gdb remote target of a guest VM fails to continue

[Chris J Arges]

[Impact]

Debugging guest VMs fail due to not building package with --enable debug.

[Test Case]

1) run qemu with the -s option
2) install qemu ddeb
3) gdb /usr/bin/qemu-system-x86_64
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
Reading symbols from /lib64/ld-linux-x86-64.so.2...Reading symbols from /usr/lib/debug//lib/x86_64-linux-gnu/ld-2.21.so...done.
done.
0x000000000052c7b5 in _start () from /lib64/ld-linux-x86-64.so.2
(gdb) c
Continuing.
Warning:
Cannot insert breakpoint -1.
Cannot access memory at address 0xbd260
Cannot insert breakpoint -6.
Temporarily disabling shared library breakpoints:
breakpoint #-6

[Fix]

Add --enable-debug debian/rules

[Chris J Arges (arges)]

I measured bootup times on an idle host by rebooting a VM and logging the same
event in dmesg 15 times. Before it took an average of 9.8934s w/ stdev of 0.32.
After installing the new version it took 9.8159s w/ stdev of 0.34.

In addition before the total size of /usr/bin/qemu-system-* was 136878083 after
it was 135008515.

So it seems that size of binaries decreases, while enabling more functionality.
In addition, boot times seem comparable but it isn't definitively slower or
faster.

[Chris J Arges (arges)]

Test packages available here:
https://launchpad.net/~arges/+archive/ubuntu/packaging

[Chris J Arges (arges)]

One thing to note going through the config file. With --enable-debug we no longer use -O2 for CFLAGS.

[Chris J Arges (arges)]

Potentially related:
https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/901944