Messages in this thread | | | Date | Thu, 5 Nov 2020 15:35:45 +0800 | From | Shuo A Liu <> | Subject | Re: [PATCH v5 06/17] virt: acrn: Introduce VM management interfaces |
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On Thu 5.Nov'20 at 7:29:07 +0100, Greg Kroah-Hartman wrote: >On Thu, Nov 05, 2020 at 11:10:29AM +0800, Shuo A Liu wrote: >> 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@intel.com 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. > >That's guaranteed to come back and bite you in the end.
OK. I can fill them with zero before passing them to hypervisor.
>You all have read the "how to write a good api" document, right?
Is it Documentation/driver-api/ioctl.rst? Or i missed..
> >> > 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. > >ioctls should not have these, again, please read the documentation. If >you need something new in the future, just make a new ioctl.
OK. I will remove some reserved fields for scalability. Though i can keep some reserved fields for alignment (and to keep same data structure layout with the hypervisor), right? Documentation/driver-api/ioctl.rst says that explicit reserved fields could be used.
> >> > > + */ >> > > +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. > >I do not understand this, please use the built-in kernel types we have.
OK. I will use that.
Thanks shuo
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