[igt-dev] [PATCH i-g-t v2 2/2] i915/gem_ctx_isolation:: change semantics of ctx isolation uAPI

Adrian Larumbe adrian.larumbe at collabora.com
Tue Aug 9 15:56:45 UTC 2022


On 03.08.2022 12:27, Petri Latvala wrote:
> On Mon, May 16, 2022 at 09:50:00PM +0100, Adrian Larumbe wrote:
> > ioctl I915_PARAM_HAS_CONTEXT_ISOLATION param is meant to report whether all
> > the engines in the system support context isolation, but the way the return
> > value was being used did not respect the contract on the uAPI.
> > 
> > Skip all engine tests for which context isolation is not supported. Also skip
> > tests that involve an engine reset if both RCS and CCS engines are present in
> > the system. This is because they belong to the same reset domain.
> > 
> > Signed-Off-By: Adrian Larumbe <adrian.larumbe at collabora.com>
> > ---
> >  include/drm-uapi/i915_drm.h    |   6 +-
> >  tests/i915/gem_ctx_isolation.c | 101 +++++++++++++++++++++++----------
> >  2 files changed, 72 insertions(+), 35 deletions(-)
> > 
> > diff --git a/include/drm-uapi/i915_drm.h b/include/drm-uapi/i915_drm.h
> > index f0067d26123e..327465ac3eb1 100644
> > --- a/include/drm-uapi/i915_drm.h
> > +++ b/include/drm-uapi/i915_drm.h
> > @@ -678,11 +678,7 @@ typedef struct drm_i915_irq_wait {
> >   * rather than default HW values. If true, it also ensures (insofar as HW
> >   * supports) that all state set by this context will not leak to any other
> >   * context.
> > - *
> > - * As not every engine across every gen support contexts, the returned
> > - * value reports the support of context isolation for individual engines by
> > - * returning a bitmask of each engine class set to true if that class supports
> > - * isolation.
> > + * 
> >   */
> 
> Is this chunk here accidentally? Modifications to files in
> include/drm-uapi/* should only be done by directly copying from the
> kernel.

I've handled that already in a parallel kernel patch, you can browse it at
https://lists.freedesktop.org/archives/intel-gfx/2022-July/302531.html

> >  #define I915_PARAM_HAS_CONTEXT_ISOLATION 50
> >  
> > diff --git a/tests/i915/gem_ctx_isolation.c b/tests/i915/gem_ctx_isolation.c
> > index 4233ea5784dc..ddfae493bc2c 100644
> > --- a/tests/i915/gem_ctx_isolation.c
> > +++ b/tests/i915/gem_ctx_isolation.c
> > @@ -45,6 +45,7 @@ enum {
> >  	VCS2 = ENGINE(I915_ENGINE_CLASS_VIDEO, 2),
> >  	VCS3 = ENGINE(I915_ENGINE_CLASS_VIDEO, 3),
> >  	VECS0 = ENGINE(I915_ENGINE_CLASS_VIDEO_ENHANCE, 0),
> > +	CCS0 = ENGINE(I915_ENGINE_CLASS_COMPUTE, 0),
> >  };
> >  
> >  #define ALL ~0u
> > @@ -627,9 +628,40 @@ static void compare_regs(int fd, const struct intel_execution_engine2 *e,
> >  		     num_errors, who);
> >  }
> >  
> > +static bool
> > +engine_has_context_isolation(const struct intel_execution_engine2 *e,
> > +			     int gen)
> > +{
> > +	if (gen > 8)
> > +		return true;
> > +
> > +	if (gen >= 6 && gen <= 8 && e->class == I915_ENGINE_CLASS_RENDER)
> > +		return true;
> > +
> > +	return false;
> > +}
> > +
> > +static bool
> > +has_engine_class(const intel_ctx_cfg_t *cfg, unsigned int class)
> > +{
> > +	const struct i915_engine_class_instance *eci;
> > +	unsigned int i;
> > +
> > +	igt_require(class <= I915_ENGINE_CLASS_COMPUTE);
> > +
> > +	for (i = 0; i < cfg->num_engines; i++) {
> > +		eci = &cfg->engines[i];
> > +		if (eci->engine_class == class)
> > +			return true;
> > +	}
> > +
> > +	return false;
> > +}
> > +
> >  static void nonpriv(int fd, const intel_ctx_cfg_t *cfg,
> >  		    const struct intel_execution_engine2 *e,
> > -		    unsigned int flags)
> > +		    unsigned int flags,
> > +		    int gen)
> >  {
> >  	static const uint32_t values[] = {
> >  		0x0,
> > @@ -646,7 +678,7 @@ static void nonpriv(int fd, const intel_ctx_cfg_t *cfg,
> >  	unsigned int num_values = ARRAY_SIZE(values);
> >  
> >  	/* Sigh -- hsw: we need cmdparser access to our own registers! */
> > -	igt_skip_on(intel_gen(intel_get_drm_devid(fd)) < 8);
> > +	igt_skip_on(!engine_has_context_isolation(e, gen));
> 
> The comment explains that hsw (among others) needs to have this test
> skipped, but this allows execution on hsw. Did the reasoning change?
> Either way the comment and the skip line tell different things, one
> needs changing.
> 
> Also, avoid unnecessary negation. igt_skip_on(!f) is equivalent to
> igt_require(f).

I could maybe leave that as:

igt_skip_on(intel_gen(intel_get_drm_devid(fd)) < 8);
igt_require(engine_has_context_isolation(e, gen));

to enforce both checks.

> >  
> >  	gem_quiescent_gpu(fd);
> >  
> > @@ -729,7 +761,8 @@ static void nonpriv(int fd, const intel_ctx_cfg_t *cfg,
> >  
> >  static void isolation(int fd, const intel_ctx_cfg_t *cfg,
> >  		      const struct intel_execution_engine2 *e,
> > -		      unsigned int flags)
> > +		      unsigned int flags,
> > +		      int gen)
> >  {
> >  	static const uint32_t values[] = {
> >  		0x0,
> > @@ -743,6 +776,8 @@ static void isolation(int fd, const intel_ctx_cfg_t *cfg,
> >  	unsigned int num_values =
> >  		flags & (DIRTY1 | DIRTY2) ? ARRAY_SIZE(values) : 1;
> >  
> > +	igt_skip_on(!engine_has_context_isolation(e, gen));
> 
> Avoid negation, igt_require instead.
> 
> > +
> >  	gem_quiescent_gpu(fd);
> >  
> >  	for (int v = 0; v < num_values; v++) {
> > @@ -865,7 +900,8 @@ static void inject_reset_context(int fd, const intel_ctx_cfg_t *cfg,
> >  
> >  static void preservation(int fd, const intel_ctx_cfg_t *cfg,
> >  			 const struct intel_execution_engine2 *e,
> > -			 unsigned int flags)
> > +			 unsigned int flags,
> > +			 int gen)
> >  {
> >  	static const uint32_t values[] = {
> >  		0x0,
> > @@ -882,6 +918,8 @@ static void preservation(int fd, const intel_ctx_cfg_t *cfg,
> >  	uint64_t ahnd[num_values + 1];
> >  	igt_spin_t *spin;
> >  
> > +	igt_skip_on(!engine_has_context_isolation(e, gen));
> 
> Avoid negation.
> 
> > +
> >  	gem_quiescent_gpu(fd);
> >  
> >  	ctx[num_values] = intel_ctx_create(fd, cfg);
> > @@ -902,8 +940,12 @@ static void preservation(int fd, const intel_ctx_cfg_t *cfg,
> >  	gem_close(fd, read_regs(fd, ahnd[num_values], ctx[num_values], e, flags));
> >  	igt_spin_free(fd, spin);
> >  
> > -	if (flags & RESET)
> > +	if (flags & RESET) {
> > +		igt_skip_on(has_engine_class(cfg, I915_ENGINE_CLASS_RENDER) &&
> > +			    has_engine_class(cfg, I915_ENGINE_CLASS_COMPUTE));
> > +
> >  		inject_reset_context(fd, cfg, e);
> > +	}
> 
> This and the other bits of this patch do what it says on the commit
> message, but I'm unable to judge whether that's correct to do so. Can
> a gem dev take a look at this? Tvrtko maybe (random selection)?

Daniel Vetter raised this issue on gitlab some time ago, maybe he could join to
have a quick look: https://gitlab.freedesktop.org/drm/intel/-/issues/4264

> -- 
> Petri Latvala
> 
> 
> >  
> >  	switch (flags & SLEEP_MASK) {
> >  	case NOSLEEP:
> > @@ -962,7 +1004,7 @@ static unsigned int __has_context_isolation(int fd)
> >  	int value = 0;
> >  
> >  	memset(&gp, 0, sizeof(gp));
> > -	gp.param = 50; /* I915_PARAM_HAS_CONTEXT_ISOLATION */
> > +	gp.param = I915_PARAM_HAS_CONTEXT_ISOLATION;
> >  	gp.value = &value;
> >  
> >  	igt_ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
> > @@ -971,21 +1013,19 @@ static unsigned int __has_context_isolation(int fd)
> >  	return value;
> >  }
> >  
> > -#define test_each_engine(e, i915, cfg, mask) \
> > +#define test_each_engine(e, i915, cfg)	  \
> >  	for_each_ctx_cfg_engine(i915, cfg, e) \
> > -		for_each_if(mask & (1 << (e)->class)) \
> > -			igt_dynamic_f("%s", (e)->name)
> > +		igt_dynamic_f("%s", (e)->name)
> >  
> >  igt_main
> >  {
> > -	unsigned int has_context_isolation = 0;
> > +	bool has_context_isolation = 0;
> >  	const struct intel_execution_engine2 *e;
> >  	intel_ctx_cfg_t cfg;
> >  	int i915 = -1;
> > +	int gen;
> >  
> >  	igt_fixture {
> > -		int gen;
> > -
> >  		i915 = drm_open_driver(DRIVER_INTEL);
> >  		igt_require_gem(i915);
> >  		igt_require(gem_has_contexts(i915));
> > @@ -995,6 +1035,7 @@ igt_main
> >  		igt_require(has_context_isolation);
> >  
> >  		gen = intel_gen(intel_get_drm_devid(i915));
> > +		igt_require(gen >= 2);
> >  
> >  		igt_warn_on_f(gen > LAST_KNOWN_GEN,
> >  			      "GEN not recognized! Test needs to be updated to run.\n");
> > @@ -1006,43 +1047,43 @@ igt_main
> >  	}
> >  
> >  	igt_subtest_with_dynamic("nonpriv") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			nonpriv(i915, &cfg, e, 0);
> > +		test_each_engine(e, i915, &cfg)
> > +			nonpriv(i915, &cfg, e, 0, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("nonpriv-switch") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			nonpriv(i915, &cfg, e, DIRTY2);
> > +		test_each_engine(e, i915, &cfg)
> > +			nonpriv(i915, &cfg, e, DIRTY2, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("clean") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			isolation(i915, &cfg, e, 0);
> > +		test_each_engine(e, i915, &cfg)
> > +			isolation(i915, &cfg, e, 0, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("dirty-create") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			isolation(i915, &cfg, e, DIRTY1);
> > +		test_each_engine(e, i915, &cfg)
> > +			isolation(i915, &cfg, e, DIRTY1, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("dirty-switch") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			isolation(i915, &cfg, e, DIRTY2);
> > +		test_each_engine(e, i915, &cfg)
> > +			isolation(i915, &cfg, e, DIRTY2, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("preservation") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			preservation(i915, &cfg, e, 0);
> > +		test_each_engine(e, i915, &cfg)
> > +			preservation(i915, &cfg, e, 0, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("preservation-S3") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			preservation(i915, &cfg, e, S3);
> > +		test_each_engine(e, i915, &cfg)
> > +			preservation(i915, &cfg, e, S3, gen);
> >  	}
> >  
> >  	igt_subtest_with_dynamic("preservation-S4") {
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			preservation(i915, &cfg, e, S4);
> > +		test_each_engine(e, i915, &cfg)
> > +			preservation(i915, &cfg, e, S4, gen);
> >  	}
> >  
> >  	igt_fixture {
> > @@ -1052,8 +1093,8 @@ igt_main
> >  	igt_subtest_with_dynamic("preservation-reset") {
> >  		igt_hang_t hang = igt_allow_hang(i915, 0, 0);
> >  
> > -		test_each_engine(e, i915, &cfg, has_context_isolation)
> > -			preservation(i915, &cfg, e, RESET);
> > +		test_each_engine(e, i915, &cfg)
> > +			preservation(i915, &cfg, e, RESET, gen);
> >  
> >  		igt_disallow_hang(i915, hang);
> >  	}
> > -- 
> > 2.35.1
> > 

Adrian Larumbe


More information about the igt-dev mailing list