swap/
lib.rs

1// Copyright 2022 The ChromiumOS Authors
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! crate for the vmm-swap feature.
6
7#![deny(missing_docs)]
8
9cfg_if::cfg_if! {
10    if #[cfg(all(unix, feature = "enable"))] {
11        mod controller;
12        mod file;
13        mod file_truncator;
14        mod pagesize;
15        mod present_list;
16        // this is public only for integration tests.
17        pub mod page_handler;
18        mod processes;
19        mod staging;
20        mod uffd_list;
21        // this is public only for integration tests.
22        pub mod userfaultfd;
23        // this is public only for integration tests.
24        pub mod worker;
25
26        pub use crate::controller::SwapDeviceHelper;
27        pub use crate::controller::PrepareFork;
28        pub use crate::controller::SwapController;
29        pub use crate::controller::SwapDeviceUffdSender;
30    }
31}
32
33use serde::Deserialize;
34use serde::Serialize;
35
36/// Current state of vmm-swap.
37///
38/// This should not contain fields but be a plain enum because this will be displayed to user using
39/// `serde_json` crate.
40#[repr(C)]
41#[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
42pub enum SwapState {
43    /// vmm-swap is ready. userfaultfd is disabled until vmm-swap is enabled.
44    Ready = 0,
45    /// swap out failed.
46    Failed = 1,
47    /// Pages in guest memory are moved to the staging memory.
48    Pending = 2,
49    /// Trimming staging memory.
50    TrimInProgress = 3,
51    /// swap-out is in progress.
52    SwapOutInProgress = 4,
53    /// swap out succeeded.
54    Active = 5,
55    /// swap-in is in progress.
56    SwapInInProgress = 6,
57}
58
59/// Latency and number of pages of swap operations (move to staging, swap out, swap in).
60///
61/// The meaning of `StateTransition` depends on `State`.
62///
63/// | `State`             | `StateTransition`                            |
64/// |---------------------|----------------------------------------------|
65/// | `Ready`             | empty or transition record of `swap disable` |
66/// | `Pending`           | transition record of `swap enable`           |
67/// | `SwapOutInProgress` | transition record of `swap out`              |
68/// | `Active`            | transition record of `swap out`              |
69/// | `SwapInInProgress`  | transition record of `swap disable`          |
70/// | `Failed`            | empty                                        |
71#[repr(C)]
72#[derive(Serialize, Deserialize, Debug, Clone, Copy, Default)]
73pub struct SwapStateTransition {
74    /// The number of pages moved for the state transition.
75    pub pages: u64,
76    /// Time taken for the state transition.
77    pub time_ms: u64,
78}
79
80/// Current metrics of vmm-swap.
81///
82/// This is only available while vmm-swap is enabled.
83#[repr(C)]
84#[derive(Serialize, Deserialize, Debug, Clone, Copy, Default)]
85pub struct SwapMetrics {
86    /// count of pages on RAM.
87    pub resident_pages: u64,
88    /// count of pages copied from the vmm-swap file.
89    pub copied_from_file_pages: u64,
90    /// count of pages copied from the staging memory.
91    pub copied_from_staging_pages: u64,
92    /// count of pages initialized with zero.
93    pub zeroed_pages: u64,
94    /// count of pages which were already initialized on page faults. This can happen when several
95    /// threads/processes access the uninitialized/removed page at the same time.
96    pub redundant_pages: u64,
97    /// count of pages in staging memory.
98    pub staging_pages: u64,
99    /// count of pages in swap files.
100    pub swap_pages: u64,
101}
102
103/// The response to `crosvm swap status` command.
104#[repr(C)]
105#[derive(Serialize, Deserialize, Debug, Clone, Copy)]
106pub struct SwapStatus {
107    /// Current vmm-swap [SwapState].
108    pub state: SwapState,
109    /// Current [SwapMetrics] of vmm-swap.
110    pub metrics: SwapMetrics,
111    /// Latency and number of pages for current [SwapState]. See [SwapStateTransition] for details.
112    pub state_transition: SwapStateTransition,
113}
114
115impl SwapStatus {
116    /// Creates dummy [SwapStatus].
117    pub fn dummy() -> Self {
118        SwapStatus {
119            state: SwapState::Pending,
120            metrics: SwapMetrics::default(),
121            state_transition: SwapStateTransition::default(),
122        }
123    }
124}
swap/lib.rs

swap/
lib.rs
