kernel/vsock: add in-svsm tests for VsockStream

Add a test that performs some basic checks on vsock functionalities:

- double connection
- recv a buffer from the host
- send a buffer to the host
- recv a buffer after local shutdown
- send a buffer after local shutdown

The vsock server is created on the host using ncat.

Signed-off-by: Luigi Leonardi <leonardi@redhat.com>

Author: luigix25

Makefile

@@ -4,7 +4,7 @@ SVSM_ARGS += --features ${FEATURES}
 XBUILD_ARGS += -f ${FEATURES}
 endif
 
-FEATURES_TEST ?= vtpm,virtio-drivers,block
+FEATURES_TEST ?= vtpm,virtio-drivers,block,vsock
 SVSM_ARGS_TEST += --no-default-features
 ifneq ($(FEATURES_TEST),)
 SVSM_ARGS_TEST += --features ${FEATURES_TEST}

kernel/src/testing.rs

@@ -42,6 +42,8 @@ pub enum IORequest {
     GetLaunchMeasurement = 0x01,
     /// Virtio-blk tests: Get Sha256 hash of the svsm state disk image
     GetStateImageSha256 = 0x02,
+    /// Virtio-vsock tests: Ask host to start a vsock server
+    StartVsockServer = 0x03,
 }
 
 /// Return the serial port to communicate with the host for a given request

kernel/src/vsock/stream.rs

@@ -175,3 +175,127 @@ impl Drop for VsockStream {
         let _ = VSOCK_DEVICE.shutdown(self.remote_cid, self.local_port, self.remote_port, true);
     }
 }
+
+#[cfg(all(test, test_in_svsm))]
+mod tests {
+    use crate::{testutils::has_test_iorequests, vsock::VMADDR_CID_HOST};
+    use zerocopy::IntoBytes;
+
+    use super::*;
+
+    fn start_vsock_server_host() -> u32 {
+        use crate::serial::Terminal;
+        use crate::testing::{IORequest, svsm_test_io};
+
+        let mut sp = svsm_test_io().unwrap();
+
+        sp.put_byte(IORequest::StartVsockServer as u8);
+
+        let mut vsock_port: u32 = 0;
+
+        sp.read(vsock_port.as_mut_bytes())
+            .expect("unable to get the vsock port");
+
+        vsock_port
+    }
+
+    #[test]
+    #[cfg_attr(not(test_in_svsm), ignore = "Can only be run inside guest")]
+    fn test_virtio_vsock_double_connect() {
+        if !has_test_iorequests() {
+            return;
+        }
+
+        let remote_port = start_vsock_server_host();
+
+        let mut stream =
+            VsockStream::connect(remote_port, VMADDR_CID_HOST).expect("connection failed");
+
+        VsockStream::connect(remote_port, VMADDR_CID_HOST)
+            .expect_err("The second connection operation was expected to fail, but it succeeded.");
+
+        stream.shutdown().expect("shutdown failed");
+    }
+
+    #[test]
+    #[cfg_attr(not(test_in_svsm), ignore = "Can only be run inside guest")]
+    fn test_virtio_vsock_write() {
+        if !has_test_iorequests() {
+            return;
+        }
+
+        let remote_port = start_vsock_server_host();
+
+        let mut stream =
+            VsockStream::connect(remote_port, VMADDR_CID_HOST).expect("connection failed");
+
+        let buffer: &[u8] = b"Hello world!";
+
+        let n_bytes = stream.write(buffer).expect("write failed");
+        assert_eq!(n_bytes, buffer.len(), "Sent less bytes than requested");
+
+        stream.shutdown().expect("shutdown failed");
+    }
+
+    #[test]
+    #[cfg_attr(not(test_in_svsm), ignore = "Can only be run inside guest")]
+    fn test_virtio_vsock_read() {
+        if !has_test_iorequests() {
+            return;
+        }
+
+        let remote_port = start_vsock_server_host();
+
+        let mut stream =
+            VsockStream::connect(remote_port, VMADDR_CID_HOST).expect("connection failed");
+
+        let mut buffer: [u8; 11] = [0; 11];
+        let n_bytes = stream.read(&mut buffer).expect("read failed");
+        assert_eq!(n_bytes, buffer.len(), "Received less bytes than requested");
+
+        let string = core::str::from_utf8(&buffer).unwrap();
+        log::info!("received: {string:?}");
+        assert_eq!(string, "hello_world", "Received wrong message");
+
+        stream.shutdown().expect("shutdown failed");
+    }
+
+    #[test]
+    #[cfg_attr(not(test_in_svsm), ignore = "Can only be run inside guest")]
+    fn test_virtio_vsock_read_shutdown() {
+        if !has_test_iorequests() {
+            return;
+        }
+
+        let remote_port = start_vsock_server_host();
+
+        let mut stream =
+            VsockStream::connect(remote_port, VMADDR_CID_HOST).expect("connection failed");
+
+        stream.shutdown().expect("shutdown failed");
+
+        let mut buffer: [u8; 11] = [0; 11];
+        stream
+            .read(&mut buffer)
+            .expect_err("The read operation was expected to fail, but it succeeded");
+    }
+
+    #[test]
+    #[cfg_attr(not(test_in_svsm), ignore = "Can only be run inside guest")]
+    fn test_virtio_vsock_write_shutdown() {
+        if !has_test_iorequests() {
+            return;
+        }
+
+        let remote_port = start_vsock_server_host();
+
+        let mut stream =
+            VsockStream::connect(remote_port, VMADDR_CID_HOST).expect("connection failed");
+
+        stream.shutdown().expect("shutdown failed");
+
+        stream
+            .write(b"hello world")
+            .expect_err("The write operation was expected to fail, but it succeeded");
+    }
+}

scripts/test-in-svsm.sh

@@ -8,6 +8,8 @@
 set -e
 
 SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+VSOCK_PORT=12345
+VSOCK_CID=10
 
 test_io(){
     PIPE_IN=$1
@@ -28,6 +30,13 @@ test_io(){
             "02")
               sha256sum "$TEST_DIR/svsm_state.raw" | cut -f 1 -d ' ' | xxd -p -r > "$PIPE_IN"
               ;;
+            "03")
+              # virtio-vsock in svsm does not handle half duplex connections.
+              echo -n "hello_world" | ncat --no-shutdown -l --vsock -p $VSOCK_PORT &
+              sleep 1
+              # write port number as an unsigned int and not as ascii
+              python3 -c "import sys,struct; sys.stdout.buffer.write(struct.pack('I', $VSOCK_PORT))" > $PIPE_IN
+              ;;
             "")
                 # skip EOF
                 ;;
@@ -44,9 +53,6 @@ mkfifo $TEST_DIR/pipe.out
 # Create a raw disk image (512kB in size) for virtio-blk tests containing random data
 dd if=/dev/urandom of="$TEST_DIR/svsm_state.raw" bs=512 count=1024
 
-test_io $TEST_DIR/pipe.in $TEST_DIR/pipe.out &
-TEST_IO_PID=$!
-
 LAUNCH_GUEST_ARGS=""
 
 while [[ $# -gt 0 ]]; do
@@ -55,6 +61,16 @@ while [[ $# -gt 0 ]]; do
       LAUNCH_GUEST_ARGS+="--nocc "
       shift
       ;;
+    --vsock-cid)
+      VSOCK_CID="$2"
+      shift
+      shift
+      ;;
+    --vsock-port)
+      VSOCK_PORT="$2"
+      shift
+      shift
+      ;;
     --)
       shift
       break
@@ -66,9 +82,12 @@ while [[ $# -gt 0 ]]; do
   esac
 done
 
+test_io $TEST_DIR/pipe.in $TEST_DIR/pipe.out &
+TEST_IO_PID=$!
 
 $SCRIPT_DIR/launch_guest.sh --igvm $SCRIPT_DIR/../bin/coconut-test-qemu.igvm \
     --state "$TEST_DIR/svsm_state.raw" \
+    --vsock "$VSOCK_CID" \
     --unit-tests $TEST_DIR/pipe \
     $LAUNCH_GUEST_ARGS "$@" || svsm_exit_code=$?