Re: [Qemu-discuss] question about QEMU configuration and build process

[Peter Maydell]

On 7 January 2017 at 08:29, Kevin Wilson <address@hidden> wrote:
> Hi,
>
> I try to build qemu on x86_64 platform from source with qemu-2.2.0
> from the official website, http://wiki.qemu.org/download/
> I ran "./configure" and make.

Why are you trying to build such an old version? The
current release is 2.8.0.

> when I try to run qemu-system-x86_64 binary with "-vga qxl"
> I got:
> Error: QXL VGA not available
> When I ran:
> ./configure --help | grep -i qxl
> I got nothing.
>
> Any ideas what should I do so that the "-vgs qxl" option will be available ?

As Boddu suggests, this is because you don't have the spice
dependencies needed for QXL. configure defaults to "see if
libraries are available, provide optional features if they
are, and not if they are not". Using --enable-foo will make
it insist that the library is available (and fail if not),
which can be helpful for testing that an optional
build dependency is present.

(Watch out that the spice library version dependencies are
sometimes quite strict -- newer QEMU may need a newer spice
than the Ubuntu packaged version.)

> Apart from it, when I try using the "-vga qxl" with qemu-system-x86_64
> binary from a qemu Ubuntu package, it succeeds.
> Is there a way to know which were the configuration options which were
> chosen for a given qemu-system-x86_64 binary ?
>
> More sepcifically, I am talking about the following quemu package:
> qemu-system-x86_64 -version
> QEMU emulator version 2.2.0 (Debian 2:2.2+dfsg-5expubuntu8+contrail3),
> Copyright (c) 2003-2008 Fabrice Bellard

You'd need to look at the debian packaging to see which configure
options they passed (and which packages they listed in their
build-depends).

You might find "apt-get build-dep qemu" useful -- this should
auto-install all the build dependencies used for the official
debian package, assuming you have your apt sources list set up
right, and is a good start on enabling a lot of the optional
extras for a QEMU build.

thanks
-- PMM