Re: [PULL v2 02/44] tests: qtest: add qtest_has_accel() to check if tested binary supports accelerator

[Igor Mammedov]

On Fri, 22 Oct 2021 09:04:43 -0400
Jason Andryuk <jandryuk@gmail.com> wrote:

> On Wed, Oct 20, 2021 at 6:23 AM Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > From: Igor Mammedov <imammedo@redhat.com>
> >
> > Currently it is not possible to create tests that have KVM as a hard
> > requirement on a host that doesn't support KVM for tested target
> > binary (modulo going through the trouble of compiling out
> > the offending test case).
> >
> > Following scenario makes test fail when it's run on non x86 host:
> >   qemu-system-x86_64 -enable-kvm -M q35,kernel-irqchip=on -smp 1,maxcpus=288
> >
> > This patch introduces qtest_has_accel() to let users check if accel is
> > available in advance and avoid executing non run-able test-cases.
> >
> > It implements detection of TCG and KVM only, the rest could be
> > added later on, when we actually start testing them in qtest.
> >
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > Message-Id: <20210902113551.461632-3-imammedo@redhat.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >  tests/qtest/libqos/libqtest.h |  8 ++++++++
> >  tests/qtest/libqtest.c        | 27 +++++++++++++++++++++++++++
> >  meson.build                   |  6 ++++++
> >  3 files changed, 41 insertions(+)
> >
> > diff --git a/tests/qtest/libqos/libqtest.h b/tests/qtest/libqos/libqtest.h
> > index a68dcd79d4..59e9271195 100644
> > --- a/tests/qtest/libqos/libqtest.h
> > +++ b/tests/qtest/libqos/libqtest.h
> > @@ -588,6 +588,14 @@ bool qtest_big_endian(QTestState *s);
> >   */
> >  const char *qtest_get_arch(void);
> >
> > +/**
> > + * qtest_has_accel:
> > + * @accel_name: Accelerator name to check for.
> > + *
> > + * Returns: true if the accelerator is built in.
> > + */
> > +bool qtest_has_accel(const char *accel_name);
> > +
> >  /**
> >   * qtest_add_func:
> >   * @str: Test case path.
> > diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
> > index 73f6b977a6..25aeea385b 100644
> > --- a/tests/qtest/libqtest.c
> > +++ b/tests/qtest/libqtest.c
> > @@ -922,6 +922,33 @@ const char *qtest_get_arch(void)
> >      return end + 1;
> >  }
> >
> > +bool qtest_has_accel(const char *accel_name)
> > +{
> > +    if (g_str_equal(accel_name, "tcg")) {
> > +#if defined(CONFIG_TCG)
> > +        return true;
> > +#else
> > +        return false;
> > +#endif
> > +    } else if (g_str_equal(accel_name, "kvm")) {
> > +        int i;
> > +        const char *arch = qtest_get_arch();
> > +        const char *targets[] = { CONFIG_KVM_TARGETS };
> > +
> > +        for (i = 0; i < ARRAY_SIZE(targets); i++) {  
> 
> A xen osstest build fails with:
> ../qemu-xen-dir-remote/tests/qtest/libqtest.c: In function 'qtest_has_accel':
> ../qemu-xen-dir-remote/tests/qtest/libqtest.c:938:23: error:
> comparison of unsigned expression < 0 is always false
> [-Werror=type-limits]
>          for (i = 0; i < ARRAY_SIZE(targets); i++) {
>                        ^
> 
> Super long osstest log
> here:http://logs.test-lab.xenproject.org/osstest/logs/165703/build-i386-xsm/6.ts-xen-build.log
> 
> It was configured like:
> $source/configure --enable-xen --target-list=i386-softmmu \
> --enable-debug \
> --enable-trace-backend=log \
> --prefix=/usr/local \
> --libdir=/usr/local/lib/xen/lib \
> --includedir=/usr/local/lib/xen/include \
> --extra-cflags="-DXC_WANT_COMPAT_EVTCHN_API=1 \
> -DXC_WANT_COMPAT_GNTTAB_API=1 \
> -DXC_WANT_COMPAT_MAP_FOREIGN_API=1 \
> -DXC_WANT_COMPAT_DEVICEMODEL_API=1 \
> " \
> --extra-ldflags="-Wl,-rpath,/usr/local/lib/xen/lib" \
> --bindir=/usr/local/lib/xen/bin \
> --datadir=/usr/local/share/qemu-xen \
> --localstatedir=/var \
> --docdir=/usr/local/lib/xen/share/doc \
> --mandir=/usr/local/lib/xen/share/man \
> --libexecdir=/usr/local/lib/xen/libexec \
> --firmwarepath=/usr/local/lib/xen/share/qemu-firmware \
> --disable-kvm \
> --disable-docs \
> --disable-guest-agent \
> --python=python3 \
> --cpu=i386 ;
> 
> --cpu=i386 may be important?  osstest is building in a 32bit debian
> environment.  My 64bit fedora workstation fails to configure with
> --cpu=i386, and it builds successfully without it.
> 
> Maybe add #if defined(CONFIG_KVM) around the code like CONFIG_TCG above?

Thanks for reporting, I'll post fix in a moment.

> Regards,
> Jason
>