vmm-task:individually specify task.debug to enable debug_console

Before this we reuse "task.log_level" to determine whether listening debug
console port, which is not so good, individually specifying task.debug to
enable debug_console is needed.

Signed-off-by: Vanient <xiadanni1@huawei.com>

docs/vmm/how-to-run-kuasar-with-isulad-and-stratovirt.md

@@ -65,7 +65,7 @@ After installation, you will find the required files in the specified path
 ## Build and configure iSulad
 
 [iSulad](https://gitee.com/openeuler/iSulad) supports Kuasar with its dev-sandbox branch at the moment. For building iSulad from scratch, please refer to [iSulad build guide](https://gitee.com/openeuler/iSulad/blob/master/docs/build_docs/guide/build_guide.md). Here we only emphasize the difference of the building steps.
- 
+
 ### Build LCR
 
 ```bash
@@ -260,6 +260,32 @@ POD ID              CREATED              STATE               NAME
 5cbcf744949d8       About a minute ago   Ready               busybox-sandbox2    default             1
 ```
 
+### 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 stratovirt 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>
+# enter the guest os debug console shell
+$ ncat --vsock 395568061 1025
+```
+
 ### Create and start container in the pod sandbox with config file
 
 Create a container in the podsandbox
@@ -296,17 +322,7 @@ c11df540f913e       docker.io/library/busybox:latest   2 minutes ago       Runni
 
 ### Test Network Connectivity
 
-Get the `vsock guest-cid` from stratovirt 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 
-...
-```
-
-Enter the guest os debug console shell environment:
 ```bash
-# ncat --vsock <guest-cid> <debug-console>
 # enter the guest os debug console shell
 $ ncat --vsock 395568061 1025
 

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);