Some time ago I watched the excellent Russian movie "The Horde" with English subtitles and got intrigued by a few expressions from there, with one of them being "только и всего." The movie is on Youtube in full, and here is the link that brings you to the scene with that expression: Link.
I see in Google that this is a very common idiomatic expression.
From the subtitles and from the research done by me I learned that the meaning of that expression is "nothing more than just this," but I cannot understand the literal logic of the expression. To me, it sounds as nonsensical as "only and everything."
First of all, I got confused as to what the conjunction "и" is doing here. I do not understand what it logically connects. In Google, I found exactly zero results with the phrase "сделай только и это" and 182 results with the same phrase but without the conjunction "и" in it.
Second, I do not understand the word "всего" here. It might be the genitive case of "everything" like in "он устал от всегo." It might be an adverb meaning "in total" like in "всего она перевела три книги." It might be a particle meaning "only" like in "у меня всего три рубля." There might be other possibilities.
Finally, I do not see how all these three words make sense together. At some point I thought that the literal meaning might be "just and only," where "всего" is interpreted as a particle meaning "only" and where the conjunction "и" is a means of connecting two synonyms, "just" and "only." However, a problem with this version is that this idiom is sometimes used with the conjunction "и" placed at the end like in the following quote from Turgenev: "Притворяется, что всё возится с Колей, а только всего и делает, что говорит о нем с умными людьми." Another problem is that I was unable to find any example with the reversed word order, "всего и только," which suggests that the word order in important.
I thought that the idiom might be a shortened version of a longer idiom, but was unable to find any.
My question is this: What is the actual precise logic of "только и всего" from the literal standpoint? I am curious how these three words logically make sense together or made sense together when the idiom came into existence.