Re: IPA range (41 bits) larger than the one supported by the host (40 bits)

[Jiatong Shen]

Hi,

   I've tried to use qemu 7.0 and indeed "qemu-system-aarch64 -cpu host -enable-kvm -machine virt -m size=4G,maxmem=512G" works this time! I also tried qemu 6.2 but it doesn't work.

we have some environments which unfortunately couldn't upgrade qemu to 7.0. So my question is is it possible to calculate a reasonable maxmem given slots for an older qemu? Thank you much for the help.

Best,

Norman

On Thu, May 26, 2022 at 5:51 PM Jiatong Shen <yshxxsjt715@gmail.com> wrote:

Thank you very much. I'll try it out.

Best,

Norman

On Thu, May 26, 2022 at 4:18 PM Peter Maydell <peter.maydell@linaro.org> wrote:

On Thu, 26 May 2022 at 07:45, Jiatong Shen <yshxxsjt715@gmail.com> wrote:
>    I am trying to run qemu-system-aarch64 on a Kylin based machine, the host kernel version is 4.19. qemu is versioned 4.2.1. The command I am running is "qemu-system-aarch64 -cpu host -enable-kvm -machine virt -m size=4G,maxmem=512G". This command failed with "qemu-system-aarch64: -m and ,maxmem option values require an IPA range (41 bits) larger than the one supported by the host (40 bits)".
>    I am confused because 2^40 is around 1TB which is greater than 512G. Would be very appreciated to get some insights. Thank you very much for the help in advance.

That's a rather old QEMU version. We reworked the handling of
highmem in the virt board for the 7.0 release -- could you
test whether that also has this problem? (I don't have a
40 bit PA host to hand but I did a quick simulation with
a gdb session and I think 7.0 should fit everything into 40 bits
with those command line options.)

thanks
-- PMM

--

Best Regards,

Jiatong Shen

--

Best Regards,

Jiatong Shen