vmm: Add "add-disk" to the API

Add the HTTP and internal API entry points for adding disks at runtime.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vmm/src/api/http.rs

@@ -4,7 +4,8 @@
 //
 
 use crate::api::http_endpoint::{
-    VmActionHandler, VmAddDevice, VmCreate, VmInfo, VmRemoveDevice, VmResize, VmmPing, VmmShutdown,
+    VmActionHandler, VmAddDevice, VmAddDisk, VmCreate, VmInfo, VmRemoveDevice, VmResize, VmmPing,
+    VmmShutdown,
 };
 use crate::api::{ApiRequest, VmAction};
 use crate::seccomp_filters::{get_seccomp_filter, Thread};
@@ -66,6 +67,7 @@ lazy_static! {
         r.routes.insert(endpoint!("/vm.resize"), Box::new(VmResize {}));
         r.routes.insert(endpoint!("/vm.add-device"), Box::new(VmAddDevice {}));
         r.routes.insert(endpoint!("/vm.remove-device"), Box::new(VmRemoveDevice {}));
+        r.routes.insert(endpoint!("/vm.add-disk"), Box::new(VmAddDisk {}));
 
         r
     };

vmm/src/api/http_endpoint.rs

@@ -5,9 +5,10 @@
 
 use crate::api::http::EndpointHandler;
 use crate::api::{
-    vm_add_device, vm_boot, vm_create, vm_delete, vm_info, vm_pause, vm_reboot, vm_remove_device,
-    vm_resize, vm_resume, vm_shutdown, vmm_ping, vmm_shutdown, ApiError, ApiRequest, ApiResult,
-    DeviceConfig, VmAction, VmConfig, VmRemoveDeviceData, VmResizeData,
+    vm_add_device, vm_add_disk, vm_boot, vm_create, vm_delete, vm_info, vm_pause, vm_reboot,
+    vm_remove_device, vm_resize, vm_resume, vm_shutdown, vmm_ping, vmm_shutdown, ApiError,
+    ApiRequest, ApiResult, DeviceConfig, DiskConfig, VmAction, VmConfig, VmRemoveDeviceData,
+    VmResizeData,
 };
 use micro_http::{Body, Method, Request, Response, StatusCode, Version};
 use serde_json::Error as SerdeError;
@@ -59,6 +60,9 @@ pub enum HttpError {
 
     /// Could not handle VMM ping
     VmmPing(ApiError),
+
+    /// Could not add a disk to a VM
+    VmAddDisk(ApiError),
 }
 
 fn error_response(error: HttpError, status: StatusCode) -> Response {
@@ -352,3 +356,42 @@ impl EndpointHandler for VmRemoveDevice {
         }
     }
 }
+
+// /api/v1/vm.add-disk handler
+pub struct VmAddDisk {}
+
+impl EndpointHandler for VmAddDisk {
+    fn handle_request(
+        &self,
+        req: &Request,
+        api_notifier: EventFd,
+        api_sender: Sender<ApiRequest>,
+    ) -> Response {
+        match req.method() {
+            Method::Put => {
+                match &req.body {
+                    Some(body) => {
+                        // Deserialize into a DiskConfig
+                        let vm_add_disk_data: DiskConfig = match serde_json::from_slice(body.raw())
+                            .map_err(HttpError::SerdeJsonDeserialize)
+                        {
+                            Ok(config) => config,
+                            Err(e) => return error_response(e, StatusCode::BadRequest),
+                        };
+
+                        // Call vm_add_device()
+                        match vm_add_disk(api_notifier, api_sender, Arc::new(vm_add_disk_data))
+                            .map_err(HttpError::VmAddDisk)
+                        {
+                            Ok(_) => Response::new(Version::Http11, StatusCode::NoContent),
+                            Err(e) => error_response(e, StatusCode::InternalServerError),
+                        }
+                    }
+
+                    None => Response::new(Version::Http11, StatusCode::BadRequest),
+                }
+            }
+            _ => Response::new(Version::Http11, StatusCode::BadRequest),
+        }
+    }
+}

vmm/src/api/mod.rs

@@ -36,7 +36,7 @@ pub use self::http::start_http_thread;
 pub mod http;
 pub mod http_endpoint;
 
-use crate::config::{DeviceConfig, VmConfig};
+use crate::config::{DeviceConfig, DiskConfig, VmConfig};
 use crate::vm::{Error as VmError, VmState};
 use std::io;
 use std::sync::mpsc::{channel, RecvError, SendError, Sender};
@@ -111,6 +111,9 @@ pub enum ApiError {
 
     /// Cannot apply seccomp filter
     ApplySeccompFilter(seccomp::Error),
+
+    /// The device could not be added to the VM.
+    VmAddDisk(VmError),
 }
 pub type ApiResult<T> = std::result::Result<T, ApiError>;
 
@@ -204,6 +207,9 @@ pub enum ApiRequest {
 
     /// Remove a device from the VM.
     VmRemoveDevice(Arc<VmRemoveDeviceData>, Sender<ApiResponse>),
+
+    /// Add a disk to the VM.
+    VmAddDisk(Arc<DiskConfig>, Sender<ApiResponse>),
 }
 
 pub fn vm_create(
@@ -392,3 +398,21 @@ pub fn vm_remove_device(
 
     Ok(())
 }
+
+pub fn vm_add_disk(
+    api_evt: EventFd,
+    api_sender: Sender<ApiRequest>,
+    data: Arc<DiskConfig>,
+) -> ApiResult<()> {
+    let (response_sender, response_receiver) = channel();
+
+    // Send the VM add-disk request.
+    api_sender
+        .send(ApiRequest::VmAddDisk(data, response_sender))
+        .map_err(ApiError::RequestSend)?;
+    api_evt.write(1).map_err(ApiError::EventFdWrite)?;
+
+    response_receiver.recv().map_err(ApiError::ResponseRecv)??;
+
+    Ok(())
+}

vmm/src/lib.rs

@@ -16,7 +16,7 @@ extern crate tempfile;
 extern crate vmm_sys_util;
 
 use crate::api::{ApiError, ApiRequest, ApiResponse, ApiResponsePayload, VmInfo, VmmPingResponse};
-use crate::config::{DeviceConfig, VmConfig};
+use crate::config::{DeviceConfig, DiskConfig, VmConfig};
 use crate::seccomp_filters::{get_seccomp_filter, Thread};
 use crate::vm::{Error as VmError, Vm, VmState};
 use libc::EFD_NONBLOCK;
@@ -415,6 +415,19 @@ impl Vmm {
         }
     }
 
+    fn vm_add_disk(&mut self, disk_cfg: DiskConfig) -> result::Result<(), VmError> {
+        if let Some(ref mut vm) = self.vm {
+            if let Err(e) = vm.add_disk(disk_cfg) {
+                error!("Error when adding new disk to the VM: {:?}", e);
+                Err(e)
+            } else {
+                Ok(())
+            }
+        } else {
+            Err(VmError::VmNotRunning)
+        }
+    }
+
     fn control_loop(&mut self, api_receiver: Arc<Receiver<ApiRequest>>) -> Result<()> {
         const EPOLL_EVENTS_LEN: usize = 100;
 
@@ -584,6 +597,13 @@ impl Vmm {
                                         .map(|_| ApiResponsePayload::Empty);
                                     sender.send(response).map_err(Error::ApiResponseSend)?;
                                 }
+                                ApiRequest::VmAddDisk(add_disk_data, sender) => {
+                                    let response = self
+                                        .vm_add_disk(add_disk_data.as_ref().clone())
+                                        .map_err(ApiError::VmAddDisk)
+                                        .map(|_| ApiResponsePayload::Empty);
+                                    sender.send(response).map_err(Error::ApiResponseSend)?;
+                                }
                             }
                         }
                     }