Cannot see I/O Registers in Debug mode
I had same situation with st-link v2 and STM32F103C8. So, situation resolved by:
1. Select device STM32F103C8 in MAIN_MENU/Project/Properties -> C/C++Build -> Settings -> Devices;
2. Rename file STM32F103xx.svd to STM32F103C8.svd and copy last to project directory (/home/my_username_dir/workspace/project_directory/STM32F103C8.svd).