Re: [PATCH v5 7/7] tests/migration-test: add qpl compression test

[Daniel P . Berrangé]

On Wed, Mar 20, 2024 at 03:30:40PM +0000, Liu, Yuan1 wrote:
> > -----Original Message-----
> > From: Daniel P. Berrangé <berrange@redhat.com>
> > Sent: Wednesday, March 20, 2024 6:46 PM
> > To: Liu, Yuan1 <yuan1.liu@intel.com>
> > Cc: peterx@redhat.com; farosas@suse.de; qemu-devel@nongnu.org;
> > hao.xiang@bytedance.com; bryan.zhang@bytedance.com; Zou, Nanhai
> > <nanhai.zou@intel.com>
> > Subject: Re: [PATCH v5 7/7] tests/migration-test: add qpl compression test
> > 
> > On Wed, Mar 20, 2024 at 12:45:27AM +0800, Yuan Liu wrote:
> > > add qpl to compression method test for multifd migration
> > >
> > > the migration with qpl compression needs to access IAA hardware
> > > resource, please run "check-qtest" with sudo or root permission,
> > > otherwise migration test will fail
> > 
> > That's not an acceptable requirement.
> > 
> > If someone builds QEMU with QPL, the migration test *must*
> > pass 100% reliably when either running on a host without
> > the QPL required hardware, or when lacking permissions.
> > 
> > The test case needs to detect these scenarios and automatically
> > skip the test if it is incapable of running successfully.
> > This raises another question though. If QPL migration requires
> > running as root, then it is effectively unusable for QEMU, as
> > no sane deployment ever runs QEMU as root.
> > 
> > Is there a way to make QPL work for non-root users ?
> 
> There are two issues here
> 1. I need to add an IAA resource detection before the QPL test begins
>    In this way, when QPL resources are unavailable, the live migration 
>    test will not be affected.
> 
> 2. I need to add some additional information about IAA configuration in 
>    the devel/qpl-compression.rst documentation. In addition to configuring 
>    IAA resources, the system administrator also needs to assign IAA resources
>    to user groups.
>    For example, the system administrator runs "chown -R user /dev/iax", then
>    all IAA resources can be accessed by "user", this method does not require 
>    sudo or root permissions

Ok, so in the test suite you likely should do something
approximately like

#ifdef CONFIG_QPL
  if (access("/dev/iax", R_OK|W_OK) == 0) {
    migration_test_add("/migration/multifd/tcp/plain/qpl",
                       test_multifd_tcp_qpl);
  }
#endif

possibly more if you need to actually query supported features
of /dev/iax before trying to use it

> 
> > > Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
> > > Reviewed-by: Nanhai Zou <nanhai.zou@intel.com>
> > > ---
> > >  tests/qtest/migration-test.c | 24 ++++++++++++++++++++++++
> > >  1 file changed, 24 insertions(+)
> > >
> > > diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> > > index 71895abb7f..052d0d60fd 100644
> > > --- a/tests/qtest/migration-test.c
> > > +++ b/tests/qtest/migration-test.c
> > > @@ -2815,6 +2815,15 @@
> > test_migrate_precopy_tcp_multifd_zstd_start(QTestState *from,
> > >  }
> > >  #endif /* CONFIG_ZSTD */
> > >
> > > +#ifdef CONFIG_QPL
> > > +static void *
> > > +test_migrate_precopy_tcp_multifd_qpl_start(QTestState *from,
> > > +                                            QTestState *to)
> > > +{
> > > +    return test_migrate_precopy_tcp_multifd_start_common(from, to,
> > "qpl");
> > > +}
> > > +#endif /* CONFIG_QPL */
> > > +
> > >  static void test_multifd_tcp_none(void)
> > >  {
> > >      MigrateCommon args = {
> > > @@ -2880,6 +2889,17 @@ static void test_multifd_tcp_zstd(void)
> > >  }
> > >  #endif
> > >
> > > +#ifdef CONFIG_QPL
> > > +static void test_multifd_tcp_qpl(void)
> > > +{
> > > +    MigrateCommon args = {
> > > +        .listen_uri = "defer",
> > > +        .start_hook = test_migrate_precopy_tcp_multifd_qpl_start,
> > > +    };
> > > +    test_precopy_common(&args);
> > > +}
> > > +#endif
> > > +
> > >  #ifdef CONFIG_GNUTLS
> > >  static void *
> > >  test_migrate_multifd_tcp_tls_psk_start_match(QTestState *from,
> > > @@ -3789,6 +3809,10 @@ int main(int argc, char **argv)
> > >      migration_test_add("/migration/multifd/tcp/plain/zstd",
> > >                         test_multifd_tcp_zstd);
> > >  #endif
> > > +#ifdef CONFIG_QPL
> > > +    migration_test_add("/migration/multifd/tcp/plain/qpl",
> > > +                       test_multifd_tcp_qpl);
> > > +#endif
> > >  #ifdef CONFIG_GNUTLS
> > >      migration_test_add("/migration/multifd/tcp/tls/psk/match",
> > >                         test_multifd_tcp_tls_psk_match);
> > > --
> > > 2.39.3
> > >
> > >
> > 
> > With regards,
> > Daniel
> > --
> > |: https://berrange.com      -o-
> > https://www.flickr.com/photos/dberrange :|
> > |: https://libvirt.org         -o-
> > https://fstop138.berrange.com :|
> > |: https://entangle-photo.org    -o-
> > https://www.instagram.com/dberrange :|
> 

With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|