Re: [PATCH v5 06/17] virt: acrn: Introduce VM management interfaces

[Shuo A Liu]

On Wed  4.Nov'20 at 20:02:35 +0100, Greg Kroah-Hartman wrote:
> On Mon, Oct 19, 2020 at 02:17:52PM +0800, shuo.a.liu@xxxxxxxxx wrote:
> > --- /dev/null
> > +++ b/include/uapi/linux/acrn.h
> > @@ -0,0 +1,56 @@
> > +/* 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.
> > + */
> > +
> > +#ifndef _UAPI_ACRN_H
> > +#define _UAPI_ACRN_H
> > +
> > +#include <linux/types.h>
> > +
> > +/**
> > + * struct acrn_vm_creation - Info to create a User VM
> > + * @vmid:		User VM ID returned from the hypervisor
> > + * @reserved0:		Reserved
> > + * @vcpu_num:		Number of vCPU in the VM. Return from hypervisor.
> > + * @reserved1:		Reserved
> > + * @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.
> > + * @reserved2:		Reserved
>
> Reserved and must be 0?  

Not a must.

> What are they reserved for?
>
> Same for all of the reserved fields, why?

Some reserved fields are to map layout in the hypervisor side, others
are for future use.

> > + */
> > +struct acrn_vm_creation {
> > +	__u16	vmid;
> > +	__u16	reserved0;
> > +	__u16	vcpu_num;
> > +	__u16	reserved1;
> > +	__u8	uuid[16];
>
> We have a userspace-visable uid structure in include/uapi/uuid.h, why
> not use that?

we just pass the uuid data from user space to hypervisor. So, we can
remove a header dependeny with using raw data format.

Thanks
shuo