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

[Jason Andryuk <jandryuk@gmail.com>]

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?

Regards,
Jason