path: root/drivers/misc/vmw_vmci/vmci_guest.c

/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 *
 * 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 version 2 and no 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.  See the GNU General Public License
 * for more details.
 */

#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/moduleparam.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/vmalloc.h>

#include "vmci_datagram.h"
#include "vmci_doorbell.h"
#include "vmci_context.h"
#include "vmci_driver.h"
#include "vmci_event.h"

#define PCI_DEVICE_ID_VMWARE_VMCI	0x0740

#define VMCI_UTIL_NUM_RESOURCES 1

static bool vmci_disable_msi;
module_param_named(disable_msi, vmci_disable_msi, bool, 0);
MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");

static bool vmci_disable_msix;
module_param_named(disable_msix, vmci_disable_msix, bool, 0);
MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");

static u32 ctx_update_sub_id = VMCI_INVALID_ID;
static u32 vm_context_id = VMCI_INVALID_ID;

struct vmci_guest_device {
	struct device *dev;	/* PCI device we are attached to */
	void __iomem *iobase;

	bool exclusive_vectors;

	struct tasklet_struct datagram_tasklet;
	struct tasklet_struct bm_tasklet;

	void *data_buffer;
	void *notification_bitmap;
	dma_addr_t notification_base;
};

static bool use_ppn64;

bool vmci_use_ppn64(void)
{
	return use_ppn64;
}

/* vmci_dev singleton device and supporting data*/
struct pci_dev *vmci_pdev;
static struct vmci_guest_device *vmci_dev_g;
static DEFINE_SPINLOCK(vmci_dev_spinlock);

static atomic_t vmci_num_guest_devices = ATOMIC_INIT(0);

bool vmci_guest_code_active(void)
{
	return atomic_read(&vmci_num_guest_devices) != 0;
}

u32 vmci_get_vm_context_id(void)
{
	if (vm_context_id == VMCI_INVALID_ID) {
		struct vmci_datagram get_cid_msg;
		get_cid_msg.dst =
		    vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
				     VMCI_GET_CONTEXT_ID);
		get_cid_msg.src = VMCI_ANON_SRC_HANDLE;
		get_cid_msg.payload_size = 0;
		vm_context_id = vmci_send_datagram(&get_cid_msg);
	}
	return vm_context_id;
}

/*
 * VM to hypervisor call mechanism. We use the standard VMware naming
 * convention since shared code is calling this function as well.
 */
int vmci_send_datagram(struct vmci_datagram *dg)
{
	unsigned long flags;
	int result;

	/* Check args. */
	if (dg == NULL)
		return VMCI_ERROR_INVALID_ARGS;

	/*
	 * Need to acquire spinlock on the device because the datagram
	 * data may be spread over multiple pages and the monitor may
	 * interleave device user rpc calls from multiple
	 * VCPUs. Acquiring the spinlock precludes that
	 * possibility. Disabling interrupts to avoid incoming
	 * datagrams during a "rep out" and possibly landing up in
	 * this function.
	 */
	spin_lock_irqsave(&vmci_dev_spinlock, flags);

	if (vmci_dev_g) {
		iowrite8_rep(vmci_dev_g->iobase + VMCI_DATA_OUT_ADDR,
			     dg, VMCI_DG_SIZE(dg));
		result = ioread32(vmci_dev_g->iobase + VMCI_RESULT_LOW_ADDR);
	} else {
		result = VMCI_ERROR_UNAVAILABLE;
	}

	spin_unlock_irqrestore(&vmci_dev_spinlock, flags);

	return result;
}
EXPORT_SYMBOL_GPL(vmci_send_datagram);

/*
 * Gets called with the new context id if updated or resumed.
 * Context id.
 */
static void vmci_guest_cid_update(u32 sub_id,
				  const struct vmci_event_data *event_data,
				  void *client_data)
{
	const struct vmci_event_payld_ctx *ev_payload =
				vmci_event_data_const_payload(event_data);

	if (sub_id != ctx_update_sub_id) {
		pr_devel("Invalid subscriber (ID=0x%x)\n", sub_id);
		return;
	}

	if (!event_data || ev_payload->context_id == VMCI_INVALID_ID) {
		pr_devel("Invalid event data\n");
		return;
	}

	pr_devel("Updating context from (ID=0x%x) to (ID=0x%x) on event (type=%d)\n",
		 vm_context_id, ev_payload->context_id, event_data->event);

	vm_context_id = ev_payload->context_id;
}

/*
 * Verify that the host supports the hypercalls we need. If it does not,
 * try to find fallback hypercalls and use those instead.  Returns
 * true if required hypercalls (or fallback hypercalls) are
 * supported by the host, false otherwise.
 */
static int vmci_check_host_caps(struct pci_dev *pdev)
{
	bool result;
	struct vmci_resource_query_msg *msg;
	u32 msg_size = sizeof(struct vmci_resource_query_hdr) +
				VMCI_UTIL_NUM_RESOURCES * sizeof(u32);
	struct vmci_datagram *check_msg;

	check_msg = kmalloc(msg_size, GFP_KERNEL);
	if (!check_msg) {
		dev_err(&pdev->dev, "%s: Insufficient memory\n", __func__);
		return -ENOMEM;
	}

	check_msg->dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
					  VMCI_RESOURCES_QUERY);
	check_msg->src = VMCI_ANON_SRC_HANDLE;
	check_msg->payload_size = msg_size - VMCI_DG_HEADERSIZE;
	msg = (struct vmci_resource_query_msg *)VMCI_DG_PAYLOAD(check_msg);

	msg->num_resources = VMCI_UTIL_NUM_RESOURCES;
	msg->resources[0] = VMCI_GET_CONTEXT_ID;

	/* Checks that hyper calls are supported */
	result = vmci_send_datagram(check_msg) == 0x01;
	kfree(check_msg);

	dev_dbg(&pdev->dev, "%s: Host capability check: %s\n",
		__func__, result ? "PASSED" : "FAILED");

	/* We need the vector. There are no fallbacks. */
	return result ? 0 : -ENXIO;
}

/*
 * Reads datagrams from the data in port and dispatches them. We
 * always start reading datagrams into only the first page of the
 * datagram buffer. If the datagrams don't fit into one page, we
 * use the maximum datagram buffer size for the remainder of the
 * invocation. This is a simple heuristic for not penalizing
 * small datagrams.
 *
 * This function assumes that it has exclusive access to the data
 * in port for the duration of the call.
 */
static void vmci_dispatch_dgs(unsigned long data)
{
	struct vmci_guest_device *vmci_dev = (struct vmci_guest_device *)data;
	u8 *dg_in_buffer = vmci_dev->data_buffer;
	struct vmci_datagram *dg;
	size_t dg_in_buffer_size = VMCI_MAX_DG_SIZE;
	size_t current_dg_in_buffer_size = PAGE_SIZE;
	size_t remaining_bytes;

	BUILD_BUG_ON(VMCI_MAX_DG_SIZE < PAGE_SIZE);

	ioread8_rep(vmci_dev->iobase + VMCI_DATA_IN_ADDR,
		    vmci_dev->data_buffer, current_dg_in_buffer_size);
	dg = (struct vmci_datagram *)dg_in_buffer;
	remaining_bytes = current_dg_in_buffer_size;

	while (dg->dst.resource != VMCI_INVALID_ID