Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 760 insertions, 0 deletions

diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
new file mode 100644
index 000000000..e8400fdab
--- /dev/null
+++ b/samples/vfio-mdev/mdpy.c
@@ -0,0 +1,760 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Mediated virtual PCI display host device driver
+ *
+ * See mdpy-defs.h for device specs
+ *
+ *   (c) Gerd Hoffmann <kraxel@redhat.com>
+ *
+ * based on mtty driver which is:
+ *   Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ *	 Author: Neo Jia <cjia@nvidia.com>
+ *		 Kirti Wankhede <kwankhede@nvidia.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/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/cdev.h>
+#include <linux/vfio.h>
+#include <linux/iommu.h>
+#include <linux/sysfs.h>
+#include <linux/mdev.h>
+#include <linux/pci.h>
+#include <drm/drm_fourcc.h>
+#include "mdpy-defs.h"
+
+#define MDPY_NAME		"mdpy"
+#define MDPY_CLASS_NAME		"mdpy"
+
+#define MDPY_CONFIG_SPACE_SIZE	0xff
+#define MDPY_MEMORY_BAR_OFFSET	PAGE_SIZE
+#define MDPY_DISPLAY_REGION	16
+
+#define STORE_LE16(addr, val)	(*(u16 *)addr = val)
+#define STORE_LE32(addr, val)	(*(u32 *)addr = val)
+
+
+MODULE_LICENSE("GPL v2");
+
+#define MDPY_TYPE_1 "vga"
+#define MDPY_TYPE_2 "xga"
+#define MDPY_TYPE_3 "hd"
+
+static struct mdpy_type {
+	struct mdev_type type;
+	u32 format;
+	u32 bytepp;
+	u32 width;
+	u32 height;
+} mdpy_types[] = {
+	{
+		.type.sysfs_name 	= MDPY_TYPE_1,
+		.type.pretty_name	= MDPY_CLASS_NAME "-" MDPY_TYPE_1,
+		.format = DRM_FORMAT_XRGB8888,
+		.bytepp = 4,
+		.width	= 640,
+		.height = 480,
+	}, {
+		.type.sysfs_name 	= MDPY_TYPE_2,
+		.type.pretty_name	= MDPY_CLASS_NAME "-" MDPY_TYPE_2,
+		.format = DRM_FORMAT_XRGB8888,
+		.bytepp = 4,
+		.width	= 1024,
+		.height = 768,
+	}, {
+		.type.sysfs_name 	= MDPY_TYPE_3,
+		.type.pretty_name	= MDPY_CLASS_NAME "-" MDPY_TYPE_3,
+		.format = DRM_FORMAT_XRGB8888,
+		.bytepp = 4,
+		.width	= 1920,
+		.height = 1080,
+	},
+};
+
+static struct mdev_type *mdpy_mdev_types[] = {
+	&mdpy_types[0].type,
+	&mdpy_types[1].type,
+	&mdpy_types[2].type,
+};
+
+static dev_t		mdpy_devt;
+static struct class	*mdpy_class;
+static struct cdev	mdpy_cdev;
+static struct device	mdpy_dev;
+static struct mdev_parent mdpy_parent;
+static const struct vfio_device_ops mdpy_dev_ops;
+
+/* State of each mdev device */
+struct mdev_state {
+	struct vfio_device vdev;
+	u8 *vconfig;
+	u32 bar_mask;
+	struct mutex ops_lock;
+	struct mdev_device *mdev;
+	struct vfio_device_info dev_info;
+
+	const struct mdpy_type *type;
+	u32 memsize;
+	void *memblk;
+};
+
+static void mdpy_create_config_space(struct mdev_state *mdev_state)
+{
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
+		   MDPY_PCI_VENDOR_ID);
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
+		   MDPY_PCI_DEVICE_ID);
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
+		   MDPY_PCI_SUBVENDOR_ID);
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
+		   MDPY_PCI_SUBDEVICE_ID);
+
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
+		   PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS],
+		   PCI_STATUS_CAP_LIST);
+	STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
+		   PCI_CLASS_DISPLAY_OTHER);
+	mdev_state->vconfig[PCI_CLASS_REVISION] =  0x01;
+
+	STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
+		   PCI_BASE_ADDRESS_SPACE_MEMORY |
+		   PCI_BASE_ADDRESS_MEM_TYPE_32	 |
+		   PCI_BASE_ADDRESS_MEM_PREFETCH);
+	mdev_state->bar_mask = ~(mdev_state->memsize) + 1;
+
+	/* vendor specific capability for the config registers */
+	mdev_state->vconfig[PCI_CAPABILITY_LIST]       = MDPY_VENDORCAP_OFFSET;
+	mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */
+	mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */
+	mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE;
+	STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET],
+		   mdev_state->type->format);
+	STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET],
+		   mdev_state->type->width);
+	STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET],
+		   mdev_state->type->height);
+}
+
+static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
+				 char *buf, u32 count)
+{
+	struct device *dev = mdev_dev(mdev_state->mdev);
+	u32 cfg_addr;
+
+	switch (offset) {
+	case PCI_BASE_ADDRESS_0:
+		cfg_addr = *(u32 *)buf;
+
+		if (cfg_addr == 0xffffffff) {
+			cfg_addr = (cfg_addr & mdev_state->bar_mask);
+		} else {
+			cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
+			if (cfg_addr)
+				dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr);
+		}
+
+		cfg_addr |= (mdev_state->vconfig[offset] &
+			     ~PCI_BASE_ADDRESS_MEM_MASK);
+		STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
+		break;
+	}
+}
+
+static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
+			   size_t count, loff_t pos, bool is_write)
+{
+	int ret = 0;
+
+	mutex_lock(&mdev_state->ops_lock);
+
+	if (pos < MDPY_CONFIG_SPACE_SIZE) {
+		if (is_write)
+			handle_pci_cfg_write(mdev_state, pos, buf, count);
+		else
+			memcpy(buf, (mdev_state->vconfig + pos), count);
+
+	} else if ((pos >= MDPY_MEMORY_BAR_OFFSET) &&
+		   (pos + count <=
+		    MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) {
+		pos -= MDPY_MEMORY_BAR_OFFSET;
+		if (is_write)
+			memcpy(mdev_state->memblk, buf, count);
+		else
+			memcpy(buf, mdev_state->memblk, count);
+
+	} else {
+		dev_info(mdev_state->vdev.dev,
+			 "%s: %s @0x%llx (unhandled)\n", __func__,
+			 is_write ? "WR" : "RD", pos);
+		ret = -1;
+		goto accessfailed;
+	}
+
+	ret = count;
+
+
+accessfailed:
+	mutex_unlock(&mdev_state->ops_lock);
+
+	return ret;
+}
+
+static int mdpy_reset(struct mdev_state *mdev_state)
+{
+	u32 stride, i;
+
+	/* initialize with gray gradient */
+	stride = mdev_state->type->width * mdev_state->type->bytepp;
+	for (i = 0; i < mdev_state->type->height; i++)
+		memset(mdev_state->memblk + i * stride,
+		       i * 255 / mdev_state->type->height,
+		       stride);
+	return 0;
+}
+
+static int mdpy_init_dev(struct vfio_device *vdev)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+	struct mdev_device *mdev = to_mdev_device(vdev->dev);
+	const struct mdpy_type *type =
+		container_of(mdev->type, struct mdpy_type, type);
+	u32 fbsize;
+	int ret = -ENOMEM;
+
+	mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
+	if (!mdev_state->vconfig)
+		return ret;
+
+	fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
+
+	mdev_state->memblk = vmalloc_user(fbsize);
+	if (!mdev_state->memblk)
+		goto out_vconfig;
+
+	mutex_init(&mdev_state->ops_lock);
+	mdev_state->mdev = mdev;
+	mdev_state->type = type;
+	mdev_state->memsize = fbsize;
+	mdpy_create_config_space(mdev_state);
+	mdpy_reset(mdev_state);
+
+	dev_info(vdev->dev, "%s: %s (%dx%d)\n", __func__, type->type.pretty_name,
+		 type->width, type->height);
+	return 0;
+
+out_vconfig:
+	kfree(mdev_state->vconfig);
+	return ret;
+}
+
+static int mdpy_probe(struct mdev_device *mdev)
+{
+	struct mdev_state *mdev_state;
+	int ret;
+
+	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
+				       &mdpy_dev_ops);
+	if (IS_ERR(mdev_state))
+		return PTR_ERR(mdev_state);
+
+	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
+	if (ret)
+		goto err_put_vdev;
+	dev_set_drvdata(&mdev->dev, mdev_state);
+	return 0;
+
+err_put_vdev:
+	vfio_put_device(&mdev_state->vdev);
+	return ret;
+}
+
+static void mdpy_release_dev(struct vfio_device *vdev)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+
+	vfree(mdev_state->memblk);
+	kfree(mdev_state->vconfig);
+}
+
+static void mdpy_remove(struct mdev_device *mdev)
+{
+	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
+
+	dev_info(&mdev->dev, "%s\n", __func__);
+
+	vfio_unregister_group_dev(&mdev_state->vdev);
+	vfio_put_device(&mdev_state->vdev);
+}
+
+static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+	unsigned int done = 0;
+	int ret;
+
+	while (count) {
+		size_t filled;
+
+		if (count >= 4 && !(*ppos % 4)) {
+			u32 val;
+
+			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
+					  *ppos, false);
+			if (ret <= 0)
+				goto read_err;
+
+			if (copy_to_user(buf, &val, sizeof(val)))
+				goto read_err;
+
+			filled = 4;
+		} else if (count >= 2 && !(*ppos % 2)) {
+			u16 val;
+
+			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
+					  *ppos, false);
+			if (ret <= 0)
+				goto read_err;
+
+			if (copy_to_user(buf, &val, sizeof(val)))
+				goto read_err;
+
+			filled = 2;
+		} else {
+			u8 val;
+
+			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
+					  *ppos, false);
+			if (ret <= 0)
+				goto read_err;
+
+			if (copy_to_user(buf, &val, sizeof(val)))
+				goto read_err;
+
+			filled = 1;
+		}
+
+		count -= filled;
+		done += filled;
+		*ppos += filled;
+		buf += filled;
+	}
+
+	return done;
+
+read_err:
+	return -EFAULT;
+}
+
+static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+	unsigned int done = 0;
+	int ret;
+
+	while (count) {
+		size_t filled;
+
+		if (count >= 4 && !(*ppos % 4)) {
+			u32 val;
+
+			if (copy_from_user(&val, buf, sizeof(val)))
+				goto write_err;
+
+			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
+					  *ppos, true);
+			if (ret <= 0)
+				goto write_err;
+
+			filled = 4;
+		} else if (count >= 2 && !(*ppos % 2)) {
+			u16 val;
+
+			if (copy_from_user(&val, buf, sizeof(val)))
+				goto write_err;
+
+			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
+					  *ppos, true);
+			if (ret <= 0)
+				goto write_err;
+
+			filled = 2;
+		} else {
+			u8 val;
+
+			if (copy_from_user(&val, buf, sizeof(val)))
+				goto write_err;
+
+			ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
+					  *ppos, true);
+			if (ret <= 0)
+				goto write_err;
+
+			filled = 1;
+		}
+		count -= filled;
+		done += filled;
+		*ppos += filled;
+		buf += filled;
+	}
+
+	return done;
+write_err:
+	return -EFAULT;
+}
+
+static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+
+	if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
+		return -EINVAL;
+	if (vma->vm_end < vma->vm_start)
+		return -EINVAL;
+	if (vma->vm_end - vma->vm_start > mdev_state->memsize)
+		return -EINVAL;
+	if ((vma->vm_flags & VM_SHARED) == 0)
+		return -EINVAL;
+
+	return remap_vmalloc_range(vma, mdev_state->memblk, 0);
+}
+
+static int mdpy_get_region_info(struct mdev_state *mdev_state,
+				struct vfio_region_info *region_info,
+				u16 *cap_type_id, void **cap_type)
+{
+	if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
+	    region_info->index != MDPY_DISPLAY_REGION)
+		return -EINVAL;
+
+	switch (region_info->index) {
+	case VFIO_PCI_CONFIG_REGION_INDEX:
+		region_info->offset = 0;
+		region_info->size   = MDPY_CONFIG_SPACE_SIZE;
+		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
+				       VFIO_REGION_INFO_FLAG_WRITE);
+		break;
+	case VFIO_PCI_BAR0_REGION_INDEX:
+	case MDPY_DISPLAY_REGION:
+		region_info->offset = MDPY_MEMORY_BAR_OFFSET;
+		region_info->size   = mdev_state->memsize;
+		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
+				       VFIO_REGION_INFO_FLAG_WRITE |
+				       VFIO_REGION_INFO_FLAG_MMAP);
+		break;
+	default:
+		region_info->size   = 0;
+		region_info->offset = 0;
+		region_info->flags  = 0;
+	}
+
+	return 0;
+}
+
+static int mdpy_get_irq_info(struct vfio_irq_info *irq_info)
+{
+	irq_info->count = 0;
+	return 0;
+}
+
+static int mdpy_get_device_info(struct vfio_device_info *dev_info)
+{
+	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
+	dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
+	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
+	return 0;
+}
+
+static int mdpy_query_gfx_plane(struct mdev_state *mdev_state,
+				struct vfio_device_gfx_plane_info *plane)
+{
+	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
+		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
+				     VFIO_GFX_PLANE_TYPE_REGION))
+			return 0;
+		return -EINVAL;
+	}
+
+	if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
+		return -EINVAL;
+
+	plane->drm_format     = mdev_state->type->format;
+	plane->width	      = mdev_state->type->width;
+	plane->height	      = mdev_state->type->height;
+	plane->stride	      = (mdev_state->type->width *
+				 mdev_state->type->bytepp);
+	plane->size	      = mdev_state->memsize;
+	plane->region_index   = MDPY_DISPLAY_REGION;
+
+	/* unused */
+	plane->drm_format_mod = 0;
+	plane->x_pos	      = 0;
+	plane->y_pos	      = 0;
+	plane->x_hot	      = 0;
+	plane->y_hot	      = 0;
+
+	return 0;
+}
+
+static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd,
+		       unsigned long arg)
+{
+	int ret = 0;
+	unsigned long minsz;
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+
+	switch (cmd) {
+	case VFIO_DEVICE_GET_INFO:
+	{
+		struct vfio_device_info info;
+
+		minsz = offsetofend(struct vfio_device_info, num_irqs);
+
+		if (copy_from_user(&info, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (info.argsz < minsz)
+			return -EINVAL;
+
+		ret = mdpy_get_device_info(&info);
+		if (ret)
+			return ret;
+
+		memcpy(&mdev_state->dev_info, &info, sizeof(info));
+
+		if (copy_to_user((void __user *)arg, &info, minsz))
+			return -EFAULT;
+
+		return 0;
+	}
+	case VFIO_DEVICE_GET_REGION_INFO:
+	{
+		struct vfio_region_info info;
+		u16 cap_type_id = 0;
+		void *cap_type = NULL;
+
+		minsz = offsetofend(struct vfio_region_info, offset);
+
+		if (copy_from_user(&info, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (info.argsz < minsz)
+			return -EINVAL;
+
+		ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id,
+					   &cap_type);
+		if (ret)
+			return ret;
+
+		if (copy_to_user((void __user *)arg, &info, minsz))
+			return -EFAULT;
+
+		return 0;
+	}
+
+	case VFIO_DEVICE_GET_IRQ_INFO:
+	{
+		struct vfio_irq_info info;
+
+		minsz = offsetofend(struct vfio_irq_info, count);
+
+		if (copy_from_user(&info, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if ((info.argsz < minsz) ||
+		    (info.index >= mdev_state->dev_info.num_irqs))
+			return -EINVAL;
+
+		ret = mdpy_get_irq_info(&info);
+		if (ret)
+			return ret;
+
+		if (copy_to_user((void __user *)arg, &info, minsz))
+			return -EFAULT;
+
+		return 0;
+	}
+
+	case VFIO_DEVICE_QUERY_GFX_PLANE:
+	{
+		struct vfio_device_gfx_plane_info plane;
+
+		minsz = offsetofend(struct vfio_device_gfx_plane_info,
+				    region_index);
+
+		if (copy_from_user(&plane, (void __user *)arg, minsz))
+			return -EFAULT;
+
+		if (plane.argsz < minsz)
+			return -EINVAL;
+
+		ret = mdpy_query_gfx_plane(mdev_state, &plane);
+		if (ret)
+			return ret;
+
+		if (copy_to_user((void __user *)arg, &plane, minsz))
+			return -EFAULT;
+
+		return 0;
+	}
+
+	case VFIO_DEVICE_SET_IRQS:
+		return -EINVAL;
+
+	case VFIO_DEVICE_RESET:
+		return mdpy_reset(mdev_state);
+	}
+	return -ENOTTY;
+}
+
+static ssize_t
+resolution_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct mdev_state *mdev_state = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%dx%d\n",
+		       mdev_state->type->width,
+		       mdev_state->type->height);
+}
+static DEVICE_ATTR_RO(resolution);
+
+static struct attribute *mdev_dev_attrs[] = {
+	&dev_attr_resolution.attr,
+	NULL,
+};
+
+static const struct attribute_group mdev_dev_group = {
+	.name  = "vendor",
+	.attrs = mdev_dev_attrs,
+};
+
+static const struct attribute_group *mdev_dev_groups[] = {
+	&mdev_dev_group,
+	NULL,
+};
+
+static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf)
+{
+	struct mdpy_type *type = container_of(mtype, struct mdpy_type, type);
+
+	return sprintf(buf, "virtual display, %dx%d framebuffer\n",
+		       type->width, type->height);
+}
+
+static const struct vfio_device_ops mdpy_dev_ops = {
+	.init = mdpy_init_dev,
+	.release = mdpy_release_dev,
+	.read = mdpy_read,
+	.write = mdpy_write,
+	.ioctl = mdpy_ioctl,
+	.mmap = mdpy_mmap,
+};
+
+static struct mdev_driver mdpy_driver = {
+	.device_api = VFIO_DEVICE_API_PCI_STRING,
+	.max_instances = 4,
+	.driver = {
+		.name = "mdpy",
+		.owner = THIS_MODULE,
+		.mod_name = KBUILD_MODNAME,
+		.dev_groups = mdev_dev_groups,
+	},
+	.probe = mdpy_probe,
+	.remove	= mdpy_remove,
+	.show_description = mdpy_show_description,
+};
+
+static const struct file_operations vd_fops = {
+	.owner		= THIS_MODULE,
+};
+
+static void mdpy_device_release(struct device *dev)
+{
+	/* nothing */
+}
+
+static int __init mdpy_dev_init(void)
+{
+	int ret = 0;
+
+	ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
+	if (ret < 0) {
+		pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
+		return ret;
+	}
+	cdev_init(&mdpy_cdev, &vd_fops);
+	cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
+	pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
+
+	ret = mdev_register_driver(&mdpy_driver);
+	if (ret)
+		goto err_cdev;
+
+	mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME);
+	if (IS_ERR(mdpy_class)) {
+		pr_err("Error: failed to register mdpy_dev class\n");
+		ret = PTR_ERR(mdpy_class);
+		goto err_driver;
+	}
+	mdpy_dev.class = mdpy_class;
+	mdpy_dev.release = mdpy_device_release;
+	dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
+
+	ret = device_register(&mdpy_dev);
+	if (ret)
+		goto err_put;
+
+	ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver,
+				   mdpy_mdev_types,
+				   ARRAY_SIZE(mdpy_mdev_types));
+	if (ret)
+		goto err_device;
+
+	return 0;
+
+err_device:
+	device_del(&mdpy_dev);
+err_put:
+	put_device(&mdpy_dev);
+	class_destroy(mdpy_class);
+err_driver:
+	mdev_unregister_driver(&mdpy_driver);
+err_cdev:
+	cdev_del(&mdpy_cdev);
+	unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
+	return ret;
+}
+
+static void __exit mdpy_dev_exit(void)
+{
+	mdpy_dev.bus = NULL;
+	mdev_unregister_parent(&mdpy_parent);
+
+	device_unregister(&mdpy_dev);
+	mdev_unregister_driver(&mdpy_driver);
+	cdev_del(&mdpy_cdev);
+	unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
+	class_destroy(mdpy_class);
+	mdpy_class = NULL;
+}
+
+module_param_named(count, mdpy_driver.max_instances, int, 0444);
+MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
+
+module_init(mdpy_dev_init)
+module_exit(mdpy_dev_exit)