--- /dev/null
+/*
+ * 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);
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