Re: [Qemu-devel] [PATCH 2/4] tests/test-vmstate.c: prove VMStateField.start broken

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Halil Pasic (pasic@linux.vnet.ibm.com) wrote:
> The handling of VMStateField.start is currently quite broken if
> VMS_ALLOC is present (that is for VMSTATE_VBUFFER_ALLOC_UINT32) but
> fortunately also quite underutilized -- nobody is using .start != 0.
> 
> Let's prove with this patch that it's really broken (as a first
> step towards fixing things up).

You can't play this trick - patch series have to work and pass
tests after each test, otherwise it messes up people in the future
trying to do a git bisect.

Dave

> Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
> Reviewed-by: Guenther Hutzl <hutzl@linux.vnet.ibm.com>
> ---
> 
> The idea is to remove .start support and this patch should
> be reverted, as soon this happens, or even better just
> dropped. If however dropping the support for .start encounters
> resistance, this patch should prove useful in an unexpected
> way.
> ---
>  tests/test-vmstate.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/test-vmstate.c b/tests/test-vmstate.c
> index 9a57aa0..a2ef4a8 100644
> --- a/tests/test-vmstate.c
> +++ b/tests/test-vmstate.c
> @@ -588,6 +588,53 @@ static void test_complex_vbuffer(void)
>  #undef FIELD_EQUAL
>  #undef BUFFER_EQUAL
>  
> +typedef struct {
> +    uint32_t vbuff_size;
> +    uint8_t *vbuff;
> +    uint64_t stuff;
> +} TestVBufStart;
> +
> +static const VMStateDescription vmstate_vbuff_alloc_start = {
> +    .name = "test/vbuff_alloc_start",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT64(stuff, TestVBufStart),
> +        VMSTATE_UINT32(vbuff_size, TestVBufStart),
> +        VMSTATE_VBUFFER_ALLOC_UINT32(vbuff, TestVBufStart, 1, 0, 1, vbuff_size),
> +        VMSTATE_END_OF_LIST()
> +    }
> +
> +};
> +
> +static void load_vmstate_one_obj(const VMStateDescription *vmsd, void *obj,
> +        int version_id)
> +{
> +        QEMUFile *fload = open_test_file(false);
> +
> +        SUCCESS(vmstate_load_state(fload, vmsd, obj, version_id));
> +        qemu_fclose(fload);
> +}
> +
> +static void test_vbuff_alloc_start(void)
> +{
> +    uint8_t my_vbuff1[] = {0, 1, 2, 3};
> +    uint8_t my_vbuff2[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
> +    TestVBufStart sample = {
> +        .stuff = 1,
> +        .vbuff_size = 3,
> +        .vbuff = my_vbuff1,
> +    };
> +    TestVBufStart load_obj = {
> +        .vbuff = my_vbuff2,
> +    };
> +
> +    save_vmstate(&vmstate_vbuff_alloc_start, &sample);
> +    load_vmstate_one_obj(&vmstate_vbuff_alloc_start, &load_obj, 1);
> +    g_assert_cmpint(load_obj.stuff, ==, 0);
> +    g_assert_cmpint((uint64_t) load_obj.vbuff, !=, (uint64_t) my_vbuff2);
> +}
> +
>  int main(int argc, char **argv)
>  {
>      temp_fd = mkstemp(temp_file);
> @@ -603,8 +650,8 @@ int main(int argc, char **argv)
>      g_test_add_func("/vmstate/field_exists/save/noskip", test_save_noskip);
>      g_test_add_func("/vmstate/field_exists/save/skip", test_save_skip);
>      g_test_add_func("/vmstate/complex/vbuffer", test_complex_vbuffer);
> +    g_test_add_func("/vmstate/vbuff/alloc_start", test_vbuff_alloc_start);
>      g_test_run();
> -
>      close(temp_fd);
>      unlink(temp_file);
>  
> -- 
> 2.8.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK