| /* |
| * Copyright (c) 2013, Microsoft Corporation. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| * more details. |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/device.h> |
| #include <linux/completion.h> |
| #include <linux/hyperv.h> |
| #include <linux/serio.h> |
| #include <linux/slab.h> |
| |
| /* |
| * Current version 1.0 |
| * |
| */ |
| #define SYNTH_KBD_VERSION_MAJOR 1 |
| #define SYNTH_KBD_VERSION_MINOR 0 |
| #define SYNTH_KBD_VERSION (SYNTH_KBD_VERSION_MINOR | \ |
| (SYNTH_KBD_VERSION_MAJOR << 16)) |
| |
| |
| /* |
| * Message types in the synthetic input protocol |
| */ |
| enum synth_kbd_msg_type { |
| SYNTH_KBD_PROTOCOL_REQUEST = 1, |
| SYNTH_KBD_PROTOCOL_RESPONSE = 2, |
| SYNTH_KBD_EVENT = 3, |
| SYNTH_KBD_LED_INDICATORS = 4, |
| }; |
| |
| /* |
| * Basic message structures. |
| */ |
| struct synth_kbd_msg_hdr { |
| __le32 type; |
| }; |
| |
| struct synth_kbd_msg { |
| struct synth_kbd_msg_hdr header; |
| char data[]; /* Enclosed message */ |
| }; |
| |
| union synth_kbd_version { |
| __le32 version; |
| }; |
| |
| /* |
| * Protocol messages |
| */ |
| struct synth_kbd_protocol_request { |
| struct synth_kbd_msg_hdr header; |
| union synth_kbd_version version_requested; |
| }; |
| |
| #define PROTOCOL_ACCEPTED BIT(0) |
| struct synth_kbd_protocol_response { |
| struct synth_kbd_msg_hdr header; |
| __le32 proto_status; |
| }; |
| |
| #define IS_UNICODE BIT(0) |
| #define IS_BREAK BIT(1) |
| #define IS_E0 BIT(2) |
| #define IS_E1 BIT(3) |
| struct synth_kbd_keystroke { |
| struct synth_kbd_msg_hdr header; |
| __le16 make_code; |
| __le16 reserved0; |
| __le32 info; /* Additional information */ |
| }; |
| |
| |
| #define HK_MAXIMUM_MESSAGE_SIZE 256 |
| |
| #define KBD_VSC_SEND_RING_BUFFER_SIZE (10 * PAGE_SIZE) |
| #define KBD_VSC_RECV_RING_BUFFER_SIZE (10 * PAGE_SIZE) |
| |
| #define XTKBD_EMUL0 0xe0 |
| #define XTKBD_EMUL1 0xe1 |
| #define XTKBD_RELEASE 0x80 |
| |
| |
| /* |
| * Represents a keyboard device |
| */ |
| struct hv_kbd_dev { |
| struct hv_device *hv_dev; |
| struct serio *hv_serio; |
| struct synth_kbd_protocol_request protocol_req; |
| struct synth_kbd_protocol_response protocol_resp; |
| /* Synchronize the request/response if needed */ |
| struct completion wait_event; |
| spinlock_t lock; /* protects 'started' field */ |
| bool started; |
| }; |
| |
| static void hv_kbd_on_receive(struct hv_device *hv_dev, |
| struct synth_kbd_msg *msg, u32 msg_length) |
| { |
| struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev); |
| struct synth_kbd_keystroke *ks_msg; |
| unsigned long flags; |
| u32 msg_type = __le32_to_cpu(msg->header.type); |
| u32 info; |
| u16 scan_code; |
| |
| switch (msg_type) { |
| case SYNTH_KBD_PROTOCOL_RESPONSE: |
| /* |
| * Validate the information provided by the host. |
| * If the host is giving us a bogus packet, |
| * drop the packet (hoping the problem |
| * goes away). |
| */ |
| if (msg_length < sizeof(struct synth_kbd_protocol_response)) { |
| dev_err(&hv_dev->device, |
| "Illegal protocol response packet (len: %d)\n", |
| msg_length); |
| break; |
| } |
| |
| memcpy(&kbd_dev->protocol_resp, msg, |
| sizeof(struct synth_kbd_protocol_response)); |
| complete(&kbd_dev->wait_event); |
| break; |
| |
| case SYNTH_KBD_EVENT: |
| /* |
| * Validate the information provided by the host. |
| * If the host is giving us a bogus packet, |
| * drop the packet (hoping the problem |
| * goes away). |
| */ |
| if (msg_length < sizeof(struct synth_kbd_keystroke)) { |
| dev_err(&hv_dev->device, |
| "Illegal keyboard event packet (len: %d)\n", |
| msg_length); |
| break; |
| } |
| |
| ks_msg = (struct synth_kbd_keystroke *)msg; |
| info = __le32_to_cpu(ks_msg->info); |
| |
| /* |
| * Inject the information through the serio interrupt. |
| */ |
| spin_lock_irqsave(&kbd_dev->lock, flags); |
| if (kbd_dev->started) { |
| if (info & IS_E0) |
| serio_interrupt(kbd_dev->hv_serio, |
| XTKBD_EMUL0, 0); |
| |
| scan_code = __le16_to_cpu(ks_msg->make_code); |
| if (info & IS_BREAK) |
| scan_code |= XTKBD_RELEASE; |
| |
| serio_interrupt(kbd_dev->hv_serio, scan_code, 0); |
| } |
| spin_unlock_irqrestore(&kbd_dev->lock, flags); |
| break; |
| |
| default: |
| dev_err(&hv_dev->device, |
| "unhandled message type %d\n", msg_type); |
| } |
| } |
| |
| static void hv_kbd_handle_received_packet(struct hv_device *hv_dev, |
| struct vmpacket_descriptor *desc, |
| u32 bytes_recvd, |
| u64 req_id) |
| { |
| struct synth_kbd_msg *msg; |
| u32 msg_sz; |
| |
| switch (desc->type) { |
| case VM_PKT_COMP: |
| break; |
| |
| case VM_PKT_DATA_INBAND: |
| /* |
| * We have a packet that has "inband" data. The API used |
| * for retrieving the packet guarantees that the complete |
| * packet is read. So, minimally, we should be able to |
| * parse the payload header safely (assuming that the host |
| * can be trusted. Trusting the host seems to be a |
| * reasonable assumption because in a virtualized |
| * environment there is not whole lot you can do if you |
| * don't trust the host. |
| * |
| * Nonetheless, let us validate if the host can be trusted |
| * (in a trivial way). The interesting aspect of this |
| * validation is how do you recover if we discover that the |
| * host is not to be trusted? Simply dropping the packet, I |
| * don't think is an appropriate recovery. In the interest |
| * of failing fast, it may be better to crash the guest. |
| * For now, I will just drop the packet! |
| */ |
| |
| msg_sz = bytes_recvd - (desc->offset8 << 3); |
| if (msg_sz <= sizeof(struct synth_kbd_msg_hdr)) { |
| /* |
| * Drop the packet and hope |
| * the problem magically goes away. |
| */ |
| dev_err(&hv_dev->device, |
| "Illegal packet (type: %d, tid: %llx, size: %d)\n", |
| desc->type, req_id, msg_sz); |
| break; |
| } |
| |
| msg = (void *)desc + (desc->offset8 << 3); |
| hv_kbd_on_receive(hv_dev, msg, msg_sz); |
| break; |
| |
| default: |
| dev_err(&hv_dev->device, |
| "unhandled packet type %d, tid %llx len %d\n", |
| desc->type, req_id, bytes_recvd); |
| break; |
| } |
| } |
| |
| static void hv_kbd_on_channel_callback(void *context) |
| { |
| struct hv_device *hv_dev = context; |
| void *buffer; |
| int bufferlen = 0x100; /* Start with sensible size */ |
| u32 bytes_recvd; |
| u64 req_id; |
| int error; |
| |
| buffer = kmalloc(bufferlen, GFP_ATOMIC); |
| if (!buffer) |
| return; |
| |
| while (1) { |
| error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen, |
| &bytes_recvd, &req_id); |
| switch (error) { |
| case 0: |
| if (bytes_recvd == 0) { |
| kfree(buffer); |
| return; |
| } |
| |
| hv_kbd_handle_received_packet(hv_dev, buffer, |
| bytes_recvd, req_id); |
| break; |
| |
| case -ENOBUFS: |
| kfree(buffer); |
| /* Handle large packet */ |
| bufferlen = bytes_recvd; |
| buffer = kmalloc(bytes_recvd, GFP_ATOMIC); |
| if (!buffer) |
| return; |
| break; |
| } |
| } |
| } |
| |
| static int hv_kbd_connect_to_vsp(struct hv_device *hv_dev) |
| { |
| struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev); |
| struct synth_kbd_protocol_request *request; |
| struct synth_kbd_protocol_response *response; |
| u32 proto_status; |
| int error; |
| |
| request = &kbd_dev->protocol_req; |
| memset(request, 0, sizeof(struct synth_kbd_protocol_request)); |
| request->header.type = __cpu_to_le32(SYNTH_KBD_PROTOCOL_REQUEST); |
| request->version_requested.version = __cpu_to_le32(SYNTH_KBD_VERSION); |
| |
| error = vmbus_sendpacket(hv_dev->channel, request, |
| sizeof(struct synth_kbd_protocol_request), |
| (unsigned long)request, |
| VM_PKT_DATA_INBAND, |
| VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); |
| if (error) |
| return error; |
| |
| if (!wait_for_completion_timeout(&kbd_dev->wait_event, 10 * HZ)) |
| return -ETIMEDOUT; |
| |
| response = &kbd_dev->protocol_resp; |
| proto_status = __le32_to_cpu(response->proto_status); |
| if (!(proto_status & PROTOCOL_ACCEPTED)) { |
| dev_err(&hv_dev->device, |
| "synth_kbd protocol request failed (version %d)\n", |
| SYNTH_KBD_VERSION); |
| return -ENODEV; |
| } |
| |
| return 0; |
| } |
| |
| static int hv_kbd_start(struct serio *serio) |
| { |
| struct hv_kbd_dev *kbd_dev = serio->port_data; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&kbd_dev->lock, flags); |
| kbd_dev->started = true; |
| spin_unlock_irqrestore(&kbd_dev->lock, flags); |
| |
| return 0; |
| } |
| |
| static void hv_kbd_stop(struct serio *serio) |
| { |
| struct hv_kbd_dev *kbd_dev = serio->port_data; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&kbd_dev->lock, flags); |
| kbd_dev->started = false; |
| spin_unlock_irqrestore(&kbd_dev->lock, flags); |
| } |
| |
| static int hv_kbd_probe(struct hv_device *hv_dev, |
| const struct hv_vmbus_device_id *dev_id) |
| { |
| struct hv_kbd_dev *kbd_dev; |
| struct serio *hv_serio; |
| int error; |
| |
| kbd_dev = kzalloc(sizeof(struct hv_kbd_dev), GFP_KERNEL); |
| hv_serio = kzalloc(sizeof(struct serio), GFP_KERNEL); |
| if (!kbd_dev || !hv_serio) { |
| error = -ENOMEM; |
| goto err_free_mem; |
| } |
| |
| kbd_dev->hv_dev = hv_dev; |
| kbd_dev->hv_serio = hv_serio; |
| spin_lock_init(&kbd_dev->lock); |
| init_completion(&kbd_dev->wait_event); |
| hv_set_drvdata(hv_dev, kbd_dev); |
| |
| hv_serio->dev.parent = &hv_dev->device; |
| hv_serio->id.type = SERIO_8042_XL; |
| hv_serio->port_data = kbd_dev; |
| strlcpy(hv_serio->name, dev_name(&hv_dev->device), |
| sizeof(hv_serio->name)); |
| strlcpy(hv_serio->phys, dev_name(&hv_dev->device), |
| sizeof(hv_serio->phys)); |
| |
| hv_serio->start = hv_kbd_start; |
| hv_serio->stop = hv_kbd_stop; |
| |
| error = vmbus_open(hv_dev->channel, |
| KBD_VSC_SEND_RING_BUFFER_SIZE, |
| KBD_VSC_RECV_RING_BUFFER_SIZE, |
| NULL, 0, |
| hv_kbd_on_channel_callback, |
| hv_dev); |
| if (error) |
| goto err_free_mem; |
| |
| error = hv_kbd_connect_to_vsp(hv_dev); |
| if (error) |
| goto err_close_vmbus; |
| |
| serio_register_port(kbd_dev->hv_serio); |
| return 0; |
| |
| err_close_vmbus: |
| vmbus_close(hv_dev->channel); |
| err_free_mem: |
| kfree(hv_serio); |
| kfree(kbd_dev); |
| return error; |
| } |
| |
| static int hv_kbd_remove(struct hv_device *hv_dev) |
| { |
| struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev); |
| |
| serio_unregister_port(kbd_dev->hv_serio); |
| vmbus_close(hv_dev->channel); |
| kfree(kbd_dev); |
| |
| hv_set_drvdata(hv_dev, NULL); |
| |
| return 0; |
| } |
| |
| /* |
| * Keyboard GUID |
| * {f912ad6d-2b17-48ea-bd65-f927a61c7684} |
| */ |
| #define HV_KBD_GUID \ |
| .guid = { \ |
| 0x6d, 0xad, 0x12, 0xf9, 0x17, 0x2b, 0xea, 0x48, \ |
| 0xbd, 0x65, 0xf9, 0x27, 0xa6, 0x1c, 0x76, 0x84 \ |
| } |
| |
| static const struct hv_vmbus_device_id id_table[] = { |
| /* Keyboard guid */ |
| { HV_KBD_GUID, }, |
| { }, |
| }; |
| |
| MODULE_DEVICE_TABLE(vmbus, id_table); |
| |
| static struct hv_driver hv_kbd_drv = { |
| .name = KBUILD_MODNAME, |
| .id_table = id_table, |
| .probe = hv_kbd_probe, |
| .remove = hv_kbd_remove, |
| }; |
| |
| static int __init hv_kbd_init(void) |
| { |
| return vmbus_driver_register(&hv_kbd_drv); |
| } |
| |
| static void __exit hv_kbd_exit(void) |
| { |
| vmbus_driver_unregister(&hv_kbd_drv); |
| } |
| |
| MODULE_LICENSE("GPL"); |
| module_init(hv_kbd_init); |
| module_exit(hv_kbd_exit); |