You just have to specify a PID of quemu process, RAM size assiciated with a VM and a pattern to scan :)
[root@rapier-v focs_vm]# ./target/release/focs_vm -h
focs_vm 0.1.0
Kamil Stawiarski kamil@ora-600.pl
Tool for finding patterns in memory
USAGE:
focs_vm [OPTIONS] --memory-size <MEMORY_SIZE> --pid <PID> --pattern <PATTERN>
OPTIONS:
-b, --buffer <BUFFER> Size of a buffer to print [default: 256]
-h, --help Print help information
-m, --memory-size <MEMORY_SIZE> Size of memory segment to scan
-p, --pid <PID> PID of the process to scan
-p, --pattern <PATTERN> Pattern in hex to search for
-P, --parallel <PARALLEL> Parallel degree [default: 4]
-V, --version Print version information
[root@rapier-v focs_vm]# ./target/release/focs_vm --pid 10922 --memory-size $((6291456*1024)) --pattern '72 6f 6f 74 3a 24 36 24' -P 4
Found map at the start offset = 140324162764800 end offset = 140330605215744
Scanning memory from 140324162764800 to 140325773377536 in a separate thread
Scanning memory from 140325773377536 to 140327383990272 in a separate thread
Scanning memory from 140328994603008 to 140330605215744 in a separate thread
Scanning memory from 140327383990272 to 140328994603008 in a separate thread
Scanned: 6 %
Position of pattern found at 140324287193088
Length: 256 (0x100) bytes
0000: 72 6f 6f 74 3a 24 36 24 75 78 6b 51 43 42 79 4d root:$6$uxkQCByM
0010: 62 50 66 35 30 74 73 35 24 72 64 67 73 46 57 47 bPf50ts5$rdgsFWG
0020: 4f 57 66 57 77 75 6f 62 2e 58 32 6d 7a 6b 35 55 OWfWwuob.X2mzk5U
0030: 42 6b 51 68 46 63 47 56 63 59 44 75 55 71 62 72 BkQhFcGVcYDuUqbr
0040: 79 33 5a 33 42 70 36 59 67 32 4b 75 50 77 56 61 y3Z3Bp6Yg2KuPwVa
0050: 36 43 61 65 4d 74 61 48 75 6e 4c 54 6c 6d 4e 61 6CaeMtaHunLTlmNa
0060: 71 6e 76 34 76 35 46 4b 53 48 54 54 33 32 31 3a qnv4v5FKSHTT321:
0070: 31 39 32 36 31 3a 30 3a 39 39 39 39 39 3a 37 3a 19261:0:99999:7:
0080: 3a 3a 0a 62 69 6e 3a 2a 3a 31 38 33 30 37 3a 30 ::.bin:*:18307:0
0090: 3a 39 39 39 39 39 3a 37 3a 3a 3a 0a 64 61 65 6d :99999:7:::.daem
00a0: 6f 6e 3a 2a 3a 31 38 33 30 37 3a 30 3a 39 39 39 on:*:18307:0:999
00b0: 39 39 3a 37 3a 3a 3a 0a 61 64 6d 3a 2a 3a 31 38 99:7:::.adm:*:18
00c0: 33 30 37 3a 30 3a 39 39 39 39 39 3a 37 3a 3a 3a 307:0:99999:7:::
00d0: 0a 6c 70 3a 2a 3a 31 38 33 30 37 3a 30 3a 39 39 .lp:*:18307:0:99
00e0: 39 39 39 3a 37 3a 3a 3a 0a 73 79 6e 63 3a 2a 3a 999:7:::.sync:*:
00f0: 31 38 33 30 37 3a 30 3a 39 39 39 39 39 3a 37 3a 18307:0:99999:7:
Scanned: 100 %