add yaml serializer for snapshot meta data

[schumilo]

QEMU-Nyx creates and stores several files representing the serialized root snapshot in the configured snapshot directory. With this PR, a YAML file is also created, in which specific snapshot metadata is stored in addition to the binary snapshot files. The file will not be used by QEMU-Nyx anymore after it has been created. However, the front end can easily read the YAML file without having to parse the binary file format used by QEMU-Nyx.
This PR is a WIP and lacks support for in-memory root snapshots.

Below is an example of the output YAML file:

---
process_trace:
    pt_ip_filter_configured_0: true
    pt_ip_filter_configured_1: false
    pt_ip_filter_configured_2: false
    pt_ip_filter_configured_3: false
    pt_ip_filter_0: [0x1000, 0xfffff000]
    pt_ip_filter_1: [0x0, 0x0]
    pt_ip_filter_2: [0x0, 0x0]
    pt_ip_filter_3: [0x0, 0x0]
    parent_cr3: 0x1fa2c000
    disassembler_word_width: 0x40
    mem_mode: 0x4
    pt_trace_mode: true

input_buffer:
    input_buffer_vaddr: 0xf7ff6000
    protect_input_buffer: false
    input_buffer_size: 0x1000

capabilites:
    cap_timeout_detection: false
    cap_only_reload_mode: false
    cap_compile_time_tracing: false
    cap_ijon_tracing: true
    cap_cr3: true
    cap_compile_time_tracing_buffer_vaddr: 0x0
    cap_ijon_tracing_buffer_vaddr: 0xf7ff8000
    cap_coverage_bitmap_size: 0x10000

...

[schumilo]

@Wenzel Feedback would be greatly appreciated!

[schumilo]

Current yaml file format:

---
qemu_nyx:
    nyx_serialized_state_version: 0x1

processor_trace:
    pt_ip_filter_configured_0: true
    pt_ip_filter_configured_1: false
    pt_ip_filter_configured_2: false
    pt_ip_filter_configured_3: false
    pt_ip_filter_0: [0x1000, 0xfffff000]
    pt_ip_filter_1: [0x0, 0x0]
    pt_ip_filter_2: [0x0, 0x0]
    pt_ip_filter_3: [0x0, 0x0]
    parent_cr3: 0x1fa2b000
    mem_mode: "mm_64_l4_paging"
    pt_trace_mode: true

input_buffer:
    input_buffer_vaddr: 0xf7ff6000
    protect_input_buffer: false
    input_buffer_size: 0x1000

capabilites:
    cap_timeout_detection: false
    cap_only_reload_mode: false
    cap_compile_time_tracing: false
    cap_ijon_tracing: true
    cap_cr3: true
    cap_compile_time_tracing_buffer_vaddr: 0x0
    cap_ijon_tracing_buffer_vaddr: 0xf7ff8000
    cap_coverage_bitmap_size: 0x10000

...```

[Wenzel]

@schumilo sorry, i replied on the ither issue, but i was discussibg your proposal as well

IntelLabs/kafl.qemu#10 (comment)

[Wenzel]

oh my bad, you added a reply and i missed the notification

i'll have a look

[Wenzel]

Facing an internal GCC 11 bug here, but it's not related to your code don't worry.
Can't build QEMU right now.