main, vmm: Add mandatory id to memory zones

In anticipation for allowing memory zones to be removed, but also in
anticipation for refactoring NUMA parameter, we introduce a mandatory
'id' option to the --memory-zone parameter.

This forces the user to provide a unique identifier for each memory zone
so that we can refer to these.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

src/main.rs

@@ -121,7 +121,7 @@ fn create_app<'a, 'b>(
                     "User defined memory zone parameters \
                      \"size=<guest_memory_region_size>,file=<backing_file>,\
                      shared=on|off,hugepages=on|off,host_numa_node=<node_id>,\
-                     guest_numa_node=<node_id>\"",
+                     guest_numa_node=<node_id>,id=<zone_identifier>\"",
                 )
                 .takes_value(true)
                 .min_values(1)

vmm/src/api/openapi/cloud-hypervisor.yaml

@@ -453,9 +453,12 @@ components:
 
     MemoryZoneConfig:
       required:
+      - id
       - size
       type: object
       properties:
+        id:
+          type: string
         size:
           type: integer
           format: int64

vmm/src/config.rs

@@ -46,6 +46,8 @@ pub enum Error {
     ParseMemory(OptionParserError),
     /// Error parsing memory zone options
     ParseMemoryZone(OptionParserError),
+    /// Missing 'id' from memory zone
+    ParseMemoryZoneIdMissing,
     /// Error parsing disk options
     ParseDisk(OptionParserError),
     /// Error parsing network options
@@ -154,6 +156,7 @@ impl fmt::Display for Error {
             ParseVsockSockMissing => write!(f, "Error parsing --vsock: socket missing"),
             ParseMemory(o) => write!(f, "Error parsing --memory: {}", o),
             ParseMemoryZone(o) => write!(f, "Error parsing --memory-zone: {}", o),
+            ParseMemoryZoneIdMissing => write!(f, "Error parsing --memory-zone: id missing"),
             ParseNetwork(o) => write!(f, "Error parsing --net: {}", o),
             ParseDisk(o) => write!(f, "Error parsing --disk: {}", o),
             ParseRNG(o) => write!(f, "Error parsing --rng: {}", o),
@@ -353,6 +356,7 @@ impl Default for CpusConfig {
 
 #[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
 pub struct MemoryZoneConfig {
+    pub id: String,
     pub size: u64,
     #[serde(default)]
     pub file: Option<PathBuf>,
@@ -440,6 +444,7 @@ impl MemoryConfig {
             for memory_zone in memory_zones.iter() {
                 let mut parser = OptionParser::new();
                 parser
+                    .add("id")
                     .add("size")
                     .add("file")
                     .add("shared")
@@ -448,6 +453,7 @@ impl MemoryConfig {
                     .add("guest_numa_node");
                 parser.parse(memory_zone).map_err(Error::ParseMemoryZone)?;
 
+                let id = parser.get("id").ok_or(Error::ParseMemoryZoneIdMissing)?;
                 let size = parser
                     .convert::<ByteSized>("size")
                     .map_err(Error::ParseMemoryZone)?
@@ -472,6 +478,7 @@ impl MemoryConfig {
                     .map_err(Error::ParseMemoryZone)?;
 
                 zones.push(MemoryZoneConfig {
+                    id,
                     size,
                     file,
                     shared,

vmm/src/memory_manager.rs

@@ -44,6 +44,8 @@ use vm_migration::{
     Transportable,
 };
 
+const DEFAULT_MEMORY_ZONE: &str = "mem0";
+
 #[cfg(target_arch = "x86_64")]
 const X86_64_IRQ_BASE: u32 = 5;
 
@@ -426,6 +428,7 @@ impl MemoryManager {
             // Create a single zone from the global memory config. This lets
             // us reuse the codepath for user defined memory zones.
             let zones = vec![MemoryZoneConfig {
+                id: String::from(DEFAULT_MEMORY_ZONE),
                 size: config.size,
                 file: None,
                 shared: config.shared,