Merge pull request #69 from Vanient/main

docs/vmm/README.md

@@ -115,6 +115,33 @@ Jul 13 15:33:41 node vmm-sandboxer[3619585]: [2023-07-13T07:33:41.644358Z ERROR
 Jul 13 15:33:41 node vmm-sandboxer[3619585]: [2023-07-13T07:33:41.742550Z INFO  containerd_sandbox::rpc] shutdown sandbox 31e668050c2031e9e7243720eaa8264c42b0283007e419948689cac2badb71cd
 ```
 
+# Developer  Guide
+
+## Set up a debug console
+
+Kuasar vmm supports setting up a shell debug console by adding `task.debug` to kernel_params in config file, this requires the guest image to include /bin/bash.
+
+```toml
+[hypervisor]
+  kernel_params = "task.debug"
+```
+
+After starting pod, get the `vsock guest-cid` from vm process:
+
+```bash
+$ ps -ef | grep stratovirt | grep 5cbcf744949d8 
+/usr/bin/stratovirt -name sandbox-5cbcf744949d8500e7159d6bd1e3894211f475549c0be15d9c60d3c502c7ede3 ...
+-device vhost-vsock-pci,id=vsock-395568061,guest-cid=395568061,bus=pcie.0,addr=0x3,vhostfd=3 
+...
+```
+
+Then developers could enter the guest os debug console shell environment by:
+
+```bash
+# ncat --vsock <guest-cid> <debug-console>
+$ ncat --vsock 395568061 1025
+```
+
 # Note
 
 Please note that this guide only teach you how to build kuasar from source code, if you want to run the kuasar, cloud hypervisor and virtiofsd are also needed!

vmm/task/src/config.rs

@@ -19,6 +19,7 @@ use tokio::fs::read_to_string;
 
 const SHAREFS_TYPE: &str = "task.sharefs_type";
 const LOG_LEVEL: &str = "task.log_level";
+const TASK_DEBUG: &str = "task.debug";
 
 macro_rules! parse_cmdline {
     ($param:ident, $key:ident, $field:expr) => {
@@ -40,13 +41,15 @@ macro_rules! parse_cmdline {
 pub struct TaskConfig {
     pub(crate) sharefs_type: String,
     pub(crate) log_level: String,
+    pub(crate) debug: bool,
 }
 
 impl Default for TaskConfig {
     fn default() -> Self {
         TaskConfig {
             sharefs_type: "9p".to_string(),
             log_level: "info".to_string(),
+            debug: false,
         }
     }
 }
@@ -62,6 +65,7 @@ impl TaskConfig {
             let param: Vec<&str> = p.split('=').collect();
             parse_cmdline!(param, SHAREFS_TYPE, config.sharefs_type, String::from);
             parse_cmdline!(param, LOG_LEVEL, config.log_level, String::from);
+            parse_cmdline!(param, TASK_DEBUG, config.debug);
         }
         Ok(config)
     }

vmm/task/src/main.rs

@@ -147,8 +147,7 @@ async fn main() {
             warn!("sharefs_type should be either 9p or virtiofs");
         }
     }
-    // TODO reuse log_level temporarily, maybe we should have a config named by "task.debug"
-    if config.log_level == "debug" {
+    if config.debug {
         debug!("listen vsock port 1025 for debug console");
         if let Err(e) = listen_debug_console("vsock://-1:1025").await {
             error!("failed to listen debug console port, {:?}", e);