Hi there ... I observe a regression in 3.13.x and initially reported it to Takuya Yoshikawa, who told me to post to this list. (I'm neither subscribed to this list nor LKML.) I just compiled 3.13.3 and it happens here too. In this very moment. All I do is running qemu to boot an ISO image like this $ qemu-kvm -cdrom systemrescuecd-x86-4.0.0.iso and the guest eventually stops running causing a high system load on the host system. Usually the guest hangs within 10-15 seconds, but I once saw it hanging only after more than 90 seconds and once even before printing the kvm: zapping shadow pages for mmiogeneration wraparound message in dmesg. It seems there are absolutely no error messages. Usually I can Ctrl-C the running qemu process and everything is just fine again. Only in the one case where qemu hang very early I had to 'kill -9' the process. In case I do not kill qemu my system becomes unusable within a few minutes. While I can start new terminals (via window manager hot- keys) and run for example 'top' and 'vmstat' ... [freeze+reboot] Thanks to Thunderbirds drafts autosave I can continue wrinting this mail, I just hung it completely running 'xload' while qemu caused a load above 6 (on a two core machine). So far I could always reco- ver by killing qemu, but on the other hand I never tried to start 'xload' in a situation like this before. (Note: There is always a copy of xload running on my desktop.) I run a i686 Gentoo Linux with qemu-1.4.2 on Intel(R) Core(TM)2 Duo CPU E8600 @ 3.33GHz. I tested 3.13.{0,1,2,3} and 3.12.{4,7,8,10}. All 3.13.x are broken, all 3.12.x worked, even running 'qemu' for several hours. $ grep KVM config-3.12.10 CONFIG_HAVE_KVM=y CONFIG_HAVE_KVM_IRQCHIP=y CONFIG_HAVE_KVM_IRQ_ROUTING=y CONFIG_HAVE_KVM_EVENTFD=y CONFIG_KVM_APIC_ARCHITECTURE=y CONFIG_KVM_MMIO=y CONFIG_KVM_ASYNC_PF=y CONFIG_HAVE_KVM_MSI=y CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT=y CONFIG_KVM=m CONFIG_KVM_INTEL=m # CONFIG_KVM_AMD is not set $ grep KVM config-3.13.2 CONFIG_HAVE_KVM=y CONFIG_HAVE_KVM_IRQCHIP=y CONFIG_HAVE_KVM_IRQ_ROUTING=y CONFIG_HAVE_KVM_EVENTFD=y CONFIG_KVM_APIC_ARCHITECTURE=y CONFIG_KVM_MMIO=y CONFIG_KVM_ASYNC_PF=y CONFIG_HAVE_KVM_MSI=y CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT=y CONFIG_KVM_VFIO=y CONFIG_KVM=m CONFIG_KVM_INTEL=m # CONFIG_KVM_AMD is not set "/usr/bin/qemu-kvm" (on gentoo) is a wrapper script containing #!/bin/sh exec /usr/bin/qemu-system-x86_64 -machine accel=kvm "$@" I tried using /usr/bin/qemu-system-i386 (as I'm running i686) but the same happend. (I must admit that I tested this only once, with one of the 3.13.x kernels.) Is there anything else I can to? Thomas -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html