virt: acrn: Introduce ACRN HSM basic driver

ACRN Hypervisor Service Module (HSM) is a kernel module in Service VM
which communicates with ACRN userspace through ioctls and talks to ACRN
Hypervisor through hypercalls.

Add a basic HSM driver which allows Service VM userspace to communicate
with ACRN. The following patches will add more ioctls, guest VM memory
mapping caching, I/O request processing, ioeventfd and irqfd into this
module. HSM exports a char device interface (/dev/acrn_hsm) to userspace.

Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Yu Wang <yu1.wang@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-6-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/MAINTAINERS b/MAINTAINERS
index 6a3d112..4ac781d 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -442,6 +442,7 @@ L:  acrn-dev@lists.projectacrn.org
 S:     Supported
 W:     https://projectacrn.org
 F:     Documentation/virt/acrn/
+F:     drivers/virt/acrn/
 
 AD1889 ALSA SOUND DRIVER
 L:     linux-parisc@vger.kernel.org

diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig
index 80c5f9c..8061e8e 100644 (file)
--- a/drivers/virt/Kconfig
+++ b/drivers/virt/Kconfig
@@ -34,4 +34,6 @@ config FSL_HV_MANAGER
 source "drivers/virt/vboxguest/Kconfig"
 
 source "drivers/virt/nitro_enclaves/Kconfig"
+
+source "drivers/virt/acrn/Kconfig"
 endif

diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile
index f28425c..3e272ea 100644 (file)
--- a/drivers/virt/Makefile
+++ b/drivers/virt/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_FSL_HV_MANAGER)    += fsl_hypervisor.o
 obj-y                          += vboxguest/
 
 obj-$(CONFIG_NITRO_ENCLAVES)   += nitro_enclaves/
+obj-$(CONFIG_ACRN_HSM)         += acrn/

diff --git a/drivers/virt/acrn/Kconfig b/drivers/virt/acrn/Kconfig
new file mode 100644 (file)
index 0000000..36c8037
--- /dev/null
+++ b/drivers/virt/acrn/Kconfig
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+config ACRN_HSM
+       tristate "ACRN Hypervisor Service Module"
+       depends on ACRN_GUEST
+       help
+         ACRN Hypervisor Service Module (HSM) is a kernel module which
+         communicates with ACRN userspace through ioctls and talks to
+         the ACRN Hypervisor through hypercalls. HSM will only run in
+         a privileged management VM, called Service VM, to manage User
+         VMs and do I/O emulation. Not required for simply running
+         under ACRN as a User VM.
+
+         To compile as a module, choose M, the module will be called
+         acrn. If unsure, say N.

diff --git a/drivers/virt/acrn/Makefile b/drivers/virt/acrn/Makefile
new file mode 100644 (file)
index 0000000..6920ed7
--- /dev/null
+++ b/drivers/virt/acrn/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_ACRN_HSM) := acrn.o
+acrn-y := hsm.o

diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h
new file mode 100644 (file)
index 0000000..29eedd6
--- /dev/null
+++ b/drivers/virt/acrn/acrn_drv.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ACRN_HSM_DRV_H
+#define __ACRN_HSM_DRV_H
+
+#include <linux/types.h>
+
+#define ACRN_INVALID_VMID (0xffffU)
+
+/**
+ * struct acrn_vm - Properties of ACRN User VM.
+ * @vmid:      User VM ID
+ */
+struct acrn_vm {
+       u16     vmid;
+};
+
+#endif /* __ACRN_HSM_DRV_H */

diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
new file mode 100644 (file)
index 0000000..a8dcb25
--- /dev/null
+++ b/drivers/virt/acrn/hsm.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACRN Hypervisor Service Module (HSM)
+ *
+ * Copyright (C) 2020 Intel Corporation. All rights reserved.
+ *
+ * Authors:
+ *     Fengwei Yin <fengwei.yin@intel.com>
+ *     Yakui Zhao <yakui.zhao@intel.com>
+ */
+
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <asm/acrn.h>
+#include <asm/hypervisor.h>
+
+#include "acrn_drv.h"
+
+/*
+ * When /dev/acrn_hsm is opened, a 'struct acrn_vm' object is created to
+ * represent a VM instance and continues to be associated with the opened file
+ * descriptor. All ioctl operations on this file descriptor will be targeted to
+ * the VM instance. Release of this file descriptor will destroy the object.
+ */
+static int acrn_dev_open(struct inode *inode, struct file *filp)
+{
+       struct acrn_vm *vm;
+
+       vm = kzalloc(sizeof(*vm), GFP_KERNEL);
+       if (!vm)
+               return -ENOMEM;
+
+       vm->vmid = ACRN_INVALID_VMID;
+       filp->private_data = vm;
+       return 0;
+}
+
+static int acrn_dev_release(struct inode *inode, struct file *filp)
+{
+       struct acrn_vm *vm = filp->private_data;
+
+       kfree(vm);
+       return 0;
+}
+
+static const struct file_operations acrn_fops = {
+       .owner          = THIS_MODULE,
+       .open           = acrn_dev_open,
+       .release        = acrn_dev_release,
+};
+
+static struct miscdevice acrn_dev = {
+       .minor  = MISC_DYNAMIC_MINOR,
+       .name   = "acrn_hsm",
+       .fops   = &acrn_fops,
+};
+
+static int __init hsm_init(void)
+{
+       int ret;
+
+       if (x86_hyper_type != X86_HYPER_ACRN)
+               return -ENODEV;
+
+       if (!(cpuid_eax(ACRN_CPUID_FEATURES) & ACRN_FEATURE_PRIVILEGED_VM))
+               return -EPERM;
+
+       ret = misc_register(&acrn_dev);
+       if (ret)
+               pr_err("Create misc dev failed!\n");
+
+       return ret;
+}
+
+static void __exit hsm_exit(void)
+{
+       misc_deregister(&acrn_dev);
+}
+module_init(hsm_init);
+module_exit(hsm_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ACRN Hypervisor Service Module (HSM)");