qemu_command_builder/args/
memory.rs

1use crate::parsers::ARG_MEMORY;
2use crate::parsers::DELIM_COMMA;
3use crate::qao;
4use crate::shell_string::ShellStringError;
5use crate::to_command::ToCommand;
6use bon::Builder;
7use proptest_derive::Arbitrary;
8use std::fmt::Display;
9use std::str::FromStr;
10
11const KEY_SIZE: &str = "size=";
12const KEY_SLOTS: &str = "slots=";
13const KEY_MAXMEM: &str = "maxmem=";
14
15/// Memory quantities accepted by QEMU `-m`.
16#[derive(Debug, Clone, Hash, Ord, PartialOrd, Eq, PartialEq, Arbitrary)]
17pub enum MemoryUnit {
18    Bytes(u64),
19    MegaBytes(u64),
20    GigaBytes(u64),
21}
22
23impl Display for MemoryUnit {
24    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
25        match self {
26            MemoryUnit::Bytes(amount) => {
27                write!(f, "{}", amount)
28            }
29            MemoryUnit::MegaBytes(amount) => {
30                write!(f, "{}M", amount)
31            }
32            MemoryUnit::GigaBytes(amount) => {
33                write!(f, "{}G", amount)
34            }
35        }
36    }
37}
38
39impl FromStr for MemoryUnit {
40    type Err = ShellStringError;
41
42    fn from_str(s: &str) -> Result<Self, Self::Err> {
43        parse_memory_unit(s).map_err(ShellStringError::new)
44    }
45}
46/// Sets guest startup RAM size to megs megabytes. Default is 128 MiB.
47/// Optionally, a suffix of "M" or "G" can be used to signify a value in
48/// megabytes or gigabytes respectively. Optional pair slots, maxmem
49/// could be used to set amount of hotpluggable memory slots and maximum
50/// amount of memory. Note that maxmem must be aligned to the page size.
51///
52/// For example, the following command-line sets the guest startup RAM
53/// size to 1GB, creates 3 slots to hotplug additional memory and sets
54/// the maximum memory the guest can reach to 4GB:
55///
56/// `-m 1G,slots=3,maxmem=4G`
57///
58/// If slots and maxmem are not specified, memory hotplug won't be
59/// enabled and the guest startup RAM will never increase.
60#[derive(Debug, Clone, Hash, Ord, PartialOrd, Eq, PartialEq, Builder, Arbitrary)]
61pub struct Memory {
62    /// Initial guest RAM size.
63    mem: MemoryUnit,
64    /// Number of hotpluggable memory slots.
65    slots: Option<usize>,
66    /// Maximum guest RAM size.
67    maxmem: Option<MemoryUnit>,
68}
69
70impl ToCommand for Memory {
71    fn command(&self) -> String {
72        ARG_MEMORY.to_string()
73    }
74    fn to_args(&self) -> Vec<String> {
75        let mut args = vec![];
76
77        args.push(self.mem.to_string());
78        qao!(self.slots, args, KEY_SLOTS);
79        qao!(&self.maxmem, args, KEY_MAXMEM);
80
81        vec![args.join(DELIM_COMMA)]
82    }
83}
84
85impl FromStr for Memory {
86    type Err = ShellStringError;
87
88    fn from_str(s: &str) -> Result<Self, Self::Err> {
89        parse_memory(s).map_err(ShellStringError::new)
90    }
91}
92
93fn parse_memory_unit(s: &str) -> Result<MemoryUnit, String> {
94    if let Some(amount) = s.strip_suffix('M') {
95        return Ok(MemoryUnit::MegaBytes(amount.parse::<u64>().map_err(|e| format!("invalid memory amount: {e}"))?));
96    }
97    if let Some(amount) = s.strip_suffix('G') {
98        return Ok(MemoryUnit::GigaBytes(amount.parse::<u64>().map_err(|e| format!("invalid memory amount: {e}"))?));
99    }
100
101    Ok(MemoryUnit::Bytes(s.parse::<u64>().map_err(|e| format!("invalid memory amount: {e}"))?))
102}
103
104fn parse_memory(s: &str) -> Result<Memory, String> {
105    let mut parts = s.split(DELIM_COMMA);
106    let first = parts.next().ok_or_else(|| "empty memory argument".to_string())?;
107
108    let mem = if let Some(value) = first.strip_prefix(KEY_SIZE) {
109        parse_memory_unit(value)?
110    } else if first.contains('=') {
111        return Err(format!("unsupported memory option: {first}"));
112    } else {
113        parse_memory_unit(first)?
114    };
115
116    let mut slots = None;
117    let mut maxmem = None;
118
119    for part in parts {
120        let (key, value) = part.split_once('=').ok_or_else(|| format!("invalid memory option: {part}"))?;
121        match key {
122            "size" => return Err("size= is only valid as the first -m component".to_string()),
123            "slots" => {
124                slots = Some(value.parse::<usize>().map_err(|e| format!("invalid slots value: {e}"))?);
125            }
126            "maxmem" => maxmem = Some(parse_memory_unit(value)?),
127            other => return Err(format!("unsupported memory option: {other}")),
128        }
129    }
130
131    Ok(Memory { mem, slots, maxmem })
132}
qemu_command_builder/args/memory.rs

qemu_command_builder/args/
memory.rs
