[PATCH net-next 4/6] selftests/vsock: add a helper to assign the g2h device to a netns
From: Bobby Eshleman <hidden>
Date: 2026-09-02 23:01:26
Also in:
kvm, linux-doc, linux-kselftest, lkml, netdev
Subsystem:
kernel selftest framework, the rest, vm sockets (af_vsock) · Maintainers:
Shuah Khan, Shuah Khan, Linus Torvalds, Stefano Garzarella
From: Bobby Eshleman <redacted> No shell tool can issue IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS, so anything that wants to move the guest's vsock device from a script needs a small program to do it. It exits with the ioctl's errno so a caller can differentiate the reasons for failure. Signed-off-by: Bobby Eshleman <redacted> --- tools/testing/selftests/vsock/.gitignore | 1 + tools/testing/selftests/vsock/Makefile | 3 +- .../selftests/vsock/vsock_assign_g2h_netns.c | 45 ++++++++++++++++++++++ 3 files changed, 47 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/vsock/.gitignore b/tools/testing/selftests/vsock/.gitignore
index 9c5bf379480f..ffca0d9c34b1 100644
--- a/tools/testing/selftests/vsock/.gitignore
+++ b/tools/testing/selftests/vsock/.gitignore@@ -1,2 +1,3 @@ vmtest.log +vsock_assign_g2h_netns vsock_test
diff --git a/tools/testing/selftests/vsock/Makefile b/tools/testing/selftests/vsock/Makefile
index c407c0afd938..d7170a15150f 100644
--- a/tools/testing/selftests/vsock/Makefile
+++ b/tools/testing/selftests/vsock/Makefile@@ -11,7 +11,6 @@ $(OUTPUT)/vsock_test: $(VSOCK_TEST_DIR)/vsock_test $(VSOCK_TEST_DIR)/vsock_test: $(VSOCK_TEST_SRCS) $(MAKE) -C $(VSOCK_TEST_DIR) vsock_test TEST_PROGS += vmtest.sh -TEST_GEN_FILES := vsock_test +TEST_GEN_FILES := vsock_test vsock_assign_g2h_netns include ../lib.mk -
diff --git a/tools/testing/selftests/vsock/vsock_assign_g2h_netns.c b/tools/testing/selftests/vsock/vsock_assign_g2h_netns.c
new file mode 100644
index 000000000000..6f15629af607
--- /dev/null
+++ b/tools/testing/selftests/vsock/vsock_assign_g2h_netns.c@@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Assign the guest->host vsock transport, i.e. the guest's virtio-vsock + * device, to the network namespace of the invoking process. + * + * Exits with the ioctl's errno, so that callers can tell why it was refused. + * + * Copyright (c) 2026 Meta Platforms, Inc. and affiliates + */ + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <string.h> +#include <sys/ioctl.h> +#include <unistd.h> + +#include <linux/vm_sockets.h> + +#ifndef IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS +#define IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS _IO(7, 0xba) +#endif + +int main(void) +{ + int fd, ret; + + fd = open("/dev/vsock", O_RDONLY); + if (fd < 0) { + fprintf(stderr, "open /dev/vsock: %s\n", strerror(errno)); + return -1; + } + + ret = ioctl(fd, IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS); + if (ret < 0) { + ret = errno; + fprintf(stderr, + "IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS: %s (errno %d)\n", + strerror(errno), errno); + } + + close(fd); + + return ret; +}
--
2.53.0-Meta