Re: [PATCH v15 4/4] qtest/cxl: Add aarch64 virt test for CXL

[Peter Maydell <peter.maydell@linaro.org>]

On Thu, 12 Jun 2025 at 14:45, Jonathan Cameron
<Jonathan.Cameron@huawei.com> wrote:
>
> Add a single complex case for aarch64 virt machine.
> Given existing much more comprehensive tests for x86 cover the
> common functionality, a single test should be enough to verify
> that the aarch64 part continue to work.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>
> ---
> v15: Dropped tags due to changes in patches 2 and 3.
> ---
>  tests/qtest/cxl-test.c  | 59 ++++++++++++++++++++++++++++++++---------
>  tests/qtest/meson.build |  1 +
>  2 files changed, 47 insertions(+), 13 deletions(-)
>
> diff --git a/tests/qtest/cxl-test.c b/tests/qtest/cxl-test.c
> index a600331843..c7189d6222 100644
> --- a/tests/qtest/cxl-test.c
> +++ b/tests/qtest/cxl-test.c
> @@ -19,6 +19,12 @@
>      "-device pxb-cxl,id=cxl.1,bus=pcie.0,bus_nr=53 " \
>      "-M cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=4G "
>
> +#define QEMU_VIRT_2PXB_CMD \
> +    "-machine virt,cxl=on -cpu max " \
> +    "-device pxb-cxl,id=cxl.0,bus=pcie.0,bus_nr=52 " \
> +    "-device pxb-cxl,id=cxl.1,bus=pcie.0,bus_nr=53 " \
> +    "-M cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=4G "
> +
>  #define QEMU_RP \
>      "-device cxl-rp,id=rp0,bus=cxl.0,chassis=0,slot=0 "
>
> @@ -197,25 +203,52 @@ static void cxl_2pxb_4rp_4t3d(void)
>      qtest_end();
>      rmdir(tmpfs);
>  }
> +
> +static void cxl_virt_2pxb_4rp_4t3d(void)
> +{
> +    g_autoptr(GString) cmdline = g_string_new(NULL);
> +    char template[] = "/tmp/cxl-test-XXXXXX";
> +    const char *tmpfs;
> +
> +    tmpfs = mkdtemp(template);

We prefer g_mkdtemp() or g_dir_make_temp() over raw mkdtemp(),
I think. Other tests in this file use g_dir_make_tmp().

Also you aren't checking whether it failed.

> +
> +    g_string_printf(cmdline, QEMU_VIRT_2PXB_CMD QEMU_4RP QEMU_4T3D,
> +                    tmpfs, tmpfs, tmpfs, tmpfs, tmpfs, tmpfs,
> +                    tmpfs, tmpfs);
> +
> +    qtest_start(cmdline->str);

We never change the GString and only use its C representation,
so I think it's simpler to use
  g_autofree char *cmdline = NULL;
  ...
  cmdline = g_strdup_printf(...);

But I see all the other tests in this file are written this
way, so I'm ok with staying consistent to that here.

-- PMM