Implement single_query_cached_kv_attention kernel (#3)

csrc/attention.cpp

@@ -0,0 +1,19 @@
+#include <torch/extension.h>
+
+void single_query_cached_kv_attention(
+  torch::Tensor& out,
+  torch::Tensor& query,
+  torch::Tensor& key_cache,
+  torch::Tensor& value_cache,
+  float scale,
+  torch::Tensor& block_tables,
+  torch::Tensor& context_lens,
+  int block_size,
+  int max_context_len);
+
+PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
+  m.def(
+    "single_query_cached_kv_attention",
+    &single_query_cached_kv_attention,
+    "Compute the attention between an input query and the cached key/value tensors");
+}