On 12/04/2017 10:59, Huang Yong wrote:
> When guest os crash, there is no way to notify qemu on the host quickly
> (within 1s), and it is
> not convenient for libvirt management. We suggest to register a IO port (with
> specific addr) when
> qemu process be launched, on the other hand, a linux module which is
> comprised of kprobe hooks will
> be inserted in VM. When guest linux os crash, kprobe hooks write IO port
> mentioned above to notify
> qemu. With this approach, VM management component (e.g.libvirt) can monitor
> VM running state in time.
QEMU already supports this using the "pvpanic" device. There is also a
driver in drivers/platform/x86/pvpanic.c.
Paolo
> Signed-off-by: Huang Yong<huang.y...@zte.com.cn>
> ---
> vl.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/vl.c b/vl.c
> index 0b4ed52..2760c52 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -129,9 +129,12 @@ int main(int argc, char **argv)
> #include "sysemu/replay.h"
> #include "qapi/qmp/qerror.h"
> #include "sysemu/iothread.h"
> +#include "exec/memory.h"
> +#include "qapi/error.h"
>
> #define MAX_VIRTIO_CONSOLES 1
> #define MAX_SCLP_CONSOLES 1
> +#define CRASH_IO_PORT (0xcff0)
>
> static const char *data_dir[16];
> static int data_dir_idx;
> @@ -2939,6 +2942,37 @@ static int qemu_read_default_config_file(void)
> return 0;
> }
>
> +static MemoryRegion crash_io;
> +
> +static uint64_t crash_io_read(void *opaque, hwaddr addr,
> + unsigned int size)
> +{
> + return 0;
> +}
> +
> +static void crash_io_write(void *opaque, hwaddr addr,
> + uint64_t value, unsigned int size)
> +{
> + qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE,
> + false, NULL, &error_abort);
> +}
> +
> +static const MemoryRegionOps crash_io_ops = {
> + .read = crash_io_read,
> + .write = crash_io_write,
> + .endianness = DEVICE_LITTLE_ENDIAN,
> +};
> +
> +static void init_crash_port(int port)
> +{
> + int addr = port;
> + MemoryRegion *system_io = get_system_io();
> +
> + memory_region_init_io(&crash_io, NULL, &crash_io_ops,
> + NULL, "crash_event_port", 2);
> + memory_region_add_subregion(system_io, addr, &crash_io);
> +}
> +
> int main(int argc, char **argv, char **envp)
> {
> int i;
> @@ -4706,6 +4740,7 @@ int main(int argc, char **argv, char **envp)
>
> os_setup_post();
>
> + init_crash_port(CRASH_IO_PORT);
> main_loop();
> replay_disable_events();
> iothread_stop_all();
>
