Libguestfs - Apr 2022 - [PATCH nbdkit] tests: Skip vsock tests unless the vsock_loopback module is loaded

It's unfortunate that vsock in Linux can be broken if some but not all
vsock modules needed are loaded.  As we are testing loopback
(VMADDR_CID_LOCAL), require that vsock_loopback is loaded.

Linux is able to autoload the correct module(s) if vsock.ko is _not_
loaded.  We could in theory enhance the test to check this, but that
leaves us with uncertainty about whether the test could work (eg. Is
vsock available as a module in this kernel?  Is this even Linux?)

Reported-by: Ming Xie
Thanks: Stefano Garzarella
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2069558
---
 tests/functions.sh.in | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tests/functions.sh.in b/tests/functions.sh.in
index 6d41f683..7877c84d 100644
--- a/tests/functions.sh.in
+++ b/tests/functions.sh.in
@@ -240,11 +240,13 @@ requires_non_root ()
 }
 
 # Tests that use the vsock interface will fail if vsock is not
-# supported.  On Linux you have to load the kernel modules: vsockmon
-# and vsock_loopback.
+# supported.  On Linux you have to load the kernel module
+# vsock_loopback.  See also
+# https://bugzilla.redhat.com/show_bug.cgi?id=2069558
 requires_vsock_support ()
 {
-    if ! grep -q ^AF_VSOCK /proc/net/protocols; then
+    if ! grep -q ^AF_VSOCK /proc/net/protocols ||
+       ! lsmod | grep ^vsock_loopback; then
         echo "$0: test skipped because AF_VSOCK is not supported."
         exit 77
     fi
-- 
2.35.1

On 04/01/22 12:46, Richard W.M. Jones wrote:
> It's unfortunate that vsock in Linux can be broken if some but not all
> vsock modules needed are loaded.  As we are testing loopback
> (VMADDR_CID_LOCAL), require that vsock_loopback is loaded.
> 
> Linux is able to autoload the correct module(s) if vsock.ko is _not_
> loaded.  We could in theory enhance the test to check this, but that
> leaves us with uncertainty about whether the test could work (eg. Is
> vsock available as a module in this kernel?  Is this even Linux?)
> 
> Reported-by: Ming Xie
> Thanks: Stefano Garzarella
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2069558
> ---
>  tests/functions.sh.in | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/functions.sh.in b/tests/functions.sh.in
> index 6d41f683..7877c84d 100644
> --- a/tests/functions.sh.in
> +++ b/tests/functions.sh.in
> @@ -240,11 +240,13 @@ requires_non_root ()
>  }
>  
>  # Tests that use the vsock interface will fail if vsock is not
> -# supported.  On Linux you have to load the kernel modules: vsockmon
> -# and vsock_loopback.
> +# supported.  On Linux you have to load the kernel module
> +# vsock_loopback.  See also
> +# https://bugzilla.redhat.com/show_bug.cgi?id=2069558
>  requires_vsock_support ()
>  {
> -    if ! grep -q ^AF_VSOCK /proc/net/protocols; then
> +    if ! grep -q ^AF_VSOCK /proc/net/protocols ||
> +       ! lsmod | grep ^vsock_loopback; then
>          echo "$0: test skipped because AF_VSOCK is not
supported."
>          exit 77
>      fi
> 
I think we should use "grep -q ^vsock_loopback" (-q option), but other
than that:

Acked-by: Laszlo Ersek <lersek at redhat.com>