[kvm-unit-tests PATCH v2 4/5] configure: Add --qemu-cpu option

[Andrew Jones]

On Thu, Mar 20, 2025 at 01:42:01PM +0000, Alexandru Elisei wrote:
...
> >  mach=$MACHINE_OVERRIDE
> > -processor=$PROCESSOR_OVERRIDE
> > +qemu_cpu=$QEMU_CPU_OVERRIDE
> 
> The name QEMU_CPU_OVERRIDE makes more sense, but I think this will break
> existing setups where people use PROCESSOR_OVERRIDE to pass a particular
> -cpu value to qemu.
> 
> If I were to guess, the environment variable was added to pass a value to
> -cpu different than what it can be specified with ./configure --processor,
> which is exactly what --qemu-cpu does. But I'll let Drew comment on that.

Yeah, ideally we wouldn't rename environment variables, but I'll cross my
fingers that nobody will notice. Indeed, it was created to avoid needing
to reconfigure for experimenting with different QEMU cpu models, so, even
with --qemu-cpu we'll want something and the renaming here makes sense.

> 
> >  firmware=$FIRMWARE_OVERRIDE
> >  
> > -[ "$PROCESSOR" = "$ARCH" ] && PROCESSOR="max"
> > +[ -z "$QEMU_CPU" ] && QEMU_CPU="max"
> >  : "${mach:=virt}"
> > -: "${processor:=$PROCESSOR}"
> > +: "${qemu_cpu:=$QEMU_CPU}"
> >  : "${firmware:=$FIRMWARE}"
> >  [ "$firmware" ] && firmware="-bios $firmware"
> >  
> > @@ -32,7 +32,7 @@ fi
> >  mach="-machine $mach"
> >  
> >  command="$qemu -nodefaults -nographic -serial mon:stdio"
> > -command+=" $mach $acc $firmware -cpu $processor "
> > +command+=" $mach $acc $firmware -cpu $qemu_cpu "
> >  command="$(migration_cmd) $(timeout_cmd) $command"
> >  
> >  if [ "$UEFI_SHELL_RUN" = "y" ]; then
> > diff --git a/configure b/configure
> > index 5306bad3..d25bd23e 100755
> > --- a/configure
> > +++ b/configure
> > @@ -52,6 +52,7 @@ page_size=
> >  earlycon=
> >  efi=
> >  efi_direct=
> > +qemu_cpu=
> >  
> >  # Enable -Werror by default for git repositories only (i.e. developer builds)
> >  if [ -e "$srcdir"/.git ]; then
> > @@ -69,6 +70,8 @@ usage() {
> >  	    --arch=ARCH            architecture to compile for ($arch). ARCH can be one of:
> >  	                           arm, arm64, i386, ppc64, riscv32, riscv64, s390x, x86_64
> >  	    --processor=PROCESSOR  processor to compile for ($processor)
> > +	    --qemu-cpu=CPU         the CPU model to run on. The default depends on
> > +	                           the configuration, usually it is "host" or "max".
> 
> Nitpick here, would you mind changing this to "The default value depends on
> the host system and the test configuration [..]", to make it clear that it also
> depends on the machine the tests are being run on?

I agree.

Thanks,
drew