Re: [PATCH v4 06/17] virt: acrn: Introduce VM management interfaces

Greg Kroah-Hartman
2020-09-27T10:47:44Z

On Tue, Sep 22, 2020 at 07:43:00PM +0800, shuo.a.liu@intel.com wrote:
> From: Shuo Liu <shuo.a.liu@intel.com>
>
> 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@intel.com>
> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
> Reviewed-by: Reinette Chatre <reinette.chatre@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>
> ---
> .../userspace-api/ioctl/ioctl-number.rst | 1 +
> MAINTAINERS | 1 +
> drivers/virt/acrn/Makefile | 2 +-
> drivers/virt/acrn/acrn_drv.h | 23 +++++-
> drivers/virt/acrn/hsm.c | 73 ++++++++++++++++-
> drivers/virt/acrn/hypercall.h | 78 +++++++++++++++++++
> drivers/virt/acrn/vm.c | 71 +++++++++++++++++
> include/uapi/linux/acrn.h | 56 +++++++++++++
> 8 files changed, 301 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 2a198838fca9..ac60efedb104 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@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
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3030d0e93d02..d4c1ef303c2d 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@vger.kernel.org
> 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..72d92b60d944 100644
> --- a/drivers/virt/acrn/acrn_drv.h
> +++ b/drivers/virt/acrn/acrn_drv.h
> @@ -3,16 +3,37 @@
> #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;

Who else needs to get to this structure in your driver?

> +
> #define ACRN_INVALID_VMID (0xffffU)
>
> +#define ACRN_VM_FLAG_DESTROYED 0U
> +extern struct list_head acrn_vm_list;
> +extern rwlock_t acrn_vm_list_lock;
> /**
> * 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 28a3052ffa55..f3e6467b8723 100644
> --- a/drivers/virt/acrn/hsm.c
> +++ b/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 +37,79 @@ 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);
> +
> + 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_err(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_err(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_err(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_warn(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);

Do not let userspace spam kernel logs with invalid stuff, that's a sure
way to cause a DoS.

thanks,

greg k-h