Well I guess for that you just look at the propaganda coming out at the time, just from Wikipedia it reads
"Stalin himself declared in a 1941 broadcast that Germany waged war to exterminate the peoples of the USSR. Propaganda published in Pravda denounced all Germans as killers, bloodsuckers, and cannibals, and much play was made of atrocity claims. Hatred was actively and overtly encouraged.They were told that the Germans took no prisoners. Partisans were encouraged to see themselves as avengers. Many anti-German films in the Nazi era revolved about the persecution of Jews in Germany, such as Professor Mamlock and The Oppenheim Family.[110] Girl No. 217 depicted the horrors inflicted on Russian POWs, especially the enslavement of the main character Tanya to an inhuman German family,[171] reflecting the harsh treatment of OST-Arbeiter in Nazi Germany."
Considering this was the official state line on the Germans... I'd say the Soviet public were very aware of the situation at hand.