Hi, I maybe find a bug about qemu-kvm(version:2.8.1.1)
*Segmentation fault info:* Program received signal SIGSEGV, Segmentation fault. 0x00007f5469220607 in blk_has_pending_reqs (blk=0x7f54672a0032, is_write=false) at block/throttle-groups.c:184 184 return blkp->pending_reqs[is_write]; (gdb) bt #0 0x00007f5469220607 in blk_has_pending_reqs (blk=0x7f54672a0032, is_write=false) at block/throttle-groups.c:184 #1 0x00007f54692206a8 in next_throttle_token (blk=0x7f546b6cd120, is_write=false) at block/throttle-groups.c:207 #2 0x00007f5469220984 in throttle_group_co_io_limits_intercept (blk=0x7f546b6cd120, bytes=512, is_write=false) at block/throttle-groups.c:322 #3 0x00007f546920bc79 in blk_co_preadv (blk=0x7f546b6cd120, offset=0, bytes=512, qiov=0x7ffcc7355060, flags=0) at block/block-backend.c:815 #4 0x00007f546920bddf in blk_read_entry (opaque=0x7ffcc7355080) at block/block-backend.c:865 #5 0x00007f54692a00f0 in coroutine_trampoline (i0=-588050448, i1=32595) at util/coroutine-ucontext.c:79 #6 0x00007f5466f34cf0 in ?? () from /lib64/libc.so.6 #7 0x00007f53f27fa9e0 in ?? () #8 0x0000000000000000 in ?? () the way how to find the bug as follows: *1、attach and detach a disk for a while,the configure of the disk as follows* <disk device="disk" type="file"> <driver cache="none" io="native" name="qemu" type="raw" /> <source file="/mnt/sdb/wangjie-kvm/core/fk8b42zr-oz" /> <target bus="virtio" dev="vdb" /> <iotune> <read_iops_sec>3000</read_iops_sec> <write_iops_sec>3000</write_iops_sec> <read_bytes_sec>120000000</read_bytes_sec> <write_bytes_sec>120000000</write_bytes_sec> </iotune> </disk> *2、run below script for a while,the qemu process of VM will crash* ret=1 while [ $ret -ne 0 ]; do virsh attach-device i-clone203_rhel_7.3_64_guestosdev add-1.xml sleep 2 virsh detach-device i-clone203_rhel_7.3_64_guestosdev add-1.xml done