Add vLLM v0.18.1 source tree with KV transfer abort fix

third_party/vllm/ now tracked in git for direct patch management.
Based on vLLM v0.18.1 release with one patch applied:

  vllm/v1/core/sched/scheduler.py:
    Replace fatal assert with graceful skip when KV transfer callback
    arrives for an already-aborted request during PD disaggregated serving.

Future vLLM modifications should be made directly in third_party/vllm/
and committed normally. The patches/ directory is kept as documentation
of what changed from upstream.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

third_party/vllm/csrc/cutlass_extensions/common.hpp

@@ -0,0 +1,165 @@
+#pragma once
+
+#include "cutlass/cutlass.h"
+#include <climits>
+#include "cuda_runtime.h"
+#include <cstdio>
+#include <cstdlib>
+
+/**
+ * Helper function for checking CUTLASS errors
+ */
+#define CUTLASS_CHECK(status)                       \
+  {                                                 \
+    cutlass::Status error = status;                 \
+    TORCH_CHECK(error == cutlass::Status::kSuccess, \
+                cutlassGetStatusString(error));     \
+  }
+
+inline int get_cuda_max_shared_memory_per_block_opt_in(int const device) {
+  int max_shared_mem_per_block_opt_in = 0;
+  cudaDeviceGetAttribute(&max_shared_mem_per_block_opt_in,
+                         cudaDevAttrMaxSharedMemoryPerBlockOptin, device);
+  return max_shared_mem_per_block_opt_in;
+}
+
+int32_t get_sm_version_num();
+
+/**
+ * A wrapper for a kernel that is used to guard against compilation on
+ * architectures that will never use the kernel. The purpose of this is to
+ * reduce the size of the compiled binary.
+ * __CUDA_ARCH__ is not defined in host code, so this lets us smuggle the ifdef
+ * into code that will be executed on the device where it is defined.
+ */
+
+template <typename Kernel>
+struct enable_sm75_to_sm80 : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE static void invoke(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ >= 750 && __CUDA_ARCH__ < 800
+    Kernel::invoke(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm[75, 80).\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm80_to_sm89 : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE static void invoke(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ >= 800 && __CUDA_ARCH__ < 890
+    Kernel::invoke(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm[80, 89).\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm89_to_sm90 : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE static void invoke(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ >= 890 && __CUDA_ARCH__ < 900
+    Kernel::invoke(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm[89, 90).\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm90_or_later : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE void operator()(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ >= 900
+    Kernel::operator()(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm >= 90.\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm90_only : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE void operator()(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ == 900
+    Kernel::operator()(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm90.\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm100f_only : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE void operator()(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ == 1000 || __CUDA_ARCH__ == 1030
+    Kernel::operator()(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm100f.\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm100a_only : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE void operator()(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ == 1000
+    Kernel::operator()(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm100a.\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+template <typename Kernel>
+struct enable_sm120_only : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE void operator()(Args&&... args) {
+#if defined __CUDA_ARCH__
+  #if __CUDA_ARCH__ == 1200
+    Kernel::operator()(std::forward<Args>(args)...);
+  #else
+    printf("This kernel only supports sm120.\n");
+    asm("trap;");
+  #endif
+#endif
+  }
+};
+
+// SM12x family includes SM120 (RTX 5090) and SM121 (DGX Spark GB10)
+template <typename Kernel>
+struct enable_sm120_family : Kernel {
+  template <typename... Args>
+  CUTLASS_DEVICE void operator()(Args&&... args) {
+#if defined __CUDA_ARCH__ && (__CUDA_ARCH__ >= 1200 && __CUDA_ARCH__ < 1300)
+    Kernel::operator()(std::forward<Args>(args)...);
+#endif
+  }
+};