feat(virtio-pmem): add API requests parsing to Firecracker

Add /pmem/id PUT request for virtio-pmem configuration.
Add corresponding metrics.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

src/firecracker/src/api_server/parsed_request.rs

@@ -24,6 +24,7 @@ use super::request::machine_configuration::{
 use super::request::metrics::parse_put_metrics;
 use super::request::mmds::{parse_get_mmds, parse_patch_mmds, parse_put_mmds};
 use super::request::net::{parse_patch_net, parse_put_net};
+use super::request::pmem::parse_put_pmem;
 use super::request::snapshot::{parse_patch_vm_state, parse_put_snapshot};
 use super::request::version::parse_get_version;
 use super::request::vsock::parse_put_vsock;
@@ -90,6 +91,7 @@ impl TryFrom<&Request> for ParsedRequest {
             (Method::Put, "boot-source", Some(body)) => parse_put_boot_source(body),
             (Method::Put, "cpu-config", Some(body)) => parse_put_cpu_config(body),
             (Method::Put, "drives", Some(body)) => parse_put_drive(body, path_tokens.next()),
+            (Method::Put, "pmem", Some(body)) => parse_put_pmem(body, path_tokens.next()),
             (Method::Put, "logger", Some(body)) => parse_put_logger(body),
             (Method::Put, "serial", Some(body)) => parse_put_serial(body),
             (Method::Put, "machine-config", Some(body)) => parse_put_machine_config(body),

src/firecracker/src/api_server/request/mod.rs

@@ -13,6 +13,7 @@ pub mod machine_configuration;
 pub mod metrics;
 pub mod mmds;
 pub mod net;
+pub mod pmem;
 pub mod serial;
 pub mod snapshot;
 pub mod version;

src/firecracker/src/api_server/request/pmem.rs

@@ -0,0 +1,75 @@
+// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+use vmm::logger::{IncMetric, METRICS};
+use vmm::rpc_interface::VmmAction;
+use vmm::vmm_config::pmem::PmemConfig;
+
+use super::super::parsed_request::{ParsedRequest, RequestError, checked_id};
+use super::{Body, StatusCode};
+
+pub(crate) fn parse_put_pmem(
+    body: &Body,
+    id_from_path: Option<&str>,
+) -> Result<ParsedRequest, RequestError> {
+    METRICS.put_api_requests.pmem_count.inc();
+    let id = if let Some(id) = id_from_path {
+        checked_id(id)?
+    } else {
+        METRICS.put_api_requests.pmem_fails.inc();
+        return Err(RequestError::EmptyID);
+    };
+
+    let device_cfg = serde_json::from_slice::<PmemConfig>(body.raw()).inspect_err(|_| {
+        METRICS.put_api_requests.pmem_fails.inc();
+    })?;
+
+    if id != device_cfg.id {
+        METRICS.put_api_requests.pmem_fails.inc();
+        Err(RequestError::Generic(
+            StatusCode::BadRequest,
+            "The id from the path does not match the id from the body!".to_string(),
+        ))
+    } else {
+        Ok(ParsedRequest::new_sync(VmmAction::InsertPmemDevice(
+            device_cfg,
+        )))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::api_server::parsed_request::tests::vmm_action_from_request;
+
+    #[test]
+    fn test_parse_put_pmem_request() {
+        parse_put_pmem(&Body::new("invalid_payload"), None).unwrap_err();
+        parse_put_pmem(&Body::new("invalid_payload"), Some("id")).unwrap_err();
+
+        let body = r#"{
+            "id": "bar",
+        }"#;
+        parse_put_pmem(&Body::new(body), Some("1")).unwrap_err();
+        let body = r#"{
+            "foo": "1",
+        }"#;
+        parse_put_pmem(&Body::new(body), Some("1")).unwrap_err();
+
+        let body = r#"{
+            "id": "1000",
+            "path_on_host": "dummy",
+            "root_device": true,
+            "read_only": true
+        }"#;
+        let r = vmm_action_from_request(parse_put_pmem(&Body::new(body), Some("1000")).unwrap());
+
+        let expected_config = PmemConfig {
+            id: "1000".to_string(),
+            path_on_host: "dummy".to_string(),
+            root_device: true,
+            read_only: true,
+        };
+        assert_eq!(r, VmmAction::InsertPmemDevice(expected_config));
+    }
+}

src/vmm/src/logger/metrics.rs

@@ -415,6 +415,10 @@ pub struct PutRequestsMetrics {
     pub vsock_count: SharedIncMetric,
     /// Number of failures in creating a vsock device.
     pub vsock_fails: SharedIncMetric,
+    /// Number of PUTs triggering a pmem attach.
+    pub pmem_count: SharedIncMetric,
+    /// Number of failures in attaching a pmem device.
+    pub pmem_fails: SharedIncMetric,
     /// Number of PUTs to /serial
     pub serial_count: SharedIncMetric,
     /// Number of failed PUTs to /serial
@@ -444,6 +448,8 @@ impl PutRequestsMetrics {
             mmds_fails: SharedIncMetric::new(),
             vsock_count: SharedIncMetric::new(),
             vsock_fails: SharedIncMetric::new(),
+            pmem_count: SharedIncMetric::new(),
+            pmem_fails: SharedIncMetric::new(),
             serial_count: SharedIncMetric::new(),
             serial_fails: SharedIncMetric::new(),
         }

tests/host_tools/fcmetrics.py

@@ -223,6 +223,8 @@ def validate_fc_metrics(metrics):
             "mmds_fails",
             "vsock_count",
             "vsock_fails",
+            "pmem_count",
+            "pmem_fails",
             "serial_count",
             "serial_fails",
         ],