Commit e6b817d4 authored by Matthew Rosato's avatar Matthew Rosato Committed by Alex Williamson
Browse files

vfio-pci/zdev: Add zPCI capabilities to VFIO_DEVICE_GET_INFO 



Define a new configuration entry VFIO_PCI_ZDEV for VFIO/PCI.

When this s390-only feature is configured we add capabilities to the
VFIO_DEVICE_GET_INFO ioctl that describe features of the associated
zPCI device and its underlying hardware.

This patch is based on work previously done by Pierre Morel.

Signed-off-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 0c633f0b

drivers/vfio/pci/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -45,3 +45,15 @@ config VFIO_PCI_NVLINK2 
	depends on VFIO_PCI && PPC_POWERNV

	help

	  VFIO PCI support for P9 Witherspoon machine with NVIDIA V100 GPUs



config VFIO_PCI_ZDEV

	bool "VFIO PCI ZPCI device CLP support"

	depends on VFIO_PCI && S390

	default y

	help

	  Enabling this option exposes VFIO capabilities containing hardware

	  configuration for zPCI devices. This enables userspace (e.g. QEMU)

	  to supply proper configuration values instead of hard-coded defaults

	  for zPCI devices passed through via VFIO on s390.



	  Say Y here.

drivers/vfio/pci/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -3,5 +3,6 @@ 
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

vfio-pci-$(CONFIG_VFIO_PCI_NVLINK2) += vfio_pci_nvlink2.o

vfio-pci-$(CONFIG_VFIO_PCI_ZDEV) += vfio_pci_zdev.o



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

drivers/vfio/pci/vfio_pci.c

+37 −0
Original line number Diff line number Diff line
@@ -807,15 +807,25 @@ static long vfio_pci_ioctl(void *device_data, 


	if (cmd == VFIO_DEVICE_GET_INFO) {

		struct vfio_device_info info;

		struct vfio_info_cap caps = { .buf = NULL, .size = 0 };

		unsigned long capsz;



		minsz = offsetofend(struct vfio_device_info, num_irqs);



		/* For backward compatibility, cannot require this */

		capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);



		if (copy_from_user(&info, (void __user *)arg, minsz))

			return -EFAULT;



		if (info.argsz < minsz)

			return -EINVAL;



		if (info.argsz >= capsz) {

			minsz = capsz;

			info.cap_offset = 0;

		}



		info.flags = VFIO_DEVICE_FLAGS_PCI;



		if (vdev->reset_works)
@@ -824,6 +834,33 @@ static long vfio_pci_ioctl(void *device_data, 
		info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;

		info.num_irqs = VFIO_PCI_NUM_IRQS;



		if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV)) {

			int ret = vfio_pci_info_zdev_add_caps(vdev, &caps);



			if (ret && ret != -ENODEV) {

				pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");

				return ret;

			}

		}



		if (caps.size) {

			info.flags |= VFIO_DEVICE_FLAGS_CAPS;

			if (info.argsz < sizeof(info) + caps.size) {

				info.argsz = sizeof(info) + caps.size;

			} else {

				vfio_info_cap_shift(&caps, sizeof(info));

				if (copy_to_user((void __user *)arg +

						  sizeof(info), caps.buf,

						  caps.size)) {

					kfree(caps.buf);

					return -EFAULT;

				}

				info.cap_offset = sizeof(info);

			}



			kfree(caps.buf);

		}



		return copy_to_user((void __user *)arg, &info, minsz) ?

			-EFAULT : 0;

drivers/vfio/pci/vfio_pci_private.h

+12 −0
Original line number Diff line number Diff line
@@ -213,4 +213,16 @@ static inline int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev) 
	return -ENODEV;

}

#endif



#ifdef CONFIG_VFIO_PCI_ZDEV

extern int vfio_pci_info_zdev_add_caps(struct vfio_pci_device *vdev,

				       struct vfio_info_cap *caps);

#else

static inline int vfio_pci_info_zdev_add_caps(struct vfio_pci_device *vdev,

					      struct vfio_info_cap *caps)

{

	return -ENODEV;

}

#endif



#endif /* VFIO_PCI_PRIVATE_H */

drivers/vfio/pci/vfio_pci_zdev.c

0 → 100644
+143 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * VFIO ZPCI devices support

 *

 * Copyright (C) IBM Corp. 2020.  All rights reserved.

 *	Author(s): Pierre Morel <pmorel@linux.ibm.com>

 *                 Matthew Rosato <mjrosato@linux.ibm.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.

 *

 */

#include <linux/io.h>

#include <linux/pci.h>

#include <linux/uaccess.h>

#include <linux/vfio.h>

#include <linux/vfio_zdev.h>

#include <asm/pci_clp.h>

#include <asm/pci_io.h>



#include "vfio_pci_private.h"



/*

 * Add the Base PCI Function information to the device info region.

 */

static int zpci_base_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,

			 struct vfio_info_cap *caps)

{

	struct vfio_device_info_cap_zpci_base cap = {

		.header.id = VFIO_DEVICE_INFO_CAP_ZPCI_BASE,

		.header.version = 1,

		.start_dma = zdev->start_dma,

		.end_dma = zdev->end_dma,

		.pchid = zdev->pchid,

		.vfn = zdev->vfn,

		.fmb_length = zdev->fmb_length,

		.pft = zdev->pft,

		.gid = zdev->pfgid

	};



	return vfio_info_add_capability(caps, &cap.header, sizeof(cap));

}



/*

 * Add the Base PCI Function Group information to the device info region.

 */

static int zpci_group_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,

			  struct vfio_info_cap *caps)

{

	struct vfio_device_info_cap_zpci_group cap = {

		.header.id = VFIO_DEVICE_INFO_CAP_ZPCI_GROUP,

		.header.version = 1,

		.dasm = zdev->dma_mask,

		.msi_addr = zdev->msi_addr,

		.flags = VFIO_DEVICE_INFO_ZPCI_FLAG_REFRESH,

		.mui = zdev->fmb_update,

		.noi = zdev->max_msi,

		.maxstbl = ZPCI_MAX_WRITE_SIZE,

		.version = zdev->version

	};



	return vfio_info_add_capability(caps, &cap.header, sizeof(cap));

}



/*

 * Add the device utility string to the device info region.

 */

static int zpci_util_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,

			 struct vfio_info_cap *caps)

{

	struct vfio_device_info_cap_zpci_util *cap;

	int cap_size = sizeof(*cap) + CLP_UTIL_STR_LEN;

	int ret;



	cap = kmalloc(cap_size, GFP_KERNEL);



	cap->header.id = VFIO_DEVICE_INFO_CAP_ZPCI_UTIL;

	cap->header.version = 1;

	cap->size = CLP_UTIL_STR_LEN;

	memcpy(cap->util_str, zdev->util_str, cap->size);



	ret = vfio_info_add_capability(caps, &cap->header, cap_size);



	kfree(cap);



	return ret;

}



/*

 * Add the function path string to the device info region.

 */

static int zpci_pfip_cap(struct zpci_dev *zdev, struct vfio_pci_device *vdev,

			 struct vfio_info_cap *caps)

{

	struct vfio_device_info_cap_zpci_pfip *cap;

	int cap_size = sizeof(*cap) + CLP_PFIP_NR_SEGMENTS;

	int ret;



	cap = kmalloc(cap_size, GFP_KERNEL);



	cap->header.id = VFIO_DEVICE_INFO_CAP_ZPCI_PFIP;

	cap->header.version = 1;

	cap->size = CLP_PFIP_NR_SEGMENTS;

	memcpy(cap->pfip, zdev->pfip, cap->size);



	ret = vfio_info_add_capability(caps, &cap->header, cap_size);



	kfree(cap);



	return ret;

}



/*

 * Add all supported capabilities to the VFIO_DEVICE_GET_INFO capability chain.

 */

int vfio_pci_info_zdev_add_caps(struct vfio_pci_device *vdev,

				struct vfio_info_cap *caps)

{

	struct zpci_dev *zdev = to_zpci(vdev->pdev);

	int ret;



	if (!zdev)

		return -ENODEV;



	ret = zpci_base_cap(zdev, vdev, caps);

	if (ret)

		return ret;



	ret = zpci_group_cap(zdev, vdev, caps);

	if (ret)

		return ret;



	if (zdev->util_str_avail) {

		ret = zpci_util_cap(zdev, vdev, caps);

		if (ret)

			return ret;

	}



	ret = zpci_pfip_cap(zdev, vdev, caps);



	return ret;

}