This patchset introduces a testing framework for Hyper-V drivers. This framework allows us to introduce delays in the packet receive path on a per-device basis. While the current code only supports introducing arbitrary delays in the host/guest communication path, we intend to expand this to support error injection in the future. changes in v5: patch 1: As per Stephen's suggestion, Moved CONFIG_HYPERV_TESTING to lib/Kconfig.debug. Fixed build issue reported by Kbuild, with Michael's suggestion to make hv_debugfs part of the hv_vmbus module. changes in v4: patch 1: Combined previous v3 patches 1 and 2, into a single patch which is now patch 1. This was done so that calls to the new debugfs functions are in the same patch as the definitions for these functions. Moved debugfs code from "vmbus_drv.c" that was in previous v3 patch 2, into a new file "debugfs.c" in drivers/hv. Updated the Makefile to compile "debugfs.c" if CONFIG_HYPERV_TESTING is enabled As per Michael's comments, added empty implementations of the new functions, so the compiler will not generate code when CONFIG_HYPERV_TESTING is not enabled. patch 2 (was previously v3 patch 3): Based on Harrys comments, made the tool more user friendly and added more error checking. changes in v3: patch 2: change call to IS_ERR_OR_NULL, to IS_ERR. patch 3: Align python tool to match Linux coding style. Changes in v2: Patch 1: As per Vitaly's suggestion, wrapped the test code under an #ifdef and updated the Kconfig file, so that the test code will only be used when the config option is set to true. (default is false). Updated hyperv_vmbus header to contain new #ifdef with new new functions for the test code. Patch 2: Moved code from under sysfs to debugfs and wrapped it under the new ifdef. Updated MAINTAINERS file with new debugfs-hyperv file under the section for hyperv. Patch 3: Updated testing tool with new debugfs location. Branden Bonaby (2): drivers: hv: vmbus: Introduce latency testing tools: hv: add vmbus testing tool Documentation/ABI/testing/debugfs-hyperv | 23 ++ MAINTAINERS | 1 + drivers/hv/Makefile | 1 + drivers/hv/connection.c | 1 + drivers/hv/hv_debugfs.c | 185 +++++++++++ drivers/hv/hyperv_vmbus.h | 31 ++ drivers/hv/ring_buffer.c | 2 + drivers/hv/vmbus_drv.c | 6 + include/linux/hyperv.h | 19 ++ lib/Kconfig.debug | 7 + tools/hv/vmbus_testing | 376 +++++++++++++++++++++++ 11 files changed, 652 insertions(+) create mode 100644 Documentation/ABI/testing/debugfs-hyperv create mode 100644 drivers/hv/hv_debugfs.c create mode 100644 tools/hv/vmbus_testing -- 2.17.1