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, 978 insertions, 0 deletions

diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
new file mode 100644
index 000000000..4f8d962bb
--- /dev/null
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -0,0 +1,978 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VMware VMCI Driver
+ *
+ * Copyright (C) 2012 VMware, Inc. All rights reserved.
+ */
+
+#include <linux/vmw_vmci_defs.h>
+#include <linux/vmw_vmci_api.h>
+#include <linux/moduleparam.h>
+#include <linux/interrupt.h>
+#include <linux/highmem.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/processor.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/vmalloc.h>
+
+#include "vmci_datagram.h"
+#include "vmci_doorbell.h"
+#include "vmci_context.h"
+#include "vmci_driver.h"
+#include "vmci_event.h"
+
+#define PCI_DEVICE_ID_VMWARE_VMCI	0x0740
+
+#define VMCI_UTIL_NUM_RESOURCES 1
+
+/*
+ * Datagram buffers for DMA send/receive must accommodate at least
+ * a maximum sized datagram and the header.
+ */
+#define VMCI_DMA_DG_BUFFER_SIZE (VMCI_MAX_DG_SIZE + PAGE_SIZE)
+
+static bool vmci_disable_msi;
+module_param_named(disable_msi, vmci_disable_msi, bool, 0);
+MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");
+
+static bool vmci_disable_msix;
+module_param_named(disable_msix, vmci_disable_msix, bool, 0);
+MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");
+
+static u32 ctx_update_sub_id = VMCI_INVALID_ID;
+static u32 vm_context_id = VMCI_INVALID_ID;
+
+struct vmci_guest_device {
+	struct device *dev;	/* PCI device we are attached to */
+	void __iomem *iobase;
+	void __iomem *mmio_base;
+
+	bool exclusive_vectors;
+
+	struct wait_queue_head inout_wq;
+
+	void *data_buffer;
+	dma_addr_t data_buffer_base;
+	void *tx_buffer;
+	dma_addr_t tx_buffer_base;
+	void *notification_bitmap;
+	dma_addr_t notification_base;
+};
+
+static bool use_ppn64;
+
+bool vmci_use_ppn64(void)
+{
+	return use_ppn64;
+}
+
+/* vmci_dev singleton device and supporting data*/
+struct pci_dev *vmci_pdev;
+static struct vmci_guest_device *vmci_dev_g;
+static DEFINE_SPINLOCK(vmci_dev_spinlock);
+
+static atomic_t vmci_num_guest_devices = ATOMIC_INIT(0);
+
+bool vmci_guest_code_active(void)
+{
+	return atomic_read(&vmci_num_guest_devices) != 0;
+}
+
+u32 vmci_get_vm_context_id(void)
+{
+	if (vm_context_id == VMCI_INVALID_ID) {
+		struct vmci_datagram get_cid_msg;
+		get_cid_msg.dst =
+		    vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+				     VMCI_GET_CONTEXT_ID);
+		get_cid_msg.src = VMCI_ANON_SRC_HANDLE;
+		get_cid_msg.payload_size = 0;
+		vm_context_id = vmci_send_datagram(&get_cid_msg);
+	}
+	return vm_context_id;
+}
+
+static unsigned int vmci_read_reg(struct vmci_guest_device *dev, u32 reg)
+{
+	if (dev->mmio_base != NULL)
+		return readl(dev->mmio_base + reg);
+	return ioread32(dev->iobase + reg);
+}
+
+static void vmci_write_reg(struct vmci_guest_device *dev, u32 val, u32 reg)
+{
+	if (dev->mmio_base != NULL)
+		writel(val, dev->mmio_base + reg);
+	else
+		iowrite32(val, dev->iobase + reg);
+}
+
+static void vmci_read_data(struct vmci_guest_device *vmci_dev,
+			   void *dest, size_t size)
+{
+	if (vmci_dev->mmio_base == NULL)
+		ioread8_rep(vmci_dev->iobase + VMCI_DATA_IN_ADDR,
+			    dest, size);
+	else {
+		/*
+		 * For DMA datagrams, the data_buffer will contain the header on the
+		 * first page, followed by the incoming datagram(s) on the following
+		 * pages. The header uses an S/G element immediately following the
+		 * header on the first page to point to the data area.
+		 */
+		struct vmci_data_in_out_header *buffer_header = vmci_dev->data_buffer;
+		struct vmci_sg_elem *sg_array = (struct vmci_sg_elem *)(buffer_header + 1);
+		size_t buffer_offset = dest - vmci_dev->data_buffer;
+
+		buffer_header->opcode = 1;
+		buffer_header->size = 1;
+		buffer_header->busy = 0;
+		sg_array[0].addr = vmci_dev->data_buffer_base + buffer_offset;
+		sg_array[0].size = size;
+
+		vmci_write_reg(vmci_dev, lower_32_bits(vmci_dev->data_buffer_base),
+			       VMCI_DATA_IN_LOW_ADDR);
+
+		wait_event(vmci_dev->inout_wq, buffer_header->busy == 1);
+	}
+}
+
+static int vmci_write_data(struct vmci_guest_device *dev,
+			   struct vmci_datagram *dg)
+{
+	int result;
+
+	if (dev->mmio_base != NULL) {
+		struct vmci_data_in_out_header *buffer_header = dev->tx_buffer;
+		u8 *dg_out_buffer = (u8 *)(buffer_header + 1);
+
+		if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE)
+			return VMCI_ERROR_INVALID_ARGS;
+
+		/*
+		 * Initialize send buffer with outgoing datagram
+		 * and set up header for inline data. Device will
+		 * not access buffer asynchronously - only after
+		 * the write to VMCI_DATA_OUT_LOW_ADDR.
+		 */
+		memcpy(dg_out_buffer, dg, VMCI_DG_SIZE(dg));
+		buffer_header->opcode = 0;
+		buffer_header->size = VMCI_DG_SIZE(dg);
+		buffer_header->busy = 1;
+
+		vmci_write_reg(dev, lower_32_bits(dev->tx_buffer_base),
+			       VMCI_DATA_OUT_LOW_ADDR);
+
+		/* Caller holds a spinlock, so cannot block. */
+		spin_until_cond(buffer_header->busy == 0);
+
+		result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
+		if (result == VMCI_SUCCESS)
+			result = (int)buffer_header->result;
+	} else {
+		iowrite8_rep(dev->iobase + VMCI_DATA_OUT_ADDR,
+			     dg, VMCI_DG_SIZE(dg));
+		result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
+	}
+
+	return result;
+}
+
+/*
+ * VM to hypervisor call mechanism. We use the standard VMware naming
+ * convention since shared code is calling this function as well.
+ */
+int vmci_send_datagram(struct vmci_datagram *dg)
+{
+	unsigned long flags;
+	int result;
+
+	/* Check args. */
+	if (dg == NULL)
+		return VMCI_ERROR_INVALID_ARGS;
+
+	/*
+	 * Need to acquire spinlock on the device because the datagram
+	 * data may be spread over multiple pages and the monitor may
+	 * interleave device user rpc calls from multiple
+	 * VCPUs. Acquiring the spinlock precludes that
+	 * possibility. Disabling interrupts to avoid incoming
+	 * datagrams during a "rep out" and possibly landing up in
+	 * this function.
+	 */
+	spin_lock_irqsave(&vmci_dev_spinlock, flags);
+
+	if (vmci_dev_g) {
+		vmci_write_data(vmci_dev_g, dg);
+		result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
+	} else {
+		result = VMCI_ERROR_UNAVAILABLE;
+	}
+
+	spin_unlock_irqrestore(&vmci_dev_spinlock, flags);
+
+	return result;
+}
+EXPORT_SYMBOL_GPL(vmci_send_datagram);
+
+/*
+ * Gets called with the new context id if updated or resumed.
+ * Context id.
+ */
+static void vmci_guest_cid_update(u32 sub_id,
+				  const struct vmci_event_data *event_data,
+				  void *client_data)
+{
+	const struct vmci_event_payld_ctx *ev_payload =
+				vmci_event_data_const_payload(event_data);
+
+	if (sub_id != ctx_update_sub_id) {
+		pr_devel("Invalid subscriber (ID=0x%x)\n", sub_id);
+		return;
+	}
+
+	if (!event_data || ev_payload->context_id == VMCI_INVALID_ID) {
+		pr_devel("Invalid event data\n");
+		return;
+	}
+
+	pr_devel("Updating context from (ID=0x%x) to (ID=0x%x) on event (type=%d)\n",
+		 vm_context_id, ev_payload->context_id, event_data->event);
+
+	vm_context_id = ev_payload->context_id;
+}
+
+/*
+ * Verify that the host supports the hypercalls we need. If it does not,
+ * try to find fallback hypercalls and use those instead.  Returns 0 if
+ * required hypercalls (or fallback hypercalls) are supported by the host,
+ * an error code otherwise.
+ */
+static int vmci_check_host_caps(struct pci_dev *pdev)
+{
+	bool result;
+	struct vmci_resource_query_msg *msg;
+	u32 msg_size = sizeof(struct vmci_resource_query_hdr) +
+				VMCI_UTIL_NUM_RESOURCES * sizeof(u32);
+	struct vmci_datagram *check_msg;
+
+	check_msg = kzalloc(msg_size, GFP_KERNEL);
+	if (!check_msg) {
+		dev_err(&pdev->dev, "%s: Insufficient memory\n", __func__);
+		return -ENOMEM;
+	}
+
+	check_msg->dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
+					  VMCI_RESOURCES_QUERY);
+	check_msg->src = VMCI_ANON_SRC_HANDLE;
+	check_msg->payload_size = msg_size - VMCI_DG_HEADERSIZE;
+	msg = (struct vmci_resource_query_msg *)VMCI_DG_PAYLOAD(check_msg);
+
+	msg->num_resources = VMCI_UTIL_NUM_RESOURCES;
+	msg->resources[0] = VMCI_GET_CONTEXT_ID;
+
+	/* Checks that hyper calls are supported */
+	result = vmci_send_datagram(check_msg) == 0x01;
+	kfree(check_msg);
+
+	dev_dbg(&pdev->dev, "%s: Host capability check: %s\n",
+		__func__, result ? "PASSED" : "FAILED");
+
+	/* We need the vector. There are no fallbacks. */
+	return result ? 0 : -ENXIO;
+}
+
+/*
+ * Reads datagrams from the device and dispatches them. For IO port
+ * based access to the device, we always start reading datagrams into
+ * only the first page of the datagram buffer. If the datagrams don't
+ * fit into one page, we use the maximum datagram buffer size for the
+ * remainder of the invocation. This is a simple heuristic for not
+ * penalizing small datagrams. For DMA-based datagrams, we always
+ * use the maximum datagram buffer size, since there is no performance
+ * penalty for doing so.
+ *
+ * This function assumes that it has exclusive access to the data
+ * in register(s) for the duration of the call.
+ */
+static void vmci_dispatch_dgs(struct vmci_guest_device *vmci_dev)
+{
+	u8 *dg_in_buffer = vmci_dev->data_buffer;
+	struct vmci_datagram *dg;
+	size_t dg_in_buffer_size = VMCI_MAX_DG_SIZE;
+	size_t current_dg_in_buffer_size;
+	size_t remaining_bytes;
+	bool is_io_port = vmci_dev->mmio_base == NULL;
+
+	BUILD_BUG_ON(VMCI_MAX_DG_SIZE < PAGE_SIZE);
+
+	if (!is_io_port) {
+		/* For mmio, the first page is used for the header. */
+		dg_in_buffer += PAGE_SIZE;
+
+		/*
+		 * For DMA-based datagram operations, there is no performance
+		 * penalty for reading the maximum buffer size.
+		 */
+		current_dg_in_buffer_size = VMCI_MAX_DG_SIZE;
+	} else {
+		current_dg_in_buffer_size = PAGE_SIZE;
+	}
+	vmci_read_data(vmci_dev, dg_in_buffer, current_dg_in_buffer_size);
+	dg = (struct vmci_datagram *)dg_in_buffer;
+	remaining_bytes = current_dg_in_buffer_size;
+
+	/*
+	 * Read through the buffer until an invalid datagram header is
+	 * encountered. The exit condition for datagrams read through
+	 * VMCI_DATA_IN_ADDR is a bit more complicated, since a datagram
+	 * can start on any page boundary in the buffer.
+	 */
+	while (dg->dst.resource != VMCI_INVALID_ID ||
+	       (is_io_port && remaining_bytes > PAGE_SIZE)) {
+		unsigned dg_in_size;
+
+		/*
+		 * If using VMCI_DATA_IN_ADDR, skip to the next page
+		 * as a datagram can start on any page boundary.
+		 */
+		if (dg->dst.resource == VMCI_INVALID_ID) {
+			dg = (struct vmci_datagram *)roundup(
+				(uintptr_t)dg + 1, PAGE_SIZE);
+			remaining_bytes =
+				(size_t)(dg_in_buffer +
+					 current_dg_in_buffer_size -
+					 (u8 *)dg);
+			continue;
+		}
+
+		dg_in_size = VMCI_DG_SIZE_ALIGNED(dg);
+
+		if (dg_in_size <= dg_in_buffer_size) {
+			int result;
+
+			/*
+			 * If the remaining bytes in the datagram
+			 * buffer doesn't contain the complete
+			 * datagram, we first make sure we have enough
+			 * room for it and then we read the reminder
+			 * of the datagram and possibly any following
+			 * datagrams.
+			 */
+			if (dg_in_size > remaining_bytes) {
+				if (remaining_bytes !=
+				    current_dg_in_buffer_size) {
+
+					/*
+					 * We move the partial
+					 * datagram to the front and
+					 * read the reminder of the
+					 * datagram and possibly
+					 * following calls into the
+					 * following bytes.
+					 */
+					memmove(dg_in_buffer, dg_in_buffer +
+						current_dg_in_buffer_size -
+						remaining_bytes,
+						remaining_bytes);
+					dg = (struct vmci_datagram *)
+					    dg_in_buffer;
+				}
+
+				if (current_dg_in_buffer_size !=
+				    dg_in_buffer_size)
+					current_dg_in_buffer_size =
+					    dg_in_buffer_size;
+
+				vmci_read_data(vmci_dev,
+					       dg_in_buffer +
+						remaining_bytes,
+					       current_dg_in_buffer_size -
+						remaining_bytes);
+			}
+
+			/*
+			 * We special case event datagrams from the
+			 * hypervisor.
+			 */
+			if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID &&
+			    dg->dst.resource == VMCI_EVENT_HANDLER) {
+				result = vmci_event_dispatch(dg);
+			} else {
+				result = vmci_datagram_invoke_guest_handler(dg);
+			}
+			if (result < VMCI_SUCCESS)
+				dev_dbg(vmci_dev->dev,
+					"Datagram with resource (ID=0x%x) failed (err=%d)\n",
+					 dg->dst.resource, result);
+
+			/* On to the next datagram. */
+			dg = (struct vmci_datagram *)((u8 *)dg +
+						      dg_in_size);
+		} else {
+			size_t bytes_to_skip;
+
+			/*
+			 * Datagram doesn't fit in datagram buffer of maximal
+			 * size. We drop it.
+			 */
+			dev_dbg(vmci_dev->dev,
+				"Failed to receive datagram (size=%u bytes)\n",
+				 dg_in_size);
+
+			bytes_to_skip = dg_in_size - remaining_bytes;
+			if (current_dg_in_buffer_size != dg_in_buffer_size)
+				current_dg_in_buffer_size = dg_in_buffer_size;
+
+			for (;;) {
+				vmci_read_data(vmci_dev, dg_in_buffer,
+					       current_dg_in_buffer_size);
+				if (bytes_to_skip <= current_dg_in_buffer_size)
+					break;
+
+				bytes_to_skip -= current_dg_in_buffer_size;
+			}
+			dg = (struct vmci_datagram *)(dg_in_buffer +
+						      bytes_to_skip);
+		}
+
+		remaining_bytes =
+		    (size_t) (dg_in_buffer + current_dg_in_buffer_size -
+			      (u8 *)dg);
+
+		if (remaining_bytes < VMCI_DG_HEADERSIZE) {
+			/* Get the next batch of datagrams. */
+
+			vmci_read_data(vmci_dev, dg_in_buffer,
+				    current_dg_in_buffer_size);
+			dg = (struct vmci_datagram *)dg_in_buffer;
+			remaining_bytes = current_dg_in_buffer_size;
+		}
+	}
+}
+
+/*
+ * Scans the notification bitmap for raised flags, clears them
+ * and handles the notifications.
+ */
+static void vmci_process_bitmap(struct vmci_guest_device *dev)
+{
+	if (!dev->notification_bitmap) {
+		dev_dbg(dev->dev, "No bitmap present in %s\n", __func__);
+		return;
+	}
+
+	vmci_dbell_scan_notification_entries(dev->notification_bitmap);
+}
+
+/*
+ * Interrupt handler for legacy or MSI interrupt, or for first MSI-X
+ * interrupt (vector VMCI_INTR_DATAGRAM).
+ */
+static irqreturn_t vmci_interrupt(int irq, void *_dev)
+{
+	struct vmci_guest_device *dev = _dev;
+
+	/*
+	 * If we are using MSI-X with exclusive vectors then we simply call
+	 * vmci_dispatch_dgs(), since we know the interrupt was meant for us.
+	 * Otherwise we must read the ICR to determine what to do.
+	 */
+
+	if (dev->exclusive_vectors) {
+		vmci_dispatch_dgs(dev);
+	} else {
+		unsigned int icr;
+
+		/* Acknowledge interrupt and determine what needs doing. */
+		icr = vmci_read_reg(dev, VMCI_ICR_ADDR);
+		if (icr == 0 || icr == ~0)
+			return IRQ_NONE;
+
+		if (icr & VMCI_ICR_DATAGRAM) {
+			vmci_dispatch_dgs(dev);
+			icr &= ~VMCI_ICR_DATAGRAM;
+		}
+
+		if (icr & VMCI_ICR_NOTIFICATION) {
+			vmci_process_bitmap(dev);
+			icr &= ~VMCI_ICR_NOTIFICATION;
+		}
+
+
+		if (icr & VMCI_ICR_DMA_DATAGRAM) {
+			wake_up_all(&dev->inout_wq);
+			icr &= ~VMCI_ICR_DMA_DATAGRAM;
+		}
+
+		if (icr != 0)
+			dev_warn(dev->dev,
+				 "Ignoring unknown interrupt cause (%d)\n",
+				 icr);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Interrupt handler for MSI-X interrupt vector VMCI_INTR_NOTIFICATION,
+ * which is for the notification bitmap.  Will only get called if we are
+ * using MSI-X with exclusive vectors.
+ */
+static irqreturn_t vmci_interrupt_bm(int irq, void *_dev)
+{
+	struct vmci_guest_device *dev = _dev;
+
+	/* For MSI-X we can just assume it was meant for us. */
+	vmci_process_bitmap(dev);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Interrupt handler for MSI-X interrupt vector VMCI_INTR_DMA_DATAGRAM,
+ * which is for the completion of a DMA datagram send or receive operation.
+ * Will only get called if we are using MSI-X with exclusive vectors.
+ */
+static irqreturn_t vmci_interrupt_dma_datagram(int irq, void *_dev)
+{
+	struct vmci_guest_device *dev = _dev;
+
+	wake_up_all(&dev->inout_wq);
+
+	return IRQ_HANDLED;
+}
+
+static void vmci_free_dg_buffers(struct vmci_guest_device *vmci_dev)
+{
+	if (vmci_dev->mmio_base != NULL) {
+		if (vmci_dev->tx_buffer != NULL)
+			dma_free_coherent(vmci_dev->dev,
+					  VMCI_DMA_DG_BUFFER_SIZE,
+					  vmci_dev->tx_buffer,
+					  vmci_dev->tx_buffer_base);
+		if (vmci_dev->data_buffer != NULL)
+			dma_free_coherent(vmci_dev->dev,
+					  VMCI_DMA_DG_BUFFER_SIZE,
+					  vmci_dev->data_buffer,
+					  vmci_dev->data_buffer_base);
+	} else {
+		vfree(vmci_dev->data_buffer);
+	}
+}
+
+/*
+ * Most of the initialization at module load time is done here.
+ */
+static int vmci_guest_probe_device(struct pci_dev *pdev,
+				   const struct pci_device_id *id)
+{
+	struct vmci_guest_device *vmci_dev;
+	void __iomem *iobase = NULL;
+	void __iomem *mmio_base = NULL;
+	unsigned int num_irq_vectors;
+	unsigned int capabilities;
+	unsigned int caps_in_use;
+	unsigned long cmd;
+	int vmci_err;
+	int error;
+
+	dev_dbg(&pdev->dev, "Probing for vmci/PCI guest device\n");
+
+	error = pcim_enable_device(pdev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"Failed to enable VMCI device: %d\n", error);
+		return error;
+	}
+
+	/*
+	 * The VMCI device with mmio access to registers requests 256KB
+	 * for BAR1. If present, driver will use new VMCI device
+	 * functionality for register access and datagram send/recv.
+	 */
+
+	if (pci_resource_len(pdev, 1) == VMCI_WITH_MMIO_ACCESS_BAR_SIZE) {
+		dev_info(&pdev->dev, "MMIO register access is available\n");
+		mmio_base = pci_iomap_range(pdev, 1, VMCI_MMIO_ACCESS_OFFSET,
+					    VMCI_MMIO_ACCESS_SIZE);
+		/* If the map fails, we fall back to IOIO access. */
+		if (!mmio_base)
+			dev_warn(&pdev->dev, "Failed to map MMIO register access\n");
+	}
+
+	if (!mmio_base) {
+		if (IS_ENABLED(CONFIG_ARM64)) {
+			dev_err(&pdev->dev, "MMIO base is invalid\n");
+			return -ENXIO;
+		}
+		error = pcim_iomap_regions(pdev, BIT(0), KBUILD_MODNAME);
+		if (error) {
+			dev_err(&pdev->dev, "Failed to reserve/map IO regions\n");
+			return error;
+		}
+		iobase = pcim_iomap_table(pdev)[0];
+	}
+
+	vmci_dev = devm_kzalloc(&pdev->dev, sizeof(*vmci_dev), GFP_KERNEL);
+	if (!vmci_dev) {
+		dev_err(&pdev->dev,
+			"Can't allocate memory for VMCI device\n");
+		return -ENOMEM;
+	}
+
+	vmci_dev->dev = &pdev->dev;
+	vmci_dev->exclusive_vectors = false;
+	vmci_dev->iobase = iobase;
+	vmci_dev->mmio_base = mmio_base;
+
+	init_waitqueue_head(&vmci_dev->inout_wq);
+
+	if (mmio_base != NULL) {
+		vmci_dev->tx_buffer = dma_alloc_coherent(&pdev->dev, VMCI_DMA_DG_BUFFER_SIZE,
+							 &vmci_dev->tx_buffer_base,
+							 GFP_KERNEL);
+		if (!vmci_dev->tx_buffer) {
+			dev_err(&pdev->dev,
+				"Can't allocate memory for datagram tx buffer\n");
+			return -ENOMEM;
+		}
+
+		vmci_dev->data_buffer = dma_alloc_coherent(&pdev->dev, VMCI_DMA_DG_BUFFER_SIZE,
+							   &vmci_dev->data_buffer_base,
+							   GFP_KERNEL);
+	} else {
+		vmci_dev->data_buffer = vmalloc(VMCI_MAX_DG_SIZE);
+	}
+	if (!vmci_dev->data_buffer) {
+		dev_err(&pdev->dev,
+			"Can't allocate memory for datagram buffer\n");
+		error = -ENOMEM;
+		goto err_free_data_buffers;
+	}
+
+	pci_set_master(pdev);	/* To enable queue_pair functionality. */
+
+	/*
+	 * Verify that the VMCI Device supports the capabilities that
+	 * we need. If the device is missing capabilities that we would
+	 * like to use, check for fallback capabilities and use those
+	 * instead (so we can run a new VM on old hosts). Fail the load if
+	 * a required capability is missing and there is no fallback.
+	 *
+	 * Right now, we need datagrams. There are no fallbacks.
+	 */
+	capabilities = vmci_read_reg(vmci_dev, VMCI_CAPS_ADDR);
+	if (!(capabilities & VMCI_CAPS_DATAGRAM)) {
+		dev_err(&pdev->dev, "Device does not support datagrams\n");
+		error = -ENXIO;
+		goto err_free_data_buffers;
+	}
+	caps_in_use = VMCI_CAPS_DATAGRAM;
+
+	/*
+	 * Use 64-bit PPNs if the device supports.
+	 *
+	 * There is no check for the return value of dma_set_mask_and_coherent
+	 * since this driver can handle the default mask values if
+	 * dma_set_mask_and_coherent fails.
+	 */
+	if (capabilities & VMCI_CAPS_PPN64) {
+		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+		use_ppn64 = true;
+		caps_in_use |= VMCI_CAPS_PPN64;
+	} else {
+		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(44));
+		use_ppn64 = false;
+	}
+
+	/*
+	 * If the hardware supports notifications, we will use that as
+	 * well.
+	 */
+	if (capabilities & VMCI_CAPS_NOTIFICATIONS) {
+		vmci_dev->notification_bitmap = dma_alloc_coherent(
+			&pdev->dev, PAGE_SIZE, &vmci_dev->notification_base,
+			GFP_KERNEL);
+		if (!vmci_dev->notification_bitmap)
+			dev_warn(&pdev->dev,
+				 "Unable to allocate notification bitmap\n");
+		else
+			caps_in_use |= VMCI_CAPS_NOTIFICATIONS;
+	}
+
+	if (mmio_base != NULL) {
+		if (capabilities & VMCI_CAPS_DMA_DATAGRAM) {
+			caps_in_use |= VMCI_CAPS_DMA_DATAGRAM;
+		} else {
+			dev_err(&pdev->dev,
+				"Missing capability: VMCI_CAPS_DMA_DATAGRAM\n");
+			error = -ENXIO;
+			goto err_free_notification_bitmap;
+		}
+	}
+
+	dev_info(&pdev->dev, "Using capabilities 0x%x\n", caps_in_use);
+
+	/* Let the host know which capabilities we intend to use. */
+	vmci_write_reg(vmci_dev, caps_in_use, VMCI_CAPS_ADDR);
+
+	if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) {
+		/* Let the device know the size for pages passed down. */
+		vmci_write_reg(vmci_dev, PAGE_SHIFT, VMCI_GUEST_PAGE_SHIFT);
+
+		/* Configure the high order parts of the data in/out buffers. */
+		vmci_write_reg(vmci_dev, upper_32_bits(vmci_dev->data_buffer_base),
+			       VMCI_DATA_IN_HIGH_ADDR);
+		vmci_write_reg(vmci_dev, upper_32_bits(vmci_dev->tx_buffer_base),
+			       VMCI_DATA_OUT_HIGH_ADDR);
+	}
+
+	/* Set up global device so that we can start sending datagrams */
+	spin_lock_irq(&vmci_dev_spinlock);
+	vmci_dev_g = vmci_dev;
+	vmci_pdev = pdev;
+	spin_unlock_irq(&vmci_dev_spinlock);
+
+	/*
+	 * Register notification bitmap with device if that capability is
+	 * used.
+	 */
+	if (caps_in_use & VMCI_CAPS_NOTIFICATIONS) {
+		unsigned long bitmap_ppn =
+			vmci_dev->notification_base >> PAGE_SHIFT;
+		if (!vmci_dbell_register_notification_bitmap(bitmap_ppn)) {
+			dev_warn(&pdev->dev,
+				 "VMCI device unable to register notification bitmap with PPN 0x%lx\n",
+				 bitmap_ppn);
+			error = -ENXIO;
+			goto err_remove_vmci_dev_g;
+		}
+	}
+
+	/* Check host capabilities. */
+	error = vmci_check_host_caps(pdev);
+	if (error)
+		goto err_remove_vmci_dev_g;
+
+	/* Enable device. */
+
+	/*
+	 * We subscribe to the VMCI_EVENT_CTX_ID_UPDATE here so we can
+	 * update the internal context id when needed.
+	 */
+	vmci_err = vmci_event_subscribe(VMCI_EVENT_CTX_ID_UPDATE,
+					vmci_guest_cid_update, NULL,
+					&ctx_update_sub_id);
+	if (vmci_err < VMCI_SUCCESS)
+		dev_warn(&pdev->dev,
+			 "Failed to subscribe to event (type=%d): %d\n",
+			 VMCI_EVENT_CTX_ID_UPDATE, vmci_err);
+
+	/*
+	 * Enable interrupts.  Try MSI-X first, then MSI, and then fallback on
+	 * legacy interrupts.
+	 */
+	if (vmci_dev->mmio_base != NULL)
+		num_irq_vectors = VMCI_MAX_INTRS;
+	else
+		num_irq_vectors = VMCI_MAX_INTRS_NOTIFICATION;
+	error = pci_alloc_irq_vectors(pdev, num_irq_vectors, num_irq_vectors,
+				      PCI_IRQ_MSIX);
+	if (error < 0) {
+		error = pci_alloc_irq_vectors(pdev, 1, 1,
+				PCI_IRQ_MSIX | PCI_IRQ_MSI | PCI_IRQ_LEGACY);
+		if (error < 0)
+			goto err_unsubscribe_event;
+	} else {
+		vmci_dev->exclusive_vectors = true;
+	}
+
+	/*
+	 * Request IRQ for legacy or MSI interrupts, or for first
+	 * MSI-X vector.
+	 */
+	error = request_threaded_irq(pci_irq_vector(pdev, 0), NULL,
+				     vmci_interrupt, IRQF_SHARED,
+				     KBUILD_MODNAME, vmci_dev);
+	if (error) {
+		dev_err(&pdev->dev, "Irq %u in use: %d\n",
+			pci_irq_vector(pdev, 0), error);
+		goto err_disable_msi;
+	}
+
+	/*
+	 * For MSI-X with exclusive vectors we need to request an
+	 * interrupt for each vector so that we get a separate
+	 * interrupt handler routine.  This allows us to distinguish
+	 * between the vectors.
+	 */
+	if (vmci_dev->exclusive_vectors) {
+		error = request_threaded_irq(pci_irq_vector(pdev, 1), NULL,
+					     vmci_interrupt_bm, 0,
+					     KBUILD_MODNAME, vmci_dev);
+		if (error) {
+			dev_err(&pdev->dev,
+				"Failed to allocate irq %u: %d\n",
+				pci_irq_vector(pdev, 1), error);
+			goto err_free_irq;
+		}
+		if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) {
+			error = request_threaded_irq(pci_irq_vector(pdev, 2),
+						     NULL,
+						    vmci_interrupt_dma_datagram,
+						     0, KBUILD_MODNAME,
+						     vmci_dev);
+			if (error) {
+				dev_err(&pdev->dev,
+					"Failed to allocate irq %u: %d\n",
+					pci_irq_vector(pdev, 2), error);
+				goto err_free_bm_irq;
+			}
+		}
+	}
+
+	dev_dbg(&pdev->dev, "Registered device\n");
+
+	atomic_inc(&vmci_num_guest_devices);
+
+	/* Enable specific interrupt bits. */
+	cmd = VMCI_IMR_DATAGRAM;
+	if (caps_in_use & VMCI_CAPS_NOTIFICATIONS)
+		cmd |= VMCI_IMR_NOTIFICATION;
+	if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM)
+		cmd |= VMCI_IMR_DMA_DATAGRAM;
+	vmci_write_reg(vmci_dev, cmd, VMCI_IMR_ADDR);
+
+	/* Enable interrupts. */
+	vmci_write_reg(vmci_dev, VMCI_CONTROL_INT_ENABLE, VMCI_CONTROL_ADDR);
+
+	pci_set_drvdata(pdev, vmci_dev);
+
+	vmci_call_vsock_callback(false);
+	return 0;
+
+err_free_bm_irq:
+	if (vmci_dev->exclusive_vectors)
+		free_irq(pci_irq_vector(pdev, 1), vmci_dev);
+
+err_free_irq:
+	free_irq(pci_irq_vector(pdev, 0), vmci_dev);
+
+err_disable_msi:
+	pci_free_irq_vectors(pdev);
+
+err_unsubscribe_event:
+	vmci_err = vmci_event_unsubscribe(ctx_update_sub_id);
+	if (vmci_err < VMCI_SUCCESS)
+		dev_warn(&pdev->dev,
+			 "Failed to unsubscribe from event (type=%d) with subscriber (ID=0x%x): %d\n",
+			 VMCI_EVENT_CTX_ID_UPDATE, ctx_update_sub_id, vmci_err);
+
+err_remove_vmci_dev_g:
+	spin_lock_irq(&vmci_dev_spinlock);
+	vmci_pdev = NULL;
+	vmci_dev_g = NULL;
+	spin_unlock_irq(&vmci_dev_spinlock);
+
+err_free_notification_bitmap:
+	if (vmci_dev->notification_bitmap) {
+		vmci_write_reg(vmci_dev, VMCI_CONTROL_RESET, VMCI_CONTROL_ADDR);
+		dma_free_coherent(&pdev->dev, PAGE_SIZE,
+				  vmci_dev->notification_bitmap,
+				  vmci_dev->notification_base);
+	}
+
+err_free_data_buffers:
+	vmci_free_dg_buffers(vmci_dev);
+
+	/* The rest are managed resources and will be freed by PCI core */
+	return error;
+}
+
+static void vmci_guest_remove_device(struct pci_dev *pdev)
+{
+	struct vmci_guest_device *vmci_dev = pci_get_drvdata(pdev);
+	int vmci_err;
+
+	dev_dbg(&pdev->dev, "Removing device\n");
+
+	atomic_dec(&vmci_num_guest_devices);
+
+	vmci_qp_guest_endpoints_exit();
+
+	vmci_err = vmci_event_unsubscribe(ctx_update_sub_id);
+	if (vmci_err < VMCI_SUCCESS)
+		dev_warn(&pdev->dev,
+			 "Failed to unsubscribe from event (type=%d) with subscriber (ID=0x%x): %d\n",
+			 VMCI_EVENT_CTX_ID_UPDATE, ctx_update_sub_id, vmci_err);
+
+	spin_lock_irq(&vmci_dev_spinlock);
+	vmci_dev_g = NULL;
+	vmci_pdev = NULL;
+	spin_unlock_irq(&vmci_dev_spinlock);
+
+	dev_dbg(&pdev->dev, "Resetting vmci device\n");
+	vmci_write_reg(vmci_dev, VMCI_CONTROL_RESET, VMCI_CONTROL_ADDR);
+
+	/*
+	 * Free IRQ and then disable MSI/MSI-X as appropriate.  For
+	 * MSI-X, we might have multiple vectors, each with their own
+	 * IRQ, which we must free too.
+	 */
+	if (vmci_dev->exclusive_vectors) {
+		free_irq(pci_irq_vector(pdev, 1), vmci_dev);
+		if (vmci_dev->mmio_base != NULL)
+			free_irq(pci_irq_vector(pdev, 2), vmci_dev);
+	}
+	free_irq(pci_irq_vector(pdev, 0), vmci_dev);
+	pci_free_irq_vectors(pdev);
+
+	if (vmci_dev->notification_bitmap) {
+		/*
+		 * The device reset above cleared the bitmap state of the
+		 * device, so we can safely free it here.
+		 */
+
+		dma_free_coherent(&pdev->dev, PAGE_SIZE,
+				  vmci_dev->notification_bitmap,
+				  vmci_dev->notification_base);
+	}
+
+	vmci_free_dg_buffers(vmci_dev);
+
+	if (vmci_dev->mmio_base != NULL)
+		pci_iounmap(pdev, vmci_dev->mmio_base);
+
+	/* The rest are managed resources and will be freed by PCI core */
+}
+
+static const struct pci_device_id vmci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_VMWARE, PCI_DEVICE_ID_VMWARE_VMCI), },
+	{ 0 },
+};
+MODULE_DEVICE_TABLE(pci, vmci_ids);
+
+static struct pci_driver vmci_guest_driver = {
+	.name		= KBUILD_MODNAME,
+	.id_table	= vmci_ids,
+	.probe		= vmci_guest_probe_device,
+	.remove		= vmci_guest_remove_device,
+};
+
+int __init vmci_guest_init(void)
+{
+	return pci_register_driver(&vmci_guest_driver);
+}
+
+void __exit vmci_guest_exit(void)
+{
+	pci_unregister_driver(&vmci_guest_driver);
+}