Re: options to fix vmalloc failure on modprobe

[Peter Maydell]

On Mon, 30 Nov 2020 at 22:49, <jim.cromie@gmail.com> wrote:
>
> so Im hacking at linux kernel, using qemu via virtme.
> which just runs kernel on the hosts environment.
> generally things are fine, so thanks for that.
>
> but when I build the graphics driver as module,
> I cannot allocate for it at modprobe.
>
> I searched vmalloc, balloon in qemu.org/doc search,
> mail-archives, google, and found nothing I recognized as responsive.
>
>
> /usr/bin/qemu-system-x86_64 -fsdev
> local,id=virtfs1,path=/,security_model=none,readonly,multidevs=remap
> -device virtio-9p-pci,fsdev=virtfs1,mount_tag=/dev/root -fsdev
> local,id=virtfs5,path=/usr/local/lib/python3.9/site-packages/virtme-0.1.1-py3.9.egg/virtme/guest,security_model=none,readonly,multidevs=remap
> -device virtio-9p-pci,fsdev=virtfs5,mount_tag=virtme.guesttools
> -machine accel=kvm:tcg -watchdog i6300esb -cpu host -parallel none
> -net none -echr 1 -serial none -chardev
> stdio,id=console,signal=off,mux=on -serial chardev:console -mon
> chardev=console -vga none -display none -kernel
> ./arch/x86/boot/bzImage -append
> 'virtme_link_mods=/home/jimc/projects/lx/wk-test/builds/v2/.virtme_mods/lib/modules/0.0.0
> earlyprintk=serial,ttyS0,115200 console=ttyS0 psmouse.proto=exps
> "virtme_stty_con=rows 24 cols 154 iutf8" TERM=xterm-256color
> rootfstype=9p rootflags=version=9p2000.L,trans=virtio,access=any
> raid=noautodetect ro nokaslr multidevs=remap dynamic_debug.verbose=3
> dynamic_debug.dyndbg=+pmf module.dyndbg=+pmf main.dyndbg=+pmf
> init=/bin/sh -- -c "mount -t tmpfs run /run;mkdir -p
> /run/virtme/guesttools;/bin/mount -n -t 9p -o
> ro,version=9p2000.L,trans=virtio,access=any virtme.guesttools
> /run/virtme/guesttools;exec /run/virtme/guesttools/virtme-init"'
> -machine dump-guest-core=on

That's a long command line, so maybe I missed the option in there
somewhere, but you don't seem to be specifying how much RAM to
give your guest, which means you'll get the default of 128MB,
which can run a really small guest, but that i915 driver
is trying to allocate 140MB of RAM... Try giving your guest
more RAM (with the -m option) and it will probably be happier.

thanks
-- PMM