Thank you, Wei. I have solved it. The error accured as 'ctx' was not correctly initailized.
On Tue, May 15, 2018 at 1:11 AM Wei Liu <[email protected]> wrote: > On Sat, May 12, 2018 at 08:55:46PM +0800, Kun Cheng wrote: > > Hello Xen devs, > > > > I'm learning code in xen-4.10.0/tools/xl to find out how to program with > > libxl. > > > > I've trying to use libxenlight.so (compiled and installed from xen 4.10.0 > > source code) to control my vms from my own code until I met this issue. > > Now my test code follows xl_vmmcontrol.c and tries to create a VM from > its > > config file (file can be used to successfully create a vm with 'xl > create'). > > > > My Xen make is successful and I can use 'xl' to manage all vms. > > > > When I test my own code, I got such an error in dmesg" > > > > test[16678]: segfault at 18 ip 00007f69fa6526ad sp 00007ffe1eadedf0 > error 4 > > in libxenlight.so.4.10.0[7f69fa61a000+bc000] in dmesg > > > > and also segmentation fault in my terminal. > > > > I dumped my debugging info, hoping could give everyone some clue. > > > > FYI, my program was compiled with: > > > > gcc -m64 -pthread -std=gnu99 -g xl_executor.c xl_parse.c xl_utils.c > > xl_nic.c -lxenlight -lxlutil -lxentoollog -lyajl -o test > > > > where xl_executor.c is my code of creating a vm, all other c file are > > copied from tools/xl/ > > > > GDB bebugging info: > > > > Breakpoint 3, parse_config_data (config_source=0x7fffffffe360 > > "/data/chengkun/vms/vm4/vm4.cfg", > > config_data=0x6155f0 "# ", '=' <repeats 69 times>, "\n# Example HVM > > guest configuration\n# ", '=' <repeats 69 times>, "\n#\n# This is a > fairly > > m"..., config_len=1543, > > d_config=0x7fffffffdde0) at xl_parse.c:993 > > > > 993 if (libxl_cpu_bitmap_alloc(ctx, &b_info->avail_vcpus, l)) { > > > > One possibility: you didn't follow the convention of using libxl types, > which means you get memory corruption all over the place. > > See libxl.h:L490 for more information. > > But for a more likely explanation, see below. > > > gic_version = LIBXL_GIC_VERSION_DEFAULT, vuart = > > LIBXL_VUART_TYPE_UNKNOWN}, altp2m = LIBXL_ALTP2M_MODE_DISABLED} > > > > (gdb) p ctx > > $5 = (libxl_ctx *) 0x0 > > A NULL pointer? See xl.c:xl_ctx_alloc. > > Wei. >
_______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
