virt: acrn: Introduce VM management interfaces

The VM management interfaces expose several VM operations to ACRN
userspace via ioctls. For example, creating VM, starting VM, destroying
VM and so on.

The ACRN Hypervisor needs to exchange data with the ACRN userspace
during the VM operations. HSM provides VM operation ioctls to the ACRN
userspace and communicates with the ACRN Hypervisor for VM operations
via hypercalls.

HSM maintains a list of User VM. Each User VM will be bound to an
existing file descriptor of /dev/acrn_hsm. The User VM will be
destroyed when the file descriptor is closed.

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: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-7-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/userspace-api/ioctl/ioctl-number.rst

@@ -320,6 +320,7 @@ Code  Seq#    Include File                                           Comments
 0xA0  all    linux/sdp/sdp.h                                         Industrial Device Project
                                                                      <mailto:kenji@bitgate.com>
 0xA1  0      linux/vtpm_proxy.h                                      TPM Emulator Proxy Driver
+0xA2  all    uapi/linux/acrn.h                                       ACRN hypervisor
 0xA3  80-8F                                                          Port ACL  in development:
                                                                      <mailto:tlewis@mindspring.com>
 0xA3  90-9F  linux/dtlk.h

MAINTAINERS

@@ -443,6 +443,7 @@ S:	Supported
 W:	https://projectacrn.org
 F:	Documentation/virt/acrn/
 F:	drivers/virt/acrn/
+F:	include/uapi/linux/acrn.h
 
 AD1889 ALSA SOUND DRIVER
 L:	linux-parisc@vger.kernel.org

drivers/virt/acrn/Makefile

@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_ACRN_HSM)	:= acrn.o
-acrn-y := hsm.o
+acrn-y := hsm.o vm.o

drivers/virt/acrn/acrn_drv.h

@@ -3,16 +3,35 @@
 #ifndef __ACRN_HSM_DRV_H
 #define __ACRN_HSM_DRV_H
 
+#include <linux/acrn.h>
+#include <linux/dev_printk.h>
+#include <linux/miscdevice.h>
 #include <linux/types.h>
 
+#include "hypercall.h"
+
+extern struct miscdevice acrn_dev;
+
 #define ACRN_INVALID_VMID (0xffffU)
 
+#define ACRN_VM_FLAG_DESTROYED		0U
 /**
  * struct acrn_vm - Properties of ACRN User VM.
+ * @list:	Entry within global list of all VMs
  * @vmid:	User VM ID
+ * @vcpu_num:	Number of virtual CPUs in the VM
+ * @flags:	Flags (ACRN_VM_FLAG_*) of the VM. This is VM flag management
+ *		in HSM which is different from the &acrn_vm_creation.vm_flag.
  */
 struct acrn_vm {
-	u16	vmid;
+	struct list_head	list;
+	u16			vmid;
+	int			vcpu_num;
+	unsigned long		flags;
 };
 
+struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
+			       struct acrn_vm_creation *vm_param);
+int acrn_vm_destroy(struct acrn_vm *vm);
+
 #endif /* __ACRN_HSM_DRV_H */

drivers/virt/acrn/hsm.c

@@ -9,7 +9,6 @@
  *	Yakui Zhao <yakui.zhao@intel.com>
  */
 
-#include <linux/miscdevice.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -38,10 +37,82 @@ static int acrn_dev_open(struct inode *inode, struct file *filp)
 	return 0;
 }
 
+/*
+ * HSM relies on hypercall layer of the ACRN hypervisor to do the
+ * sanity check against the input parameters.
+ */
+static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
+			   unsigned long ioctl_param)
+{
+	struct acrn_vm *vm = filp->private_data;
+	struct acrn_vm_creation *vm_param;
+	int ret = 0;
+
+	if (vm->vmid == ACRN_INVALID_VMID && cmd != ACRN_IOCTL_CREATE_VM) {
+		dev_dbg(acrn_dev.this_device,
+			"ioctl 0x%x: Invalid VM state!\n", cmd);
+		return -EINVAL;
+	}
+
+	switch (cmd) {
+	case ACRN_IOCTL_CREATE_VM:
+		vm_param = memdup_user((void __user *)ioctl_param,
+				       sizeof(struct acrn_vm_creation));
+		if (IS_ERR(vm_param))
+			return PTR_ERR(vm_param);
+
+		if ((vm_param->reserved0 | vm_param->reserved1) != 0)
+			return -EINVAL;
+
+		vm = acrn_vm_create(vm, vm_param);
+		if (!vm) {
+			ret = -EINVAL;
+			kfree(vm_param);
+			break;
+		}
+
+		if (copy_to_user((void __user *)ioctl_param, vm_param,
+				 sizeof(struct acrn_vm_creation))) {
+			acrn_vm_destroy(vm);
+			ret = -EFAULT;
+		}
+
+		kfree(vm_param);
+		break;
+	case ACRN_IOCTL_START_VM:
+		ret = hcall_start_vm(vm->vmid);
+		if (ret < 0)
+			dev_dbg(acrn_dev.this_device,
+				"Failed to start VM %u!\n", vm->vmid);
+		break;
+	case ACRN_IOCTL_PAUSE_VM:
+		ret = hcall_pause_vm(vm->vmid);
+		if (ret < 0)
+			dev_dbg(acrn_dev.this_device,
+				"Failed to pause VM %u!\n", vm->vmid);
+		break;
+	case ACRN_IOCTL_RESET_VM:
+		ret = hcall_reset_vm(vm->vmid);
+		if (ret < 0)
+			dev_dbg(acrn_dev.this_device,
+				"Failed to restart VM %u!\n", vm->vmid);
+		break;
+	case ACRN_IOCTL_DESTROY_VM:
+		ret = acrn_vm_destroy(vm);
+		break;
+	default:
+		dev_dbg(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);
+		ret = -ENOTTY;
+	}
+
+	return ret;
+}
+
 static int acrn_dev_release(struct inode *inode, struct file *filp)
 {
 	struct acrn_vm *vm = filp->private_data;
 
+	acrn_vm_destroy(vm);
 	kfree(vm);
 	return 0;
 }
@@ -50,9 +121,10 @@ static const struct file_operations acrn_fops = {
 	.owner		= THIS_MODULE,
 	.open		= acrn_dev_open,
 	.release	= acrn_dev_release,
+	.unlocked_ioctl = acrn_dev_ioctl,
 };
 
-static struct miscdevice acrn_dev = {
+struct miscdevice acrn_dev = {
 	.minor	= MISC_DYNAMIC_MINOR,
 	.name	= "acrn_hsm",
 	.fops	= &acrn_fops,

drivers/virt/acrn/hypercall.h

@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ACRN HSM: hypercalls of ACRN Hypervisor
+ */
+#ifndef __ACRN_HSM_HYPERCALL_H
+#define __ACRN_HSM_HYPERCALL_H
+#include <asm/acrn.h>
+
+/*
+ * Hypercall IDs of the ACRN Hypervisor
+ */
+#define _HC_ID(x, y) (((x) << 24) | (y))
+
+#define HC_ID 0x80UL
+
+#define HC_ID_VM_BASE			0x10UL
+#define HC_CREATE_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x00)
+#define HC_DESTROY_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x01)
+#define HC_START_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x02)
+#define HC_PAUSE_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x03)
+#define HC_RESET_VM			_HC_ID(HC_ID, HC_ID_VM_BASE + 0x05)
+
+/**
+ * hcall_create_vm() - Create a User VM
+ * @vminfo:	Service VM GPA of info of User VM creation
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_create_vm(u64 vminfo)
+{
+	return acrn_hypercall1(HC_CREATE_VM, vminfo);
+}
+
+/**
+ * hcall_start_vm() - Start a User VM
+ * @vmid:	User VM ID
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_start_vm(u64 vmid)
+{
+	return acrn_hypercall1(HC_START_VM, vmid);
+}
+
+/**
+ * hcall_pause_vm() - Pause a User VM
+ * @vmid:	User VM ID
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_pause_vm(u64 vmid)
+{
+	return acrn_hypercall1(HC_PAUSE_VM, vmid);
+}
+
+/**
+ * hcall_destroy_vm() - Destroy a User VM
+ * @vmid:	User VM ID
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_destroy_vm(u64 vmid)
+{
+	return acrn_hypercall1(HC_DESTROY_VM, vmid);
+}
+
+/**
+ * hcall_reset_vm() - Reset a User VM
+ * @vmid:	User VM ID
+ *
+ * Return: 0 on success, <0 on failure
+ */
+static inline long hcall_reset_vm(u64 vmid)
+{
+	return acrn_hypercall1(HC_RESET_VM, vmid);
+}
+
+#endif /* __ACRN_HSM_HYPERCALL_H */

drivers/virt/acrn/vm.c

@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACRN_HSM: Virtual Machine management
+ *
+ * Copyright (C) 2020 Intel Corporation. All rights reserved.
+ *
+ * Authors:
+ *	Jason Chen CJ <jason.cj.chen@intel.com>
+ *	Yakui Zhao <yakui.zhao@intel.com>
+ */
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include "acrn_drv.h"
+
+/* List of VMs */
+static LIST_HEAD(acrn_vm_list);
+/* To protect acrn_vm_list */
+static DEFINE_MUTEX(acrn_vm_list_lock);
+
+struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
+			       struct acrn_vm_creation *vm_param)
+{
+	int ret;
+
+	ret = hcall_create_vm(virt_to_phys(vm_param));
+	if (ret < 0 || vm_param->vmid == ACRN_INVALID_VMID) {
+		dev_err(acrn_dev.this_device,
+			"Failed to create VM! Error: %d\n", ret);
+		return NULL;
+	}
+
+	vm->vmid = vm_param->vmid;
+	vm->vcpu_num = vm_param->vcpu_num;
+
+	mutex_lock(&acrn_vm_list_lock);
+	list_add(&vm->list, &acrn_vm_list);
+	mutex_unlock(&acrn_vm_list_lock);
+
+	dev_dbg(acrn_dev.this_device, "VM %u created.\n", vm->vmid);
+	return vm;
+}
+
+int acrn_vm_destroy(struct acrn_vm *vm)
+{
+	int ret;
+
+	if (vm->vmid == ACRN_INVALID_VMID ||
+	    test_and_set_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags))
+		return 0;
+
+	/* Remove from global VM list */
+	mutex_lock(&acrn_vm_list_lock);
+	list_del_init(&vm->list);
+	mutex_unlock(&acrn_vm_list_lock);
+
+	ret = hcall_destroy_vm(vm->vmid);
+	if (ret < 0) {
+		dev_err(acrn_dev.this_device,
+			"Failed to destroy VM %u\n", vm->vmid);
+		clear_bit(ACRN_VM_FLAG_DESTROYED, &vm->flags);
+		return ret;
+	}
+	dev_dbg(acrn_dev.this_device, "VM %u destroyed.\n", vm->vmid);
+	vm->vmid = ACRN_INVALID_VMID;
+	return 0;
+}

include/uapi/linux/acrn.h

@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Userspace interface for /dev/acrn_hsm - ACRN Hypervisor Service Module
+ *
+ * This file can be used by applications that need to communicate with the HSM
+ * via the ioctl interface.
+ *
+ * Copyright (C) 2021 Intel Corporation. All rights reserved.
+ */
+
+#ifndef _UAPI_ACRN_H
+#define _UAPI_ACRN_H
+
+#include <linux/types.h>
+#include <linux/uuid.h>
+
+/**
+ * struct acrn_vm_creation - Info to create a User VM
+ * @vmid:		User VM ID returned from the hypervisor
+ * @reserved0:		Reserved and must be 0
+ * @vcpu_num:		Number of vCPU in the VM. Return from hypervisor.
+ * @reserved1:		Reserved and must be 0
+ * @uuid:		UUID of the VM. Pass to hypervisor directly.
+ * @vm_flag:		Flag of the VM creating. Pass to hypervisor directly.
+ * @ioreq_buf:		Service VM GPA of I/O request buffer. Pass to
+ *			hypervisor directly.
+ * @cpu_affinity:	CPU affinity of the VM. Pass to hypervisor directly.
+ * 			It's a bitmap which indicates CPUs used by the VM.
+ */
+struct acrn_vm_creation {
+	__u16	vmid;
+	__u16	reserved0;
+	__u16	vcpu_num;
+	__u16	reserved1;
+	guid_t	uuid;
+	__u64	vm_flag;
+	__u64	ioreq_buf;
+	__u64	cpu_affinity;
+};
+
+/* The ioctl type, documented in ioctl-number.rst */
+#define ACRN_IOCTL_TYPE			0xA2
+
+/*
+ * Common IOCTL IDs definition for ACRN userspace
+ */
+#define ACRN_IOCTL_CREATE_VM		\
+	_IOWR(ACRN_IOCTL_TYPE, 0x10, struct acrn_vm_creation)
+#define ACRN_IOCTL_DESTROY_VM		\
+	_IO(ACRN_IOCTL_TYPE, 0x11)
+#define ACRN_IOCTL_START_VM		\
+	_IO(ACRN_IOCTL_TYPE, 0x12)
+#define ACRN_IOCTL_PAUSE_VM		\
+	_IO(ACRN_IOCTL_TYPE, 0x13)
+#define ACRN_IOCTL_RESET_VM		\
+	_IO(ACRN_IOCTL_TYPE, 0x15)
+
+#endif /* _UAPI_ACRN_H */