Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 404 insertions, 0 deletions

diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
new file mode 100644
index 000000000..3d0ec2bbe
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -0,0 +1,404 @@
+/*
+ * VFIO PCI I/O Port & MMIO access
+ *
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ */
+
+#include <linux/fs.h>
+#include <linux/pci.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/vfio.h>
+#include <linux/vgaarb.h>
+
+#include "vfio_pci_private.h"
+
+#ifdef __LITTLE_ENDIAN
+#define vfio_ioread64	ioread64
+#define vfio_iowrite64	iowrite64
+#define vfio_ioread32	ioread32
+#define vfio_iowrite32	iowrite32
+#define vfio_ioread16	ioread16
+#define vfio_iowrite16	iowrite16
+#else
+#define vfio_ioread64	ioread64be
+#define vfio_iowrite64	iowrite64be
+#define vfio_ioread32	ioread32be
+#define vfio_iowrite32	iowrite32be
+#define vfio_ioread16	ioread16be
+#define vfio_iowrite16	iowrite16be
+#endif
+#define vfio_ioread8	ioread8
+#define vfio_iowrite8	iowrite8
+
+/*
+ * Read or write from an __iomem region (MMIO or I/O port) with an excluded
+ * range which is inaccessible.  The excluded range drops writes and fills
+ * reads with -1.  This is intended for handling MSI-X vector tables and
+ * leftover space for ROM BARs.
+ */
+static ssize_t do_io_rw(void __iomem *io, char __user *buf,
+			loff_t off, size_t count, size_t x_start,
+			size_t x_end, bool iswrite)
+{
+	ssize_t done = 0;
+
+	while (count) {
+		size_t fillable, filled;
+
+		if (off < x_start)
+			fillable = min(count, (size_t)(x_start - off));
+		else if (off >= x_end)
+			fillable = count;
+		else
+			fillable = 0;
+
+		if (fillable >= 4 && !(off % 4)) {
+			u32 val;
+
+			if (iswrite) {
+				if (copy_from_user(&val, buf, 4))
+					return -EFAULT;
+
+				vfio_iowrite32(val, io + off);
+			} else {
+				val = vfio_ioread32(io + off);
+
+				if (copy_to_user(buf, &val, 4))
+					return -EFAULT;
+			}
+
+			filled = 4;
+		} else if (fillable >= 2 && !(off % 2)) {
+			u16 val;
+
+			if (iswrite) {
+				if (copy_from_user(&val, buf, 2))
+					return -EFAULT;
+
+				vfio_iowrite16(val, io + off);
+			} else {
+				val = vfio_ioread16(io + off);
+
+				if (copy_to_user(buf, &val, 2))
+					return -EFAULT;
+			}
+
+			filled = 2;
+		} else if (fillable) {
+			u8 val;
+
+			if (iswrite) {
+				if (copy_from_user(&val, buf, 1))
+					return -EFAULT;
+
+				vfio_iowrite8(val, io + off);
+			} else {
+				val = vfio_ioread8(io + off);
+
+				if (copy_to_user(buf, &val, 1))
+					return -EFAULT;
+			}
+
+			filled = 1;
+		} else {
+			/* Fill reads with -1, drop writes */
+			filled = min(count, (size_t)(x_end - off));
+			if (!iswrite) {
+				u8 val = 0xFF;
+				size_t i;
+
+				for (i = 0; i < filled; i++)
+					if (copy_to_user(buf + i, &val, 1))
+						return -EFAULT;
+			}
+		}
+
+		count -= filled;
+		done += filled;
+		off += filled;
+		buf += filled;
+	}
+
+	return done;
+}
+
+static int vfio_pci_setup_barmap(struct vfio_pci_device *vdev, int bar)
+{
+	struct pci_dev *pdev = vdev->pdev;
+	int ret;
+	void __iomem *io;
+
+	if (vdev->barmap[bar])
+		return 0;
+
+	ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
+	if (ret)
+		return ret;
+
+	io = pci_iomap(pdev, bar, 0);
+	if (!io) {
+		pci_release_selected_regions(pdev, 1 << bar);
+		return -ENOMEM;
+	}
+
+	vdev->barmap[bar] = io;
+
+	return 0;
+}
+
+ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
+			size_t count, loff_t *ppos, bool iswrite)
+{
+	struct pci_dev *pdev = vdev->pdev;
+	loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+	int bar = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+	size_t x_start = 0, x_end = 0;
+	resource_size_t end;
+	void __iomem *io;
+	struct resource *res = &vdev->pdev->resource[bar];
+	ssize_t done;
+
+	if (pci_resource_start(pdev, bar))
+		end = pci_resource_len(pdev, bar);
+	else if (bar == PCI_ROM_RESOURCE &&
+		 pdev->resource[bar].flags & IORESOURCE_ROM_SHADOW)
+		end = 0x20000;
+	else
+		return -EINVAL;
+
+	if (pos >= end)
+		return -EINVAL;
+
+	count = min(count, (size_t)(end - pos));
+
+	if (res->flags & IORESOURCE_MEM) {
+		down_read(&vdev->memory_lock);
+		if (!__vfio_pci_memory_enabled(vdev)) {
+			up_read(&vdev->memory_lock);
+			return -EIO;
+		}
+	}
+
+	if (bar == PCI_ROM_RESOURCE) {
+		/*
+		 * The ROM can fill less space than the BAR, so we start the
+		 * excluded range at the end of the actual ROM.  This makes
+		 * filling large ROM BARs much faster.
+		 */
+		io = pci_map_rom(pdev, &x_start);
+		if (!io) {
+			done = -ENOMEM;
+			goto out;
+		}
+		x_end = end;
+	} else {
+		int ret = vfio_pci_setup_barmap(vdev, bar);
+		if (ret) {
+			done = ret;
+			goto out;
+		}
+
+		io = vdev->barmap[bar];
+	}
+
+	if (bar == vdev->msix_bar) {
+		x_start = vdev->msix_offset;
+		x_end = vdev->msix_offset + vdev->msix_size;
+	}
+
+	done = do_io_rw(io, buf, pos, count, x_start, x_end, iswrite);
+
+	if (done >= 0)
+		*ppos += done;
+
+	if (bar == PCI_ROM_RESOURCE)
+		pci_unmap_rom(pdev, io);
+out:
+	if (res->flags & IORESOURCE_MEM)
+		up_read(&vdev->memory_lock);
+
+	return done;
+}
+
+ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
+			       size_t count, loff_t *ppos, bool iswrite)
+{
+	int ret;
+	loff_t off, pos = *ppos & VFIO_PCI_OFFSET_MASK;
+	void __iomem *iomem = NULL;
+	unsigned int rsrc;
+	bool is_ioport;
+	ssize_t done;
+
+	if (!vdev->has_vga)
+		return -EINVAL;
+
+	if (pos > 0xbfffful)
+		return -EINVAL;
+
+	switch ((u32)pos) {
+	case 0xa0000 ... 0xbffff:
+		count = min(count, (size_t)(0xc0000 - pos));
+		iomem = ioremap_nocache(0xa0000, 0xbffff - 0xa0000 + 1);
+		off = pos - 0xa0000;
+		rsrc = VGA_RSRC_LEGACY_MEM;
+		is_ioport = false;
+		break;
+	case 0x3b0 ... 0x3bb:
+		count = min(count, (size_t)(0x3bc - pos));
+		iomem = ioport_map(0x3b0, 0x3bb - 0x3b0 + 1);
+		off = pos - 0x3b0;
+		rsrc = VGA_RSRC_LEGACY_IO;
+		is_ioport = true;
+		break;
+	case 0x3c0 ... 0x3df:
+		count = min(count, (size_t)(0x3e0 - pos));
+		iomem = ioport_map(0x3c0, 0x3df - 0x3c0 + 1);
+		off = pos - 0x3c0;
+		rsrc = VGA_RSRC_LEGACY_IO;
+		is_ioport = true;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (!iomem)
+		return -ENOMEM;
+
+	ret = vga_get_interruptible(vdev->pdev, rsrc);
+	if (ret) {
+		is_ioport ? ioport_unmap(iomem) : iounmap(iomem);
+		return ret;
+	}
+
+	done = do_io_rw(iomem, buf, off, count, 0, 0, iswrite);
+
+	vga_put(vdev->pdev, rsrc);
+
+	is_ioport ? ioport_unmap(iomem) : iounmap(iomem);
+
+	if (done >= 0)
+		*ppos += done;
+
+	return done;
+}
+
+static int vfio_pci_ioeventfd_handler(void *opaque, void *unused)
+{
+	struct vfio_pci_ioeventfd *ioeventfd = opaque;
+
+	switch (ioeventfd->count) {
+	case 1:
+		vfio_iowrite8(ioeventfd->data, ioeventfd->addr);
+		break;
+	case 2:
+		vfio_iowrite16(ioeventfd->data, ioeventfd->addr);
+		break;
+	case 4:
+		vfio_iowrite32(ioeventfd->data, ioeventfd->addr);
+		break;
+#ifdef iowrite64
+	case 8:
+		vfio_iowrite64(ioeventfd->data, ioeventfd->addr);
+		break;
+#endif
+	}
+
+	return 0;
+}
+
+long vfio_pci_ioeventfd(struct vfio_pci_device *vdev, loff_t offset,
+			uint64_t data, int count, int fd)
+{
+	struct pci_dev *pdev = vdev->pdev;
+	loff_t pos = offset & VFIO_PCI_OFFSET_MASK;
+	int ret, bar = VFIO_PCI_OFFSET_TO_INDEX(offset);
+	struct vfio_pci_ioeventfd *ioeventfd;
+
+	/* Only support ioeventfds into BARs */
+	if (bar > VFIO_PCI_BAR5_REGION_INDEX)
+		return -EINVAL;
+
+	if (pos + count > pci_resource_len(pdev, bar))
+		return -EINVAL;
+
+	/* Disallow ioeventfds working around MSI-X table writes */
+	if (bar == vdev->msix_bar &&
+	    !(pos + count <= vdev->msix_offset ||
+	      pos >= vdev->msix_offset + vdev->msix_size))
+		return -EINVAL;
+
+#ifndef iowrite64
+	if (count == 8)
+		return -EINVAL;
+#endif
+
+	ret = vfio_pci_setup_barmap(vdev, bar);
+	if (ret)
+		return ret;
+
+	mutex_lock(&vdev->ioeventfds_lock);
+
+	list_for_each_entry(ioeventfd, &vdev->ioeventfds_list, next) {
+		if (ioeventfd->pos == pos && ioeventfd->bar == bar &&
+		    ioeventfd->data == data && ioeventfd->count == count) {
+			if (fd == -1) {
+				vfio_virqfd_disable(&ioeventfd->virqfd);
+				list_del(&ioeventfd->next);
+				vdev->ioeventfds_nr--;
+				kfree(ioeventfd);
+				ret = 0;
+			} else
+				ret = -EEXIST;
+
+			goto out_unlock;
+		}
+	}
+
+	if (fd < 0) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	if (vdev->ioeventfds_nr >= VFIO_PCI_IOEVENTFD_MAX) {
+		ret = -ENOSPC;
+		goto out_unlock;
+	}
+
+	ioeventfd = kzalloc(sizeof(*ioeventfd), GFP_KERNEL);
+	if (!ioeventfd) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+
+	ioeventfd->addr = vdev->barmap[bar] + pos;
+	ioeventfd->data = data;
+	ioeventfd->pos = pos;
+	ioeventfd->bar = bar;
+	ioeventfd->count = count;
+
+	ret = vfio_virqfd_enable(ioeventfd, vfio_pci_ioeventfd_handler,
+				 NULL, NULL, &ioeventfd->virqfd, fd);
+	if (ret) {
+		kfree(ioeventfd);
+		goto out_unlock;
+	}
+
+	list_add(&ioeventfd->next, &vdev->ioeventfds_list);
+	vdev->ioeventfds_nr++;
+
+out_unlock:
+	mutex_unlock(&vdev->ioeventfds_lock);
+
+	return ret;
+}