Move driver/linux into the main repository rather than a submodule.
Change-Id: I3e49fbd0b52379ff1729eefc31467fe8487529e4
diff --git a/.gitmodules b/.gitmodules
index 180293c..13fb56f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -2,9 +2,6 @@
path = prebuilts
url = https://hafnium.googlesource.com/hafnium/prebuilts
shallow = true
-[submodule "driver/linux"]
- path = driver/linux
- url = https://hafnium.googlesource.com/hafnium/driver/linux
[submodule "project/reference"]
path = project/reference
url = https://hafnium.googlesource.com/hafnium/project/reference
diff --git a/driver/linux b/driver/linux
deleted file mode 160000
index 81b9069..0000000
--- a/driver/linux
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 81b90698b40fdcdd886e733a597ced435bd108b9
diff --git a/driver/linux/.gitignore b/driver/linux/.gitignore
new file mode 100644
index 0000000..8fd2089
--- /dev/null
+++ b/driver/linux/.gitignore
@@ -0,0 +1,7 @@
+*.ko
+*.mod.c
+*.o
+.*o.cmd
+.tmp_versions/
+Module.symvers
+modules.order
diff --git a/driver/linux/BUILD.gn b/driver/linux/BUILD.gn
new file mode 100644
index 0000000..6c7d688
--- /dev/null
+++ b/driver/linux/BUILD.gn
@@ -0,0 +1,21 @@
+# Copyright 2019 The Hafnium Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import("//build/linux/linux.gni")
+
+linux_kernel_module("linux") {
+ module_name = "hafnium"
+ kernel_target = "//third_party/linux:linux"
+ kernel_dir = "//third_party/linux"
+}
diff --git a/driver/linux/LICENSE b/driver/linux/LICENSE
new file mode 100644
index 0000000..d159169
--- /dev/null
+++ b/driver/linux/LICENSE
@@ -0,0 +1,339 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
+ The licenses for most software are designed to take away your
+freedom to share and change it. By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users. This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it. (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.) You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
+price. Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
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+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+ For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have. You must make sure that they, too, receive or can get the
+source code. And you must show them these terms so they know their
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+ We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
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+that everyone understands that there is no warranty for this free
+software. If the software is modified by someone else and passed on, we
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+patent must be licensed for everyone's free use or not licensed at all.
+
+ The precise terms and conditions for copying, distribution and
+modification follow.
+
+ GNU GENERAL PUBLIC LICENSE
+ TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+ 0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License. The "Program", below,
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+that is to say, a work containing the Program or a portion of it,
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+language. (Hereinafter, translation is included without limitation in
+the term "modification".) Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope. The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
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+ 1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
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+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
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+ 2. You may modify your copy or copies of the Program or any portion
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+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+ a) You must cause the modified files to carry prominent notices
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+ b) You must cause any work that you distribute or publish, that in
+ whole or in part contains or is derived from the Program or any
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+These requirements apply to the modified work as a whole. If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works. But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
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+Thus, it is not the intent of this section to claim rights or contest
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+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
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+
+ 3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
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+ a) Accompany it with the complete corresponding machine-readable
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+ 5. You are not required to accept this License, since you have not
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+infringement or for any other reason (not limited to patent issues),
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+ 8. If the distribution and/or use of the Program is restricted in
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+original copyright holder who places the Program under this License
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+ 9. The Free Software Foundation may publish revised and/or new versions
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+
+Each version is given a distinguishing version number. If the Program
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+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation. If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+ 10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
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+of promoting the sharing and reuse of software generally.
+
+ NO WARRANTY
+
+ 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
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+ 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
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+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+ <one line to give the program's name and a brief idea of what it does.>
+ Copyright (C) <year> <name of author>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ 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.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+ Gnomovision version 69, Copyright (C) year name of author
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary. Here is a sample; alter the names:
+
+ Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+ `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+ <signature of Ty Coon>, 1 April 1989
+ Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs. If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/driver/linux/Makefile b/driver/linux/Makefile
new file mode 100644
index 0000000..0add537
--- /dev/null
+++ b/driver/linux/Makefile
@@ -0,0 +1,45 @@
+# Copyright 2018 The Hafnium Authors.
+#
+# 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.
+#
+# 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.
+
+# By default, assume this was checked out as a submodule of the Hafnium repo
+# and that Linux was checked out along side that checkout. These paths can be
+# overridden if that assumption is incorrect.
+HAFNIUM_PATH ?= $(CURDIR)/../..
+
+ifneq ($(KERNELRELEASE),)
+
+obj-m += hafnium.o
+
+hafnium-y += main.o
+hafnium-y += vmlib/aarch64/call.o
+hafnium-y += vmlib/spci.o
+
+ccflags-y = -I$(HAFNIUM_PATH)/inc/vmapi -I$(M)/inc
+
+else
+
+KERNEL_PATH ?= $(HAFNIUM_PATH)/third_party/linux
+ARCH ?= arm64
+CROSS_COMPILE ?= aarch64-linux-gnu-
+CHECKPATCH ?= $(KERNEL_PATH)/scripts/checkpatch.pl -q
+
+all:
+ cp -r $(HAFNIUM_PATH)/vmlib/ $(CURDIR)
+ make -C $(KERNEL_PATH) HAFNIUM_PATH=$(HAFNIUM_PATH) M=$(CURDIR) O=$(O) ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) modules
+
+clean:
+ make -C $(KERNEL_PATH) HAFNIUM_PATH=$(HAFNIUM_PATH) M=$(CURDIR) O=$(O) clean
+ rm -rf vmlib
+
+checkpatch:
+ $(CHECKPATCH) -f main.c
+
+endif
diff --git a/driver/linux/inc/uapi/hf/socket.h b/driver/linux/inc/uapi/hf/socket.h
new file mode 100644
index 0000000..26d6432
--- /dev/null
+++ b/driver/linux/inc/uapi/hf/socket.h
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2019 The Hafnium Authors.
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <linux/socket.h>
+
+#include <hf/spci.h>
+
+/* TODO: Reusing AF_ECONET for now as it's otherwise unused. */
+#define AF_HF AF_ECONET
+#define PF_HF AF_HF
+
+/*
+ * Address of a Hafnium socket
+ */
+struct hf_sockaddr {
+ __kernel_sa_family_t family;
+ spci_vm_id_t vm_id;
+ uint64_t port;
+};
diff --git a/driver/linux/main.c b/driver/linux/main.c
new file mode 100644
index 0000000..5bd5709
--- /dev/null
+++ b/driver/linux/main.c
@@ -0,0 +1,1162 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2018 The Hafnium Authors.
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <clocksource/arm_arch_timer.h>
+#include <linux/atomic.h>
+#include <linux/cpuhotplug.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sched/task.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+
+#include <hf/call.h>
+#include <hf/spci.h>
+#include <hf/transport.h>
+
+#include "uapi/hf/socket.h"
+
+#define HYPERVISOR_TIMER_NAME "el2_timer"
+
+#define CONFIG_HAFNIUM_MAX_VMS 16
+#define CONFIG_HAFNIUM_MAX_VCPUS 32
+
+#define FIRST_SECONDARY_VM_ID (HF_VM_ID_OFFSET + 1)
+
+struct hf_vcpu {
+ struct hf_vm *vm;
+ spci_vcpu_index_t vcpu_index;
+ struct task_struct *task;
+ atomic_t abort_sleep;
+ atomic_t waiting_for_message;
+ struct hrtimer timer;
+};
+
+struct hf_vm {
+ spci_vm_id_t id;
+ spci_vcpu_count_t vcpu_count;
+ struct hf_vcpu *vcpu;
+};
+
+struct hf_sock {
+ /* This needs to be the first field. */
+ struct sock sk;
+
+ /*
+ * The following fields are immutable after the socket transitions to
+ * SS_CONNECTED state.
+ */
+ uint64_t local_port;
+ uint64_t remote_port;
+ struct hf_vm *peer_vm;
+};
+
+static struct proto hf_sock_proto = {
+ .name = "hafnium",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct hf_sock),
+};
+
+static struct hf_vm *hf_vms;
+static spci_vm_count_t hf_vm_count;
+static struct page *hf_send_page;
+static struct page *hf_recv_page;
+static atomic64_t hf_next_port = ATOMIC64_INIT(0);
+static DEFINE_SPINLOCK(hf_send_lock);
+static DEFINE_HASHTABLE(hf_local_port_hash, 7);
+static DEFINE_SPINLOCK(hf_local_port_hash_lock);
+static int hf_irq;
+static enum cpuhp_state hf_cpuhp_state;
+static spci_vm_id_t current_vm_id;
+
+/**
+ * Retrieves a VM from its ID, returning NULL if the VM doesn't exist.
+ */
+static struct hf_vm *hf_vm_from_id(spci_vm_id_t vm_id)
+{
+ if (vm_id < FIRST_SECONDARY_VM_ID ||
+ vm_id >= FIRST_SECONDARY_VM_ID + hf_vm_count)
+ return NULL;
+
+ return &hf_vms[vm_id - FIRST_SECONDARY_VM_ID];
+}
+
+/**
+ * Wakes up the kernel thread responsible for running the given vcpu.
+ *
+ * Returns 0 if the thread was already running, 1 otherwise.
+ */
+static int hf_vcpu_wake_up(struct hf_vcpu *vcpu)
+{
+ /* Set a flag indicating that the thread should not go to sleep. */
+ atomic_set(&vcpu->abort_sleep, 1);
+
+ /* Set the thread to running state. */
+ return wake_up_process(vcpu->task);
+}
+
+/**
+ * Puts the current thread to sleep. The current thread must be responsible for
+ * running the given vcpu.
+ *
+ * Going to sleep will fail if hf_vcpu_wake_up() or kthread_stop() was called on
+ * this vcpu/thread since the last time it [re]started running.
+ */
+static void hf_vcpu_sleep(struct hf_vcpu *vcpu)
+{
+ int abort;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ /* Check the sleep-abort flag after making thread interruptible. */
+ abort = atomic_read(&vcpu->abort_sleep);
+ if (!abort && !kthread_should_stop())
+ schedule();
+
+ /* Set state back to running on the way out. */
+ set_current_state(TASK_RUNNING);
+}
+
+/**
+ * Wakes up the thread associated with the vcpu that owns the given timer. This
+ * is called when the timer the thread is waiting on expires.
+ */
+static enum hrtimer_restart hf_vcpu_timer_expired(struct hrtimer *timer)
+{
+ struct hf_vcpu *vcpu = container_of(timer, struct hf_vcpu, timer);
+ /* TODO: Inject interrupt. */
+ hf_vcpu_wake_up(vcpu);
+ return HRTIMER_NORESTART;
+}
+
+/**
+ * This function is called when Hafnium requests that the primary VM wake up a
+ * vCPU that belongs to a secondary VM.
+ *
+ * It wakes up the thread if it's sleeping, or kicks it if it's already running.
+ */
+static void hf_handle_wake_up_request(spci_vm_id_t vm_id,
+ spci_vcpu_index_t vcpu)
+{
+ struct hf_vm *vm = hf_vm_from_id(vm_id);
+
+ if (!vm) {
+ pr_warn("Request to wake up non-existent VM id: %u\n", vm_id);
+ return;
+ }
+
+ if (vcpu >= vm->vcpu_count) {
+ pr_warn("Request to wake up non-existent vCPU: %u.%u\n",
+ vm_id, vcpu);
+ return;
+ }
+
+ if (hf_vcpu_wake_up(&vm->vcpu[vcpu]) == 0) {
+ /*
+ * The task was already running (presumably on a different
+ * physical CPU); interrupt it. This gives Hafnium a chance to
+ * inject any new interrupts.
+ */
+ kick_process(vm->vcpu[vcpu].task);
+ }
+}
+
+/**
+ * Injects an interrupt into a vCPU of the VM and ensures the vCPU will run to
+ * handle the interrupt.
+ */
+static void hf_interrupt_vm(spci_vm_id_t vm_id, uint64_t int_id)
+{
+ struct hf_vm *vm = hf_vm_from_id(vm_id);
+ spci_vcpu_index_t vcpu;
+ int64_t ret;
+
+ if (!vm) {
+ pr_warn("Request to wake up non-existent VM id: %u\n", vm_id);
+ return;
+ }
+
+ /*
+ * TODO: For now we're picking the first vcpu to interrupt, but
+ * we want to be smarter.
+ */
+ vcpu = 0;
+ ret = hf_interrupt_inject(vm_id, vcpu, int_id);
+
+ if (ret == -1) {
+ pr_warn("Failed to inject interrupt %lld to vCPU %d of VM %d",
+ int_id, vcpu, vm_id);
+ return;
+ }
+
+ if (ret != 1) {
+ /* We don't need to wake up the vcpu. */
+ return;
+ }
+
+ hf_handle_wake_up_request(vm_id, vcpu);
+}
+
+/**
+ * Notify all waiters on the given VM.
+ */
+static void hf_notify_waiters(spci_vm_id_t vm_id)
+{
+ spci_vm_id_t waiter_vm_id;
+
+ while ((waiter_vm_id = hf_mailbox_waiter_get(vm_id)) != -1) {
+ if (waiter_vm_id == HF_PRIMARY_VM_ID) {
+ /*
+ * TODO: Use this information when implementing per-vm
+ * queues.
+ */
+ } else {
+ hf_interrupt_vm(waiter_vm_id,
+ HF_MAILBOX_WRITABLE_INTID);
+ }
+ }
+}
+
+/**
+ * Delivers a message to a VM.
+ */
+static void hf_deliver_message(spci_vm_id_t vm_id)
+{
+ struct hf_vm *vm = hf_vm_from_id(vm_id);
+ spci_vcpu_index_t i;
+
+ if (!vm) {
+ pr_warn("Tried to deliver message to non-existent VM id: %u\n",
+ vm_id);
+ return;
+ }
+
+ /* Try to wake a vCPU that is waiting for a message. */
+ for (i = 0; i < vm->vcpu_count; i++) {
+ if (atomic_read(&vm->vcpu[i].waiting_for_message)) {
+ hf_handle_wake_up_request(vm->id,
+ vm->vcpu[i].vcpu_index);
+ return;
+ }
+ }
+
+ /* None were waiting for a message so interrupt one. */
+ hf_interrupt_vm(vm->id, HF_MAILBOX_READABLE_INTID);
+}
+
+/**
+ * Handles a message delivered to this VM by validating that it's well-formed
+ * and then queueing it for delivery to the appropriate socket.
+ */
+static void hf_handle_message(struct hf_vm *sender, size_t len,
+ const void *message)
+{
+ struct hf_sock *hsock;
+ const struct hf_msg_hdr *hdr = (struct hf_msg_hdr *)message;
+ struct sk_buff *skb;
+ int err;
+
+ /* Ignore messages that are too small to hold a header. */
+ if (len < sizeof(struct hf_msg_hdr)) {
+ pr_err("Message received without header of length %d\n", len);
+ spci_rx_release();
+ return;
+ }
+
+ len -= sizeof(struct hf_msg_hdr);
+
+ /* Go through the colliding sockets. */
+ rcu_read_lock();
+ hash_for_each_possible_rcu(hf_local_port_hash, hsock, sk.sk_node,
+ hdr->dst_port) {
+ if (hsock->peer_vm == sender &&
+ hsock->remote_port == hdr->src_port) {
+ sock_hold(&hsock->sk);
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ /* Nothing to do if we couldn't find the target. */
+ if (!hsock) {
+ spci_rx_release();
+ return;
+ }
+
+ /*
+ * TODO: From this point on, there are two failure paths: when we
+ * create the skb below, and when we enqueue it to the socket. What
+ * should we do if they fail? Ideally we would have some form of flow
+ * control to prevent message loss, but how to do it efficiently?
+ *
+ * One option is to have a pre-allocated message that indicates to the
+ * sender that a message was dropped. This way we guarantee that the
+ * sender will be aware of loss and should back-off.
+ */
+ /* Create the skb. */
+ skb = alloc_skb(len, GFP_KERNEL);
+ if (!skb)
+ goto exit;
+
+ memcpy(skb_put(skb, len), hdr + 1, len);
+
+ /*
+ * Add the skb to the receive queue of the target socket. On success it
+ * calls sk->sk_data_ready, which is currently set to sock_def_readable,
+ * which wakes up any waiters.
+ */
+ err = sock_queue_rcv_skb(&hsock->sk, skb);
+ if (err)
+ kfree_skb(skb);
+
+exit:
+ sock_put(&hsock->sk);
+
+ if (spci_rx_release().func == SPCI_RX_RELEASE_32)
+ hf_notify_waiters(HF_PRIMARY_VM_ID);
+}
+
+/**
+ * This is the main loop of each vcpu.
+ */
+static int hf_vcpu_thread(void *data)
+{
+ struct hf_vcpu *vcpu = data;
+ struct spci_value ret;
+
+ hrtimer_init(&vcpu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ vcpu->timer.function = &hf_vcpu_timer_expired;
+
+ while (!kthread_should_stop()) {
+ spci_vcpu_index_t i;
+
+ /*
+ * We're about to run the vcpu, so we can reset the abort-sleep
+ * flag.
+ */
+ atomic_set(&vcpu->abort_sleep, 0);
+
+ /* Call into Hafnium to run vcpu. */
+ ret = spci_run(vcpu->vm->id, vcpu->vcpu_index);
+
+ switch (ret.func) {
+ /* Preempted. */
+ case SPCI_INTERRUPT_32:
+ if (need_resched())
+ schedule();
+ break;
+
+ /* Yield. */
+ case SPCI_YIELD_32:
+ if (!kthread_should_stop())
+ schedule();
+ break;
+
+ /* WFI. */
+ case HF_SPCI_RUN_WAIT_FOR_INTERRUPT:
+ if (ret.arg2 != SPCI_SLEEP_INDEFINITE) {
+ hrtimer_start(&vcpu->timer, ret.arg2,
+ HRTIMER_MODE_REL);
+ }
+ hf_vcpu_sleep(vcpu);
+ hrtimer_cancel(&vcpu->timer);
+ break;
+
+ /* Waiting for a message. */
+ case SPCI_MSG_WAIT_32:
+ atomic_set(&vcpu->waiting_for_message, 1);
+ if (ret.arg2 != SPCI_SLEEP_INDEFINITE) {
+ hrtimer_start(&vcpu->timer, ret.arg2,
+ HRTIMER_MODE_REL);
+ }
+ hf_vcpu_sleep(vcpu);
+ hrtimer_cancel(&vcpu->timer);
+ atomic_set(&vcpu->waiting_for_message, 0);
+ break;
+
+ /* Wake up another vcpu. */
+ case HF_SPCI_RUN_WAKE_UP:
+ hf_handle_wake_up_request(spci_vm_id(ret),
+ spci_vcpu_index(ret));
+ break;
+
+ /* Response available. */
+ case SPCI_MSG_SEND_32:
+ if (spci_msg_send_receiver(ret) == HF_PRIMARY_VM_ID) {
+ hf_handle_message(vcpu->vm,
+ spci_msg_send_size(ret),
+ page_address(hf_recv_page));
+ } else {
+ hf_deliver_message(spci_msg_send_receiver(ret));
+ }
+ break;
+
+ /* Notify all waiters. */
+ case SPCI_RX_RELEASE_32:
+ hf_notify_waiters(vcpu->vm->id);
+ break;
+
+ case SPCI_ERROR_32:
+ pr_warn("SPCI error %d running VM %d vCPU %d", ret.arg2,
+ vcpu->vm->id, vcpu->vcpu_index);
+ switch (ret.arg2) {
+ /* Abort was triggered. */
+ case SPCI_ABORTED:
+ for (i = 0; i < vcpu->vm->vcpu_count; i++) {
+ if (i == vcpu->vcpu_index)
+ continue;
+ hf_handle_wake_up_request(vcpu->vm->id,
+ i);
+ }
+ hf_vcpu_sleep(vcpu);
+ break;
+ default:
+ /* Treat as a yield and try again later. */
+ if (!kthread_should_stop())
+ schedule();
+ break;
+ }
+ break;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * Converts a pointer to a struct sock into a pointer to a struct hf_sock. It
+ * relies on the fact that the first field of hf_sock is a sock.
+ */
+static struct hf_sock *hsock_from_sk(struct sock *sk)
+{
+ return (struct hf_sock *)sk;
+}
+
+/**
+ * This is called when the last reference to the outer socket is released. For
+ * example, if it's a user-space socket, when the last file descriptor pointing
+ * to this socket is closed.
+ *
+ * It begins cleaning up resources, though some can only be cleaned up after all
+ * references to the underlying socket are released, which is handled by
+ * hf_sock_destruct().
+ */
+static int hf_sock_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct hf_sock *hsock = hsock_from_sk(sk);
+ unsigned long flags;
+
+ if (!sk)
+ return 0;
+
+ /* Shutdown for both send and receive. */
+ lock_sock(sk);
+ sk->sk_shutdown |= RCV_SHUTDOWN | SEND_SHUTDOWN;
+ sk->sk_state_change(sk);
+ release_sock(sk);
+
+ /* Remove from the hash table, so lookups from now on won't find it. */
+ spin_lock_irqsave(&hf_local_port_hash_lock, flags);
+ hash_del_rcu(&hsock->sk.sk_node);
+ spin_unlock_irqrestore(&hf_local_port_hash_lock, flags);
+
+ /*
+ * TODO: When we implement a tx queue, we need to clear it here so that
+ * sk_wmem_alloc will not prevent sk from being freed (sk_free).
+ */
+
+ /*
+ * Wait for in-flight lookups to finish. We need to do this here because
+ * in-flight lookups rely on the reference to the socket we're about to
+ * release.
+ */
+ synchronize_rcu();
+ sock_put(sk);
+ sock->sk = NULL;
+
+ return 0;
+}
+
+/**
+ * This is called when there are no more references to the socket. It frees all
+ * resources that haven't been freed during release.
+ */
+static void hf_sock_destruct(struct sock *sk)
+{
+ /*
+ * Clear the receive queue now that the handler cannot add any more
+ * skbs to it.
+ */
+ skb_queue_purge(&sk->sk_receive_queue);
+}
+
+/**
+ * Connects the Hafnium socket to the provided VM and port. After the socket is
+ * connected, it can be used to exchange datagrams with the specified peer.
+ */
+static int hf_sock_connect(struct socket *sock, struct sockaddr *saddr, int len,
+ int connect_flags)
+{
+ struct sock *sk = sock->sk;
+ struct hf_sock *hsock = hsock_from_sk(sk);
+ struct hf_vm *vm;
+ struct hf_sockaddr *addr;
+ int err;
+ unsigned long flags;
+
+ /* Basic address validation. */
+ if (len < sizeof(struct hf_sockaddr) || saddr->sa_family != AF_HF)
+ return -EINVAL;
+
+ addr = (struct hf_sockaddr *)saddr;
+ vm = hf_vm_from_id(addr->vm_id);
+ if (!vm)
+ return -ENETUNREACH;
+
+ /*
+ * TODO: Once we implement access control in Hafnium, check that the
+ * caller is allowed to contact the specified VM. Return -ECONNREFUSED
+ * if access is denied.
+ */
+
+ /* Take lock to make sure state doesn't change as we connect. */
+ lock_sock(sk);
+
+ /* Only unconnected sockets are allowed to become connected. */
+ if (sock->state != SS_UNCONNECTED) {
+ err = -EISCONN;
+ goto exit;
+ }
+
+ hsock->local_port = atomic64_inc_return(&hf_next_port);
+ hsock->remote_port = addr->port;
+ hsock->peer_vm = vm;
+
+ sock->state = SS_CONNECTED;
+
+ /* Add socket to hash table now that it's fully initialised. */
+ spin_lock_irqsave(&hf_local_port_hash_lock, flags);
+ hash_add_rcu(hf_local_port_hash, &sk->sk_node, hsock->local_port);
+ spin_unlock_irqrestore(&hf_local_port_hash_lock, flags);
+
+ err = 0;
+exit:
+ release_sock(sk);
+ return err;
+}
+
+/**
+ * Sends the given skb to the appropriate VM by calling Hafnium. It will also
+ * trigger the wake up of a recipient VM.
+ *
+ * Takes ownership of the skb on success.
+ */
+static int hf_send_skb(struct sk_buff *skb)
+{
+ unsigned long flags;
+ struct spci_value ret;
+ struct hf_sock *hsock = hsock_from_sk(skb->sk);
+ struct hf_vm *vm = hsock->peer_vm;
+ void *message = page_address(hf_send_page);
+
+ /*
+ * Call Hafnium under the send lock so that we serialize the use of the
+ * global send buffer.
+ */
+ spin_lock_irqsave(&hf_send_lock, flags);
+ memcpy(message, skb->data, skb->len);
+
+ ret = spci_msg_send(current_vm_id, vm->id, skb->len, 0);
+ spin_unlock_irqrestore(&hf_send_lock, flags);
+
+ if (ret.func == SPCI_ERROR_32) {
+ switch (ret.arg2) {
+ case SPCI_INVALID_PARAMETERS:
+ return -ENXIO;
+ case SPCI_NOT_SUPPORTED:
+ return -EIO;
+ case SPCI_DENIED:
+ case SPCI_BUSY:
+ default:
+ return -EAGAIN;
+ }
+ }
+
+ /* Ensure the VM will run to pick up the message. */
+ hf_deliver_message(vm->id);
+
+ kfree_skb(skb);
+
+ return 0;
+}
+
+/**
+ * Determines if the given socket is in the connected state. It acquires and
+ * releases the socket lock.
+ */
+static bool hf_sock_is_connected(struct socket *sock)
+{
+ bool ret;
+
+ lock_sock(sock->sk);
+ ret = sock->state == SS_CONNECTED;
+ release_sock(sock->sk);
+
+ return ret;
+}
+
+/**
+ * Sends a message to the VM & port the socket is connected to. All variants
+ * of write/send/sendto/sendmsg eventually call this function.
+ */
+static int hf_sock_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
+{
+ struct sock *sk = sock->sk;
+ struct sk_buff *skb;
+ int err;
+ struct hf_msg_hdr *hdr;
+ struct hf_sock *hsock = hsock_from_sk(sk);
+ size_t payload_max_len = HF_MAILBOX_SIZE - sizeof(struct hf_msg_hdr);
+
+ /* Check length. */
+ if (len > payload_max_len)
+ return -EMSGSIZE;
+
+ /* We don't allow the destination address to be specified. */
+ if (m->msg_namelen > 0)
+ return -EISCONN;
+
+ /* We don't support out of band messages. */
+ if (m->msg_flags & MSG_OOB)
+ return -EOPNOTSUPP;
+
+ /*
+ * Ensure that the socket is connected. We don't need to hold the socket
+ * lock (acquired and released by hf_sock_is_connected) for the
+ * remainder of the function because the fields we care about are
+ * immutable once the state is SS_CONNECTED.
+ */
+ if (!hf_sock_is_connected(sock))
+ return -ENOTCONN;
+
+ /*
+ * Allocate an skb for this write. If there isn't enough room in the
+ * socket's send buffer (sk_wmem_alloc >= sk_sndbuf), this will block
+ * (if it's a blocking call). On success, it increments sk_wmem_alloc
+ * and sets up the skb such that sk_wmem_alloc gets decremented when
+ * the skb is freed (sock_wfree gets called).
+ */
+ skb = sock_alloc_send_skb(sk, len + sizeof(struct hf_msg_hdr),
+ m->msg_flags & MSG_DONTWAIT, &err);
+ if (!skb)
+ return err;
+
+ /* Reserve room for the header and initialise it. */
+ skb_reserve(skb, sizeof(struct hf_msg_hdr));
+ hdr = skb_push(skb, sizeof(struct hf_msg_hdr));
+ hdr->src_port = hsock->local_port;
+ hdr->dst_port = hsock->remote_port;
+
+ /* Allocate area for the contents, then copy into skb. */
+ if (!copy_from_iter_full(skb_put(skb, len), len, &m->msg_iter)) {
+ err = -EFAULT;
+ goto err_cleanup;
+ }
+
+ /*
+ * TODO: We currently do this inline, but when we have support for
+ * readiness notification from Hafnium, we must add this to a per-VM tx
+ * queue that can make progress when the VM becomes writable. This will
+ * fix send buffering and poll readiness notification.
+ */
+ err = hf_send_skb(skb);
+ if (err)
+ goto err_cleanup;
+
+ return 0;
+
+err_cleanup:
+ kfree_skb(skb);
+ return err;
+}
+
+/**
+ * Receives a message originated from the VM & port the socket is connected to.
+ * All variants of read/recv/recvfrom/recvmsg eventually call this function.
+ */
+static int hf_sock_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
+ int flags)
+{
+ struct sock *sk = sock->sk;
+ struct sk_buff *skb;
+ int err;
+ size_t copy_len;
+
+ if (!hf_sock_is_connected(sock))
+ return -ENOTCONN;
+
+ /* Grab the next skb from the receive queue. */
+ skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
+ if (!skb)
+ return err;
+
+ /* Make sure we don't copy more than what fits in the output buffer. */
+ copy_len = skb->len;
+ if (copy_len > len) {
+ copy_len = len;
+ m->msg_flags |= MSG_TRUNC;
+ }
+
+ /* Make sure we don't overflow the return value type. */
+ if (copy_len > INT_MAX) {
+ copy_len = INT_MAX;
+ m->msg_flags |= MSG_TRUNC;
+ }
+
+ /* Copy skb to output iterator, then free it. */
+ err = skb_copy_datagram_msg(skb, 0, m, copy_len);
+ skb_free_datagram(sk, skb);
+ if (err)
+ return err;
+
+ return copy_len;
+}
+
+/**
+ * This function is called when a Hafnium socket is created. It initialises all
+ * state such that the caller will be able to connect the socket and then send
+ * and receive messages through it.
+ */
+static int hf_sock_create(struct net *net, struct socket *sock, int protocol,
+ int kern)
+{
+ static const struct proto_ops ops = {
+ .family = PF_HF,
+ .owner = THIS_MODULE,
+ .release = hf_sock_release,
+ .bind = sock_no_bind,
+ .connect = hf_sock_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = sock_no_accept,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = sock_no_setsockopt,
+ .getsockopt = sock_no_getsockopt,
+ .sendmsg = hf_sock_sendmsg,
+ .recvmsg = hf_sock_recvmsg,
+ .mmap = sock_no_mmap,
+ .sendpage = sock_no_sendpage,
+ .poll = datagram_poll,
+ };
+ struct sock *sk;
+
+ if (sock->type != SOCK_DGRAM)
+ return -ESOCKTNOSUPPORT;
+
+ if (protocol != 0)
+ return -EPROTONOSUPPORT;
+
+ /*
+ * For now we only allow callers with sys admin capability to create
+ * Hafnium sockets.
+ */
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ /* Allocate and initialise socket. */
+ sk = sk_alloc(net, PF_HF, GFP_KERNEL, &hf_sock_proto, kern);
+ if (!sk)
+ return -ENOMEM;
+
+ sock_init_data(sock, sk);
+
+ sk->sk_destruct = hf_sock_destruct;
+ sock->ops = &ops;
+ sock->state = SS_UNCONNECTED;
+
+ return 0;
+}
+
+/**
+ * Frees all resources, including threads, associated with the Hafnium driver.
+ */
+static void hf_free_resources(void)
+{
+ uint16_t i;
+ spci_vcpu_index_t j;
+
+ /*
+ * First stop all worker threads. We need to do this before freeing
+ * resources because workers may reference each other, so it is only
+ * safe to free resources after they have all stopped.
+ */
+ for (i = 0; i < hf_vm_count; i++) {
+ struct hf_vm *vm = &hf_vms[i];
+
+ for (j = 0; j < vm->vcpu_count; j++)
+ kthread_stop(vm->vcpu[j].task);
+ }
+
+ /* Free resources. */
+ for (i = 0; i < hf_vm_count; i++) {
+ struct hf_vm *vm = &hf_vms[i];
+
+ for (j = 0; j < vm->vcpu_count; j++)
+ put_task_struct(vm->vcpu[j].task);
+ kfree(vm->vcpu);
+ }
+
+ kfree(hf_vms);
+}
+
+/**
+ * Handles the hypervisor timer interrupt.
+ */
+static irqreturn_t hf_nop_irq_handler(int irq, void *dev)
+{
+ /*
+ * No need to do anything, the interrupt only exists to return to the
+ * primary vCPU so that the virtual timer will be restored and fire as
+ * normal.
+ */
+ return IRQ_HANDLED;
+}
+
+/**
+ * Enables the hypervisor timer interrupt on a CPU, when it starts or after the
+ * driver is first loaded.
+ */
+static int hf_starting_cpu(unsigned int cpu)
+{
+ if (hf_irq != 0) {
+ /* Enable the interrupt, and set it to be edge-triggered. */
+ enable_percpu_irq(hf_irq, IRQ_TYPE_EDGE_RISING);
+ }
+
+ return 0;
+}
+
+/**
+ * Disables the hypervisor timer interrupt on a CPU when it is powered down.
+ */
+static int hf_dying_cpu(unsigned int cpu)
+{
+ if (hf_irq != 0) {
+ /* Disable the interrupt while the CPU is asleep. */
+ disable_percpu_irq(hf_irq);
+ }
+
+ return 0;
+}
+
+/**
+ * Registers for the hypervisor timer interrupt.
+ */
+static int hf_int_driver_probe(struct platform_device *pdev)
+{
+ int irq;
+ int ret;
+
+ /*
+ * Register a handler for the hyperviser timer IRQ, as it is needed for
+ * Hafnium to emulate the virtual timer for Linux while a secondary vCPU
+ * is running.
+ */
+ irq = platform_get_irq(pdev, ARCH_TIMER_HYP_PPI);
+ if (irq < 0) {
+ pr_err("Error getting hypervisor timer IRQ: %d\n", irq);
+ return irq;
+ }
+ hf_irq = irq;
+
+ ret = request_percpu_irq(irq, hf_nop_irq_handler, HYPERVISOR_TIMER_NAME,
+ pdev);
+ if (ret != 0) {
+ pr_err("Error registering hypervisor timer IRQ %d: %d\n",
+ irq, ret);
+ return ret;
+ }
+ pr_info("Hafnium registered for IRQ %d\n", irq);
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "hafnium/hypervisor_timer:starting",
+ hf_starting_cpu, hf_dying_cpu);
+ if (ret < 0) {
+ pr_err("Error enabling timer on all CPUs: %d\n", ret);
+ free_percpu_irq(irq, pdev);
+ return ret;
+ }
+ hf_cpuhp_state = ret;
+
+ return 0;
+}
+
+/**
+ * Unregisters for the hypervisor timer interrupt.
+ */
+static int hf_int_driver_remove(struct platform_device *pdev)
+{
+ /*
+ * This will cause hf_dying_cpu to be called on each CPU, which will
+ * disable the IRQs.
+ */
+ cpuhp_remove_state(hf_cpuhp_state);
+ free_percpu_irq(hf_irq, pdev);
+
+ return 0;
+}
+
+static const struct of_device_id hf_int_driver_id[] = {
+ {.compatible = "arm,armv7-timer"},
+ {.compatible = "arm,armv8-timer"},
+ {}
+};
+
+static struct platform_driver hf_int_driver = {
+ .driver = {
+ .name = HYPERVISOR_TIMER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(hf_int_driver_id),
+ },
+ .probe = hf_int_driver_probe,
+ .remove = hf_int_driver_remove,
+};
+
+/**
+ * Initializes the Hafnium driver by creating a thread for each vCPU of each
+ * virtual machine.
+ */
+static int __init hf_init(void)
+{
+ static const struct net_proto_family proto_family = {
+ .family = PF_HF,
+ .create = hf_sock_create,
+ .owner = THIS_MODULE,
+ };
+ int64_t ret;
+ struct spci_value spci_ret;
+ spci_vm_id_t i;
+ spci_vcpu_index_t j;
+ spci_vm_count_t secondary_vm_count;
+ uint32_t total_vcpu_count;
+
+ /* Allocate a page for send and receive buffers. */
+ hf_send_page = alloc_page(GFP_KERNEL);
+ if (!hf_send_page) {
+ pr_err("Unable to allocate send buffer\n");
+ return -ENOMEM;
+ }
+
+ hf_recv_page = alloc_page(GFP_KERNEL);
+ if (!hf_recv_page) {
+ __free_page(hf_send_page);
+ pr_err("Unable to allocate receive buffer\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * Configure both addresses. Once configured, we cannot free these pages
+ * because the hypervisor will use them, even if the module is
+ * unloaded.
+ */
+ spci_ret = spci_rxtx_map(page_to_phys(hf_send_page),
+ page_to_phys(hf_recv_page));
+ if (spci_ret.func != SPCI_SUCCESS_32) {
+ __free_page(hf_send_page);
+ __free_page(hf_recv_page);
+ pr_err("Unable to configure VM\n");
+ if (spci_ret.func == SPCI_ERROR_32)
+ pr_err("SPCI error code %d\n", spci_ret.arg2);
+ else
+ pr_err("Unexpected SPCI function %#x\n", spci_ret.func);
+ return -EIO;
+ }
+
+ /* Get the number of secondary VMs. */
+ secondary_vm_count = hf_vm_get_count() - 1;
+
+ /* Confirm the maximum number of VMs looks sane. */
+ BUILD_BUG_ON(CONFIG_HAFNIUM_MAX_VMS < 1);
+ BUILD_BUG_ON(CONFIG_HAFNIUM_MAX_VMS > U16_MAX);
+
+ /* Validate the number of VMs. There must at least be the primary. */
+ if (secondary_vm_count > CONFIG_HAFNIUM_MAX_VMS - 1) {
+ pr_err("Number of VMs is out of range: %d\n",
+ secondary_vm_count);
+ return -EDQUOT;
+ }
+
+ /* Only track the secondary VMs. */
+ hf_vms = kmalloc_array(secondary_vm_count, sizeof(struct hf_vm),
+ GFP_KERNEL);
+ if (!hf_vms)
+ return -ENOMEM;
+
+ /* Cache the VM id for later usage. */
+ current_vm_id = hf_vm_get_id();
+
+ /* Initialize each VM. */
+ total_vcpu_count = 0;
+ for (i = 0; i < secondary_vm_count; i++) {
+ struct hf_vm *vm = &hf_vms[i];
+ spci_vcpu_count_t vcpu_count;
+
+ /* Adjust the ID as only the secondaries are tracked. */
+ vm->id = i + FIRST_SECONDARY_VM_ID;
+
+ vcpu_count = hf_vcpu_get_count(vm->id);
+ if (vcpu_count < 0) {
+ pr_err("HF_VCPU_GET_COUNT failed for vm=%u: %d",
+ vm->id, vcpu_count);
+ ret = -EIO;
+ goto fail_with_cleanup;
+ }
+
+ /* Avoid overflowing the vcpu count. */
+ if (vcpu_count > (U32_MAX - total_vcpu_count)) {
+ pr_err("Too many vcpus: %u\n", total_vcpu_count);
+ ret = -EDQUOT;
+ goto fail_with_cleanup;
+ }
+
+ /* Confirm the maximum number of VCPUs looks sane. */
+ BUILD_BUG_ON(CONFIG_HAFNIUM_MAX_VCPUS < 1);
+ BUILD_BUG_ON(CONFIG_HAFNIUM_MAX_VCPUS > U16_MAX);
+
+ /* Enforce the limit on vcpus. */
+ total_vcpu_count += vcpu_count;
+ if (total_vcpu_count > CONFIG_HAFNIUM_MAX_VCPUS) {
+ pr_err("Too many vcpus: %u\n", total_vcpu_count);
+ ret = -EDQUOT;
+ goto fail_with_cleanup;
+ }
+
+ vm->vcpu_count = vcpu_count;
+ vm->vcpu = kmalloc_array(vm->vcpu_count, sizeof(struct hf_vcpu),
+ GFP_KERNEL);
+ if (!vm->vcpu) {
+ ret = -ENOMEM;
+ goto fail_with_cleanup;
+ }
+
+ /* Update the number of initialized VMs. */
+ hf_vm_count = i + 1;
+
+ /* Create a kernel thread for each vcpu. */
+ for (j = 0; j < vm->vcpu_count; j++) {
+ struct hf_vcpu *vcpu = &vm->vcpu[j];
+
+ vcpu->task =
+ kthread_create(hf_vcpu_thread, vcpu,
+ "vcpu_thread_%u_%u", vm->id, j);
+ if (IS_ERR(vcpu->task)) {
+ pr_err("Error creating task (vm=%u,vcpu=%u): %ld\n",
+ vm->id, j, PTR_ERR(vcpu->task));
+ vm->vcpu_count = j;
+ ret = PTR_ERR(vcpu->task);
+ goto fail_with_cleanup;
+ }
+
+ get_task_struct(vcpu->task);
+ vcpu->vm = vm;
+ vcpu->vcpu_index = j;
+ atomic_set(&vcpu->abort_sleep, 0);
+ atomic_set(&vcpu->waiting_for_message, 0);
+ }
+ }
+
+ /* Register protocol and socket family. */
+ ret = proto_register(&hf_sock_proto, 0);
+ if (ret) {
+ pr_err("Unable to register protocol: %lld\n", ret);
+ goto fail_with_cleanup;
+ }
+
+ ret = sock_register(&proto_family);
+ if (ret) {
+ pr_err("Unable to register Hafnium's socket family: %lld\n",
+ ret);
+ goto fail_unregister_proto;
+ }
+
+ /*
+ * Register as a driver for the timer device, so we can register a
+ * handler for the hyperviser timer IRQ.
+ */
+ ret = platform_driver_register(&hf_int_driver);
+ if (ret != 0) {
+ pr_err("Error registering timer driver %lld\n", ret);
+ goto fail_unregister_socket;
+ }
+
+ /*
+ * Start running threads now that all is initialized.
+ *
+ * Any failures from this point on must also unregister the driver with
+ * platform_driver_unregister().
+ */
+ for (i = 0; i < hf_vm_count; i++) {
+ struct hf_vm *vm = &hf_vms[i];
+
+ for (j = 0; j < vm->vcpu_count; j++)
+ wake_up_process(vm->vcpu[j].task);
+ }
+
+ /* Dump vm/vcpu count info. */
+ pr_info("Hafnium successfully loaded with %u VMs:\n", hf_vm_count);
+ for (i = 0; i < hf_vm_count; i++) {
+ struct hf_vm *vm = &hf_vms[i];
+
+ pr_info("\tVM %u: %u vCPUS\n", vm->id, vm->vcpu_count);
+ }
+
+ return 0;
+
+fail_unregister_socket:
+ sock_unregister(PF_HF);
+fail_unregister_proto:
+ proto_unregister(&hf_sock_proto);
+fail_with_cleanup:
+ hf_free_resources();
+ return ret;
+}
+
+/**
+ * Frees up all resources used by the Hafnium driver in preparation for
+ * unloading it.
+ */
+static void __exit hf_exit(void)
+{
+ pr_info("Preparing to unload Hafnium\n");
+ sock_unregister(PF_HF);
+ proto_unregister(&hf_sock_proto);
+ hf_free_resources();
+ platform_driver_unregister(&hf_int_driver);
+ pr_info("Hafnium ready to unload\n");
+}
+
+MODULE_LICENSE("GPL v2");
+
+module_init(hf_init);
+module_exit(hf_exit);
