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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 */

#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/processor.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

/*
 * Datagram buffers for DMA send/receive must accommodate at least
 * a maximum sized datagram and the header.
 */
#define VMCI_DMA_DG_BUFFER_SIZE (VMCI_MAX_DG_SIZE + PAGE_SIZE)

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;
	void __iomem *mmio_base;

	bool exclusive_vectors;

	struct wait_queue_head inout_wq;

	void *data_buffer;
	dma_addr_t data_buffer_base;
	void *tx_buffer;
	dma_addr_t tx_buffer_base;
	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;
}

static unsigned int vmci_read_reg(struct vmci_guest_device *dev, u32 reg)
{
	if (dev->mmio_base != NULL)
		return readl(dev->mmio_base + reg);
	return ioread32(dev->iobase + reg);
}

static void vmci_write_reg(struct vmci_guest_device *dev, u32 val, u32 reg)
{
	if (dev->mmio_base != NULL)
		writel(val, dev->mmio_base + reg);
	else
		iowrite32(val, dev->iobase + reg);
}

static void vmci_read_data(struct vmci_guest_device *vmci_dev,
			   void *dest, size_t size)
{
	if (vmci_dev->mmio_base == NULL)
		ioread8_rep(vmci_dev->iobase + VMCI_DATA_IN_ADDR,
			    dest, size);
	else {
		/*
		 * For DMA datagrams, the data_buffer will contain the header on the
		 * first page, followed by the incoming datagram(s) on the following
		 * pages. The header uses an S/G element immediately following the
		 * header on the first page to point to the data area.
		 */
		struct vmci_data_in_out_header *buffer_header = vmci_dev->data_buffer;
		struct vmci_sg_elem *sg_array = (struct vmci_sg_elem *)(buffer_header + 1);
		size_t buffer_offset = dest - vmci_dev->data_buffer;

		buffer_header->opcode = 1;
		buffer_header->size = 1;
		buffer_header->busy = 0;
		sg_array[0].addr = vmci_dev->data_buffer_base + buffer_offset;
		sg_array[0].size = size;

		vmci_write_reg(vmci_dev, lower_32_bits(vmci_dev->data_buffer_base),
			       VMCI_DATA_IN_LOW_ADDR);

		wait_event(vmci_dev->inout_wq, buffer_header->busy == 1);
	}
}

static int vmci_write_data(struct vmci_guest_device *dev,
			   struct vmci_datagram *dg)
{
	int result;

	if (dev->mmio_base != NULL) {
		struct vmci_data_in_out_header *buffer_header = dev->tx_buffer;
		u8 *dg_out_buffer = (u8 *)(buffer_header + 1);

		if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE)
			return VMCI_ERROR_I