I don't believe the general populace of Germany, particularly young housewives like my grandmother, knew what was going on. Even the Jews didn't understand what was happening until it was too late.
I tend to see such considerations being complicated, based largely on two major factors:
* Geographical and physical proximity to mass murder.
* The likelihood of military versus civilian exposure to such atrocities.
Most civilians
physically and geographically removed from concentrations camps in urban areas of Germany probably didn't know, short of being directly involved as party administrators. However OTOH those living nearby weren't stupid, either. Knowing not to ask questions yet being able to see, hear and smell something most unnatural. Do as you're told and do not ask questions. A major tenet of life in a totalitarian system, apart from a culture that inherently respected authority. With many citizens instantly in denial if questioned, just out of an understandable sense for self-preservation.
Conversely for so many Germans serving on the Eastern Front, I suspect it would have been difficult for them not to see so many actions taken against civilians in terms of race and having partaken in partisan actions or political administrators resulting in summary executions. Not to mention that the Einsatzgruppen who conducted so many such murders in occupied territories consisted from both the ranks of the regular army, as well as the SS. In other words, far too many witnesses for such events to deny that they happened.
Hearing from former veterans of the US Army who actually liberated such camps on the Western Front and that portion of Germany they occupied towards the end of the war seemed pretty certain that the locals nearby knew exactly what was happening. Being quite skeptical of German civilians so apt to proclaim, "Ich bin kein Nazi!" (I am not a Nazi). Though it could also be surmised that a soldier's impression of the Germans would be prejudiced, fueled by victory.
There was also a common element of incredulity amongst Jews and gentiles alike. The rational notion that mass murder on such a scale was morally and ethically inconceivable. Even as Nazi oppression incrementally increased in the 30s, many Jews always thought that there would be point in time when such acts would diminish or even cease altogether to further national policy among the civilized world. -Which never happened.
As far as blame for entire populations regarding such regimes, the dynamics of totalitarianism seldom change. That in the beginning of such struggles the masses certainly played their part in them, but not all of them. Conversely once most any totalitarian regime is firmly in power, that the slightest degree of political dissent becomes nearly impossible without the threat of imprisonment or death. When day-to-day existence for most citizens is like "being in a vacuum" being subject to a barrage of forced obedience and propaganda.
With opposing views of thought on such issues, there's no telling what Hollywood would or will do when it comes to the truth of such events outside the realm of a pure documentary, if there even is such a thing among creators of mass media these days. That their primary goal remains entertainment rather than enlightenment, all to accrue box office receipts and perpetuate shareholder equity.
Leaving real creativity and historical accuracy primarily to only a few independent filmmakers who may have less financial obligations to themselves and private investors. Though they too may also be at times more interested
in the art of film than those same considerations of historical accuracy. Yet another reason to sense that historical accuracy in the media will remain within hopes and dreams at best.