menu
>
> At this point, it appears to me the program failed, but what is worse 
> the developers failed. You have just bought yourself a brand spanking 
> new car, the dealer handed you the keys, and you cannot open the car 
> door or find where the ignition key gets inserted.

it may appear the program has failed but it hasn't and neither have the 
developers. every thing you have been describing sounds like it has been 
behaving as the developers intended but only appears to be broken due to 
a mis-understanding.

for your original problem of the virtual machines being slow, i would 
recommend adding the --enable-kvm to you qemu-system-x86_64 or 
qemu-system-i386 commands. i am assuming that you are using a linux 
system to run qemu on. using --enable-kvm will enable qemu to use the 
kvm kernel module to accelerate the performance of the vm. you may need 
to make sure that the kvm kernel module and either the kvm_intel or 
kvm_amd kernel module are loaded. the user executing qemu-system-x86_64 
or -i386 will need permission to read and write to /dev/kvm.

i hope that all helps.

mike