Re: [igt-dev] [PATCH i-g-t 13/24] i915/gem_ctx_param: Test set/get (copy) VM

Tvrtko Ursulin
2019-03-26T10:33:04Z

On 26/03/2019 10:22, Tvrtko Ursulin wrote:
>
> On 22/03/2019 09:21, Chris Wilson wrote:
>> Exercise reusing the GTT of one ctx in another.
>>
>> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>> ---
>>   tests/i915/gem_ctx_param.c | 83 ++++++++++++++++++++++++++++++++------
>>   1 file changed, 71 insertions(+), 12 deletions(-)
>>
>> diff --git a/tests/i915/gem_ctx_param.c b/tests/i915/gem_ctx_param.c
>> index b3f8637df..54ade8b4b 100644
>> --- a/tests/i915/gem_ctx_param.c
>> +++ b/tests/i915/gem_ctx_param.c
>> @@ -36,17 +36,6 @@ IGT_TEST_DESCRIPTION("Basic test for context
>> set/get param input validation.");
>>   #define NEW_CTX    BIT(0)
>>   #define USER BIT(1)
>> -static int reopen_driver(int fd)
>> -{
>> -    char path[256];
>> -
>> -    snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
>> -    fd = open(path, O_RDWR);
>> -    igt_assert_lte(0, fd);
>> -
>> -    return fd;
>> -}
>> -
>>   static void set_priority(int i915)
>>   {
>>       static const int64_t test_values[] = {
>> @@ -91,7 +80,7 @@ static void set_priority(int i915)
>>       igt_permute_array(values, size, igt_exchange_int64);
>>       igt_fork(flags, NEW_CTX | USER) {
>> -        int fd = reopen_driver(i915);
>> +        int fd = gem_reopen_driver(i915);
>>           struct drm_i915_gem_context_param arg = {
>>               .param = I915_CONTEXT_PARAM_PRIORITY,
>>               .ctx_id = flags & NEW_CTX ? gem_context_create(fd) : 0,
>> @@ -143,6 +132,73 @@ static void set_priority(int i915)
>>       free(values);
>>   }
>> +static uint32_t __batch_create(int i915, uint32_t offset)
>> +{
>> +    const uint32_t bbe = MI_BATCH_BUFFER_END;
>> +    uint32_t handle;
>> +
>> +    handle = gem_create(i915, ALIGN(offset + 4, 4096));
>> +    gem_write(i915, handle, offset, &bbe, sizeof(bbe));
>> +
>> +    return handle;
>> +}
>> +
>> +static uint32_t batch_create(int i915)
>> +{
>> +    return __batch_create(i915, 0);
>> +}
>
> Looks familiar. :)
>
>> +
>> +static void test_vm(int i915)
>> +{
>> +    struct drm_i915_gem_exec_object2 batch = {
>> +        .handle = batch_create(i915),
>> +    };
>> +    struct drm_i915_gem_execbuffer2 eb = {
>> +        .buffers_ptr = to_user_pointer(&batch),
>> +        .buffer_count = 1,
>> +    };
>> +    struct drm_i915_gem_context_param arg = {
>> +        .param = I915_CONTEXT_PARAM_VM,
>> +    };
>> +    uint32_t parent, child;
>> +
>> +    arg.value = -1ull;
>> +    igt_require(__gem_context_set_param(i915, &arg) == -ENOENT);
>> +
>> +    parent = gem_context_create(i915);
>> +    child = gem_context_create(i915);
>> +
>> +    eb.rsvd1 = parent;
>> +    batch.offset = 48 << 20;
>> +    gem_execbuf(i915, &eb);
>> +    igt_assert_eq_u64(batch.offset, 48 << 20);
>> +
>> +    eb.rsvd1 = child;
>> +    batch.offset = 0;
>> +    gem_execbuf(i915, &eb);
>> +    igt_assert_eq_u64(batch.offset, 0);
>> +
>> +    eb.rsvd1 = parent;
>> +    gem_execbuf(i915, &eb);
>> +    igt_assert_eq_u64(batch.offset, 48 << 20);
>
> Please drop a comment at the start of these execbuf operations to
> explain what and why. We don't need softpin to guarantee they will get
> pinned to where we want them to?
>
>> +
>> +    arg.ctx_id = parent;
>> +    gem_context_get_param(i915, &arg);
>> +
>> +    arg.ctx_id = child;
>> +    gem_context_set_param(i915, &arg);
>
> Another get param to assert child vm id is the same as the parent?
>
> Also, try self-assign? I mean set the same vm id as already have?

And a test to check vm id space is per fd - that same id can be obtained
in two fds, if not too fragile/white-box wrt idr allocator.

And also that different id from one fd cannot be passed to set_vm in
another. This one should be robust.

Regards,

Tvrtko

>> +
>> +    eb.rsvd1 = child;
>> +    gem_execbuf(i915, &eb);
>> +    igt_assert_eq_u64(batch.offset, 48 << 20);
>
> Interesting, for me at least. Please put a comment here.
>
>> +
>> +    gem_context_destroy(i915, child);
>> +    gem_context_destroy(i915, parent);
>> +
>> +    gem_sync(i915, batch.handle);
>> +    gem_close(i915, batch.handle);
>> +}
>> +
>>   igt_main
>>   {
>>       struct drm_i915_gem_context_param arg;
>> @@ -253,6 +309,9 @@ igt_main
>>           gem_context_set_param(fd, &arg);
>>       }
>> +    igt_subtest("vm")
>> +        test_vm(fd);
>> +
>>       arg.param = I915_CONTEXT_PARAM_PRIORITY;
>>       igt_subtest("set-priority-not-supported") {
>>
>
> Add to basic test list? Or call basic-vm? Honestly don't remember how we
> do it these days..
>
> Regards,
>
> Tvrtko