Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1190 insertions, 0 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
new file mode 100644
index 000000000..50fa3df0b
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -0,0 +1,1190 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright 2016 VMware, Inc., Palo Alto, CA., USA
+ *
+ * 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/objtool.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/cc_platform.h>
+
+#include <asm/hypervisor.h>
+#include <drm/drm_ioctl.h>
+
+#include "vmwgfx_drv.h"
+#include "vmwgfx_msg_x86.h"
+#include "vmwgfx_msg_arm64.h"
+#include "vmwgfx_mksstat.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_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 VMW_PORT_CMD_MKS_GUEST_STATS   85
+#define VMW_PORT_CMD_MKSGS_RESET       (0 << 16 | VMW_PORT_CMD_MKS_GUEST_STATS)
+#define VMW_PORT_CMD_MKSGS_ADD_PPN     (1 << 16 | VMW_PORT_CMD_MKS_GUEST_STATS)
+#define VMW_PORT_CMD_MKSGS_REMOVE_PPN  (2 << 16 | VMW_PORT_CMD_MKS_GUEST_STATS)
+
+#define HIGH_WORD(X) ((X & 0xFFFF0000) >> 16)
+
+#define MAX_USER_MSG_LENGTH	PAGE_SIZE
+
+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,
+		0,
+		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,
+		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_port_hb_out - Send the message payload either through the
+ * high-bandwidth port if available, or through the backdoor otherwise.
+ * @channel: The rpc channel.
+ * @msg: NULL-terminated message.
+ * @hb: Whether the high-bandwidth port is available.
+ *
+ * Return: The port status.
+ */
+static unsigned long vmw_port_hb_out(struct rpc_channel *channel,
+				     const char *msg, bool hb)
+{
+	unsigned long si, di, eax, ebx, ecx, edx;
+	unsigned long msg_len = strlen(msg);
+
+	/* HB port can't access encrypted memory. */
+	if (hb && !cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
+		unsigned long bp = channel->cookie_high;
+		u32 channel_id = (channel->channel_id << 16);
+
+		si = (uintptr_t) msg;
+		di = channel->cookie_low;
+
+		VMW_PORT_HB_OUT(
+			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
+			msg_len, si, di,
+			VMWARE_HYPERVISOR_HB | channel_id |
+			VMWARE_HYPERVISOR_OUT,
+			VMW_HYPERVISOR_MAGIC, bp,
+			eax, ebx, ecx, edx, si, di);
+
+		return ebx;
+	}
+
+	/* HB port not available. Send the message 4 bytes at a time. */
+	ecx = MESSAGE_STATUS_SUCCESS << 16;
+	while (msg_len && (HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS)) {
+		unsigned int bytes = min_t(size_t, msg_len, 4);
+		unsigned long word = 0;
+
+		memcpy(&word, msg, bytes);
+		msg_len -= bytes;
+		msg += bytes;
+		si = channel->cookie_high;
+		di = channel->cookie_low;
+
+		VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_SENDPAYLOAD << 16),
+			 word, si, di,
+			 channel->channel_id << 16,
+			 VMW_HYPERVISOR_MAGIC,
+			 eax, ebx, ecx, edx, si, di);
+	}
+
+	return ecx;
+}
+
+/**
+ * vmw_port_hb_in - Receive the message payload either through the
+ * high-bandwidth port if available, or through the backdoor otherwise.
+ * @channel: The rpc channel.
+ * @reply: Pointer to buffer holding reply.
+ * @reply_len: Length of the reply.
+ * @hb: Whether the high-bandwidth port is available.
+ *
+ * Return: The port status.
+ */
+static unsigned long vmw_port_hb_in(struct rpc_channel *channel, char *reply,
+				    unsigned long reply_len, bool hb)
+{
+	unsigned long si, di, eax, ebx, ecx, edx;
+
+	/* HB port can't access encrypted memory */
+	if (hb && !cc_platform_has(CC_ATTR_MEM_ENCRYPT)) {
+		unsigned long bp = channel->cookie_low;
+		u32 channel_id = (channel->channel_id << 16);
+
+		si = channel->cookie_high;
+		di = (uintptr_t) reply;
+
+		VMW_PORT_HB_IN(
+			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
+			reply_len, si, di,
+			VMWARE_HYPERVISOR_HB | channel_id,
+			VMW_HYPERVISOR_MAGIC, bp,
+			eax, ebx, ecx, edx, si, di);
+
+		return ebx;
+	}
+
+	/* HB port not available. Retrieve the message 4 bytes at a time. */
+	ecx = MESSAGE_STATUS_SUCCESS << 16;
+	while (reply_len) {
+		unsigned int bytes = min_t(unsigned long, reply_len, 4);
+
+		si = channel->cookie_high;
+		di = channel->cookie_low;
+
+		VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_RECVPAYLOAD << 16),
+			 MESSAGE_STATUS_SUCCESS, si, di,
+			 channel->channel_id << 16,
+			 VMW_HYPERVISOR_MAGIC,
+			 eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
+			break;
+
+		memcpy(reply, &ebx, bytes);
+		reply_len -= bytes;
+		reply += bytes;
+	}
+
+	return ecx;
+}
+
+
+/**
+ * vmw_send_msg: Sends a message to the host
+ *
+ * @channel: RPC channel
+ * @msg: 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;
+	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,
+			channel->channel_id << 16,
+			VMW_HYPERVISOR_MAGIC,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
+			/* Expected success. Give up. */
+			return -EINVAL;
+		}
+
+		/* Send msg */
+		ebx = vmw_port_hb_out(channel, msg,
+				      !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
+
+		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;
+}
+STACK_FRAME_NON_STANDARD(vmw_send_msg);
+
+
+/**
+ * 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;
+	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,
+			channel->channel_id << 16,
+			VMW_HYPERVISOR_MAGIC,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
+			DRM_ERROR("Failed to get reply size for host message.\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) {
+			DRM_ERROR("Cannot allocate memory for host message reply.\n");
+			return -ENOMEM;
+		}
+
+
+		/* Receive buffer */
+		ebx = vmw_port_hb_in(channel, reply, reply_len,
+				     !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
+		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) == 0) {
+			kfree(reply);
+			reply = NULL;
+			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,
+			channel->channel_id << 16,
+			VMW_HYPERVISOR_MAGIC,
+			eax, ebx, ecx, edx, si, di);
+
+		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
+			kfree(reply);
+			reply = NULL;
+			if ((HIGH_WORD(ecx) & MESSAGE_STATUS_CPT) != 0) {
+				/* A checkpoint occurred. Retry. */
+				continue;
+			}
+
+			return -EINVAL;
+		}
+
+		break;
+	}
+
+	if (!reply)
+		return -EINVAL;
+
+	*msg_len = reply_len;
+	*msg     = reply;
+
+	return 0;
+}
+STACK_FRAME_NON_STANDARD(vmw_recv_msg);
+
+
+/**
+ * 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 reply_len = 0;
+
+	if (!vmw_msg_enabled)
+		return -ENODEV;
+
+	if (!guest_info_param || !length)
+		return -EINVAL;
+
+	msg = kasprintf(GFP_KERNEL, "info-get %s", guest_info_param);
+	if (!msg) {
+		DRM_ERROR("Cannot allocate memory to get guest info \"%s\".",
+			  guest_info_param);
+		return -ENOMEM;
+	}
+
+	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
+		goto out_open;
+
+	if (vmw_send_msg(&channel, msg) ||
+	    vmw_recv_msg(&channel, (void *) &reply, &reply_len))
+		goto out_msg;
+
+	vmw_close_channel(&channel);
+	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 0;
+
+out_msg:
+	vmw_close_channel(&channel);
+	kfree(reply);
+out_open:
+	*length = 0;
+	kfree(msg);
+	DRM_ERROR("Failed to get guest info \"%s\".", guest_info_param);
+
+	return -EINVAL;
+}
+
+
+/**
+ * vmw_host_printf: Sends a log message to the host
+ *
+ * @fmt: Regular printf format string and arguments
+ *
+ * Returns: 0 on success
+ */
+__printf(1, 2)
+int vmw_host_printf(const char *fmt, ...)
+{
+	va_list ap;
+	struct rpc_channel channel;
+	char *msg;
+	char *log;
+	int ret = 0;
+
+	if (!vmw_msg_enabled)
+		return -ENODEV;
+
+	if (!fmt)
+		return ret;
+
+	va_start(ap, fmt);
+	log = kvasprintf(GFP_KERNEL, fmt, ap);
+	va_end(ap);
+	if (!log) {
+		DRM_ERROR("Cannot allocate memory for the log message.\n");
+		return -ENOMEM;
+	}
+
+	msg = kasprintf(GFP_KERNEL, "log %s", log);
+	if (!msg) {
+		DRM_ERROR("Cannot allocate memory for host log message.\n");
+		kfree(log);
+		return -ENOMEM;
+	}
+
+	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
+		goto out_open;
+
+	if (vmw_send_msg(&channel, msg))
+		goto out_msg;
+
+	vmw_close_channel(&channel);
+	kfree(msg);
+	kfree(log);
+
+	return 0;
+
+out_msg:
+	vmw_close_channel(&channel);
+out_open:
+	kfree(msg);
+	kfree(log);
+	DRM_ERROR("Failed to send host log message.\n");
+
+	return -EINVAL;
+}
+
+
+/**
+ * vmw_msg_ioctl: Sends and receveives a message to/from host from/to user-space
+ *
+ * Sends a message from user-space to host.
+ * Can also receive a result from host and return that to user-space.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller.
+ * Return: Zero on success, negative error code on error.
+ */
+
+int vmw_msg_ioctl(struct drm_device *dev, void *data,
+		  struct drm_file *file_priv)
+{
+	struct drm_vmw_msg_arg *arg =
+			(struct drm_vmw_msg_arg *)data;
+	struct rpc_channel channel;
+	char *msg;
+	int length;
+
+	msg = kmalloc(MAX_USER_MSG_LENGTH, GFP_KERNEL);
+	if (!msg) {
+		DRM_ERROR("Cannot allocate memory for log message.\n");
+		return -ENOMEM;
+	}
+
+	length = strncpy_from_user(msg, (void __user *)((unsigned long)arg->send),
+				   MAX_USER_MSG_LENGTH);
+	if (length < 0 || length >= MAX_USER_MSG_LENGTH) {
+		DRM_ERROR("Userspace message access failure.\n");
+		kfree(msg);
+		return -EINVAL;
+	}
+
+
+	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM)) {
+		DRM_ERROR("Failed to open channel.\n");
+		goto out_open;
+	}
+
+	if (vmw_send_msg(&channel, msg)) {
+		DRM_ERROR("Failed to send message to host.\n");
+		goto out_msg;
+	}
+
+	if (!arg->send_only) {
+		char *reply = NULL;
+		size_t reply_len = 0;
+
+		if (vmw_recv_msg(&channel, (void *) &reply, &reply_len)) {
+			DRM_ERROR("Failed to receive message from host.\n");
+			goto out_msg;
+		}
+		if (reply && reply_len > 0) {
+			if (copy_to_user((void __user *)((unsigned long)arg->receive),
+					 reply, reply_len)) {
+				DRM_ERROR("Failed to copy message to userspace.\n");
+				kfree(reply);
+				goto out_msg;
+			}
+			arg->receive_len = (__u32)reply_len;
+		}
+		kfree(reply);
+	}
+
+	vmw_close_channel(&channel);
+	kfree(msg);
+
+	return 0;
+
+out_msg:
+	vmw_close_channel(&channel);
+out_open:
+	kfree(msg);
+
+	return -EINVAL;
+}
+
+/**
+ * reset_ppn_array: Resets a PPN64 array to INVALID_PPN64 content
+ *
+ * @arr: Array to reset.
+ * @size: Array length.
+ */
+static inline void reset_ppn_array(PPN64 *arr, size_t size)
+{
+	size_t i;
+
+	BUG_ON(!arr || size == 0);
+
+	for (i = 0; i < size; ++i)
+		arr[i] = INVALID_PPN64;
+}
+
+/**
+ * hypervisor_ppn_reset_all: Removes all mksGuestStat instance descriptors from
+ * the hypervisor. All related pages should be subsequently unpinned or freed.
+ *
+ */
+static inline void hypervisor_ppn_reset_all(void)
+{
+	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
+
+	VMW_PORT(VMW_PORT_CMD_MKSGS_RESET,
+		0, si, di,
+		0,
+		VMW_HYPERVISOR_MAGIC,
+		eax, ebx, ecx, edx, si, di);
+}
+
+/**
+ * hypervisor_ppn_add: Adds a single mksGuestStat instance descriptor to the
+ * hypervisor. Any related userspace pages should be pinned in advance.
+ *
+ * @pfn: Physical page number of the instance descriptor
+ */
+static inline void hypervisor_ppn_add(PPN64 pfn)
+{
+	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
+
+	VMW_PORT(VMW_PORT_CMD_MKSGS_ADD_PPN,
+		(unsigned long)pfn, si, di,
+		0,
+		VMW_HYPERVISOR_MAGIC,
+		eax, ebx, ecx, edx, si, di);
+}
+
+/**
+ * hypervisor_ppn_remove: Removes a single mksGuestStat instance descriptor from
+ * the hypervisor. All related pages should be subsequently unpinned or freed.
+ *
+ * @pfn: Physical page number of the instance descriptor
+ */
+static inline void hypervisor_ppn_remove(PPN64 pfn)
+{
+	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
+
+	VMW_PORT(VMW_PORT_CMD_MKSGS_REMOVE_PPN,
+		(unsigned long)pfn, si, di,
+		0,
+		VMW_HYPERVISOR_MAGIC,
+		eax, ebx, ecx, edx, si, di);
+}
+
+#if IS_ENABLED(CONFIG_DRM_VMWGFX_MKSSTATS)
+
+/* Order of the total number of pages used for kernel-internal mksGuestStat; at least 2 */
+#define MKSSTAT_KERNEL_PAGES_ORDER 2
+/* Header to the text description of mksGuestStat instance descriptor */
+#define MKSSTAT_KERNEL_DESCRIPTION "vmwgfx"
+
+/* Kernel mksGuestStats counter names and desciptions; same order as enum mksstat_kern_stats_t */
+static const char* const mksstat_kern_name_desc[MKSSTAT_KERN_COUNT][2] =
+{
+	{ "vmw_execbuf_ioctl", "vmw_execbuf_ioctl" },
+};
+
+/**
+ * mksstat_init_record: Initializes an MKSGuestStatCounter-based record
+ * for the respective mksGuestStat index.
+ *
+ * @stat_idx: Index of the MKSGuestStatCounter-based mksGuestStat record.
+ * @pstat: Pointer to array of MKSGuestStatCounterTime.
+ * @pinfo: Pointer to array of MKSGuestStatInfoEntry.
+ * @pstrs: Pointer to current end of the name/description sequence.
+ * Return: Pointer to the new end of the names/description sequence.
+ */
+
+static inline char *mksstat_init_record(mksstat_kern_stats_t stat_idx,
+	MKSGuestStatCounterTime *pstat, MKSGuestStatInfoEntry *pinfo, char *pstrs)
+{
+	char *const pstrd = pstrs + strlen(mksstat_kern_name_desc[stat_idx][0]) + 1;
+	strcpy(pstrs, mksstat_kern_name_desc[stat_idx][0]);
+	strcpy(pstrd, mksstat_kern_name_desc[stat_idx][1]);
+
+	pinfo[stat_idx].name.s = pstrs;
+	pinfo[stat_idx].description.s = pstrd;
+	pinfo[stat_idx].flags = MKS_GUEST_STAT_FLAG_NONE;
+	pinfo[stat_idx].stat.counter = (MKSGuestStatCounter *)&pstat[stat_idx];
+
+	return pstrd + strlen(mksstat_kern_name_desc[stat_idx][1]) + 1;
+}
+
+/**
+ * mksstat_init_record_time: Initializes an MKSGuestStatCounterTime-based record
+ * for the respective mksGuestStat index.
+ *
+ * @stat_idx: Index of the MKSGuestStatCounterTime-based mksGuestStat record.
+ * @pstat: Pointer to array of MKSGuestStatCounterTime.
+ * @pinfo: Pointer to array of MKSGuestStatInfoEntry.
+ * @pstrs: Pointer to current end of the name/description sequence.
+ * Return: Pointer to the new end of the names/description sequence.
+ */
+
+static inline char *mksstat_init_record_time(mksstat_kern_stats_t stat_idx,
+	MKSGuestStatCounterTime *pstat, MKSGuestStatInfoEntry *pinfo, char *pstrs)
+{
+	char *const pstrd = pstrs + strlen(mksstat_kern_name_desc[stat_idx][0]) + 1;
+	strcpy(pstrs, mksstat_kern_name_desc[stat_idx][0]);
+	strcpy(pstrd, mksstat_kern_name_desc[stat_idx][1]);
+
+	pinfo[stat_idx].name.s = pstrs;
+	pinfo[stat_idx].description.s = pstrd;
+	pinfo[stat_idx].flags = MKS_GUEST_STAT_FLAG_TIME;
+	pinfo[stat_idx].stat.counterTime = &pstat[stat_idx];
+
+	return pstrd + strlen(mksstat_kern_name_desc[stat_idx][1]) + 1;
+}
+
+/**
+ * mksstat_init_kern_id: Creates a single mksGuestStat instance descriptor and
+ * kernel-internal counters. Adds PFN mapping to the hypervisor.
+ *
+ * Create a single mksGuestStat instance descriptor and corresponding structures
+ * for all kernel-internal counters. The corresponding PFNs are mapped with the
+ * hypervisor.
+ *
+ * @ppage: Output pointer to page containing the instance descriptor.
+ * Return: Zero on success, negative error code on error.
+ */
+
+static int mksstat_init_kern_id(struct page **ppage)
+{
+	MKSGuestStatInstanceDescriptor *pdesc;
+	MKSGuestStatCounterTime *pstat;
+	MKSGuestStatInfoEntry *pinfo;
+	char *pstrs, *pstrs_acc;
+
+	/* Allocate pages for the kernel-internal instance descriptor */
+	struct page *page = alloc_pages(GFP_KERNEL | __GFP_ZERO, MKSSTAT_KERNEL_PAGES_ORDER);
+
+	if (!page)
+		return -ENOMEM;
+
+	pdesc = page_address(page);
+	pstat = vmw_mksstat_get_kern_pstat(pdesc);
+	pinfo = vmw_mksstat_get_kern_pinfo(pdesc);
+	pstrs = vmw_mksstat_get_kern_pstrs(pdesc);
+
+	/* Set up all kernel-internal counters and corresponding structures */
+	pstrs_acc = pstrs;
+	pstrs_acc = mksstat_init_record_time(MKSSTAT_KERN_EXECBUF, pstat, pinfo, pstrs_acc);
+
+	/* Add new counters above, in their order of appearance in mksstat_kern_stats_t */
+
+	BUG_ON(pstrs_acc - pstrs > PAGE_SIZE);
+
+	/* Set up the kernel-internal instance descriptor */
+	pdesc->reservedMBZ = 0;
+	pdesc->statStartVA = (uintptr_t)pstat;
+	pdesc->strsStartVA = (uintptr_t)pstrs;
+	pdesc->statLength = sizeof(*pstat) * MKSSTAT_KERN_COUNT;
+	pdesc->infoLength = sizeof(*pinfo) * MKSSTAT_KERN_COUNT;
+	pdesc->strsLength = pstrs_acc - pstrs;
+	snprintf(pdesc->description, ARRAY_SIZE(pdesc->description) - 1, "%s pid=%d",
+		MKSSTAT_KERNEL_DESCRIPTION, current->pid);
+
+	pdesc->statPPNs[0] = page_to_pfn(virt_to_page(pstat));
+	reset_ppn_array(pdesc->statPPNs + 1, ARRAY_SIZE(pdesc->statPPNs) - 1);
+
+	pdesc->infoPPNs[0] = page_to_pfn(virt_to_page(pinfo));
+	reset_ppn_array(pdesc->infoPPNs + 1, ARRAY_SIZE(pdesc->infoPPNs) - 1);
+
+	pdesc->strsPPNs[0] = page_to_pfn(virt_to_page(pstrs));
+	reset_ppn_array(pdesc->strsPPNs + 1, ARRAY_SIZE(pdesc->strsPPNs) - 1);
+
+	*ppage = page;
+
+	hypervisor_ppn_add((PPN64)page_to_pfn(page));
+
+	return 0;
+}
+
+/**
+ * vmw_mksstat_get_kern_slot: Acquires a slot for a single kernel-internal
+ * mksGuestStat instance descriptor.
+ *
+ * Find a slot for a single kernel-internal mksGuestStat instance descriptor.
+ * In case no such was already present, allocate a new one and set up a kernel-
+ * internal mksGuestStat instance descriptor for the former.
+ *
+ * @pid: Process for which a slot is sought.
+ * @dev_priv: Identifies the drm private device.
+ * Return: Non-negative slot on success, negative error code on error.
+ */
+
+int vmw_mksstat_get_kern_slot(pid_t pid, struct vmw_private *dev_priv)
+{
+	const size_t base = (u32)hash_32(pid, MKSSTAT_CAPACITY_LOG2);
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(dev_priv->mksstat_kern_pids); ++i) {
+		const size_t slot = (i + base) % ARRAY_SIZE(dev_priv->mksstat_kern_pids);
+
+		/* Check if an instance descriptor for this pid is already present */
+		if (pid == (pid_t)atomic_read(&dev_priv->mksstat_kern_pids[slot]))
+			return (int)slot;
+
+		/* Set up a new instance descriptor for this pid */
+		if (!atomic_cmpxchg(&dev_priv->mksstat_kern_pids[slot], 0, MKSSTAT_PID_RESERVED)) {
+			const int ret = mksstat_init_kern_id(&dev_priv->mksstat_kern_pages[slot]);
+
+			if (!ret) {
+				/* Reset top-timer tracking for this slot */
+				dev_priv->mksstat_kern_top_timer[slot] = MKSSTAT_KERN_COUNT;
+
+				atomic_set(&dev_priv->mksstat_kern_pids[slot], pid);
+				return (int)slot;
+			}
+
+			atomic_set(&dev_priv->mksstat_kern_pids[slot], 0);
+			return ret;
+		}
+	}
+
+	return -ENOSPC;
+}
+
+#endif
+
+/**
+ * vmw_mksstat_cleanup_descriptor: Frees a single userspace-originating
+ * mksGuestStat instance-descriptor page and unpins all related user pages.
+ *
+ * Unpin all user pages realated to this instance descriptor and free
+ * the instance-descriptor page itself.
+ *
+ * @page: Page of the instance descriptor.
+ */
+
+static void vmw_mksstat_cleanup_descriptor(struct page *page)
+{
+	MKSGuestStatInstanceDescriptor *pdesc = page_address(page);
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(pdesc->statPPNs) && pdesc->statPPNs[i] != INVALID_PPN64; ++i)
+		unpin_user_page(pfn_to_page(pdesc->statPPNs[i]));
+
+	for (i = 0; i < ARRAY_SIZE(pdesc->infoPPNs) && pdesc->infoPPNs[i] != INVALID_PPN64; ++i)
+		unpin_user_page(pfn_to_page(pdesc->infoPPNs[i]));
+
+	for (i = 0; i < ARRAY_SIZE(pdesc->strsPPNs) && pdesc->strsPPNs[i] != INVALID_PPN64; ++i)
+		unpin_user_page(pfn_to_page(pdesc->strsPPNs[i]));
+
+	__free_page(page);
+}
+
+/**
+ * vmw_mksstat_remove_all: Resets all mksGuestStat instance descriptors
+ * from the hypervisor.
+ *
+ * Discard all hypervisor PFN mappings, containing active mksGuestState instance
+ * descriptors, unpin the related userspace pages and free the related kernel pages.
+ *
+ * @dev_priv: Identifies the drm private device.
+ * Return: Zero on success, negative error code on error.
+ */
+
+int vmw_mksstat_remove_all(struct vmw_private *dev_priv)
+{
+	int ret = 0;
+	size_t i;
+
+	/* Discard all PFN mappings with the hypervisor */
+	hypervisor_ppn_reset_all();
+
+	/* Discard all userspace-originating instance descriptors and unpin all related pages */
+	for (i = 0; i < ARRAY_SIZE(dev_priv->mksstat_user_pids); ++i) {
+		const pid_t pid0 = (pid_t)atomic_read(&dev_priv->mksstat_user_pids[i]);
+
+		if (!pid0)
+			continue;
+
+		if (pid0 != MKSSTAT_PID_RESERVED) {
+			const pid_t pid1 = atomic_cmpxchg(&dev_priv->mksstat_user_pids[i], pid0, MKSSTAT_PID_RESERVED);
+
+			if (!pid1)
+				continue;
+
+			if (pid1 == pid0) {
+				struct page *const page = dev_priv->mksstat_user_pages[i];
+
+				BUG_ON(!page);
+
+				dev_priv->mksstat_user_pages[i] = NULL;
+				atomic_set(&dev_priv->mksstat_user_pids[i], 0);
+
+				vmw_mksstat_cleanup_descriptor(page);
+				continue;
+			}
+		}
+
+		ret = -EAGAIN;
+	}
+
+#if IS_ENABLED(CONFIG_DRM_VMWGFX_MKSSTATS)
+	/* Discard all kernel-internal instance descriptors and free all related pages */
+	for (i = 0; i < ARRAY_SIZE(dev_priv->mksstat_kern_pids); ++i) {
+		const pid_t pid0 = (pid_t)atomic_read(&dev_priv->mksstat_kern_pids[i]);
+
+		if (!pid0)
+			continue;
+
+		if (pid0 != MKSSTAT_PID_RESERVED) {
+			const pid_t pid1 = atomic_cmpxchg(&dev_priv->mksstat_kern_pids[i], pid0, MKSSTAT_PID_RESERVED);
+
+			if (!pid1)
+				continue;
+
+			if (pid1 == pid0) {
+				struct page *const page = dev_priv->mksstat_kern_pages[i];
+
+				BUG_ON(!page);
+
+				dev_priv->mksstat_kern_pages[i] = NULL;
+				atomic_set(&dev_priv->mksstat_kern_pids[i], 0);
+
+				__free_pages(page, MKSSTAT_KERNEL_PAGES_ORDER);
+				continue;
+			}
+		}
+
+		ret = -EAGAIN;
+	}
+
+#endif
+	return ret;
+}
+
+/**
+ * vmw_mksstat_reset_ioctl: Resets all mksGuestStat instance descriptors
+ * from the hypervisor.
+ *
+ * Discard all hypervisor PFN mappings, containing active mksGuestStat instance
+ * descriptors, unpin the related userspace pages and free the related kernel pages.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller; unused.
+ * Return: Zero on success, negative error code on error.
+ */
+
+int vmw_mksstat_reset_ioctl(struct drm_device *dev, void *data,
+				struct drm_file *file_priv)
+{
+	struct vmw_private *const dev_priv = vmw_priv(dev);
+	return vmw_mksstat_remove_all(dev_priv);
+}
+
+/**
+ * vmw_mksstat_add_ioctl: Creates a single userspace-originating mksGuestStat
+ * instance descriptor and registers that with the hypervisor.
+ *
+ * Create a hypervisor PFN mapping, containing a single mksGuestStat instance
+ * descriptor and pin the corresponding userspace pages.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller; unused.
+ * Return: Zero on success, negative error code on error.
+ */
+
+int vmw_mksstat_add_ioctl(struct drm_device *dev, void *data,
+				struct drm_file *file_priv)
+{
+	struct drm_vmw_mksstat_add_arg *arg =
+		(struct drm_vmw_mksstat_add_arg *) data;
+
+	struct vmw_private *const dev_priv = vmw_priv(dev);
+
+	struct page *page;
+	MKSGuestStatInstanceDescriptor *pdesc;
+	const size_t num_pages_stat = PFN_UP(arg->stat_len);
+	const size_t num_pages_info = PFN_UP(arg->info_len);
+	const size_t num_pages_strs = PFN_UP(arg->strs_len);
+	long desc_len;
+	long nr_pinned_stat;
+	long nr_pinned_info;
+	long nr_pinned_strs;
+	struct page *pages_stat[ARRAY_SIZE(pdesc->statPPNs)];
+	struct page *pages_info[ARRAY_SIZE(pdesc->infoPPNs)];
+	struct page *pages_strs[ARRAY_SIZE(pdesc->strsPPNs)];
+	size_t i, slot;
+
+	arg->id = -1;
+
+	if (!arg->stat || !arg->info || !arg->strs)
+		return -EINVAL;
+
+	if (!arg->stat_len || !arg->info_len || !arg->strs_len)
+		return -EINVAL;
+
+	if (!arg->description)
+		return -EINVAL;
+
+	if (num_pages_stat > ARRAY_SIZE(pdesc->statPPNs) ||
+		num_pages_info > ARRAY_SIZE(pdesc->infoPPNs) ||
+		num_pages_strs > ARRAY_SIZE(pdesc->strsPPNs))
+		return -EINVAL;
+
+	/* Find an available slot in the mksGuestStats user array and reserve it */
+	for (slot = 0; slot < ARRAY_SIZE(dev_priv->mksstat_user_pids); ++slot)
+		if (!atomic_cmpxchg(&dev_priv->mksstat_user_pids[slot], 0, MKSSTAT_PID_RESERVED))
+			break;
+
+	if (slot == ARRAY_SIZE(dev_priv->mksstat_user_pids))
+		return -ENOSPC;
+
+	BUG_ON(dev_priv->mksstat_user_pages[slot]);
+
+	/* Allocate a page for the instance descriptor */
+	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+
+	if (!page) {
+		atomic_set(&dev_priv->mksstat_user_pids[slot], 0);
+		return -ENOMEM;
+	}
+
+	/* Set up the instance descriptor */
+	pdesc = page_address(page);
+
+	pdesc->reservedMBZ = 0;
+	pdesc->statStartVA = arg->stat;
+	pdesc->strsStartVA = arg->strs;
+	pdesc->statLength = arg->stat_len;
+	pdesc->infoLength = arg->info_len;
+	pdesc->strsLength = arg->strs_len;
+	desc_len = strncpy_from_user(pdesc->description, u64_to_user_ptr(arg->description),
+		ARRAY_SIZE(pdesc->description) - 1);
+
+	if (desc_len < 0) {
+		atomic_set(&dev_priv->mksstat_user_pids[slot], 0);
+		__free_page(page);
+		return -EFAULT;
+	}
+
+	reset_ppn_array(pdesc->statPPNs, ARRAY_SIZE(pdesc->statPPNs));
+	reset_ppn_array(pdesc->infoPPNs, ARRAY_SIZE(pdesc->infoPPNs));
+	reset_ppn_array(pdesc->strsPPNs, ARRAY_SIZE(pdesc->strsPPNs));
+
+	/* Pin mksGuestStat user pages and store those in the instance descriptor */
+	nr_pinned_stat = pin_user_pages_fast(arg->stat, num_pages_stat, FOLL_LONGTERM, pages_stat);
+	if (num_pages_stat != nr_pinned_stat)
+		goto err_pin_stat;
+
+	for (i = 0; i < num_pages_stat; ++i)
+		pdesc->statPPNs[i] = page_to_pfn(pages_stat[i]);
+
+	nr_pinned_info = pin_user_pages_fast(arg->info, num_pages_info, FOLL_LONGTERM, pages_info);
+	if (num_pages_info != nr_pinned_info)
+		goto err_pin_info;
+
+	for (i = 0; i < num_pages_info; ++i)
+		pdesc->infoPPNs[i] = page_to_pfn(pages_info[i]);
+
+	nr_pinned_strs = pin_user_pages_fast(arg->strs, num_pages_strs, FOLL_LONGTERM, pages_strs);
+	if (num_pages_strs != nr_pinned_strs)
+		goto err_pin_strs;
+
+	for (i = 0; i < num_pages_strs; ++i)
+		pdesc->strsPPNs[i] = page_to_pfn(pages_strs[i]);
+
+	/* Send the descriptor to the host via a hypervisor call. The mksGuestStat
+	   pages will remain in use until the user requests a matching remove stats
+	   or a stats reset occurs. */
+	hypervisor_ppn_add((PPN64)page_to_pfn(page));
+
+	dev_priv->mksstat_user_pages[slot] = page;
+	atomic_set(&dev_priv->mksstat_user_pids[slot], task_pgrp_vnr(current));
+
+	arg->id = slot;
+
+	DRM_DEV_INFO(dev->dev, "pid=%d arg.description='%.*s' id=%zu\n", current->pid, (int)desc_len, pdesc->description, slot);
+
+	return 0;
+
+err_pin_strs:
+	if (nr_pinned_strs > 0)
+		unpin_user_pages(pages_strs, nr_pinned_strs);
+
+err_pin_info:
+	if (nr_pinned_info > 0)
+		unpin_user_pages(pages_info, nr_pinned_info);
+
+err_pin_stat:
+	if (nr_pinned_stat > 0)
+		unpin_user_pages(pages_stat, nr_pinned_stat);
+
+	atomic_set(&dev_priv->mksstat_user_pids[slot], 0);
+	__free_page(page);
+	return -ENOMEM;
+}
+
+/**
+ * vmw_mksstat_remove_ioctl: Removes a single userspace-originating mksGuestStat
+ * instance descriptor from the hypervisor.
+ *
+ * Discard a hypervisor PFN mapping, containing a single mksGuestStat instance
+ * descriptor and unpin the corresponding userspace pages.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller; unused.
+ * Return: Zero on success, negative error code on error.
+ */
+
+int vmw_mksstat_remove_ioctl(struct drm_device *dev, void *data,
+				struct drm_file *file_priv)
+{
+	struct drm_vmw_mksstat_remove_arg *arg =
+		(struct drm_vmw_mksstat_remove_arg *) data;
+
+	struct vmw_private *const dev_priv = vmw_priv(dev);
+
+	const size_t slot = arg->id;
+	pid_t pgid, pid;
+
+	if (slot >= ARRAY_SIZE(dev_priv->mksstat_user_pids))
+		return -EINVAL;
+
+	DRM_DEV_INFO(dev->dev, "pid=%d arg.id=%zu\n", current->pid, slot);
+
+	pgid = task_pgrp_vnr(current);
+	pid = atomic_cmpxchg(&dev_priv->mksstat_user_pids[slot], pgid, MKSSTAT_PID_RESERVED);
+
+	if (!pid)
+		return 0;
+
+	if (pid == pgid) {
+		struct page *const page = dev_priv->mksstat_user_pages[slot];
+
+		BUG_ON(!page);
+
+		dev_priv->mksstat_user_pages[slot] = NULL;
+		atomic_set(&dev_priv->mksstat_user_pids[slot], 0);
+
+		hypervisor_ppn_remove((PPN64)page_to_pfn(page));
+
+		vmw_mksstat_cleanup_descriptor(page);
+		return 0;
+	}
+
+	return -EAGAIN;
+}