diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/device_drivers/google/gve.rst | 82 | ||||
| -rw-r--r-- | Documentation/networking/device_drivers/index.rst | 1 |
2 files changed, 83 insertions, 0 deletions
diff --git a/Documentation/networking/device_drivers/google/gve.rst b/Documentation/networking/device_drivers/google/gve.rst new file mode 100644 index 000000000000..7397c82f4c8f --- /dev/null +++ b/Documentation/networking/device_drivers/google/gve.rst @@ -0,0 +1,82 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +============================================================== +Linux kernel driver for Compute Engine Virtual Ethernet (gve): +============================================================== + +Supported Hardware +=================== +The GVE driver binds to a single PCI device id used by the virtual +Ethernet device found in some Compute Engine VMs. + ++--------------+----------+---------+ +|Field | Value | Comments| ++==============+==========+=========+ +|Vendor ID | `0x1AE0` | Google | ++--------------+----------+---------+ +|Device ID | `0x0042` | | ++--------------+----------+---------+ +|Sub-vendor ID | `0x1AE0` | Google | ++--------------+----------+---------+ +|Sub-device ID | `0x0058` | | ++--------------+----------+---------+ +|Revision ID | `0x0` | | ++--------------+----------+---------+ +|Device Class | `0x200` | Ethernet| ++--------------+----------+---------+ + +PCI Bars +======== +The gVNIC PCI device exposes three 32-bit memory BARS: +- Bar0 - Device configuration and status registers. +- Bar1 - MSI-X vector table +- Bar2 - IRQ, RX and TX doorbells + +Device Interactions +=================== +The driver interacts with the device in the following ways: + - Registers + - A block of MMIO registers + - See gve_register.h for more detail + - Admin Queue + - See description below + - Interrupts + - See supported interrupts below + +Registers +--------- +All registers are MMIO and big endian. + +The registers are used for initializing and configuring the device as well as +querying device status in response to management interrupts. + +Admin Queue (AQ) +---------------- +The Admin Queue is a PAGE_SIZE memory block, treated as an array of AQ +commands, used by the driver to issue commands to the device and set up +resources.The driver and the device maintain a count of how many commands +have been submitted and executed. To issue AQ commands, the driver must do +the following (with proper locking): + +1) Copy new commands into next available slots in the AQ array +2) Increment its counter by he number of new commands +3) Write the counter into the GVE_ADMIN_QUEUE_DOORBELL register +4) Poll the ADMIN_QUEUE_EVENT_COUNTER register until it equals + the value written to the doorbell, or until a timeout. + +The device will update the status field in each AQ command reported as +executed through the ADMIN_QUEUE_EVENT_COUNTER register. + +Interrupts +---------- +The following interrupts are supported by the driver: + +Management Interrupt +~~~~~~~~~~~~~~~~~~~~ +The management interrupt is used by the device to tell the driver to +look at the GVE_DEVICE_STATUS register. + +Notification Block Interrupts +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The notification block interrupts are used to tell the driver to poll +the queues associated with that interrupt. diff --git a/Documentation/networking/device_drivers/index.rst b/Documentation/networking/device_drivers/index.rst index 24598d5f8ffa..2b7fefe72351 100644 --- a/Documentation/networking/device_drivers/index.rst +++ b/Documentation/networking/device_drivers/index.rst @@ -21,6 +21,7 @@ Contents: intel/i40e intel/iavf intel/ice + google/gve mellanox/mlx5 .. only:: subproject |