Re: [PATCH] pseries: fix migration-test and pxe-test

[Greg Kurz <groug@kaod.org>]

On Wed, 20 Nov 2019 15:25:39 +0100
Laurent Vivier <lvivier@redhat.com> wrote:

> Commit 29cb4187497d ("spapr: Set VSMT to smp_threads by default")
> has introduced a new default value for VSMT that is not supported
> by old kernels (before 4.13 kernel) and this breaks "make check"
> on these kernels.
> 
> To fix that, explicitly set in the involved tests the value that was
> used as the default value before the change.
> 

Some more details: the 'make check' failure was observed on a POWER8 host
with an old kernel RHEL7 kernel without VSMT support. Passing vsmt=8 to QEMU
causes spapr_set_vsmt_mode() to simply not even try to change the VSMT in KVM
since POWER8 hosts are SMT8 by default, and the VM starts just fine.

> Cc: Greg Kurz <groug@kaod.org>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---

Reviewed-by: Greg Kurz <groug@kaod.org>

I could also check this is doesn't break the following setups:
- KVM HV on POWER9 host
- KVM PR on POWER8 host (just spits a non-fatal warning)
- TCG

Note that migration-test explicitly requires KVM HV. It simply
exits otherwise.

Tested-by: Greg Kurz <groug@kaod.org>

>  tests/migration-test.c | 4 ++--
>  tests/pxe-test.c       | 6 +++---
>  2 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/migration-test.c b/tests/migration-test.c
> index ac780dffdaad..ebd77a581aff 100644
> --- a/tests/migration-test.c
> +++ b/tests/migration-test.c
> @@ -614,7 +614,7 @@ static int test_migrate_start(QTestState **from, QTestState **to,
>          end_address = S390_TEST_MEM_END;
>      } else if (strcmp(arch, "ppc64") == 0) {
>          extra_opts = use_shmem ? get_shmem_opts("256M", shmem_path) : NULL;
> -        cmd_src = g_strdup_printf("-machine accel=%s -m 256M -nodefaults"
> +        cmd_src = g_strdup_printf("-machine accel=%s,vsmt=8 -m 256M -nodefaults"
>                                    " -name source,debug-threads=on"
>                                    " -serial file:%s/src_serial"
>                                    " -prom-env 'use-nvramrc?=true' -prom-env "
> @@ -623,7 +623,7 @@ static int test_migrate_start(QTestState **from, QTestState **to,
>                                    "until' %s %s",  accel, tmpfs, end_address,
>                                    start_address, extra_opts ? extra_opts : "",
>                                    opts_src);
> -        cmd_dst = g_strdup_printf("-machine accel=%s -m 256M"
> +        cmd_dst = g_strdup_printf("-machine accel=%s,vsmt=8 -m 256M"
>                                    " -name target,debug-threads=on"
>                                    " -serial file:%s/dest_serial"
>                                    " -incoming %s %s %s",
> diff --git a/tests/pxe-test.c b/tests/pxe-test.c
> index 948b0fbdc727..aaae54f7550d 100644
> --- a/tests/pxe-test.c
> +++ b/tests/pxe-test.c
> @@ -46,15 +46,15 @@ static testdef_t x86_tests_slow[] = {
>  
>  static testdef_t ppc64_tests[] = {
>      { "pseries", "spapr-vlan",
> -      "-machine cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken" },
> +      "-machine cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken,vsmt=8" },
>      { "pseries", "virtio-net-pci",
> -      "-machine cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken" },
> +      "-machine cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken,vsmt=8" },
>      { NULL },
>  };
>  
>  static testdef_t ppc64_tests_slow[] = {
>      { "pseries", "e1000",
> -      "-machine cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken" },
> +      "-machine cap-cfpc=broken,cap-sbbc=broken,cap-ibs=broken,vsmt=8" },
>      { NULL },
>  };
>