From 30ba3e7bbe9e0542cf480f44bc6845a8dbd2a6ba Mon Sep 17 00:00:00 2001
From: Sebastien Boeuf <sebastien.boeuf@intel.com>
Date: Fri, 4 Jun 2021 15:54:19 +0200
Subject: [PATCH] vhost_user: Add header flags support

Introduce a new method set_flags() in order to let the caller define the
expected set of flags that should be applied to the header for the
following messages.

Fixes #40

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
---
 coverage_config_x86_64.json |  2 +-
 src/vhost_user/master.rs    | 22 +++++++++++++++-------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/coverage_config_x86_64.json b/coverage_config_x86_64.json
index 2b2c164..f9164a8 100644
--- a/coverage_config_x86_64.json
+++ b/coverage_config_x86_64.json
@@ -1 +1 @@
-{"coverage_score": 81.2, "exclude_path": "src/vhost_kern/", "crate_features": "vhost-user-master,vhost-user-slave"}
+{"coverage_score": 81.0, "exclude_path": "src/vhost_kern/", "crate_features": "vhost-user-master,vhost-user-slave"}
diff --git a/src/vhost_user/master.rs b/src/vhost_user/master.rs
index 0a4bef8..b8ba0af 100644
--- a/src/vhost_user/master.rs
+++ b/src/vhost_user/master.rs
@@ -84,6 +84,7 @@ impl Master {
                 protocol_features_ready: false,
                 max_queue_num,
                 error: None,
+                hdr_flags: VhostUserHeaderFlag::empty(),
             })),
         }
     }
@@ -125,6 +126,12 @@ impl Master {
 
         Ok(Self::new(endpoint, max_queue_num))
     }
+
+    /// Set the header flags that should be applied to all following messages.
+    pub fn set_hdr_flags(&self, flags: VhostUserHeaderFlag) {
+        let mut node = self.node();
+        node.hdr_flags = flags;
+    }
 }
 
 impl VhostBackend for Master {
@@ -546,6 +553,8 @@ struct MasterInternal {
     max_queue_num: u64,
     // Internal flag to mark failure state.
     error: Option<i32>,
+    // List of header flags.
+    hdr_flags: VhostUserHeaderFlag,
 }
 
 impl MasterInternal {
@@ -555,7 +564,7 @@ impl MasterInternal {
         fds: Option<&[RawFd]>,
     ) -> VhostUserResult<VhostUserMsgHeader<MasterReq>> {
         self.check_state()?;
-        let hdr = Self::new_request_header(code, 0);
+        let hdr = self.new_request_header(code, 0);
         self.main_sock.send_header(&hdr, fds)?;
         Ok(hdr)
     }
@@ -571,7 +580,7 @@ impl MasterInternal {
         }
         self.check_state()?;
 
-        let hdr = Self::new_request_header(code, mem::size_of::<T>() as u32);
+        let hdr = self.new_request_header(code, mem::size_of::<T>() as u32);
         self.main_sock.send_message(&hdr, msg, fds)?;
         Ok(hdr)
     }
@@ -594,7 +603,7 @@ impl MasterInternal {
         }
         self.check_state()?;
 
-        let hdr = Self::new_request_header(code, len as u32);
+        let hdr = self.new_request_header(code, len as u32);
         self.main_sock
             .send_message_with_payload(&hdr, msg, payload, fds)?;
         Ok(hdr)
@@ -615,7 +624,7 @@ impl MasterInternal {
         // This flag is set when there is no file descriptor in the ancillary data. This signals
         // that polling will be used instead of waiting for the call.
         let msg = VhostUserU64::new(queue_index as u64);
-        let hdr = Self::new_request_header(code, mem::size_of::<VhostUserU64>() as u32);
+        let hdr = self.new_request_header(code, mem::size_of::<VhostUserU64>() as u32);
         self.main_sock.send_message(&hdr, &msg, Some(&[fd]))?;
         Ok(hdr)
     }
@@ -698,9 +707,8 @@ impl MasterInternal {
     }
 
     #[inline]
-    fn new_request_header(request: MasterReq, size: u32) -> VhostUserMsgHeader<MasterReq> {
-        // TODO: handle NEED_REPLY flag
-        VhostUserMsgHeader::new(request, 0x1, size)
+    fn new_request_header(&self, request: MasterReq, size: u32) -> VhostUserMsgHeader<MasterReq> {
+        VhostUserMsgHeader::new(request, self.hdr_flags.bits() | 0x1, size)
     }
 }