Thanks for the information. Yes, I also found the memory backend options on s390x, and also copy the command to x86, but failed.
The following is the command used to start qemu + virtiofs + ubuntu 20.04. One is worked well using NUMA, another one is failed without NUMA. Is there anything wrong? The worked one with NUMA options: qemu-system-x86_64 -M pc -cpu host --enable-kvm -smp 2 -m 4G -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on -numa node,memdev=mem -chardev socket,id=char0,path=/tmp/vfsd.sock -device vhost-user-fs-pci,queue-size=1024,chardev=char0,tag=myfs -chardev stdio,mux=on,id=mon -mon chardev=mon,mode=readline -device virtio-serial-pci -device virtconsole,chardev=mon -vga none -display none -drive if=virtio,file=ubuntu.img The failed one without NUMA options: qemu-system-x86_64 -M pc -cpu host --enable-kvm -smp 2 -m 4G -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on -machine q35,memory-backend=mem -chardev socket,id=char0,path=/tmp/vfsd.sock -device vhost-user-fs-pci,queue-size=1024,chardev=char0,tag=myfs -chardev stdio,mux=on,id=mon -mon chardev=mon,mode=readline -device virtio-serial-pci -device virtconsole,chardev=mon -vga none -display none -drive if=virtio,file=ubuntu.img Thanks. - Shirley -----Original Message----- From: Dr. David Alan Gilbert <dgilb...@redhat.com> Sent: Tuesday, July 5, 2022 4:04 PM To: Thomas Huth <th...@redhat.com> Cc: Zhao, Shirley <shirley.z...@intel.com>; qemu-devel@nongnu.org; virtio...@redhat.com; Stefan Hajnoczi <stefa...@redhat.com> Subject: Re: [Qemu] how to use viriofs in qemu without NUMA * Thomas Huth (th...@redhat.com) wrote: > On 05/07/2022 03.02, Zhao, Shirley wrote: > > Hi, all, > > > > I want to use virtiofs to share folder between host and guest. > > > > From the guide, it must set the NUMA node. > > https://virtio-fs.gitlab.io/howto-qemu.html > > > > But my guest doesn’t support NUMA. > > > > Is there any guide to use qemu + virtiofs without NUMA? > > > > Or does qemu have any plan to support it? > > Hi! > > At least on s390x, you can also specify the memory backend via the > -machine option instead of using the -numa option, e.g.: > > qemu-system-s390x -machine memory-backend=mem \ > -object memory-backend-file,id=mem,... > > Not sure whether that works on other architectures, too, though. > Stefan, David, do you know? Right, that's the way I do it on x86. We wrote virtiofs before the memory-backend option existed, which is why the old docs talk about using the NUMA stuff. Dave > Thomas > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
