[PATCH v4 3/9] virt: geniezone: Add vcpu support

[Yi-De Wu]

From: "Yingshiuan Pan" <yingshiuan.pan@xxxxxxxxxxxx>

VMM use this interface to create vcpu instance which is a fd, and this
fd will be for any vcpu operations, such as setting vcpu registers and
accepts the most important ioctl GZVM_VCPU_RUN which requests GenieZone
hypervisor to do context switch to execute VM's vcpu context.

Signed-off-by: Yingshiuan Pan <yingshiuan.pan@xxxxxxxxxxxx>
Signed-off-by: Jerry Wang <ze-yu.wang@xxxxxxxxxxxx>
Signed-off-by: Liju Chen <liju-clr.chen@xxxxxxxxxxxx>
Signed-off-by: Yi-De Wu <yi-de.wu@xxxxxxxxxxxx>
---
 arch/arm64/geniezone/Makefile           |   2 +-
 arch/arm64/geniezone/gzvm_arch_common.h |  19 ++
 arch/arm64/geniezone/vcpu.c             |  84 +++++++++
 arch/arm64/include/uapi/asm/gzvm_arch.h |  29 +++
 drivers/virt/geniezone/Makefile         |   3 +-
 drivers/virt/geniezone/gzvm_vcpu.c      | 234 ++++++++++++++++++++++++
 drivers/virt/geniezone/gzvm_vm.c        |   5 +
 include/linux/gzvm_drv.h                |  19 ++
 include/uapi/linux/gzvm.h               | 101 ++++++++++
 9 files changed, 494 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/geniezone/vcpu.c
 create mode 100644 drivers/virt/geniezone/gzvm_vcpu.c

diff --git a/arch/arm64/geniezone/Makefile b/arch/arm64/geniezone/Makefile
index 2957898cdd05..69b0a4abeab0 100644
--- a/arch/arm64/geniezone/Makefile
+++ b/arch/arm64/geniezone/Makefile
@@ -4,6 +4,6 @@
 #
 include $(srctree)/drivers/virt/geniezone/Makefile
 
-gzvm-y += vm.o
+gzvm-y += vm.o vcpu.o
 
 obj-$(CONFIG_MTK_GZVM) += gzvm.o
diff --git a/arch/arm64/geniezone/gzvm_arch_common.h b/arch/arm64/geniezone/gzvm_arch_common.h
index 797989468c88..1b315264bf24 100644
--- a/arch/arm64/geniezone/gzvm_arch_common.h
+++ b/arch/arm64/geniezone/gzvm_arch_common.h
@@ -67,4 +67,23 @@ static inline gzvm_id_t get_vmid_from_tuple(unsigned int tuple)
 	return (gzvm_id_t)(tuple >> 16);
 }
 
+static inline gzvm_vcpu_id_t get_vcpuid_from_tuple(unsigned int tuple)
+{
+	return (gzvm_vcpu_id_t)(tuple & 0xffff);
+}
+
+static inline unsigned int
+assemble_vm_vcpu_tuple(gzvm_id_t vmid, gzvm_vcpu_id_t vcpuid)
+{
+	return ((unsigned int)vmid << 16 | vcpuid);
+}
+
+static inline void
+disassemble_vm_vcpu_tuple(unsigned int tuple, gzvm_id_t *vmid,
+			  gzvm_vcpu_id_t *vcpuid)
+{
+	*vmid = get_vmid_from_tuple(tuple);
+	*vcpuid = get_vcpuid_from_tuple(tuple);
+}
+
 #endif /* __GZVM_ARCH_COMMON_H__ */
diff --git a/arch/arm64/geniezone/vcpu.c b/arch/arm64/geniezone/vcpu.c
new file mode 100644
index 000000000000..8d2572bdf053
--- /dev/null
+++ b/arch/arm64/geniezone/vcpu.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 MediaTek Inc.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/err.h>
+#include <linux/uaccess.h>
+
+#include <linux/gzvm.h>
+#include <linux/gzvm_drv.h>
+#include "gzvm_arch_common.h"
+
+int gzvm_arch_vcpu_update_one_reg(struct gzvm_vcpu *vcpu, __u64 reg_id,
+				  bool is_write, __u64 *data)
+{
+	struct arm_smccc_res res;
+	unsigned long a1;
+	int ret;
+
+	/* reg id follows KVM's encoding */
+	switch (reg_id & GZVM_REG_ARM_COPROC_MASK) {
+	case GZVM_REG_ARM_CORE:
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	a1 = assemble_vm_vcpu_tuple(vcpu->gzvm->vm_id, vcpu->vcpuid);
+	if (!is_write) {
+		ret = gzvm_hypcall_wrapper(MT_HVC_GZVM_GET_ONE_REG,
+					   a1, reg_id, 0, 0, 0, 0, 0, &res);
+		if (ret == 0)
+			*data = res.a1;
+	} else {
+		ret = gzvm_hypcall_wrapper(MT_HVC_GZVM_SET_ONE_REG,
+					   a1, reg_id, *data, 0, 0, 0, 0, &res);
+	}
+
+	return ret;
+}
+
+int gzvm_arch_vcpu_run(struct gzvm_vcpu *vcpu, __u64 *exit_reason)
+{
+	struct arm_smccc_res res;
+	unsigned long a1;
+	int ret;
+
+	a1 = assemble_vm_vcpu_tuple(vcpu->gzvm->vm_id, vcpu->vcpuid);
+	ret = gzvm_hypcall_wrapper(MT_HVC_GZVM_RUN, a1, 0, 0, 0, 0, 0,
+				   0, &res);
+	*exit_reason = res.a1;
+	return ret;
+}
+
+int gzvm_arch_destroy_vcpu(gzvm_id_t vm_id, int vcpuid)
+{
+	struct arm_smccc_res res;
+	unsigned long a1;
+
+	a1 = assemble_vm_vcpu_tuple(vm_id, vcpuid);
+	gzvm_hypcall_wrapper(MT_HVC_GZVM_DESTROY_VCPU, a1, 0, 0, 0, 0, 0, 0,
+			     &res);
+
+	return 0;
+}
+
+/**
+ * gzvm_arch_create_vcpu() - Call smc to gz hypervisor to create vcpu
+ * @run: Virtual address of vcpu->run
+ */
+int gzvm_arch_create_vcpu(gzvm_id_t vm_id, int vcpuid, void *run)
+{
+	struct arm_smccc_res res;
+	unsigned long a1, a2;
+	int ret;
+
+	a1 = assemble_vm_vcpu_tuple(vm_id, vcpuid);
+	a2 = (__u64)virt_to_phys(run);
+	ret = gzvm_hypcall_wrapper(MT_HVC_GZVM_CREATE_VCPU, a1, a2, 0, 0, 0, 0,
+				   0, &res);
+
+	return ret;
+}
diff --git a/arch/arm64/include/uapi/asm/gzvm_arch.h b/arch/arm64/include/uapi/asm/gzvm_arch.h
index 847bb627a65d..e45e8e9e1bea 100644
--- a/arch/arm64/include/uapi/asm/gzvm_arch.h
+++ b/arch/arm64/include/uapi/asm/gzvm_arch.h
@@ -17,4 +17,33 @@
 /* GZVM_CAP_ARM_PVM_SET_PROTECTED_VM only sets protected but not load pvmfw */
 #define GZVM_CAP_ARM_PVM_SET_PROTECTED_VM	2
 
+/**
+ * Architecture specific registers are to be defined in arch headers and
+ * ORed with the arch identifier.
+ */
+#define GZVM_REG_ARM		0x4000000000000000ULL
+#define GZVM_REG_ARM64		0x6000000000000000ULL
+
+#define GZVM_REG_SIZE_SHIFT	52
+#define GZVM_REG_SIZE_MASK	0x00f0000000000000ULL
+#define GZVM_REG_SIZE_U8	0x0000000000000000ULL
+#define GZVM_REG_SIZE_U16	0x0010000000000000ULL
+#define GZVM_REG_SIZE_U32	0x0020000000000000ULL
+#define GZVM_REG_SIZE_U64	0x0030000000000000ULL
+#define GZVM_REG_SIZE_U128	0x0040000000000000ULL
+#define GZVM_REG_SIZE_U256	0x0050000000000000ULL
+#define GZVM_REG_SIZE_U512	0x0060000000000000ULL
+#define GZVM_REG_SIZE_U1024	0x0070000000000000ULL
+#define GZVM_REG_SIZE_U2048	0x0080000000000000ULL
+
+#define GZVM_REG_ARCH_MASK	0xff00000000000000ULL
+
+/* If you need to interpret the index values, here is the key: */
+#define GZVM_REG_ARM_COPROC_MASK	0x000000000FFF0000
+#define GZVM_REG_ARM_COPROC_SHIFT	16
+
+/* Normal registers are mapped as coprocessor 16. */
+#define GZVM_REG_ARM_CORE		(0x0010 << GZVM_REG_ARM_COPROC_SHIFT)
+#define GZVM_REG_ARM_CORE_REG(name)	(offsetof(struct gzvm_regs, name) / sizeof(__u32))
+
 #endif /* __GZVM_ARCH_H__ */
diff --git a/drivers/virt/geniezone/Makefile b/drivers/virt/geniezone/Makefile
index 066efddc0b9c..8ebf2db0c970 100644
--- a/drivers/virt/geniezone/Makefile
+++ b/drivers/virt/geniezone/Makefile
@@ -6,5 +6,6 @@
 
 GZVM_DIR ?= ../../../drivers/virt/geniezone
 
-gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_vm.o
+gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_vm.o \
+	  $(GZVM_DIR)/gzvm_vcpu.o
 
diff --git a/drivers/virt/geniezone/gzvm_vcpu.c b/drivers/virt/geniezone/gzvm_vcpu.c
new file mode 100644
index 000000000000..5e9d34fcc1ea
--- /dev/null
+++ b/drivers/virt/geniezone/gzvm_vcpu.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 MediaTek Inc.
+ */
+
+#include <asm/sysreg.h>
+#include <linux/anon_inodes.h>
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/gzvm_drv.h>
+
+/* maximum size needed for holding an integer */
+#define ITOA_MAX_LEN 12
+
+static long gzvm_vcpu_update_one_reg(struct gzvm_vcpu *vcpu, void * __user argp,
+				     bool is_write)
+{
+	struct gzvm_one_reg reg;
+	void __user *reg_addr;
+	u64 data = 0;
+	u64 reg_size;
+	long ret;
+
+	if (copy_from_user(&reg, argp, sizeof(reg)))
+		return -EFAULT;
+
+	reg_addr = (void __user *)reg.addr;
+	reg_size = (reg.id & GZVM_REG_SIZE_MASK) >> GZVM_REG_SIZE_SHIFT;
+	reg_size = BIT(reg_size);
+
+	if (is_write) {
+		if (copy_from_user(&data, reg_addr, reg_size))
+			return -EFAULT;
+	}
+
+	ret = gzvm_arch_vcpu_update_one_reg(vcpu, reg.id, is_write, &data);
+
+	if (ret)
+		return ret;
+
+	if (!is_write) {
+		if (copy_to_user(reg_addr, &data, reg_size))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+/**
+ * gzvm_vcpu_run() - Handle vcpu run ioctl, entry point to guest and exit
+ *		     point from guest
+ * @argp: Pointer to struct gzvm_vcpu_run in userspace
+ */
+static long gzvm_vcpu_run(struct gzvm_vcpu *vcpu, void * __user argp)
+{
+	bool need_userspace = false;
+	u64 exit_reason;
+
+	if (copy_from_user(vcpu->run, argp, sizeof(struct gzvm_vcpu_run)))
+		return -EFAULT;
+
+	if (vcpu->run->immediate_exit == 1)
+		return -EINTR;
+
+	while (!need_userspace && !signal_pending(current)) {
+		gzvm_arch_vcpu_run(vcpu, &exit_reason);
+
+		switch (exit_reason) {
+		case GZVM_EXIT_MMIO:
+			need_userspace = true;
+			break;
+		/**
+		 * it's geniezone's responsibility to fill corresponding data
+		 * structure
+		 */
+		case GZVM_EXIT_HYPERCALL:
+			fallthrough;
+		case GZVM_EXIT_EXCEPTION:
+			fallthrough;
+		case GZVM_EXIT_DEBUG:
+			fallthrough;
+		case GZVM_EXIT_FAIL_ENTRY:
+			fallthrough;
+		case GZVM_EXIT_INTERNAL_ERROR:
+			fallthrough;
+		case GZVM_EXIT_SYSTEM_EVENT:
+			fallthrough;
+		case GZVM_EXIT_SHUTDOWN:
+			need_userspace = true;
+			break;
+		case GZVM_EXIT_IRQ:
+			break;
+		case GZVM_EXIT_UNKNOWN:
+			fallthrough;
+		default:
+			dev_err(gzvm_debug_dev->this_device, "vcpu unknown exit\n");
+			need_userspace = true;
+			goto out;
+		}
+	}
+
+out:
+	if (copy_to_user(argp, vcpu->run, sizeof(struct gzvm_vcpu_run)))
+		return -EFAULT;
+	if (signal_pending(current))
+		return -ERESTARTSYS;
+	return 0;
+}
+
+static long gzvm_vcpu_ioctl(struct file *filp, unsigned int ioctl,
+			    unsigned long arg)
+{
+	int ret = -ENOTTY;
+	void __user *argp = (void __user *)arg;
+	struct gzvm_vcpu *vcpu = filp->private_data;
+
+	switch (ioctl) {
+	case GZVM_RUN:
+		ret = gzvm_vcpu_run(vcpu, argp);
+		break;
+	case GZVM_GET_ONE_REG:
+		/* is_write */
+		ret = gzvm_vcpu_update_one_reg(vcpu, argp, false);
+		break;
+	case GZVM_SET_ONE_REG:
+		/* is_write */
+		ret = gzvm_vcpu_update_one_reg(vcpu, argp, true);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static const struct file_operations gzvm_vcpu_fops = {
+	.unlocked_ioctl = gzvm_vcpu_ioctl,
+	.llseek		= noop_llseek,
+};
+
+/* caller must hold the vm lock */
+static void gzvm_destroy_vcpu(struct gzvm_vcpu *vcpu)
+{
+	if (!vcpu)
+		return;
+
+	gzvm_arch_destroy_vcpu(vcpu->gzvm->vm_id, vcpu->vcpuid);
+	/* clean guest's data */
+	memset(vcpu->run, 0, GZVM_VCPU_RUN_MAP_SIZE);
+	free_pages_exact(vcpu->run, GZVM_VCPU_RUN_MAP_SIZE);
+	kfree(vcpu);
+}
+
+/**
+ * gzvm_destroy_vcpus() - Destroy all vcpus, caller has to hold the vm lock
+ *
+ * @gzvm: vm struct that owns the vcpus
+ */
+void gzvm_destroy_vcpus(struct gzvm *gzvm)
+{
+	int i;
+
+	for (i = 0; i < GZVM_MAX_VCPUS; i++) {
+		gzvm_destroy_vcpu(gzvm->vcpus[i]);
+		gzvm->vcpus[i] = NULL;
+	}
+}
+
+/* create_vcpu_fd() - Allocates an inode for the vcpu. */
+static int create_vcpu_fd(struct gzvm_vcpu *vcpu)
+{
+	/* sizeof("gzvm-vcpu:") + max(strlen(itoa(vcpuid))) + null */
+	char name[10 + ITOA_MAX_LEN + 1];
+
+	snprintf(name, sizeof(name), "gzvm-vcpu:%d", vcpu->vcpuid);
+	return anon_inode_getfd(name, &gzvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
+}
+
+/**
+ * gzvm_vm_ioctl_create_vcpu()
+ *
+ * @cpuid: equals arg
+ *
+ * Return: Fd of vcpu, negative errno if error occurs
+ */
+int gzvm_vm_ioctl_create_vcpu(struct gzvm *gzvm, u32 cpuid)
+{
+	struct gzvm_vcpu *vcpu;
+	int ret;
+
+	if (cpuid >= GZVM_MAX_VCPUS)
+		return -EINVAL;
+
+	vcpu = kzalloc(sizeof(*vcpu), GFP_KERNEL);
+	if (!vcpu)
+		return -ENOMEM;
+
+	/**
+	 * Allocate 2 pages for data sharing between driver and gz hypervisor
+	 *
+	 * |- page 0           -|- page 1      -|
+	 * |gzvm_vcpu_run|......|hwstate|.......|
+	 *
+	 */
+	vcpu->run = alloc_pages_exact(GZVM_VCPU_RUN_MAP_SIZE,
+				      GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!vcpu->run) {
+		ret = -ENOMEM;
+		goto free_vcpu;
+	}
+	vcpu->vcpuid = cpuid;
+	vcpu->gzvm = gzvm;
+	mutex_init(&vcpu->lock);
+
+	ret = gzvm_arch_create_vcpu(gzvm->vm_id, vcpu->vcpuid, vcpu->run);
+	if (ret < 0)
+		goto free_vcpu_run;
+
+	ret = create_vcpu_fd(vcpu);
+	if (ret < 0)
+		goto free_vcpu_run;
+	gzvm->vcpus[cpuid] = vcpu;
+
+	return ret;
+
+free_vcpu_run:
+	free_pages_exact(vcpu->run, GZVM_VCPU_RUN_MAP_SIZE);
+free_vcpu:
+	kfree(vcpu);
+	return ret;
+}
diff --git a/drivers/virt/geniezone/gzvm_vm.c b/drivers/virt/geniezone/gzvm_vm.c
index 34a1f024f8e5..f777c3bdb5ac 100644
--- a/drivers/virt/geniezone/gzvm_vm.c
+++ b/drivers/virt/geniezone/gzvm_vm.c
@@ -270,6 +270,10 @@ static long gzvm_vm_ioctl(struct file *filp, unsigned int ioctl,
 		ret = gzvm_dev_ioctl_check_extension(gzvm, arg);
 		break;
 	}
+	case GZVM_CREATE_VCPU: {
+		ret = gzvm_vm_ioctl_create_vcpu(gzvm, arg);
+		break;
+	}
 	case GZVM_SET_USER_MEMORY_REGION: {
 		struct gzvm_userspace_memory_region userspace_mem;
 
@@ -304,6 +308,7 @@ static void gzvm_destroy_vm(struct gzvm *gzvm)
 
 	mutex_lock(&gzvm->lock);
 
+	gzvm_destroy_vcpus(gzvm);
 	gzvm_arch_destroy_vm(gzvm->vm_id);
 
 	mutex_lock(&gzvm_list_lock);
diff --git a/include/linux/gzvm_drv.h b/include/linux/gzvm_drv.h
index c6bbfd9894c1..7768bd35113a 100644
--- a/include/linux/gzvm_drv.h
+++ b/include/linux/gzvm_drv.h
@@ -34,6 +34,8 @@
 #define GZVM_MAX_VCPUS		 8
 #define GZVM_MAX_MEM_REGION	10
 
+#define GZVM_VCPU_RUN_MAP_SIZE		(PAGE_SIZE * 2)
+
 /* struct mem_region_addr_range - Identical to ffa memory constituent */
 struct mem_region_addr_range {
 	/* the base IPA of the constituent memory region, aligned to 4 kiB */
@@ -61,7 +63,16 @@ struct gzvm_memslot {
 	u32 slot_id;
 };
 
+struct gzvm_vcpu {
+	struct gzvm *gzvm;
+	int vcpuid;
+	/* lock of vcpu*/
+	struct mutex lock;
+	struct gzvm_vcpu_run *run;
+};
+
 struct gzvm {
+	struct gzvm_vcpu *vcpus[GZVM_MAX_VCPUS];
 	/* userspace tied to this vm */
 	struct mm_struct *mm;
 	struct gzvm_memslot memslot[GZVM_MAX_MEM_REGION];
@@ -78,6 +89,8 @@ int gz_err_to_errno(unsigned long err);
 
 void destroy_all_vm(void);
 
+void gzvm_destroy_vcpus(struct gzvm *gzvm);
+
 /* arch-dependant functions */
 int gzvm_arch_probe(void);
 int gzvm_arch_set_memregion(gzvm_id_t vm_id, size_t buf_size,
@@ -89,6 +102,12 @@ int gzvm_vm_ioctl_arch_enable_cap(struct gzvm *gzvm,
 				  struct gzvm_enable_cap *cap,
 				  void __user *argp);
 u64 hva_to_pa_arch(u64 hva);
+int gzvm_vm_ioctl_create_vcpu(struct gzvm *gzvm, u32 cpuid);
+int gzvm_arch_vcpu_update_one_reg(struct gzvm_vcpu *vcpu, __u64 reg_id,
+				  bool is_write, __u64 *data);
+int gzvm_arch_create_vcpu(gzvm_id_t vm_id, int vcpuid, void *run);
+int gzvm_arch_vcpu_run(struct gzvm_vcpu *vcpu, __u64 *exit_reason);
+int gzvm_arch_destroy_vcpu(gzvm_id_t vm_id, int vcpuid);
 
 extern struct miscdevice *gzvm_debug_dev;
 
diff --git a/include/uapi/linux/gzvm.h b/include/uapi/linux/gzvm.h
index 1f06d950043d..38b3f20114ab 100644
--- a/include/uapi/linux/gzvm.h
+++ b/include/uapi/linux/gzvm.h
@@ -41,6 +41,11 @@ struct gzvm_memory_region {
 
 #define GZVM_SET_MEMORY_REGION     _IOW(GZVM_IOC_MAGIC,  0x40, \
 					struct gzvm_memory_region)
+/**
+ * GZVM_CREATE_VCPU receives as a parameter the vcpu slot,
+ * and returns a vcpu fd.
+ */
+#define GZVM_CREATE_VCPU           _IO(GZVM_IOC_MAGIC,   0x41)
 
 /* for GZVM_SET_USER_MEMORY_REGION */
 struct gzvm_userspace_memory_region {
@@ -56,6 +61,89 @@ struct gzvm_userspace_memory_region {
 #define GZVM_SET_USER_MEMORY_REGION _IOW(GZVM_IOC_MAGIC, 0x46, \
 					 struct gzvm_userspace_memory_region)
 
+/**
+ * ioctls for vcpu fds
+ */
+#define GZVM_RUN                   _IO(GZVM_IOC_MAGIC,   0x80)
+
+/* VM exit reason */
+enum {
+	GZVM_EXIT_UNKNOWN = 0x92920000,
+	GZVM_EXIT_MMIO,
+	GZVM_EXIT_HYPERCALL,
+	GZVM_EXIT_IRQ,
+	GZVM_EXIT_EXCEPTION,
+	GZVM_EXIT_DEBUG,
+	GZVM_EXIT_FAIL_ENTRY,
+	GZVM_EXIT_INTERNAL_ERROR,
+	GZVM_EXIT_SYSTEM_EVENT,
+	GZVM_EXIT_SHUTDOWN,
+};
+
+/**
+ * struct gzvm_cpu_run: Same purpose as kvm_run, this struct is
+ *			shared between userspace, kernel and
+ *			GenieZone hypervisor
+ *
+ * Keep identical layout between the 3 modules
+ */
+struct gzvm_vcpu_run {
+	/* to userspace */
+	__u32 exit_reason;
+	__u8 immediate_exit;
+	__u8 padding1[3];
+	/* union structure of collection of guest exit reason */
+	union {
+		/* GZVM_EXIT_MMIO */
+		struct {
+			/* from FAR_EL2 */
+			__u64 phys_addr;
+			__u8 data[8];
+			/* from ESR_EL2 as */
+			__u64 size;
+			/* from ESR_EL2 */
+			__u32 reg_nr;
+			/* from ESR_EL2 */
+			__u8 is_write;
+		} mmio;
+		/* GZVM_EXIT_FAIL_ENTRY */
+		struct {
+			__u64 hardware_entry_failure_reason;
+			__u32 cpu;
+		} fail_entry;
+		/* GZVM_EXIT_EXCEPTION */
+		struct {
+			__u32 exception;
+			__u32 error_code;
+		} exception;
+		/* GZVM_EXIT_HYPERCALL */
+		struct {
+			__u64 args[8];	/* in-out */
+		} hypercall;
+		/* GZVM_EXIT_INTERNAL_ERROR */
+		struct {
+			__u32 suberror;
+			__u32 ndata;
+			__u64 data[16];
+		} internal;
+		/* GZVM_EXIT_SYSTEM_EVENT */
+		struct {
+#define GZVM_SYSTEM_EVENT_SHUTDOWN       1
+#define GZVM_SYSTEM_EVENT_RESET          2
+#define GZVM_SYSTEM_EVENT_CRASH          3
+#define GZVM_SYSTEM_EVENT_WAKEUP         4
+#define GZVM_SYSTEM_EVENT_SUSPEND        5
+#define GZVM_SYSTEM_EVENT_SEV_TERM       6
+#define GZVM_SYSTEM_EVENT_S2IDLE         7
+			__u32 type;
+			__u32 ndata;
+			__u64 data[16];
+		} system_event;
+		/* Fix the size of the union. */
+		char padding[256];
+	};
+};
+
 /* for GZVM_ENABLE_CAP */
 struct gzvm_enable_cap {
 	/* in */
@@ -70,4 +158,17 @@ struct gzvm_enable_cap {
 #define GZVM_ENABLE_CAP            _IOW(GZVM_IOC_MAGIC,  0xa3, \
 					struct gzvm_enable_cap)
 
+/* for GZVM_GET/SET_ONE_REG */
+struct gzvm_one_reg {
+	__u64 id;
+	__u64 addr;
+};
+
+#define GZVM_GET_ONE_REG	   _IOW(GZVM_IOC_MAGIC,  0xab, \
+					struct gzvm_one_reg)
+#define GZVM_SET_ONE_REG	   _IOW(GZVM_IOC_MAGIC,  0xac, \
+					struct gzvm_one_reg)
+
+#define GZVM_REG_GENERIC	   0x0000000000000000ULL
+
 #endif /* __GZVM_H__ */
-- 
2.18.0