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, 598 insertions, 0 deletions

diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c
new file mode 100644
index 000000000..a15729beb
--- /dev/null
+++ b/drivers/xen/gntalloc.c
@@ -0,0 +1,598 @@
+/******************************************************************************
+ * gntalloc.c
+ *
+ * Device for creating grant references (in user-space) that may be shared
+ * with other domains.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * This driver exists to allow userspace programs in Linux to allocate kernel
+ * memory that will later be shared with another domain.  Without this device,
+ * Linux userspace programs cannot create grant references.
+ *
+ * How this stuff works:
+ *   X -> granting a page to Y
+ *   Y -> mapping the grant from X
+ *
+ *   1. X uses the gntalloc device to allocate a page of kernel memory, P.
+ *   2. X creates an entry in the grant table that says domid(Y) can access P.
+ *      This is done without a hypercall unless the grant table needs expansion.
+ *   3. X gives the grant reference identifier, GREF, to Y.
+ *   4. Y maps the page, either directly into kernel memory for use in a backend
+ *      driver, or via a the gntdev device to map into the address space of an
+ *      application running in Y. This is the first point at which Xen does any
+ *      tracking of the page.
+ *   5. A program in X mmap()s a segment of the gntalloc device that corresponds
+ *      to the shared page, and can now communicate with Y over the shared page.
+ *
+ *
+ * NOTE TO USERSPACE LIBRARIES:
+ *   The grant allocation and mmap()ing are, naturally, two separate operations.
+ *   You set up the sharing by calling the create ioctl() and then the mmap().
+ *   Teardown requires munmap() and either close() or ioctl().
+ *
+ * WARNING: Since Xen does not allow a guest to forcibly end the use of a grant
+ * reference, this device can be used to consume kernel memory by leaving grant
+ * references mapped by another domain when an application exits. Therefore,
+ * there is a global limit on the number of pages that can be allocated. When
+ * all references to the page are unmapped, it will be freed during the next
+ * grant operation.
+ */
+
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
+#include <linux/atomic.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+
+#include <xen/xen.h>
+#include <xen/page.h>
+#include <xen/grant_table.h>
+#include <xen/gntalloc.h>
+#include <xen/events.h>
+
+static int limit = 1024;
+module_param(limit, int, 0644);
+MODULE_PARM_DESC(limit, "Maximum number of grants that may be allocated by "
+		"the gntalloc device");
+
+static LIST_HEAD(gref_list);
+static DEFINE_MUTEX(gref_mutex);
+static int gref_size;
+
+struct notify_info {
+	uint16_t pgoff:12;    /* Bits 0-11: Offset of the byte to clear */
+	uint16_t flags:2;     /* Bits 12-13: Unmap notification flags */
+	int event;            /* Port (event channel) to notify */
+};
+
+/* Metadata on a grant reference. */
+struct gntalloc_gref {
+	struct list_head next_gref;  /* list entry gref_list */
+	struct list_head next_file;  /* list entry file->list, if open */
+	struct page *page;	     /* The shared page */
+	uint64_t file_index;         /* File offset for mmap() */
+	unsigned int users;          /* Use count - when zero, waiting on Xen */
+	grant_ref_t gref_id;         /* The grant reference number */
+	struct notify_info notify;   /* Unmap notification */
+};
+
+struct gntalloc_file_private_data {
+	struct list_head list;
+	uint64_t index;
+};
+
+struct gntalloc_vma_private_data {
+	struct gntalloc_gref *gref;
+	int users;
+	int count;
+};
+
+static void __del_gref(struct gntalloc_gref *gref);
+
+static void do_cleanup(void)
+{
+	struct gntalloc_gref *gref, *n;
+	list_for_each_entry_safe(gref, n, &gref_list, next_gref) {
+		if (!gref->users)
+			__del_gref(gref);
+	}
+}
+
+static int add_grefs(struct ioctl_gntalloc_alloc_gref *op,
+	uint32_t *gref_ids, struct gntalloc_file_private_data *priv)
+{
+	int i, rc, readonly;
+	LIST_HEAD(queue_gref);
+	LIST_HEAD(queue_file);
+	struct gntalloc_gref *gref, *next;
+
+	readonly = !(op->flags & GNTALLOC_FLAG_WRITABLE);
+	for (i = 0; i < op->count; i++) {
+		gref = kzalloc(sizeof(*gref), GFP_KERNEL);
+		if (!gref) {
+			rc = -ENOMEM;
+			goto undo;
+		}
+		list_add_tail(&gref->next_gref, &queue_gref);
+		list_add_tail(&gref->next_file, &queue_file);
+		gref->users = 1;
+		gref->file_index = op->index + i * PAGE_SIZE;
+		gref->page = alloc_page(GFP_KERNEL|__GFP_ZERO);
+		if (!gref->page) {
+			rc = -ENOMEM;
+			goto undo;
+		}
+
+		/* Grant foreign access to the page. */
+		rc = gnttab_grant_foreign_access(op->domid,
+						 xen_page_to_gfn(gref->page),
+						 readonly);
+		if (rc < 0)
+			goto undo;
+		gref_ids[i] = gref->gref_id = rc;
+	}
+
+	/* Add to gref lists. */
+	mutex_lock(&gref_mutex);
+	list_splice_tail(&queue_gref, &gref_list);
+	list_splice_tail(&queue_file, &priv->list);
+	mutex_unlock(&gref_mutex);
+
+	return 0;
+
+undo:
+	mutex_lock(&gref_mutex);
+	gref_size -= (op->count - i);
+
+	list_for_each_entry_safe(gref, next, &queue_file, next_file) {
+		list_del(&gref->next_file);
+		__del_gref(gref);
+	}
+
+	mutex_unlock(&gref_mutex);
+	return rc;
+}
+
+static void __del_gref(struct gntalloc_gref *gref)
+{
+	if (gref->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
+		uint8_t *tmp = kmap_local_page(gref->page);
+		tmp[gref->notify.pgoff] = 0;
+		kunmap_local(tmp);
+	}
+	if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
+		notify_remote_via_evtchn(gref->notify.event);
+		evtchn_put(gref->notify.event);
+	}
+
+	gref->notify.flags = 0;
+
+	if (gref->gref_id) {
+		if (gref->page)
+			gnttab_end_foreign_access(gref->gref_id, gref->page);
+		else
+			gnttab_free_grant_reference(gref->gref_id);
+	}
+
+	gref_size--;
+	list_del(&gref->next_gref);
+
+	kfree(gref);
+}
+
+/* finds contiguous grant references in a file, returns the first */
+static struct gntalloc_gref *find_grefs(struct gntalloc_file_private_data *priv,
+		uint64_t index, uint32_t count)
+{
+	struct gntalloc_gref *rv = NULL, *gref;
+	list_for_each_entry(gref, &priv->list, next_file) {
+		if (gref->file_index == index && !rv)
+			rv = gref;
+		if (rv) {
+			if (gref->file_index != index)
+				return NULL;
+			index += PAGE_SIZE;
+			count--;
+			if (count == 0)
+				return rv;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * -------------------------------------
+ *  File operations.
+ * -------------------------------------
+ */
+static int gntalloc_open(struct inode *inode, struct file *filp)
+{
+	struct gntalloc_file_private_data *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		goto out_nomem;
+	INIT_LIST_HEAD(&priv->list);
+
+	filp->private_data = priv;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	return 0;
+
+out_nomem:
+	return -ENOMEM;
+}
+
+static int gntalloc_release(struct inode *inode, struct file *filp)
+{
+	struct gntalloc_file_private_data *priv = filp->private_data;
+	struct gntalloc_gref *gref;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	mutex_lock(&gref_mutex);
+	while (!list_empty(&priv->list)) {
+		gref = list_entry(priv->list.next,
+			struct gntalloc_gref, next_file);
+		list_del(&gref->next_file);
+		gref->users--;
+		if (gref->users == 0)
+			__del_gref(gref);
+	}
+	kfree(priv);
+	mutex_unlock(&gref_mutex);
+
+	return 0;
+}
+
+static long gntalloc_ioctl_alloc(struct gntalloc_file_private_data *priv,
+		struct ioctl_gntalloc_alloc_gref __user *arg)
+{
+	int rc = 0;
+	struct ioctl_gntalloc_alloc_gref op;
+	uint32_t *gref_ids;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	if (copy_from_user(&op, arg, sizeof(op))) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	gref_ids = kcalloc(op.count, sizeof(gref_ids[0]), GFP_KERNEL);
+	if (!gref_ids) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	mutex_lock(&gref_mutex);
+	/* Clean up pages that were at zero (local) users but were still mapped
+	 * by remote domains. Since those pages count towards the limit that we
+	 * are about to enforce, removing them here is a good idea.
+	 */
+	do_cleanup();
+	if (gref_size + op.count > limit) {
+		mutex_unlock(&gref_mutex);
+		rc = -ENOSPC;
+		goto out_free;
+	}
+	gref_size += op.count;
+	op.index = priv->index;
+	priv->index += op.count * PAGE_SIZE;
+	mutex_unlock(&gref_mutex);
+
+	rc = add_grefs(&op, gref_ids, priv);
+	if (rc < 0)
+		goto out_free;
+
+	/* Once we finish add_grefs, it is unsafe to touch the new reference,
+	 * since it is possible for a concurrent ioctl to remove it (by guessing
+	 * its index). If the userspace application doesn't provide valid memory
+	 * to write the IDs to, then it will need to close the file in order to
+	 * release - which it will do by segfaulting when it tries to access the
+	 * IDs to close them.
+	 */
+	if (copy_to_user(arg, &op, sizeof(op))) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+	if (copy_to_user(arg->gref_ids, gref_ids,
+			sizeof(gref_ids[0]) * op.count)) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+
+out_free:
+	kfree(gref_ids);
+out:
+	return rc;
+}
+
+static long gntalloc_ioctl_dealloc(struct gntalloc_file_private_data *priv,
+		void __user *arg)
+{
+	int i, rc = 0;
+	struct ioctl_gntalloc_dealloc_gref op;
+	struct gntalloc_gref *gref, *n;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	if (copy_from_user(&op, arg, sizeof(op))) {
+		rc = -EFAULT;
+		goto dealloc_grant_out;
+	}
+
+	mutex_lock(&gref_mutex);
+	gref = find_grefs(priv, op.index, op.count);
+	if (gref) {
+		/* Remove from the file list only, and decrease reference count.
+		 * The later call to do_cleanup() will remove from gref_list and
+		 * free the memory if the pages aren't mapped anywhere.
+		 */
+		for (i = 0; i < op.count; i++) {
+			n = list_entry(gref->next_file.next,
+				struct gntalloc_gref, next_file);
+			list_del(&gref->next_file);
+			gref->users--;
+			gref = n;
+		}
+	} else {
+		rc = -EINVAL;
+	}
+
+	do_cleanup();
+
+	mutex_unlock(&gref_mutex);
+dealloc_grant_out:
+	return rc;
+}
+
+static long gntalloc_ioctl_unmap_notify(struct gntalloc_file_private_data *priv,
+		void __user *arg)
+{
+	struct ioctl_gntalloc_unmap_notify op;
+	struct gntalloc_gref *gref;
+	uint64_t index;
+	int pgoff;
+	int rc;
+
+	if (copy_from_user(&op, arg, sizeof(op)))
+		return -EFAULT;
+
+	index = op.index & ~(PAGE_SIZE - 1);
+	pgoff = op.index & (PAGE_SIZE - 1);
+
+	mutex_lock(&gref_mutex);
+
+	gref = find_grefs(priv, index, 1);
+	if (!gref) {
+		rc = -ENOENT;
+		goto unlock_out;
+	}
+
+	if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) {
+		rc = -EINVAL;
+		goto unlock_out;
+	}
+
+	/* We need to grab a reference to the event channel we are going to use
+	 * to send the notify before releasing the reference we may already have
+	 * (if someone has called this ioctl twice). This is required so that
+	 * it is possible to change the clear_byte part of the notification
+	 * without disturbing the event channel part, which may now be the last
+	 * reference to that event channel.
+	 */
+	if (op.action & UNMAP_NOTIFY_SEND_EVENT) {
+		if (evtchn_get(op.event_channel_port)) {
+			rc = -EINVAL;
+			goto unlock_out;
+		}
+	}
+
+	if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT)
+		evtchn_put(gref->notify.event);
+
+	gref->notify.flags = op.action;
+	gref->notify.pgoff = pgoff;
+	gref->notify.event = op.event_channel_port;
+	rc = 0;
+
+ unlock_out:
+	mutex_unlock(&gref_mutex);
+	return rc;
+}
+
+static long gntalloc_ioctl(struct file *filp, unsigned int cmd,
+		unsigned long arg)
+{
+	struct gntalloc_file_private_data *priv = filp->private_data;
+
+	switch (cmd) {
+	case IOCTL_GNTALLOC_ALLOC_GREF:
+		return gntalloc_ioctl_alloc(priv, (void __user *)arg);
+
+	case IOCTL_GNTALLOC_DEALLOC_GREF:
+		return gntalloc_ioctl_dealloc(priv, (void __user *)arg);
+
+	case IOCTL_GNTALLOC_SET_UNMAP_NOTIFY:
+		return gntalloc_ioctl_unmap_notify(priv, (void __user *)arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static void gntalloc_vma_open(struct vm_area_struct *vma)
+{
+	struct gntalloc_vma_private_data *priv = vma->vm_private_data;
+
+	if (!priv)
+		return;
+
+	mutex_lock(&gref_mutex);
+	priv->users++;
+	mutex_unlock(&gref_mutex);
+}
+
+static void gntalloc_vma_close(struct vm_area_struct *vma)
+{
+	struct gntalloc_vma_private_data *priv = vma->vm_private_data;
+	struct gntalloc_gref *gref, *next;
+	int i;
+
+	if (!priv)
+		return;
+
+	mutex_lock(&gref_mutex);
+	priv->users--;
+	if (priv->users == 0) {
+		gref = priv->gref;
+		for (i = 0; i < priv->count; i++) {
+			gref->users--;
+			next = list_entry(gref->next_gref.next,
+					  struct gntalloc_gref, next_gref);
+			if (gref->users == 0)
+				__del_gref(gref);
+			gref = next;
+		}
+		kfree(priv);
+	}
+	mutex_unlock(&gref_mutex);
+}
+
+static const struct vm_operations_struct gntalloc_vmops = {
+	.open = gntalloc_vma_open,
+	.close = gntalloc_vma_close,
+};
+
+static int gntalloc_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct gntalloc_file_private_data *priv = filp->private_data;
+	struct gntalloc_vma_private_data *vm_priv;
+	struct gntalloc_gref *gref;
+	int count = vma_pages(vma);
+	int rv, i;
+
+	if (!(vma->vm_flags & VM_SHARED)) {
+		pr_err("%s: Mapping must be shared\n", __func__);
+		return -EINVAL;
+	}
+
+	vm_priv = kmalloc(sizeof(*vm_priv), GFP_KERNEL);
+	if (!vm_priv)
+		return -ENOMEM;
+
+	mutex_lock(&gref_mutex);
+
+	pr_debug("%s: priv %p,%p, page %lu+%d\n", __func__,
+		       priv, vm_priv, vma->vm_pgoff, count);
+
+	gref = find_grefs(priv, vma->vm_pgoff << PAGE_SHIFT, count);
+	if (gref == NULL) {
+		rv = -ENOENT;
+		pr_debug("%s: Could not find grant reference",
+				__func__);
+		kfree(vm_priv);
+		goto out_unlock;
+	}
+
+	vm_priv->gref = gref;
+	vm_priv->users = 1;
+	vm_priv->count = count;
+
+	vma->vm_private_data = vm_priv;
+
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+
+	vma->vm_ops = &gntalloc_vmops;
+
+	for (i = 0; i < count; i++) {
+		gref->users++;
+		rv = vm_insert_page(vma, vma->vm_start + i * PAGE_SIZE,
+				gref->page);
+		if (rv)
+			goto out_unlock;
+
+		gref = list_entry(gref->next_file.next,
+				struct gntalloc_gref, next_file);
+	}
+	rv = 0;
+
+out_unlock:
+	mutex_unlock(&gref_mutex);
+	return rv;
+}
+
+static const struct file_operations gntalloc_fops = {
+	.owner = THIS_MODULE,
+	.open = gntalloc_open,
+	.release = gntalloc_release,
+	.unlocked_ioctl = gntalloc_ioctl,
+	.mmap = gntalloc_mmap
+};
+
+/*
+ * -------------------------------------
+ * Module creation/destruction.
+ * -------------------------------------
+ */
+static struct miscdevice gntalloc_miscdev = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name	= "xen/gntalloc",
+	.fops	= &gntalloc_fops,
+};
+
+static int __init gntalloc_init(void)
+{
+	int err;
+
+	if (!xen_domain())
+		return -ENODEV;
+
+	err = misc_register(&gntalloc_miscdev);
+	if (err != 0) {
+		pr_err("Could not register misc gntalloc device\n");
+		return err;
+	}
+
+	pr_debug("Created grant allocation device at %d,%d\n",
+			MISC_MAJOR, gntalloc_miscdev.minor);
+
+	return 0;
+}
+
+static void __exit gntalloc_exit(void)
+{
+	misc_deregister(&gntalloc_miscdev);
+}
+
+module_init(gntalloc_init);
+module_exit(gntalloc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Carter Weatherly <carter.weatherly@jhuapl.edu>, "
+		"Daniel De Graaf <dgdegra@tycho.nsa.gov>");
+MODULE_DESCRIPTION("User-space grant reference allocator driver");