feat: Dump with CPU template

Previously we needed to provide a custom CPU template path indirectly
via config file. Since we went through the trouble of enabling it to
dump without config file, allows users to specify a CPU template path
directly without config file when dumping.

Signed-off-by: Takahiro Itazuri <[email protected]>

Author: zulinx86

docs/cpu_templates/cpu-template-helper.md

@@ -18,6 +18,7 @@ format.
 ```
 cpu-template-helper template dump \
     --output <cpu-config> \
+    [--template <cpu-template>] \
     [--config <firecracker-config>]
 ```
 
@@ -70,7 +71,7 @@ This command verifies that the given custom CPU template is applied correctly.
 
 ```
 cpu-template-helper template verify \
-    --template <cpu-template>
+    --template <cpu-template> \
     [--config <firecracker-config>]
 ```
 
@@ -98,6 +99,7 @@ information that could affect the validity of custom CPU templates.
 ```
 cpu-template-helper fingerprint dump \
     --output <output-path> \
+    [--template <cpu-template>] \
     [--config <firecracker-config>]
 ```
 

src/cpu-template-helper/src/main.rs

@@ -57,6 +57,9 @@ enum TemplateOperation {
         /// Path of firecracker config file.
         #[arg(short, long, value_name = "PATH")]
         config: Option<PathBuf>,
+        /// Path of CPU template to apply.
+        #[arg(short, long, value_name = "PATH")]
+        template: Option<PathBuf>,
         /// Path of output file.
         #[arg(short, long, value_name = "PATH", default_value = "cpu_config.json")]
         output: PathBuf,
@@ -88,6 +91,9 @@ enum FingerprintOperation {
         /// Path of firecracker config file.
         #[arg(short, long, value_name = "PATH")]
         config: Option<PathBuf>,
+        /// Path of CPU template to apply.
+        #[arg(short, long, value_name = "PATH")]
+        template: Option<PathBuf>,
         /// Path of output file.
         #[arg(short, long, value_name = "PATH", default_value = "fingerprint.json")]
         output: PathBuf,
@@ -115,9 +121,17 @@ enum FingerprintOperation {
 fn run(cli: Cli) -> Result<(), HelperError> {
     match cli.command {
         Command::Template(op) => match op {
-            TemplateOperation::Dump { config, output } => {
+            TemplateOperation::Dump {
+                config,
+                template,
+                output,
+            } => {
                 let config = config.map(read_to_string).transpose()?;
-                let (vmm, _) = utils::build_microvm_from_config(config, None)?;
+                let template = template
+                    .as_ref()
+                    .map(utils::load_cpu_template)
+                    .transpose()?;
+                let (vmm, _) = utils::build_microvm_from_config(config, template)?;
 
                 let cpu_config = template::dump::dump(vmm)?;
 
@@ -157,9 +171,17 @@ fn run(cli: Cli) -> Result<(), HelperError> {
             }
         },
         Command::Fingerprint(op) => match op {
-            FingerprintOperation::Dump { config, output } => {
+            FingerprintOperation::Dump {
+                config,
+                template,
+                output,
+            } => {
                 let config = config.map(read_to_string).transpose()?;
-                let (vmm, _) = utils::build_microvm_from_config(config, None)?;
+                let template = template
+                    .as_ref()
+                    .map(utils::load_cpu_template)
+                    .transpose()?;
+                let (vmm, _) = utils::build_microvm_from_config(config, template)?;
 
                 let fingerprint = fingerprint::dump::dump(vmm)?;