[blk-threaded - 11/12] api: expose threaded virtio-block

src/firecracker/swagger/firecracker.yaml

@@ -1238,6 +1238,12 @@ definitions:
         description:
           Is block read only.
           This field is required for virtio-block config and should be omitted for vhost-user-block configuration.
+      threaded:
+        type: boolean
+        description:
+          Whether to process requests on a dedicated worker thread.
+          This field is supported only for virtio-block configuration.
+        default: false
       path_on_host:
         type: string
         description:

src/vmm/src/builder.rs

@@ -905,6 +905,7 @@ pub(crate) mod tests {
                 cache_type: custom_block_cfg.cache_type,
 
                 is_read_only: Some(custom_block_cfg.is_read_only),
+                threaded: false,
                 path_on_host: Some(
                     block_files
                         .last()

src/vmm/src/device_manager/mod.rs

@@ -921,6 +921,7 @@ pub(crate) mod tests {
             is_root_device: is_root,
             cache_type: CacheType::Unsafe,
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(f.as_path().to_str().unwrap().to_string()),
             rate_limiter: None,
             file_engine_type: None,

src/vmm/src/device_manager/pci_mngr.rs

@@ -840,6 +840,7 @@ mod tests {
       "is_root_device": true,
       "cache_type": "Unsafe",
       "is_read_only": true,
+      "threaded": false,
       "path_on_host": "{}",
       "rate_limiter": null,
       "io_engine": "Sync",

src/vmm/src/device_manager/persist.rs

@@ -834,6 +834,7 @@ mod tests {
       "is_root_device": true,
       "cache_type": "Unsafe",
       "is_read_only": true,
+      "threaded": false,
       "path_on_host": "{}",
       "rate_limiter": null,
       "io_engine": "Sync",

src/vmm/src/devices/virtio/block/device.rs

@@ -9,6 +9,7 @@ use vmm_sys_util::eventfd::EventFd;
 use super::BlockError;
 use super::persist::{BlockConstructorArgs, BlockState};
 use super::vhost_user::device::{VhostUserBlock, VhostUserBlockConfig};
+use super::virtio::VirtioBlockError;
 use super::virtio::device::{VirtioBlock, VirtioBlockConfig};
 use crate::devices::virtio::ActivateError;
 use crate::devices::virtio::device::{VirtioDevice, VirtioDeviceType};
@@ -118,10 +119,14 @@ impl Block {
 
     pub(crate) fn spawn_worker(
         &mut self,
-        _seccomp_filter: Option<Arc<BpfProgram>>,
+        seccomp_filter: Option<Arc<BpfProgram>>,
     ) -> Result<(), BlockError> {
         match self {
-            Self::Virtio(_) | Self::VhostUser(_) => Ok(()),
+            Self::Virtio(b) if b.config.threaded => b
+                .spawn_worker(seccomp_filter.ok_or(BlockError::MissingSeccompFilter)?)
+                .map_err(BlockError::VirtioBackend),
+            Self::Virtio(_) => Ok(()),
+            Self::VhostUser(_) => Ok(()),
         }
     }
 }

src/vmm/src/devices/virtio/block/vhost_user/device.rs

@@ -67,6 +67,10 @@ impl TryFrom<&BlockDeviceConfig> for VhostUserBlockConfig {
     type Error = VhostUserBlockError;
 
     fn try_from(value: &BlockDeviceConfig) -> Result<Self, Self::Error> {
+        if value.threaded {
+            return Err(VhostUserBlockError::Config);
+        }
+
         if let (Some(socket), None, None, None, None) = (
             &value.socket,
             &value.is_read_only,
@@ -97,6 +101,7 @@ impl From<VhostUserBlockConfig> for BlockDeviceConfig {
             cache_type: value.cache_type,
 
             is_read_only: None,
+            threaded: false,
             path_on_host: None,
             rate_limiter: None,
             file_engine_type: None,
@@ -428,6 +433,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: None,
+            threaded: false,
             path_on_host: None,
             rate_limiter: None,
             file_engine_type: None,
@@ -443,6 +449,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some("path".to_string()),
             rate_limiter: None,
             file_engine_type: Some(FileEngineType::Sync),
@@ -458,6 +465,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some("path".to_string()),
             rate_limiter: None,
             file_engine_type: Some(FileEngineType::Sync),

src/vmm/src/devices/virtio/block/virtio/device.rs

@@ -188,6 +188,9 @@ pub struct VirtioBlockConfig {
     /// If set to true, the drive is opened in read-only mode. Otherwise, the
     /// drive is opened as read-write.
     pub is_read_only: bool,
+    /// If set to true, process requests on a dedicated worker thread.
+    #[serde(default)]
+    pub threaded: bool,
     /// Path of the backing file on the host
     pub path_on_host: String,
     /// Rate Limiter for I/O operations.
@@ -210,6 +213,7 @@ impl TryFrom<&BlockDeviceConfig> for VirtioBlockConfig {
                 cache_type: value.cache_type,
 
                 is_read_only: value.is_read_only.unwrap_or(false),
+                threaded: value.threaded,
                 path_on_host: path_on_host.clone(),
                 rate_limiter: value.rate_limiter,
                 file_engine_type: value.file_engine_type.unwrap_or_default(),
@@ -229,6 +233,7 @@ impl From<VirtioBlockConfig> for BlockDeviceConfig {
             cache_type: value.cache_type,
 
             is_read_only: Some(value.is_read_only),
+            threaded: value.threaded,
             path_on_host: Some(value.path_on_host),
             rate_limiter: value.rate_limiter,
             file_engine_type: Some(value.file_engine_type),
@@ -832,6 +837,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some("path".to_string()),
             rate_limiter: None,
             file_engine_type: Default::default(),
@@ -847,6 +853,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: None,
+            threaded: false,
             path_on_host: None,
             rate_limiter: None,
             file_engine_type: Default::default(),
@@ -862,6 +869,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some("path".to_string()),
             rate_limiter: None,
             file_engine_type: Default::default(),
@@ -1970,6 +1978,7 @@ mod tests {
             for threaded in [false, true] {
                 let mut block = default_block(engine);
                 if threaded {
+                    block.config.threaded = true;
                     block.spawn_worker(Arc::new(vec![])).unwrap();
                 }
 

src/vmm/src/devices/virtio/block/virtio/persist.rs

@@ -62,6 +62,8 @@ pub struct VirtioBlockState {
     pub virtio_state: VirtioDeviceState,
     rate_limiter_state: RateLimiterState,
     file_engine_type: FileEngineTypeState,
+    #[serde(default)]
+    threaded: bool,
 }
 
 impl Persist<'_> for VirtioBlock {
@@ -91,6 +93,7 @@ impl Persist<'_> for VirtioBlock {
             virtio_state,
             rate_limiter_state: self.rate_limiter().save(),
             file_engine_type: FileEngineTypeState::from(self.file_engine_type()),
+            threaded: self.config.threaded,
         }
     }
 
@@ -108,6 +111,7 @@ impl Persist<'_> for VirtioBlock {
             is_root_device: state.root_device,
             cache_type: state.cache_type,
             is_read_only,
+            threaded: state.threaded,
             path_on_host: state.disk_path.clone(),
             rate_limiter: rate_limiter_config.into_option(),
             file_engine_type: state.file_engine_type.into(),
@@ -178,6 +182,7 @@ mod tests {
             is_root_device: false,
             partuuid: None,
             is_read_only: false,
+            threaded: false,
             cache_type: CacheType::Writeback,
             rate_limiter: None,
             file_engine_type: FileEngineType::default(),
@@ -219,6 +224,7 @@ mod tests {
             is_root_device: false,
             partuuid: None,
             is_read_only: false,
+            threaded: false,
             cache_type: CacheType::Unsafe,
             rate_limiter: None,
             file_engine_type: FileEngineType::default(),

src/vmm/src/devices/virtio/block/virtio/test_utils.rs

@@ -43,6 +43,7 @@ pub fn default_block_with_path(path: String, file_engine_type: FileEngineType) -
         is_root_device: false,
         partuuid: None,
         is_read_only: false,
+        threaded: false,
         cache_type: CacheType::Unsafe,
         // Rate limiting is enabled but with a high operation rate (10 million ops/s).
         rate_limiter: Some(RateLimiterConfig {

src/vmm/src/resources.rs

@@ -620,6 +620,7 @@ mod tests {
                 cache_type: CacheType::Unsafe,
 
                 is_read_only: Some(false),
+                threaded: false,
                 path_on_host: Some(tmp_file.as_path().to_str().unwrap().to_string()),
                 rate_limiter: Some(RateLimiterConfig::default()),
                 file_engine_type: None,

src/vmm/src/vmm_config/drive.rs

@@ -51,6 +51,9 @@ pub struct BlockDeviceConfig {
     /// If set to true, the drive is opened in read-only mode. Otherwise, the
     /// drive is opened as read-write.
     pub is_read_only: Option<bool>,
+    /// If set to true, process requests on a dedicated worker thread.
+    #[serde(default)]
+    pub threaded: bool,
     /// Path of the drive.
     pub path_on_host: Option<String>,
     /// Rate Limiter for I/O operations.
@@ -208,6 +211,7 @@ mod tests {
                 partuuid: self.partuuid.clone(),
                 is_root_device: self.is_root_device,
                 is_read_only: self.is_read_only,
+                threaded: self.threaded,
                 cache_type: self.cache_type,
 
                 path_on_host: self.path_on_host.clone(),
@@ -237,6 +241,7 @@ mod tests {
             cache_type: CacheType::Writeback,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path),
             rate_limiter: None,
             file_engine_type: None,
@@ -271,6 +276,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some(dummy_path),
             rate_limiter: None,
             file_engine_type: None,
@@ -303,6 +309,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some(dummy_path),
             rate_limiter: None,
             file_engine_type: None,
@@ -332,6 +339,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_1),
             rate_limiter: None,
             file_engine_type: None,
@@ -348,6 +356,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_2),
             rate_limiter: None,
             file_engine_type: None,
@@ -375,6 +384,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_1),
             rate_limiter: None,
             file_engine_type: None,
@@ -391,6 +401,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_2),
             rate_limiter: None,
             file_engine_type: None,
@@ -407,6 +418,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_3),
             rate_limiter: None,
             file_engine_type: None,
@@ -448,6 +460,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_1),
             rate_limiter: None,
             file_engine_type: None,
@@ -464,6 +477,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_2),
             rate_limiter: None,
             file_engine_type: None,
@@ -480,6 +494,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_3),
             rate_limiter: None,
             file_engine_type: None,
@@ -522,6 +537,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_1.clone()),
             rate_limiter: None,
             file_engine_type: None,
@@ -538,6 +554,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_2.clone()),
             rate_limiter: None,
             file_engine_type: None,
@@ -610,6 +627,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_1),
             rate_limiter: None,
             file_engine_type: None,
@@ -626,6 +644,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(false),
+            threaded: false,
             path_on_host: Some(dummy_path_2),
             rate_limiter: None,
             file_engine_type: None,
@@ -652,6 +671,7 @@ mod tests {
             cache_type: CacheType::Unsafe,
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some(dummy_file.as_path().to_str().unwrap().to_string()),
             rate_limiter: None,
             file_engine_type: Some(FileEngineType::Sync),
@@ -682,6 +702,7 @@ mod tests {
             cache_type: CacheType::default(),
 
             is_read_only: Some(true),
+            threaded: false,
             path_on_host: Some(backing_file.as_path().to_str().unwrap().to_string()),
             rate_limiter: None,
             file_engine_type: None,

src/vmm/tests/integration_tests.rs

@@ -426,6 +426,7 @@ fn test_preboot_load_snap_disallowed_after_boot_resources() {
         cache_type: CacheType::Unsafe,
 
         is_read_only: Some(false),
+        threaded: false,
         path_on_host: Some(tmp_file),
         rate_limiter: None,
         file_engine_type: None,