Re: [PATCH v7 06/18] virt: acrn: Introduce VM management interfaces

From: Greg Kroah-Hartman
Date: Fri Jan 08 2021 - 10:31:16 EST


On Wed, Jan 06, 2021 at 03:50:43PM +0800, shuo.a.liu@xxxxxxxxx wrote:
> From: Shuo Liu <shuo.a.liu@xxxxxxxxx>
>
> 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.
>
> Signed-off-by: Shuo Liu <shuo.a.liu@xxxxxxxxx>
> Reviewed-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>
> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Cc: Zhi Wang <zhi.a.wang@xxxxxxxxx>
> Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
> Cc: Yu Wang <yu1.wang@xxxxxxxxx>
> Cc: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> .../userspace-api/ioctl/ioctl-number.rst | 1 +
> MAINTAINERS | 1 +
> drivers/virt/acrn/Makefile | 2 +-
> drivers/virt/acrn/acrn_drv.h | 21 ++++-
> drivers/virt/acrn/hsm.c | 76 +++++++++++++++++-
> drivers/virt/acrn/hypercall.h | 78 +++++++++++++++++++
> drivers/virt/acrn/vm.c | 68 ++++++++++++++++
> include/uapi/linux/acrn.h | 55 +++++++++++++
> 8 files changed, 298 insertions(+), 4 deletions(-)
> create mode 100644 drivers/virt/acrn/hypercall.h
> create mode 100644 drivers/virt/acrn/vm.c
> create mode 100644 include/uapi/linux/acrn.h
>
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index a4c75a28c839..0aec83c01368 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -319,6 +319,7 @@ Code Seq# Include File Comments
> 0xA0 all linux/sdp/sdp.h Industrial Device Project
> <mailto:kenji@xxxxxxxxxxx>
> 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@xxxxxxxxxxxxxx>
> 0xA3 90-9F linux/dtlk.h
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f1c481c829cf..69f3cefed7e5 100644
> --- a/MAINTAINERS
> +++ b/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@xxxxxxxxxxxxxxx
> diff --git a/drivers/virt/acrn/Makefile b/drivers/virt/acrn/Makefile
> index 6920ed798aaf..cf8b4ed5e74e 100644
> --- a/drivers/virt/acrn/Makefile
> +++ b/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
> diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h
> index 29eedd696327..e5aba86cad8c 100644
> --- a/drivers/virt/acrn/acrn_drv.h
> +++ b/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 */
> diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
> index a8dcb250649d..5fd933471683 100644
> --- a/drivers/virt/acrn/hsm.c
> +++ b/drivers/virt/acrn/hsm.c
> @@ -9,7 +9,6 @@
> * Yakui Zhao <yakui.zhao@xxxxxxxxx>
> */
>
> -#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,
> diff --git a/drivers/virt/acrn/hypercall.h b/drivers/virt/acrn/hypercall.h
> new file mode 100644
> index 000000000000..426b66cadb1f
> --- /dev/null
> +++ b/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 */
> diff --git a/drivers/virt/acrn/vm.c b/drivers/virt/acrn/vm.c
> new file mode 100644
> index 000000000000..3f667ac8ac1e
> --- /dev/null
> +++ b/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@xxxxxxxxx>
> + * Yakui Zhao <yakui.zhao@xxxxxxxxx>
> + */
> +#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;
> +}
> diff --git a/include/uapi/linux/acrn.h b/include/uapi/linux/acrn.h
> new file mode 100644
> index 000000000000..e1608b8a50a2
> --- /dev/null
> +++ b/include/uapi/linux/acrn.h
> @@ -0,0 +1,55 @@
> +/* 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.

No copyright notice on this file? Intel is being brave :)


> + */
> +
> +#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

That's good, but you are not checking this. Why not?

> + * @vcpu_num: Number of vCPU in the VM. Return from hypervisor.
> + * @reserved1: Reserved and must be 0

Again, I failed to see a check, so this "must be" is not true.

> + * @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.

What format is this affinity?

> + */
> +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;
> +};

As these values go outside the kernel, you need to specify the endian of
them. You do that for other ioctl structures, but not this one, why?

thanks,

greg k-h