Fix: move snapshot into module under vmm

Moved `snapshot` into module under `vmm`. Many of these crates
could be modules and the number of crates in our workspace
greatly reduced. This reduces the binary size and makes the
workspace more ergonomic.

Signed-off-by: Ashwin Ginoria <aginoria@amazon.com>

Author: Ashwin Ginoria

Cargo.lock

@@ -25,7 +25,6 @@ thiserror = "1.0.53"
 timerfd = "1.5.0"
 
 seccompiler = { path = "../seccompiler" }
-snapshot = { path = "../snapshot" }
 utils = { path = "../utils" }
 vmm = { path = "../vmm" }
 
@@ -45,7 +44,7 @@ serde = { version = "1.0.193" }
 serde_json = "1.0.109"
 
 [features]
-tracing = ["log-instrument", "seccompiler/tracing", "snapshot/tracing", "utils/tracing", "vmm/tracing"]
+tracing = ["log-instrument", "seccompiler/tracing", "utils/tracing", "vmm/tracing"]
 
 [[example]]
 name = "uffd_malicious_handler"

src/firecracker/Cargo.toml

@@ -17,7 +17,6 @@ use api_server_adapter::ApiServerError;
 use event_manager::SubscriberOps;
 use seccomp::FilterError;
 use seccompiler::BpfThreadMap;
-use snapshot::{Error as SnapshotError, Snapshot};
 use utils::arg_parser::{ArgParser, Argument};
 use utils::terminal::Terminal;
 use utils::validators::validate_instance_id;
@@ -28,6 +27,7 @@ use vmm::logger::{
 use vmm::persist::SNAPSHOT_VERSION;
 use vmm::resources::VmResources;
 use vmm::signal_handler::register_signal_handlers;
+use vmm::snapshot::{Error as SnapshotError, Snapshot};
 use vmm::vmm_config::instance_info::{InstanceInfo, VmState};
 use vmm::vmm_config::metrics::{init_metrics, MetricsConfig, MetricsConfigError};
 use vmm::{EventManager, FcExitCode, HTTP_MAX_PAYLOAD_SIZE};

src/firecracker/src/main.rs

@@ -15,7 +15,6 @@ displaydoc = "0.2.4"
 libc = "0.2.151"
 log-instrument = { path = "../log-instrument", optional = true }
 semver = "1.0.20"
-snapshot = { path = "../snapshot" }
 thiserror = "1.0.53"
 vmm = { path = "../vmm" }
 

src/snapshot-editor/Cargo.toml

@@ -6,8 +6,8 @@ use std::path::PathBuf;
 
 use fc_utils::u64_to_usize;
 use semver::Version;
-use snapshot::Snapshot;
 use vmm::persist::MicrovmState;
+use vmm::snapshot::Snapshot;
 
 // Some errors are only used in aarch64 code
 #[allow(unused)]
@@ -18,11 +18,11 @@ pub enum UtilsError {
     /// Can not retrieve metadata for snapshot file: {0}
     VmStateFileMeta(std::io::Error),
     /// Can not load snapshot: {0}
-    VmStateLoad(snapshot::Error),
+    VmStateLoad(vmm::snapshot::Error),
     /// Can not open output file: {0}
     OutputFileOpen(std::io::Error),
     /// Can not save snapshot: {0}
-    VmStateSave(snapshot::Error),
+    VmStateSave(vmm::snapshot::Error),
 }
 
 #[allow(unused)]

src/snapshot-editor/src/utils.rs

@@ -36,9 +36,9 @@ base64 = "0.21.0"
 bincode = "1.2.1"
 micro_http = { git = "https://github.com/firecracker-microvm/micro-http" }
 log-instrument = { path = "../log-instrument", optional = true }
+crc64 = "2.0.0"
 
 seccompiler = { path = "../seccompiler" }
-snapshot = { path = "../snapshot"}
 utils = { path = "../utils" }
 smallvec = "1.11.2"
 

src/snapshot/Cargo.toml

@@ -478,9 +478,8 @@ reg_data_array!([u8; 256], 256);
 
 #[cfg(test)]
 mod tests {
-    use snapshot::Snapshot;
-
     use super::*;
+    use crate::snapshot::Snapshot;
 
     #[test]
     fn test_reg_size() {

src/vmm/Cargo.toml

@@ -18,7 +18,6 @@ use linux_loader::loader::elf::Elf as Loader;
 use linux_loader::loader::pe::PE as Loader;
 use linux_loader::loader::KernelLoader;
 use seccompiler::BpfThreadMap;
-use snapshot::Persist;
 use userfaultfd::Uffd;
 use utils::eventfd::EventFd;
 use utils::time::TimestampUs;
@@ -53,6 +52,7 @@ use crate::devices::BusDevice;
 use crate::logger::{debug, error};
 use crate::persist::{MicrovmState, MicrovmStateError};
 use crate::resources::VmResources;
+use crate::snapshot::Persist;
 use crate::vmm_config::boot_source::BootConfig;
 use crate::vmm_config::drive::BlockDeviceType;
 use crate::vmm_config::instance_info::InstanceInfo;

src/vmm/src/arch/aarch64/regs.rs

@@ -10,7 +10,6 @@ use event_manager::{MutEventSubscriber, SubscriberOps};
 use kvm_ioctls::VmFd;
 use log::{error, warn};
 use serde::{Deserialize, Serialize};
-use snapshot::Persist;
 use vm_allocator::AllocPolicy;
 
 use super::mmio::*;
@@ -45,6 +44,7 @@ use crate::devices::virtio::vsock::{
 use crate::devices::virtio::{TYPE_BALLOON, TYPE_BLOCK, TYPE_NET, TYPE_RNG};
 use crate::mmds::data_store::MmdsVersion;
 use crate::resources::VmResources;
+use crate::snapshot::Persist;
 use crate::vmm_config::mmds::MmdsConfigError;
 use crate::vstate::memory::GuestMemoryMmap;
 use crate::EventManager;
@@ -646,13 +646,13 @@ impl<'a> Persist<'a> for MMIODeviceManager {
 
 #[cfg(test)]
 mod tests {
-    use snapshot::Snapshot;
     use utils::tempfile::TempFile;
 
     use super::*;
     use crate::builder::tests::*;
     use crate::devices::virtio::block_common::CacheType;
     use crate::resources::VmmConfig;
+    use crate::snapshot::Snapshot;
     use crate::vmm_config::balloon::BalloonDeviceConfig;
     use crate::vmm_config::entropy::EntropyDeviceConfig;
     use crate::vmm_config::net::NetworkInterfaceConfig;