On 6/17/20 10:23 AM, Philippe Mathieu-Daudé wrote: > On 6/11/20 11:14 AM, Andrew Jones wrote: >> On Thu, Jun 11, 2020 at 04:46:45PM +0800, Haibo Xu wrote: >>> Hi, >>> >>> I met a qemu core dump issue when starting a VM with cpu feature >>> "pmu=on" on an arm server. >>> The commands to start the machine is: >>> >>> ./qemu-system-aarch64 \ >>> -cpu host,pmu=on -M virt,accel=kvm,gic-version=3 -nographic >>> -m 2048M \ >>> -kernel ./Image \ >>> -initrd /boot/initrd.img-5.6.0-rc2+ \ >>> -append "root=/dev/vda rw console=ttyAMA0" -nodefaults -serial >>> stdio\ >>> -drive if=none,file=./xenial.rootfs.ext4,id=hd0,format=raw \ >>> -device virtio-blk-device,drive=hd0 >>> >>> >>> And here is the stack dump: >>> >>> Core was generated by `./qemu-system-aarch64 -cpu host,pmu=on -M >>> virt,accel=kvm,gic-version=3 -nograph'. >>> Program terminated with signal SIGSEGV, Segmentation fault. >>> #0 kvm_ioctl (s=0x0, type=type@entry=44547) at >> >> s=0x0 means cpu->kvm_state is NULL >> >>> The root cause is in the arm_get_pmu() operation which was introduced >>> in ae502508f83. >> >> Actually the root cause is d70c996df23f ("target/arm/kvm: Use >> CPUState::kvm_state in kvm_arm_pmu_supported()"). ae502508f83 used >> the machine kvm_state, not the cpu kvm_state, and that allows pmu=on >> to work. d70c996df23f changed that saying that "KVMState is already >> accessible via CPUState::kvm_state, use it.", but I'm not sure why, >> since kvm_init_vcpu() doesn't run until the vcpu thread is created. >> >> Philippe? > > Sorry for some reason I missed this email. I'll look at this today.
Quick reproducer: $ qemu-system-aarch64 -cpu host,pmu=on -M virt,accel=kvm,gic-version=3 Segmentation fault (core dumped) Eduardo, I thought we had a 'machine' qtest testing for various combination of properties, but I can't find it, do you remember? Or maybe it was Thomas? Or Markus? =) > >> >> Thanks, >> drew >> >