Re: [Qemu-devel] [PATCH] Introduce machine specific default memory size

[Thomas Huth]

On Wed, 04 Mar 2015 14:00:17 +0530
Nikunj A Dadhania <address@hidden> wrote:

> Markus Armbruster <address@hidden> writes:
> 
> > Nikunj A Dadhania <address@hidden> writes:
> >
> >> diff --git a/vl.c b/vl.c
> >> index eb89d62..dd56754 100644
> >> --- a/vl.c
> >> +++ b/vl.c
> >> @@ -4053,6 +4053,18 @@ int main(int argc, char **argv, char **envp)
> >>          exit(1);
> >>      }
> >>  
> >> +    if (machine_class->default_ram_size && ram_size < 
> >> machine_class->default_ram_size) {
> >> +        fprintf(stderr, "qemu: %s guest ram size defaulting to %ld MB\n",
> >> +                machine_class->name,
> >> +                machine_class->default_ram_size / (1024 * 1024));
> >
> > If the user explicitly asks for something, we either provide it
> > silently, or we error out.  This does neither.  Why?
> 
> In case the user has provided memory not enough to boot the machine, I
> could error out. My idea was to have a sane default which is provided by
> the machine.
> 
> Initially, I had just "ram_size == default_ram_size", but then it was
> allowing "-m 128M" to go through. And the VM would not boot. 
> 
> This can as well be converted to an error report and fail here to boot
> the VM.

What does exactly fail with 128MB? Linux? SLOF? IIRC, a couple of years
ago, 128MB were enough to boot a Linux guest in the spapr machine...

 Thomas