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Mark Rutland
0161ed7758
When VCPU #0 exits (e.g. due to KVM_EXIT_SYSTEM_EVENT), it sends SIGKVMEXIT to all other VCPUs, waits for them to exit, then tears down any remaining context. The signalling of SIGKVMEXIT is critical to forcing VCPUs to shut down in response to a system event (e.g. PSCI SYSTEM_OFF). VCPUs other that VCPU #0 simply exit in kvm_cpu_thread without forcing other CPUs to shut down. Thus if a system event is taken on a VCPU other than VCPU #0, the remaining CPUs are left online. This results in KVM tool not exiting as expected when a system event is taken on a VCPU other than VCPU #0 (as may happen if the guest panics). Fix this by tearing down all CPUs upon a system event, regardless of the CPU on which the event occurred. While this means the VCPU thread will signal itself, and VCPU #0 will signal all other VCPU threads a second time, these are harmless. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Native Linux KVM tool ===================== kvmtool is a lightweight tool for hosting KVM guests. As a pure virtualization tool it only supports guests using the same architecture, though it supports running 32-bit guests on those 64-bit architectures that allow this. From the original announcement email: ------------------------------------------------------- The goal of this tool is to provide a clean, from-scratch, lightweight KVM host tool implementation that can boot Linux guest images (just a hobby, won't be big and professional like QEMU) with no BIOS dependencies and with only the minimal amount of legacy device emulation. It's great as a learning tool if you want to get your feet wet in virtualization land: it's only 5 KLOC of clean C code that can already boot a guest Linux image. Right now it can boot a Linux image and provide you output via a serial console, over the host terminal, i.e. you can use it to boot a guest Linux image in a terminal or over ssh and log into the guest without much guest or host side setup work needed. -------------------------- This is the stand-alone version which does not live inside a Linux kernel tree. 1. To check it out, clone the main git repository: git clone git://git.kernel.org/pub/scm/linux/kernel/git/will/kvmtool.git 2. Compile the tool (for more elaborate instructions see INSTALL): cd kvmtool && make 3. Download a raw userspace image: wget http://wiki.qemu.org/download/linux-0.2.img.bz2 && bunzip2 linux-0.2.img.bz2 4. The guest kernel has to be built with the following configuration: - For the default console output: CONFIG_SERIAL_8250=y CONFIG_SERIAL_8250_CONSOLE=y - For running 32bit images on 64bit hosts: CONFIG_IA32_EMULATION=y - Proper FS options according to image FS (e.g. CONFIG_EXT2_FS, CONFIG_EXT4_FS). - For all virtio devices listed below: CONFIG_VIRTIO=y CONFIG_VIRTIO_RING=y CONFIG_VIRTIO_PCI=y - For virtio-blk devices (--disk, -d): CONFIG_VIRTIO_BLK=y - For virtio-net devices ([--network, -n] virtio): CONFIG_VIRTIO_NET=y - For virtio-9p devices (--virtio-9p): CONFIG_NET_9P=y CONFIG_NET_9P_VIRTIO=y CONFIG_9P_FS=y - For virtio-balloon device (--balloon): CONFIG_VIRTIO_BALLOON=y - For virtio-console device (--console virtio): CONFIG_VIRTIO_CONSOLE=y - For virtio-rng device (--rng): CONFIG_HW_RANDOM_VIRTIO=y - For vesa device (--sdl or --vnc): CONFIG_FB_VESA=y 5. And finally, launch the hypervisor: ./lkvm run --disk linux-0.2.img \ --kernel ../../arch/x86/boot/bzImage \ or sudo ./lkvm run --disk linux-0.2.img \ --kernel ../../arch/x86/boot/bzImage \ --network virtio The tool has been written by Pekka Enberg, Cyrill Gorcunov, Asias He, Sasha Levin and Prasad Joshi. Special thanks to Avi Kivity for his help on KVM internals and Ingo Molnar for all-around support and encouragement! See the following thread for original discussion for motivation of this project: http://thread.gmane.org/gmane.linux.kernel/962051/focus=962620 Contributing ------------ Please send patches for kvmtool to kvm@vger.kernel.org , in the usual git patch format. Include "kvmtool" in the mail subject.