On Mon, Oct 24, 2016 at 08:03:33PM +0800, Shannon Zhao wrote: > Hi, > > I have a testcase which fails on host linux kernel 4.1.32. The testcase > is that resetting the guest outside while rebooting inside at the same time. > > By the way, the guest kernel is linux 4.4 with debian filesystem. > > Here is the qemu command line: > > qemu-kvm \ > -smp 4 \ > -enable-kvm \ > -m 1024 -M virt,gic-version=2 \ > -monitor telnet::5444,server,nowait \ > -cpu host -nographic \ > -device virtio-net-device,netdev=net0,mac="52:54:00:12:34:55" \ > -netdev type=tap,id=net0,script=./qemu-ifup,downscript=no \ > -drive file=debian.raw,if=none,id=drive-virtio-disk0,format=raw \ > -device virtio-blk-device,drive=drive-virtio-disk0,id=virtio-disk0 \ > -kernel Image-4.4 \ > -append "console=ttyAMA0 root=/dev/vda1 earlycon=pl011,0x9000000 rw > dhcp" > > And the test command is: > > # ssh guest_ip reboot;echo system_reset|nc host_ip 5444 > > After executing above command several times, the guest gets stuck. The > guest log as follow: > > ... > Architected cp15 timer(s) running at 66.00MHz (virt). > clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: > 0xf38bc32cd, max_idle_ns: 440795204298 ns > sched_clock: 56 bits at 66MHz, resolution 15ns, wraps every 2199023255548ns > Console: colour dummy device 80x25 > Calibrating delay loop (skipped), value calculated using timer > frequency.. 132.00 BogoMIPS (lpj=264000) > pid_max: default: 32768 minimum: 301 > Security Framework initialized > Mount-cache hash table entries: 2048 (order: 2, 16384 bytes) > Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes) > Initializing cgroup subsys memory > Initializing cgroup subsys hugetlb > EFI services will not be available. > ASID allocator initialised with 65536 entries > > I found the guest is stuck at > while ((now = jiffies) == j) in the function do_xor_speed(). Looks like > there is no timer interrupt injected to guest any more. > > And the kernel 4.6 has fixed this bug, but I'm not sure if there is some > way to fix this in stable 4.1. > Hmmm, v4.1 still used edge-triggered semantics for the timer, which was causing reset issues with UEFI, so I wonder if that's related? You could attempt at backporting the rework of the timers: https://lists.cs.columbia.edu/pipermail/kvmarm/2015-September/016588.html You might also need these commits on top: 0e3dfda91d9fe8e2c4d0b5d21434b173a241eeaf 1c5631c73fc2261a5df64a72c155cb53dcdc0c45 Thanks, -Christoffer _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
