hexagon: support for multi-NPU devices (IQ9, IQ10) and fully asynchronous backend

docs/backend/snapdragon/CMakeUserPresets.json

@@ -8,7 +8,7 @@
         "toolset":      { "value": "host=x86_64", "strategy": "external" },
         "cacheVariables": {
             "ANDROID_ABI":      "arm64-v8a",
-            "ANDROID_PLATFORM": "android-31",
+            "ANDROID_PLATFORM": "android-34",
             "CMAKE_TOOLCHAIN_FILE": "$env{ANDROID_NDK_ROOT}/build/cmake/android.toolchain.cmake",
             "CMAKE_C_FLAGS":   "-march=armv8.7a+fp16+dotprod+i8mm -fvectorize -ffp-model=fast -fno-finite-math-only -flto -D_GNU_SOURCE",
             "CMAKE_CXX_FLAGS": "-march=armv8.7a+fp16+dotprod+i8mm -fvectorize -ffp-model=fast -fno-finite-math-only -flto -D_GNU_SOURCE",

docs/backend/snapdragon/developer.md

@@ -39,22 +39,21 @@ the repacking.
 
 ## Large model handling
 
-Hexagon NPU session (aka Process Domain (PD) in the Hexagon docs) is limited to a memory mapping of around 3.5GB.
-In llama.cpp/GGML the Hexagon session is mapped to a single GGML backend device (HTP0, HTP1, etc).
+Hexagon NPU sessions (aka Process Domains (PD) in the Hexagon SDK) are limited to a maximum memory mapping window of around 3.5GB.
+In llama.cpp/GGML, each Hexagon session is mapped to a single GGML backend device (e.g., `HTP0:0`, `HTP0:1`, etc. when using
+`GGML_HEXAGON_DEVICES`, or `HTP0`, `HTP1` in legacy mode).
 
-In order to map models larger than 3.5GB we need to allocate multiple devices and split the model.
-For this we're taking advantage of the llama.cpp/GGML multi-GPU layer-splitting support.
-Each Hexagon device behaves like a GPU from the offload and model splitting perspective.
+To support running models larger than 3.5GB on a single device, the Hexagon backend dynamically maps and unmaps execution buffers
+during the graph execution cycle to stay within the Process Domain window. This enables large models to run successfully on a single
+NPU device.
 
-Here is an example of running GPT-OSS-20B model on a newer Snapdragon device with 16GB of DDR.
+Alternatively, users can choose to use standard llama.cpp/GGML layer-splitting mode to partition and split the model across
+multiple Hexagon devices or virtual sessions (which behave like multiple GPUs from the offload and splitting perspective).
+
+Here is an example of running GPT-OSS-20B model on a Snapdragon device using 4 virtual sessions on a single NPU (physical index 0).
 
 ```
-M=gpt-oss-20b-Q4_0.gguf NDEV=4 D=HTP0,HTP1,HTP2,HTP3 P=surfing.txt scripts/snapdragon/adb/run-completion.sh -f surfing.txt -n 32
-...
-LD_LIBRARY_PATH=/data/local/tmp/llama.cpp/lib
-ADSP_LIBRARY_PATH=/data/local/tmp/llama.cpp/lib
-GGML_HEXAGON_NDEV=4 ./bin/llama-cli --load-mode none -m /data/local/tmp/llama.cpp/../gguf/gpt-oss-20b-Q4_0.gguf
-      -t 4 --ctx-size 8192 --batch-size 128 -ctk q8_0 -ctv q8_0 -fa on -ngl 99 --device HTP0,HTP1,HTP2,HTP3 -no-cnv -f surfing.txt
+~/src/llama.cpp$ ./scripts/snapdragon/run.py --target adb --devices HTP0:0,HTP0:1,HTP0:2,HTP0:3 -- llama-cli --load-mode none -m /data/local/tmp/gguf/gpt-oss-20b-Q4_0.gguf -t 4 --ctx-size 8192 --batch-size 128 -ctk q8_0 -ctv q8_0 -fa on -ngl 99 -no-cnv -f surfing.txt
 ...
 llama_model_loader: - type  f32:  289 tensors
 llama_model_loader: - type q4_0:   96 tensors
@@ -63,47 +62,39 @@ llama_model_loader: - type mxfp4:  72 tensors
 ...
 load_tensors: offloaded 25/25 layers to GPU
 load_tensors:          CPU model buffer size =  1182.09 MiB
-load_tensors:         HTP1 model buffer size =     6.64 MiB
-load_tensors:  HTP1-REPACK model buffer size =  2505.94 MiB
-load_tensors:         HTP3 model buffer size =     5.55 MiB
-load_tensors:  HTP3-REPACK model buffer size =  2088.28 MiB
-load_tensors:         HTP0 model buffer size =     7.75 MiB
-load_tensors:  HTP0-REPACK model buffer size =  2923.59 MiB
-load_tensors:         HTP2 model buffer size =     6.64 MiB
-load_tensors:  HTP2-REPACK model buffer size =  2505.94 MiB
+load_tensors:       HTP0:1 model buffer size =  2512.58 MiB
+load_tensors:       HTP0:3 model buffer size =  2093.83 MiB
+load_tensors:       HTP0:0 model buffer size =  2931.34 MiB
+load_tensors:       HTP0:2 model buffer size =  2512.58 MiB
 ...
 llama_context: n_ctx_per_seq (8192) < n_ctx_train (131072) -- the full capacity of the model will not be utilized
 llama_context:        CPU  output buffer size =     0.77 MiB
 llama_kv_cache_iswa: creating non-SWA KV cache, size = 8192 cells
-llama_kv_cache:       HTP1 KV buffer size =    25.50 MiB
-llama_kv_cache:       HTP3 KV buffer size =    25.50 MiB
-llama_kv_cache:       HTP0 KV buffer size =    25.50 MiB
-llama_kv_cache:       HTP2 KV buffer size =    25.50 MiB
+llama_kv_cache:     HTP0:1 KV buffer size =    25.50 MiB
+llama_kv_cache:     HTP0:3 KV buffer size =    25.50 MiB
+llama_kv_cache:     HTP0:0 KV buffer size =    25.50 MiB
+llama_kv_cache:     HTP0:2 KV buffer size =    25.50 MiB
 llama_kv_cache: size =  102.00 MiB (  8192 cells,  12 layers,  1/1 seqs), K (q8_0):   51.00 MiB, V (q8_0):   51.00 MiB
 llama_kv_cache_iswa: creating     SWA KV cache, size = 256 cells
-llama_kv_cache:       HTP1 KV buffer size =     0.80 MiB
-llama_kv_cache:       HTP3 KV buffer size =     0.53 MiB
-llama_kv_cache:       HTP0 KV buffer size =     1.06 MiB
-llama_kv_cache:       HTP2 KV buffer size =     0.80 MiB
+llama_kv_cache:     HTP0:1 KV buffer size =     0.80 MiB
+llama_kv_cache:     HTP0:3 KV buffer size =     0.53 MiB
+llama_kv_cache:     HTP0:0 KV buffer size =     1.06 MiB
+llama_kv_cache:     HTP0:2 KV buffer size =     0.80 MiB
 llama_kv_cache: size =    3.19 MiB (   256 cells,  12 layers,  1/1 seqs), K (q8_0):    1.59 MiB, V (q8_0):    1.59 MiB
-llama_context:       HTP0 compute buffer size =    16.06 MiB
-llama_context:       HTP1 compute buffer size =    16.06 MiB
-llama_context:       HTP2 compute buffer size =    16.06 MiB
-llama_context:       HTP3 compute buffer size =    16.06 MiB
+llama_context:     HTP0:0 compute buffer size =    16.06 MiB
+llama_context:     HTP0:1 compute buffer size =    16.06 MiB
+llama_context:     HTP0:2 compute buffer size =    16.06 MiB
+llama_context:     HTP0:3 compute buffer size =    16.06 MiB
 llama_context:        CPU compute buffer size =    98.19 MiB
 ...
 llama_perf_context_print: prompt eval time =    3843.67 ms /   197 tokens ( 19.51 ms per token, 51.25 tokens per second)
 llama_perf_context_print:        eval time =    1686.13 ms /    31 runs   ( 54.39 ms per token, 18.39 tokens per second)
 llama_perf_context_print:       total time =    6266.30 ms /   228 tokens
 llama_perf_context_print:    graphs reused =         30
 llama_memory_breakdown_print: | memory breakdown [MiB] | total   free    self   model   context   compute    unaccounted |
-llama_memory_breakdown_print: |   - HTP0 (Hexagon)     |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
-llama_memory_breakdown_print: |   - HTP1 (Hexagon)     |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
-llama_memory_breakdown_print: |   - HTP2 (Hexagon)     |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
-llama_memory_breakdown_print: |   - HTP3 (Hexagon)     |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
+llama_memory_breakdown_print: |   - HTP0:0 (Hexagon)   |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
+llama_memory_breakdown_print: |   - HTP0:1 (Hexagon)   |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
+llama_memory_breakdown_print: |   - HTP0:2 (Hexagon)   |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
+llama_memory_breakdown_print: |   - HTP0:3 (Hexagon)   |  2048 = 2048 + (   0 =     0 +       0 +       0) +           0 |
 llama_memory_breakdown_print: |   - Host               |                 1476 =  1208 +     105 +     162                |
-llama_memory_breakdown_print: |   - HTP1-REPACK        |                 2505 =  2505 +       0 +       0                |
-llama_memory_breakdown_print: |   - HTP3-REPACK        |                 2088 =  2088 +       0 +       0                |
-llama_memory_breakdown_print: |   - HTP0-REPACK        |                 2923 =  2923 +       0 +       0                |
-llama_memory_breakdown_print: |   - HTP2-REPACK        |                 2505 =  2505 +       0 +       0                |
 ```

docs/backend/snapdragon/linux.md

@@ -1,25 +1,37 @@
 # Snapdragon-based Linux devices
 
-## Docker Setup
+The cross-compilation is performed using the Snapdragon Linux Docker toolchain image (see
+[github.com/snapdragon-toolchain](https://github.com/snapdragon-toolchain)):
 
-The easiest way to build llama.cpp for a Snapdragon-based Linux device is using the toolchain Docker image (see [github.com/snapdragon-toolchain](https://github.com/snapdragon-toolchain)).
-This image includes OpenCL SDK, Hexagon SDK, CMake, and the ARM64 Linux cross-compilation toolchain.
+* **Linux toolchain**: `ghcr.io/snapdragon-toolchain/arm64-linux:v0.7`
 
-Cross-compilation is supported on **Linux X86** hosts. The resulting binaries are deployed to and run on the target **Qualcomm Snapdragon ARM64 Linux** device.
+The unified build utility (`scripts/snapdragon/build.py`) automatically pulls
+and orchestrates this container to perform target compilation. You only need to
+ensure that Docker is running on your host machine.
 
+
+## How to Build
+
+### Using build.py script (Recommended)
+
+The easiest way to build llama.cpp is by using the `scripts/snapdragon/build.py` script. It automatically copies the CMake presets,
+launches the correct compilation Docker container, builds the libraries and tools,
+installs them, and optionally pushes them to your target device.
+
+Build and deploy for a Linux target (using SSH deployment alias `lnx` or `linux`):
 ```
-~/src/llama.cpp$ docker run -it -u $(id -u):$(id -g) --volume $(pwd):/workspace --platform linux/amd64 ghcr.io/snapdragon-toolchain/arm64-linux:v0.1
-[d]/> cd /workspace
+$ ./scripts/snapdragon/build.py --target lnx:user@host --push
 ```
 
-Note: The rest of the **Linux** build process assumes that you're running inside the toolchain container.
+### Manual CMake Build
 
+Alternatively, you can build llama.cpp manually by entering the cross-compilation Docker container and running the CMake commands:
 
-## How to Build
+```bash
+# Start the cross-compilation container manually:
+~/src/llama.cpp$ docker run -it --rm -u $(id -u):$(id -g) --volume $(pwd):/workspace --platform linux/amd64 ghcr.io/snapdragon-toolchain/arm64-linux:v0.7
 
-Let's build llama.cpp with CPU, OpenCL, and Hexagon backends via CMake presets:
-
-```
+# Inside the container, build the project using presets:
 [d]/workspace> cp docs/backend/snapdragon/CMakeUserPresets.json .
 
 [d]/workspace> cmake --preset arm64-linux-snapdragon-release -B build-snapdragon
@@ -30,17 +42,19 @@ Let's build llama.cpp with CPU, OpenCL, and Hexagon backends via CMake presets:
 To generate an installable "package" simply use cmake --install, then zip it:
 
 ```
-[d]/workspace> cmake --install build-snapdragon --prefix pkg-snapdragon
-[d]/workspace> zip -r pkg-snapdragon.zip pkg-snapdragon
+[d]/workspace> cmake --install build-snapdragon --prefix pkg-linux
+[d]/workspace> zip -r pkg-linux.zip pkg-linux
 ```
 
 ## How to Install
 
-For this step, you will deploy the built binaries and libraries to the target Linux device. Transfer `pkg-snapdragon.zip` to the target device, then unzip it and set up the environment variables:
+For this step, you will deploy the built binaries and libraries to the target
+Linux device. Transfer `pkg-linux.zip` to the target device, then unzip it
+and set up the environment variables:
 
 ```
-$ unzip pkg-snapdragon.zip
-$ cd pkg-snapdragon
+$ unzip pkg-linux.zip
+$ cd pkg-linux
 $ export LD_LIBRARY_PATH=./lib
 $ export ADSP_LIBRARY_PATH=./lib
 ```
@@ -52,7 +66,28 @@ $ wget https://huggingface.co/bartowski/Llama-3.2-3B-Instruct-GGUF/resolve/main/
 ```
 
 ## How to Run
-Next, since we have setup the environment variables, we can run the llama-cli with the Hexagon backends:
+You can run locally on the Snapdragon Linux device:
+```
+$ ./scripts/snapdragon/run.py --devices HTP0 -- llama-cli -m Llama-3.2-3B-Instruct-Q4_0.gguf -ngl 99 -p "what is the most popular cookie in the world?"
+```
+
+Or run remotely from your host development machine using the SSH target option:
+```
+$ ./scripts/snapdragon/run.py --target lnx:user@host --devices HTP0 -- llama-cli -m Llama-3.2-3B-Instruct-Q4_0.gguf -ngl 99 -p "what is the most popular cookie in the world?"
+```
+
+For multi-NPU systems, you can run a tensor split completion command targeting a remote Linux system:
+```
+$ ./scripts/snapdragon/run.py --target ubuntu:maxk@192.168.1.87 --device HTP0:0,HTP1:0 -- llama-completion -m models/gemma-2b-it-Q4_0.gguf -f prompts/sample_prompt_1024.txt --jinja -st --split-mode tensor --ctx-size 8192
+```
+
+This translates to the following command being executed remotely via SSH:
+```
++ ssh maxk@192.168.1.87 "cd ~/llama.cpp && ulimit -c unlimited && LD_LIBRARY_PATH=./lib ADSP_LIBRARY_PATH=./lib GGML_HEXAGON_DEVICES=HTP0:0,HTP1:0 GGML_HEXAGON_OPPOLL=1 ./bin/llama-completion -m models/gemma-2b-it-Q4_0.gguf -f prompts/sample_prompt_1024.txt --jinja -st --split-mode tensor --ctx-size 8192 -v -n 16 --device HTP0:0,HTP1:0 -ngl 99 --ubatch-size 1024 -fa on -t 6"
+```
+
+Alternatively, you can run the binary directly on the device:
 ```
 $ ./bin/llama-cli -m Llama-3.2-3B-Instruct-Q4_0.gguf --device HTP0 -ngl 99 -p "what is the most popular cookie in the world?"
 ```
+

docs/backend/snapdragon/windows.md

@@ -1,3 +1,18 @@
+# Snapdragon-based Windows devices
+
+## Tool Dependencies
+
+Native Windows 11 arm64 builds have the following tool dependencies:
+- MS Visual Studio 2026 (Community Edition or Pro)
+  - MSVC arm64 standard and runtime libraries
+  - UCRT and Driver Kit
+- LLVM core libraries and Clang compiler (winget)
+- CMake, Git, Python (winget)
+- Hexagon SDK Community Edition 6.6 or later (see below)
+- OpenCL SDK 2.3 or later (see below)
+
+Note: The rest of the **Windows** build process assumes that you're running natively in Powershell.
+
 ## Overview
 
 The document covers procedures for installing the latest GPU and NPU drivers, and OpenCL and Hexagon SDKs.
@@ -53,7 +68,8 @@ Download the driver from
 
     https://softwarecenter.qualcomm.com/catalog/item/Qualcomm_HND
 
-After the automated installation and reboot please make sure that the Hexagon NPU device shows up in the `Device Manager` (under `Neural Processors`).
+After the automated installation and reboot please make sure that the Hexagon NPU device shows up in the `Device Manager`
+(under `Neural Processors`).
 
 If the device is not available you can try installing all components (`qcnspmcdm8380`, `qcnspmcdm8380_ext`) manually.
 The components are extracted into
@@ -130,12 +146,12 @@ However, additional settings are required for generating and signing HTP Ops lib
 
 > cmake --preset arm64-windows-snapdragon-release -B build-wos
 ...
-> cmake --install build-wos --prefix pkg-snapdragon
+> cmake --install build-wos --prefix pkg-wos
 ```
 
 Once the build is complete HTP ops libraries will be installed like this
 ```
-> dir pkg-snapdragon/lib
+> dir pkg-wos/lib
 ...
 -a----         1/22/2026   6:01 PM         187656 libggml-htp-v73.so
 -a----         1/22/2026   6:01 PM         191752 libggml-htp-v75.so
@@ -147,15 +163,15 @@ Once the build is complete HTP ops libraries will be installed like this
 The .cat file, the signature and proper certificate installation can be verified with
 
 ```
-> signtool.exe verify /v /pa .\pkg-snapdragon\lib\libggml-htp.cat
-Verifying: .\pkg-snapdragon\lib\libggml-htp.cat
+> signtool.exe verify /v /pa .\pkg-wos\lib\libggml-htp.cat
+Verifying: .\pkg-wos\lib\libggml-htp.cat
 
 Signature Index: 0 (Primary Signature)
 Hash of file (sha256): 9820C664DA59D5EAE31DBB664127FCDAEF59CDC31502496BC567544EC2F401CF
 
 Signing Certificate Chain:
         Issued to: GGML.HTP.v1
 ...
-Successfully verified: .\pkg-snapdragon\lib\libggml-htp.cat
+Successfully verified: .\pkg-wos\lib\libggml-htp.cat
 ...
 ```