From a3423a4483762dd9d7743fa19fae67e80cb71540 Mon Sep 17 00:00:00 2001
From: Muminul Islam <muislam@microsoft.com>
Date: Sat, 21 Mar 2026 18:43:39 -0700
Subject: [PATCH] tests: extract _test_tap_from_fd to tests_wrappers

Extract test logic from test_tap_from_fd into a shared
_test_tap_from_fd wrapper function in tests_wrappers.rs.
Update the parent test case to use the basic_regular_guest
macro with with_cpu(2). The wrapper uses
default_kernel_cmdline() for kernel/cmdline setup.

Signed-off-by: Muminul Islam <muislam@microsoft.com>
---
 .../tests/common/tests_wrappers.rs            | 70 ++++++++++++++++++
 cloud-hypervisor/tests/integration.rs         | 73 +------------------
 2 files changed, 72 insertions(+), 71 deletions(-)

diff --git a/cloud-hypervisor/tests/common/tests_wrappers.rs b/cloud-hypervisor/tests/common/tests_wrappers.rs
index bfc954b25..0b8ffd7fe 100644
--- a/cloud-hypervisor/tests/common/tests_wrappers.rs
+++ b/cloud-hypervisor/tests/common/tests_wrappers.rs
@@ -4,6 +4,7 @@
 use std::ffi::CStr;
 use std::fs::{self, OpenOptions};
 use std::io::{Read, Seek, SeekFrom, Write};
+use std::os::unix::io::AsRawFd;
 use std::path::{Path, PathBuf};
 use std::string::String;
 use std::sync::mpsc;
@@ -3193,3 +3194,72 @@ pub(crate) fn _test_pvpanic(guest: &Guest) {
 
     handle_child_output(r, &output);
 }
+
+pub(crate) fn _test_tap_from_fd(guest: &Guest) {
+    // Create a TAP interface with multi-queue enabled
+    let num_queue_pairs: usize = 2;
+
+    use std::str::FromStr;
+    let taps = net_util::open_tap(
+        Some("chtap0"),
+        Some(std::net::IpAddr::V4(
+            std::net::Ipv4Addr::from_str(&guest.network.host_ip0).unwrap(),
+        )),
+        None,
+        &mut None,
+        None,
+        num_queue_pairs,
+        Some(libc::O_RDWR | libc::O_NONBLOCK),
+    )
+    .unwrap();
+
+    let mut child = GuestCommand::new(guest)
+        .default_cpus()
+        .default_memory()
+        .default_kernel_cmdline()
+        .default_disks()
+        .args([
+            "--net",
+            &format!(
+                "fd=[{},{}],mac={},num_queues={}",
+                taps[0].as_raw_fd(),
+                taps[1].as_raw_fd(),
+                guest.network.guest_mac0,
+                num_queue_pairs * 2
+            ),
+        ])
+        .capture_output()
+        .spawn()
+        .unwrap();
+
+    let r = std::panic::catch_unwind(|| {
+        guest.wait_vm_boot().unwrap();
+
+        assert_eq!(
+            guest
+                .ssh_command("ip -o link | wc -l")
+                .unwrap()
+                .trim()
+                .parse::<u32>()
+                .unwrap_or_default(),
+            2
+        );
+
+        guest.reboot_linux(0);
+
+        assert_eq!(
+            guest
+                .ssh_command("ip -o link | wc -l")
+                .unwrap()
+                .trim()
+                .parse::<u32>()
+                .unwrap_or_default(),
+            2
+        );
+    });
+
+    kill_child(&mut child);
+    let output = child.wait_with_output().unwrap();
+
+    handle_child_output(r, &output);
+}
diff --git a/cloud-hypervisor/tests/integration.rs b/cloud-hypervisor/tests/integration.rs
index e31c08a40..744986fee 100644
--- a/cloud-hypervisor/tests/integration.rs
+++ b/cloud-hypervisor/tests/integration.rs
@@ -5111,77 +5111,8 @@ mod common_parallel {
 
     #[test]
     fn test_tap_from_fd() {
-        let disk_config = UbuntuDiskConfig::new(JAMMY_IMAGE_NAME.to_string());
-        let guest = Guest::new(Box::new(disk_config));
-        let kernel_path = direct_kernel_boot_path();
-
-        // Create a TAP interface with multi-queue enabled
-        let num_queue_pairs: usize = 2;
-
-        use std::str::FromStr;
-        let taps = net_util::open_tap(
-            Some("chtap0"),
-            Some(std::net::IpAddr::V4(
-                std::net::Ipv4Addr::from_str(&guest.network.host_ip0).unwrap(),
-            )),
-            None,
-            &mut None,
-            None,
-            num_queue_pairs,
-            Some(libc::O_RDWR | libc::O_NONBLOCK),
-        )
-        .unwrap();
-
-        let mut child = GuestCommand::new(&guest)
-            .args(["--cpus", &format!("boot={num_queue_pairs}")])
-            .default_memory()
-            .args(["--kernel", kernel_path.to_str().unwrap()])
-            .args(["--cmdline", DIRECT_KERNEL_BOOT_CMDLINE])
-            .default_disks()
-            .args([
-                "--net",
-                &format!(
-                    "fd=[{},{}],mac={},num_queues={}",
-                    taps[0].as_raw_fd(),
-                    taps[1].as_raw_fd(),
-                    guest.network.guest_mac0,
-                    num_queue_pairs * 2
-                ),
-            ])
-            .capture_output()
-            .spawn()
-            .unwrap();
-
-        let r = std::panic::catch_unwind(|| {
-            guest.wait_vm_boot().unwrap();
-
-            assert_eq!(
-                guest
-                    .ssh_command("ip -o link | wc -l")
-                    .unwrap()
-                    .trim()
-                    .parse::<u32>()
-                    .unwrap_or_default(),
-                2
-            );
-
-            guest.reboot_linux(0);
-
-            assert_eq!(
-                guest
-                    .ssh_command("ip -o link | wc -l")
-                    .unwrap()
-                    .trim()
-                    .parse::<u32>()
-                    .unwrap_or_default(),
-                2
-            );
-        });
-
-        kill_child(&mut child);
-        let output = child.wait_with_output().unwrap();
-
-        handle_child_output(r, &output);
+        let guest = basic_regular_guest!(JAMMY_IMAGE_NAME).with_cpu(2);
+        _test_tap_from_fd(&guest);
     }
 
     // By design, a guest VM won't be able to connect to the host