vfio/pci: Split the pci_driver code out of vfio_pci_core.c

Split the vfio_pci driver into two logical parts, the 'struct
pci_driver' (vfio_pci.c) which implements "Generic VFIO support for any
PCI device" and a library of code (vfio_pci_core.c) that helps
implementing a struct vfio_device on top of a PCI device.

vfio_pci.ko continues to present the same interface under sysfs and this
change should have no functional impact.

Following patches will turn vfio_pci and vfio_pci_core into a separate
module.

This is a preparation for allowing another module to provide the
pci_driver and allow that module to customize how VFIO is setup, inject
its own operations, and easily extend vendor specific functionality.

At this point the vfio_pci_core still contains a lot of vfio_pci
functionality mixed into it. Following patches will move more of the
large scale items out, but another cleanup series will be needed to get
everything.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-7-yishaih@nvidia.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/pci/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 
-vfio-pci-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
+vfio-pci-y := vfio_pci.o vfio_pci_core.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_S390) += vfio_pci_zdev.o
 

drivers/vfio/pci/vfio_pci.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved
+ *
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/eventfd.h>
+#include <linux/file.h>
+#include <linux/interrupt.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include "vfio_pci_core.h"
+
+#define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
+#define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
+
+static char ids[1024] __initdata;
+module_param_string(ids, ids, sizeof(ids), 0);
+MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified");
+
+static bool enable_sriov;
+#ifdef CONFIG_PCI_IOV
+module_param(enable_sriov, bool, 0644);
+MODULE_PARM_DESC(enable_sriov, "Enable support for SR-IOV configuration.  Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF.");
+#endif
+
+static bool disable_denylist;
+module_param(disable_denylist, bool, 0444);
+MODULE_PARM_DESC(disable_denylist, "Disable use of device denylist. Disabling the denylist allows binding to devices with known errata that may lead to exploitable stability or security issues when accessed by untrusted users.");
+
+static bool vfio_pci_dev_in_denylist(struct pci_dev *pdev)
+{
+	switch (pdev->vendor) {
+	case PCI_VENDOR_ID_INTEL:
+		switch (pdev->device) {
+		case PCI_DEVICE_ID_INTEL_QAT_C3XXX:
+		case PCI_DEVICE_ID_INTEL_QAT_C3XXX_VF:
+		case PCI_DEVICE_ID_INTEL_QAT_C62X:
+		case PCI_DEVICE_ID_INTEL_QAT_C62X_VF:
+		case PCI_DEVICE_ID_INTEL_QAT_DH895XCC:
+		case PCI_DEVICE_ID_INTEL_QAT_DH895XCC_VF:
+			return true;
+		default:
+			return false;
+		}
+	}
+
+	return false;
+}
+
+static bool vfio_pci_is_denylisted(struct pci_dev *pdev)
+{
+	if (!vfio_pci_dev_in_denylist(pdev))
+		return false;
+
+	if (disable_denylist) {
+		pci_warn(pdev,
+			 "device denylist disabled - allowing device %04x:%04x.\n",
+			 pdev->vendor, pdev->device);
+		return false;
+	}
+
+	pci_warn(pdev, "%04x:%04x exists in vfio-pci device denylist, driver probing disallowed.\n",
+		 pdev->vendor, pdev->device);
+
+	return true;
+}
+
+static const struct vfio_device_ops vfio_pci_ops = {
+	.name		= "vfio-pci",
+	.open_device	= vfio_pci_core_open_device,
+	.close_device	= vfio_pci_core_close_device,
+	.ioctl		= vfio_pci_core_ioctl,
+	.read		= vfio_pci_core_read,
+	.write		= vfio_pci_core_write,
+	.mmap		= vfio_pci_core_mmap,
+	.request	= vfio_pci_core_request,
+	.match		= vfio_pci_core_match,
+};
+
+static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct vfio_pci_core_device *vdev;
+	int ret;
+
+	if (vfio_pci_is_denylisted(pdev))
+		return -EINVAL;
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+	vfio_pci_core_init_device(vdev, pdev, &vfio_pci_ops);
+
+	ret = vfio_pci_core_register_device(vdev);
+	if (ret)
+		goto out_free;
+	return 0;
+
+out_free:
+	vfio_pci_core_uninit_device(vdev);
+	kfree(vdev);
+	return ret;
+}
+
+static void vfio_pci_remove(struct pci_dev *pdev)
+{
+	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
+
+	vfio_pci_core_unregister_device(vdev);
+	vfio_pci_core_uninit_device(vdev);
+	kfree(vdev);
+}
+
+static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
+{
+	if (!enable_sriov)
+		return -ENOENT;
+
+	return vfio_pci_core_sriov_configure(pdev, nr_virtfn);
+}
+
+static struct pci_driver vfio_pci_driver = {
+	.name			= "vfio-pci",
+	.id_table		= NULL, /* only dynamic ids */
+	.probe			= vfio_pci_probe,
+	.remove			= vfio_pci_remove,
+	.sriov_configure	= vfio_pci_sriov_configure,
+	.err_handler		= &vfio_pci_core_err_handlers,
+};
+
+static void __init vfio_pci_fill_ids(void)
+{
+	char *p, *id;
+	int rc;
+
+	/* no ids passed actually */
+	if (ids[0] == '\0')
+		return;
+
+	/* add ids specified in the module parameter */
+	p = ids;
+	while ((id = strsep(&p, ","))) {
+		unsigned int vendor, device, subvendor = PCI_ANY_ID,
+			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
+		int fields;
+
+		if (!strlen(id))
+			continue;
+
+		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
+				&vendor, &device, &subvendor, &subdevice,
+				&class, &class_mask);
+
+		if (fields < 2) {
+			pr_warn("invalid id string \"%s\"\n", id);
+			continue;
+		}
+
+		rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
+				   subvendor, subdevice, class, class_mask, 0);
+		if (rc)
+			pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
+				vendor, device, subvendor, subdevice,
+				class, class_mask, rc);
+		else
+			pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n",
+				vendor, device, subvendor, subdevice,
+				class, class_mask);
+	}
+}
+
+static int __init vfio_pci_init(void)
+{
+	int ret;
+
+	ret = vfio_pci_core_init();
+	if (ret)
+		return ret;
+
+	/* Register and scan for devices */
+	ret = pci_register_driver(&vfio_pci_driver);
+	if (ret)
+		goto out;
+
+	vfio_pci_fill_ids();
+
+	if (disable_denylist)
+		pr_warn("device denylist disabled.\n");
+
+	return 0;
+
+out:
+	vfio_pci_core_cleanup();
+	return ret;
+}
+module_init(vfio_pci_init);
+
+static void __exit vfio_pci_cleanup(void)
+{
+	pci_unregister_driver(&vfio_pci_driver);
+	vfio_pci_core_cleanup();
+}
+module_exit(vfio_pci_cleanup);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);

drivers/vfio/pci/vfio_pci_core.h

@@ -206,4 +206,27 @@ static inline int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
 }
 #endif
 
+/* Will be exported for vfio pci drivers usage */
+void vfio_pci_core_cleanup(void);
+int vfio_pci_core_init(void);
+void vfio_pci_core_close_device(struct vfio_device *core_vdev);
+int vfio_pci_core_open_device(struct vfio_device *core_vdev);
+void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
+			       struct pci_dev *pdev,
+			       const struct vfio_device_ops *vfio_pci_ops);
+int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev);
+void vfio_pci_core_uninit_device(struct vfio_pci_core_device *vdev);
+void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev);
+int vfio_pci_core_sriov_configure(struct pci_dev *pdev, int nr_virtfn);
+extern const struct pci_error_handlers vfio_pci_core_err_handlers;
+long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
+		unsigned long arg);
+ssize_t vfio_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
+		size_t count, loff_t *ppos);
+ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *buf,
+		size_t count, loff_t *ppos);
+int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma);
+void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count);
+int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf);
+
 #endif /* VFIO_PCI_CORE_H */