drm/vmwgfx: Add VMWare host messaging capability

This patch adds capabilities for a VMWare guest to send and
receive messages from the host, and adds functions to sending log
messages to vmware.log and to request device settings that aren't
available through the virtual hardware, e.g. certain settings in
the VMX file.

Signed-off-by: Sinclair Yeh <[e-mail]>
Reviewed-by: Thomas Hellstrom <[e-mail]>

drivers/gpu/drm/vmwgfx/vmwgfx_msg.c

···
+/*
+ * Copyright © 2016 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <asm/hypervisor.h>
+#include "drmP.h"
+#include "vmwgfx_msg.h"
+
+
+#define MESSAGE_STATUS_SUCCESS  0x0001
+#define MESSAGE_STATUS_DORECV   0x0002
+#define MESSAGE_STATUS_CPT      0x0010
+#define MESSAGE_STATUS_HB       0x0080
+
+#define RPCI_PROTOCOL_NUM       0x49435052
+#define GUESTMSG_FLAG_COOKIE    0x80000000
+
+#define RETRIES                 3
+
+#define VMW_HYPERVISOR_MAGIC    0x564D5868
+#define VMW_HYPERVISOR_PORT     0x5658
+#define VMW_HYPERVISOR_HB_PORT  0x5659
+
+#define VMW_PORT_CMD_MSG        30
+#define VMW_PORT_CMD_HB_MSG     0
+#define VMW_PORT_CMD_OPEN_CHANNEL  (MSG_TYPE_OPEN << 16 | VMW_PORT_CMD_MSG)
+#define VMW_PORT_CMD_CLOSE_CHANNEL (MSG_TYPE_CLOSE << 16 | VMW_PORT_CMD_MSG)
+#define VMW_PORT_CMD_SENDSIZE   (MSG_TYPE_SENDSIZE << 16 | VMW_PORT_CMD_MSG)
+#define VMW_PORT_CMD_RECVSIZE   (MSG_TYPE_RECVSIZE << 16 | VMW_PORT_CMD_MSG)
+#define VMW_PORT_CMD_RECVSTATUS (MSG_TYPE_RECVSTATUS << 16 | VMW_PORT_CMD_MSG)
+
+#define HIGH_WORD(X) ((X & 0xFFFF0000) >> 16)
+
+static u32 vmw_msg_enabled = 1;
+
+enum rpc_msg_type {
+	MSG_TYPE_OPEN,
+	MSG_TYPE_SENDSIZE,
+	MSG_TYPE_SENDPAYLOAD,
+	MSG_TYPE_RECVSIZE,
+	MSG_TYPE_RECVPAYLOAD,
+	MSG_TYPE_RECVSTATUS,
+	MSG_TYPE_CLOSE,
+};
+
+struct rpc_channel {
+	u16 channel_id;
+	u32 cookie_high;
+	u32 cookie_low;
+};
+
+
+
+/**
+ * vmw_open_channel
+ *
+ * @channel: RPC channel
+ * @protocol:
+ *
+ * Returns: 0 on success
+ */
+static int vmw_open_channel(struct rpc_channel *channel, unsigned int protocol)
+{
+	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
+
+	VMW_PORT(VMW_PORT_CMD_OPEN_CHANNEL,
+		(protocol | GUESTMSG_FLAG_COOKIE), si, di,
+		VMW_HYPERVISOR_PORT,
+		VMW_HYPERVISOR_MAGIC,
+		eax, ebx, ecx, edx, si, di);
+
+	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
+		return -EINVAL;
+
+	channel->channel_id  = HIGH_WORD(edx);
+	channel->cookie_high = si;
+	channel->cookie_low  = di;
+
+	return 0;
+}
+
+
+
+/**
+ * vmw_close_channel
+ *
+ * @channel: RPC channel
+ *
+ * Returns: 0 on success
+ */
+static int vmw_close_channel(struct rpc_channel *channel)
+{
+	unsigned long eax, ebx, ecx, edx, si, di;
+
+	/* Set up additional parameters */
+	si  = channel->cookie_high;
+	di  = channel->cookie_low;
+
+	VMW_PORT(VMW_PORT_CMD_CLOSE_CHANNEL,
+		0, si, di,
+		(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
+		VMW_HYPERVISOR_MAGIC,
+		eax, ebx, ecx, edx, si, di);
+
+	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+
+
+/**
+ * vmw_send_msg: Sends a message to the host
+ *
+ * @channel: RPC channel
+ * @logmsg: NULL terminated string
+ *
+ * Returns: 0 on success
+ */
+static int vmw_send_msg(struct rpc_channel *channel, const char *msg)
+{
+	unsigned long eax, ebx, ecx, edx, si, di, bp;
+	size_t msg_len = strlen(msg);
+	int retries = 0;
+
+
+	while (retries < RETRIES) {
+		retries++;
+
+		/* Set up additional parameters */
+		si  = channel->cookie_high;
+		di  = channel->cookie_low;
+
+		VMW_PORT(VMW_PORT_CMD_SENDSIZE,
+			msg_len, si, di,
+			VMW_HYPERVISOR_PORT | (channel->channel_id << 16),
+			VMW_HYPERVISOR_MAGIC,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0 ||
+		    (HIGH_WORD(ecx) & MESSAGE_STATUS_HB) == 0) {
+			/* Expected success + high-bandwidth. Give up. */
+			return -EINVAL;
+		}
+
+		/* Send msg */
+		si  = (uintptr_t) msg;
+		di  = channel->cookie_low;
+		bp  = channel->cookie_high;
+
+		VMW_PORT_HB_OUT(
+			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
+			msg_len, si, di,
+			VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16),
+			VMW_HYPERVISOR_MAGIC, bp,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) != 0) {
+			return 0;
+		} else if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
+			/* A checkpoint occurred. Retry. */
+			continue;
+		} else {
+			break;
+		}
+	}
+
+	return -EINVAL;
+}
+
+
+
+/**
+ * vmw_recv_msg: Receives a message from the host
+ *
+ * Note:  It is the caller's responsibility to call kfree() on msg.
+ *
+ * @channel:  channel opened by vmw_open_channel
+ * @msg:  [OUT] message received from the host
+ * @msg_len: message length
+ */
+static int vmw_recv_msg(struct rpc_channel *channel, void **msg,
+			size_t *msg_len)
+{
+	unsigned long eax, ebx, ecx, edx, si, di, bp;
+	char *reply;
+	size_t reply_len;
+	int retries = 0;
+
+
+	*msg_len = 0;
+	*msg = NULL;
+
+	while (retries < RETRIES) {
+		retries++;
+
+		/* Set up additional parameters */
+		si  = channel->cookie_high;
+		di  = channel->cookie_low;
+
+		VMW_PORT(VMW_PORT_CMD_RECVSIZE,
+			0, si, di,
+			(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
+			VMW_HYPERVISOR_MAGIC,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0 ||
+		    (HIGH_WORD(ecx) & MESSAGE_STATUS_HB) == 0) {
+			DRM_ERROR("Failed to get reply size\n");
+			return -EINVAL;
+		}
+
+		/* No reply available.  This is okay. */
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_DORECV) == 0)
+			return 0;
+
+		reply_len = ebx;
+		reply     = kzalloc(reply_len + 1, GFP_KERNEL);
+		if (reply == NULL) {
+			DRM_ERROR("Cannot allocate memory for reply\n");
+			return -ENOMEM;
+		}
+
+
+		/* Receive buffer */
+		si  = channel->cookie_high;
+		di  = (uintptr_t) reply;
+		bp  = channel->cookie_low;
+
+		VMW_PORT_HB_IN(
+			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
+			reply_len, si, di,
+			VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16),
+			VMW_HYPERVISOR_MAGIC, bp,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) == 0) {
+			kfree(reply);
+
+			if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
+				/* A checkpoint occurred. Retry. */
+				continue;
+			}
+
+			return -EINVAL;
+		}
+
+		reply[reply_len] = '\0';
+
+
+		/* Ack buffer */
+		si  = channel->cookie_high;
+		di  = channel->cookie_low;
+
+		VMW_PORT(VMW_PORT_CMD_RECVSTATUS,
+			MESSAGE_STATUS_SUCCESS, si, di,
+			(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
+			VMW_HYPERVISOR_MAGIC,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
+			kfree(reply);
+
+			if ((HIGH_WORD(ecx) & MESSAGE_STATUS_CPT) != 0) {
+				/* A checkpoint occurred. Retry. */
+				continue;
+			}
+
+			return -EINVAL;
+		}
+
+		break;
+	}
+
+	*msg_len = reply_len;
+	*msg     = reply;
+
+	return 0;
+}
+
+
+/**
+ * vmw_host_get_guestinfo: Gets a GuestInfo parameter
+ *
+ * Gets the value of a  GuestInfo.* parameter.  The value returned will be in
+ * a string, and it is up to the caller to post-process.
+ *
+ * @guest_info_param:  Parameter to get, e.g. GuestInfo.svga.gl3
+ * @buffer: if NULL, *reply_len will contain reply size.
+ * @length: size of the reply_buf.  Set to size of reply upon return
+ *
+ * Returns: 0 on success
+ */
+int vmw_host_get_guestinfo(const char *guest_info_param,
+			   char *buffer, size_t *length)
+{
+	struct rpc_channel channel;
+	char *msg, *reply = NULL;
+	size_t msg_len, reply_len = 0;
+	int ret = 0;
+
+
+	if (!vmw_msg_enabled)
+		return -ENODEV;
+
+	if (!guest_info_param || !length)
+		return -EINVAL;
+
+	msg_len = strlen(guest_info_param) + strlen("info-get ") + 1;
+	msg = kzalloc(msg_len, GFP_KERNEL);
+	if (msg == NULL) {
+		DRM_ERROR("Cannot allocate memory to get %s", guest_info_param);
+		return -ENOMEM;
+	}
+
+	sprintf(msg, "info-get %s", guest_info_param);
+
+	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM) ||
+	    vmw_send_msg(&channel, msg) ||
+	    vmw_recv_msg(&channel, (void *) &reply, &reply_len) ||
+	    vmw_close_channel(&channel)) {
+		DRM_ERROR("Failed to get %s", guest_info_param);
+
+		ret = -EINVAL;
+	}
+
+	if (buffer && reply && reply_len > 0) {
+		/* Remove reply code, which are the first 2 characters of
+		 * the reply
+		 */
+		reply_len = max(reply_len - 2, (size_t) 0);
+		reply_len = min(reply_len, *length);
+
+		if (reply_len > 0)
+			memcpy(buffer, reply + 2, reply_len);
+	}
+
+	*length = reply_len;
+
+	kfree(reply);
+	kfree(msg);
+
+	return ret;
+}
+
+
+
+/**
+ * vmw_host_log: Sends a log message to the host
+ *
+ * @log: NULL terminated string
+ *
+ * Returns: 0 on success
+ */
+int vmw_host_log(const char *log)
+{
+	struct rpc_channel channel;
+	char *msg;
+	int msg_len;
+	int ret = 0;
+
+
+	if (!vmw_msg_enabled)
+		return -ENODEV;
+
+	if (!log)
+		return ret;
+
+	msg_len = strlen(log) + strlen("log ") + 1;
+	msg = kzalloc(msg_len, GFP_KERNEL);
+	if (msg == NULL) {
+		DRM_ERROR("Cannot allocate memory for log message\n");
+		return -ENOMEM;
+	}
+
+	sprintf(msg, "log %s", log);
+
+	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM) ||
+	    vmw_send_msg(&channel, msg) ||
+	    vmw_close_channel(&channel)) {
+		DRM_ERROR("Failed to send log\n");
+
+		ret = -EINVAL;
+	}
+
+	kfree(msg);
+
+	return ret;
+}

drivers/gpu/drm/vmwgfx/vmwgfx_msg.h

···
+/*
+ * Copyright (C) 2016, VMware, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * Based on code from vmware.c and vmmouse.c.
+ * Author:
+ *   Sinclair Yeh <[e-mail]>
+ */
+#ifndef _VMWGFX_MSG_H
+#define _VMWGFX_MSG_H
+
+
+/**
+ * Hypervisor-specific bi-directional communication channel.  Should never
+ * execute on bare metal hardware.  The caller must make sure to check for
+ * supported hypervisor before using these macros.
+ *
+ * The last two parameters are both input and output and must be initialized.
+ *
+ * @cmd: [IN] Message Cmd
+ * @in_ebx: [IN] Message Len, through EBX
+ * @in_si: [IN] Input argument through SI, set to 0 if not used
+ * @in_di: [IN] Input argument through DI, set ot 0 if not used
+ * @port_num: [IN] port number + [channel id]
+ * @magic: [IN] hypervisor magic value
+ * @eax: [OUT] value of EAX register
+ * @ebx: [OUT] e.g. status from an HB message status command
+ * @ecx: [OUT] e.g. status from a non-HB message status command
+ * @edx: [OUT] e.g. channel id
+ * @si:  [OUT]
+ * @di:  [OUT]
+ */
+#define VMW_PORT(cmd, in_ebx, in_si, in_di,	\
+		 port_num, magic,		\
+		 eax, ebx, ecx, edx, si, di)	\
+({						\
+	asm volatile ("inl %%dx, %%eax;" :	\
+		"=a"(eax),			\
+		"=b"(ebx),			\
+		"=c"(ecx),			\
+		"=d"(edx),			\
+		"=S"(si),			\
+		"=D"(di) :			\
+		"a"(magic),			\
+		"b"(in_ebx),			\
+		"c"(cmd),			\
+		"d"(port_num),			\
+		"S"(in_si),			\
+		"D"(in_di) :			\
+		"memory");			\
+})
+
+
+/**
+ * Hypervisor-specific bi-directional communication channel.  Should never
+ * execute on bare metal hardware.  The caller must make sure to check for
+ * supported hypervisor before using these macros.
+ *
+ * The last 3 parameters are both input and output and must be initialized.
+ *
+ * @cmd: [IN] Message Cmd
+ * @in_ecx: [IN] Message Len, through ECX
+ * @in_si: [IN] Input argument through SI, set to 0 if not used
+ * @in_di: [IN] Input argument through DI, set to 0 if not used
+ * @port_num: [IN] port number + [channel id]
+ * @magic: [IN] hypervisor magic value
+ * @bp:  [IN]
+ * @eax: [OUT] value of EAX register
+ * @ebx: [OUT] e.g. status from an HB message status command
+ * @ecx: [OUT] e.g. status from a non-HB message status command
+ * @edx: [OUT] e.g. channel id
+ * @si:  [OUT]
+ * @di:  [OUT]
+ */
+#ifdef __x86_64__
+
+#define VMW_PORT_HB_OUT(cmd, in_ecx, in_si, in_di,	\
+			port_num, magic, bp,		\
+			eax, ebx, ecx, edx, si, di)	\
+({							\
+	asm volatile ("push %%rbp;"			\
+		"mov %12, %%rbp;"			\
+		"rep outsb;"				\
+		"pop %%rbp;" :				\
+		"=a"(eax),				\
+		"=b"(ebx),				\
+		"=c"(ecx),				\
+		"=d"(edx),				\
+		"=S"(si),				\
+		"=D"(di) :				\
+		"a"(magic),				\
+		"b"(cmd),				\
+		"c"(in_ecx),				\
+		"d"(port_num),				\
+		"S"(in_si),				\
+		"D"(in_di),				\
+		"r"(bp) :				\
+		"memory", "cc");			\
+})
+
+
+#define VMW_PORT_HB_IN(cmd, in_ecx, in_si, in_di,	\
+		       port_num, magic, bp,		\
+		       eax, ebx, ecx, edx, si, di)	\
+({							\
+	asm volatile ("push %%rbp;"			\
+		"mov %12, %%rbp;"			\
+		"rep insb;"				\
+		"pop %%rbp" :				\
+		"=a"(eax),				\
+		"=b"(ebx),				\
+		"=c"(ecx),				\
+		"=d"(edx),				\
+		"=S"(si),				\
+		"=D"(di) :				\
+		"a"(magic),				\
+		"b"(cmd),				\
+		"c"(in_ecx),				\
+		"d"(port_num),				\
+		"S"(in_si),				\
+		"D"(in_di),				\
+		"r"(bp) :				\
+		"memory", "cc");			\
+})
+
+#else
+
+/* In the 32-bit version of this macro, we use "m" because there is no
+ * more register left for bp
+ */
+#define VMW_PORT_HB_OUT(cmd, in_ecx, in_si, in_di,	\
+			port_num, magic, bp,		\
+			eax, ebx, ecx, edx, si, di)	\
+({							\
+	asm volatile ("push %%ebp;"			\
+		"mov %12, %%ebp;"			\
+		"rep outsb;"				\
+		"pop %%ebp;" :				\
+		"=a"(eax),				\
+		"=b"(ebx),				\
+		"=c"(ecx),				\
+		"=d"(edx),				\
+		"=S"(si),				\
+		"=D"(di) :				\
+		"a"(magic),				\
+		"b"(cmd),				\
+		"c"(in_ecx),				\
+		"d"(port_num),				\
+		"S"(in_si),				\
+		"D"(in_di),				\
+		"m"(bp) :				\
+		"memory", "cc");			\
+})
+
+
+#define VMW_PORT_HB_IN(cmd, in_ecx, in_si, in_di,	\
+		       port_num, magic, bp,		\
+		       eax, ebx, ecx, edx, si, di)	\
+({							\
+	asm volatile ("push %%ebp;"			\
+		"mov %12, %%ebp;"			\
+		"rep insb;"				\
+		"pop %%ebp" :				\
+		"=a"(eax),				\
+		"=b"(ebx),				\
+		"=c"(ecx),				\
+		"=d"(edx),				\
+		"=S"(si),				\
+		"=D"(di) :				\
+		"a"(magic),				\
+		"b"(cmd),				\
+		"c"(in_ecx),				\
+		"d"(port_num),				\
+		"S"(in_si),				\
+		"D"(in_di),				\
+		"m"(bp) :				\
+		"memory", "cc");			\
+})
+#endif /* #if __x86_64__ */
+
+#endif