Commit 5846ff54 authored by Alex Williamson's avatar Alex Williamson
Browse files

vfio/pci: Intel IGD OpRegion support 



This is the first consumer of vfio device specific resource support,
providing read-only access to the OpRegion for Intel graphics devices.

Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 345d7104

drivers/vfio/pci/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -26,3 +26,7 @@ config VFIO_PCI_MMAP 
config VFIO_PCI_INTX

	depends on VFIO_PCI

	def_bool y if !S390



config VFIO_PCI_IGD

	depends on VFIO_PCI

	def_bool y if X86

drivers/vfio/pci/Makefile

+1 −0
Original line number Diff line number Diff line 


vfio-pci-y := vfio_pci.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o

vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o



obj-$(CONFIG_VFIO_PCI) += vfio-pci.o

drivers/vfio/pci/vfio_pci.c

+7 −0
Original line number Diff line number Diff line
@@ -169,6 +169,13 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) 
	if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))

		vdev->has_vga = true;





	if (vfio_pci_is_vga(pdev) && pdev->vendor == PCI_VENDOR_ID_INTEL) {

		if (vfio_pci_igd_opregion_init(vdev) == 0)

			dev_info(&pdev->dev,

				 "Intel IGD OpRegion support enabled\n");

	}



	return 0;

}

drivers/vfio/pci/vfio_pci_igd.c

0 → 100644
+111 −0
Original line number Diff line number Diff line 
/*

 * VFIO PCI Intel Graphics support

 *

 * Copyright (C) 2016 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.

 *

 * Register a device specific region through which to provide read-only

 * access to the Intel IGD opregion.  The register defining the opregion

 * address is also virtualized to prevent user modification.

 */



#include <linux/io.h>

#include <linux/pci.h>

#include <linux/uaccess.h>

#include <linux/vfio.h>



#include "vfio_pci_private.h"



#define OPREGION_SIGNATURE	"IntelGraphicsMem"

#define OPREGION_SIZE		(8 * 1024)

#define OPREGION_PCI_ADDR	0xfc



static size_t vfio_pci_igd_rw(struct vfio_pci_device *vdev, char __user *buf,

			      size_t count, loff_t *ppos, bool iswrite)

{

	unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;

	void *base = vdev->region[i].data;

	loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;



	if (pos >= vdev->region[i].size || iswrite)

		return -EINVAL;



	count = min(count, (size_t)(vdev->region[i].size - pos));



	if (copy_to_user(buf, base + pos, count))

		return -EFAULT;



	*ppos += count;



	return count;

}



static void vfio_pci_igd_release(struct vfio_pci_device *vdev,

				 struct vfio_pci_region *region)

{

	memunmap(region->data);

}



static const struct vfio_pci_regops vfio_pci_igd_regops = {

	.rw		= vfio_pci_igd_rw,

	.release	= vfio_pci_igd_release,

};



int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)

{

	__le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR);

	u32 addr, size;

	void *base;

	int ret;



	ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);

	if (ret)

		return ret;



	if (!addr || !(~addr))

		return -ENODEV;



	base = memremap(addr, OPREGION_SIZE, MEMREMAP_WB);

	if (!base)

		return -ENOMEM;



	if (memcmp(base, OPREGION_SIGNATURE, 16)) {

		memunmap(base);

		return -EINVAL;

	}



	size = le32_to_cpu(*(__le32 *)(base + 16));

	if (!size) {

		memunmap(base);

		return -EINVAL;

	}



	size *= 1024; /* In KB */



	if (size != OPREGION_SIZE) {

		memunmap(base);

		base = memremap(addr, size, MEMREMAP_WB);

		if (!base)

			return -ENOMEM;

	}



	ret = vfio_pci_register_dev_region(vdev,

		PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,

		VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION,

		&vfio_pci_igd_regops, size, VFIO_REGION_INFO_FLAG_READ, base);

	if (ret) {

		memunmap(base);

		return ret;

	}



	/* Fill vconfig with the hw value and virtualize register */

	*dwordp = cpu_to_le32(addr);

	memset(vdev->pci_config_map + OPREGION_PCI_ADDR,

	       PCI_CAP_ID_INVALID_VIRT, 4);



	return ret;

}

drivers/vfio/pci/vfio_pci_private.h

+8 −0
Original line number Diff line number Diff line
@@ -122,4 +122,12 @@ extern int vfio_pci_register_dev_region(struct vfio_pci_device *vdev, 
					unsigned int type, unsigned int subtype,

					const struct vfio_pci_regops *ops,

					size_t size, u32 flags, void *data);

#ifdef CONFIG_VFIO_PCI_IGD

extern int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev);

#else

static inline int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)

{

	return -ENODEV;

}

#endif

#endif /* VFIO_PCI_PRIVATE_H */