Hyper-V is adding multiple low speed "speciality" synthetic devices. Instead of writing a new kernel-level VMBus driver for each device, make the devices accessible to user space through a UIO-based hv_vmbus_client driver. Each device can then be supported by a user space driver. This approach optimizes the development process and provides flexibility to user space applications to control the key interactions with the VMBus ring buffer. The new synthetic devices are low speed devices that don't support VMBus monitor bits, and so they must use vmbus_setevent() to notify the host of ring buffer updates. The new driver provides this functionality along with a configurable ring buffer size. Moreover, this series of patches incorporates an update to the fcopy application, enabling it to seamlessly utilize the new interface. The older fcopy driver and application will be phased out gradually. Development of other similar userspace drivers is still underway. Moreover, this patch series adds a new implementation of the fcopy application that uses the new UIO driver. The older fcopy driver and application will be phased out gradually. Development of other similar userspace drivers is still underway. [V3] - Removed ringbuffer sysfs entry and used uio framework for mmap - Remove ".id_table = NULL" - kasprintf -> devm_kasprintf - Change global variable ring_size to per device - More checks on value which can be set for ring_size - Remove driverctl, and used echo command instead for driver documentation - Remove unnecessary one time use macros - Change kernel version and date for sysfs documentation - Update documentation. - Made ring buffer data offset depend on page size - remove rte_smp_rwmb macro and reused rte_compiler_barrier instead - Added legal counsel sign-off - simplify mmap - Removed "Link:" tag - Improve cover letter and commit messages - Improve debug prints - Instead of hardcoded instance id, query from class id sysfs - Set the ring_size value from application - new application compilation dependent on x86 - Not removing the old driver and application for backward compatibility [V2] - Update driver info in Documentation/driver-api/uio-howto.rst - Update ring_size sysfs info in Documentation/ABI/stable/sysfs-bus-vmbus - Remove DRIVER_VERSION - Remove refcnt - scnprintf -> sysfs_emit - sysfs_create_file -> ATTRIBUTE_GROUPS + ".driver.groups"; - sysfs_create_bin_file -> device_create_bin_file - dev_notice -> dev_err - remove MODULE_VERSION - simpler sysfs path, less parsing Saurabh Sengar (3): uio: Add hv_vmbus_client driver tools: hv: Add vmbus_bufring tools: hv: Add new fcopy application based on uio driver Documentation/ABI/stable/sysfs-bus-vmbus | 10 + Documentation/driver-api/uio-howto.rst | 54 +++ drivers/uio/Kconfig | 12 + drivers/uio/Makefile | 1 + drivers/uio/uio_hv_vmbus_client.c | 218 +++++++++ tools/hv/Build | 2 + tools/hv/Makefile | 21 +- tools/hv/hv_fcopy_uio_daemon.c | 578 +++++++++++++++++++++++ tools/hv/vmbus_bufring.c | 297 ++++++++++++ tools/hv/vmbus_bufring.h | 154 ++++++ 10 files changed, 1346 insertions(+), 1 deletion(-) create mode 100644 drivers/uio/uio_hv_vmbus_client.c create mode 100644 tools/hv/hv_fcopy_uio_daemon.c create mode 100644 tools/hv/vmbus_bufring.c create mode 100644 tools/hv/vmbus_bufring.h -- 2.34.1
