On Thu, 26 May 2022 at 07:45, Jiatong Shen <yshxxsjt...@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