Re: [PATCH v3 1/1] virt: acrn: Mark the uuid field as unused

[Rafael J. Wysocki]

On Wed, Aug 31, 2022 at 2:23 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> After the commits for userspace (see Link tags below) the uuid field is
> not being used in the ACRN code. Update kernel to reflect these changes.
> I.e. we do the following:
> - adding a comment explaining that it's not used anymore
> - replacing the specific type by a raw buffer
> - updating the example code accordingly
>
> The advertised field confused users and actually never been used. So
> the wrong part here is that kernel puts something which userspace never
> used and hence this may confuse a reader of this code.
>
> Link: https://github.com/projectacrn/acrn-hypervisor/commit/da0d24326ed6
> Link: https://github.com/projectacrn/acrn-hypervisor/commit/bb0327e70097
> Fixes: 5b06931d7f8b ("sample/acrn: Introduce a sample of HSM ioctl interface usage")
> Fixes: 9c5137aedd11 ("virt: acrn: Introduce VM management interfaces")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

Looks good to me:

Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>

Thanks!

> ---
> v3: converted to Link tags (Rafael), explained what was wrong (Rafael)
> v2: added tag (Fei)
>  include/uapi/linux/acrn.h | 5 ++---
>  samples/acrn/vm-sample.c  | 3 ---
>  2 files changed, 2 insertions(+), 6 deletions(-)
>
> diff --git a/include/uapi/linux/acrn.h b/include/uapi/linux/acrn.h
> index ccf47ed92500..04fa83647ae5 100644
> --- a/include/uapi/linux/acrn.h
> +++ b/include/uapi/linux/acrn.h
> @@ -12,7 +12,6 @@
>  #define _UAPI_ACRN_H
>
>  #include <linux/types.h>
> -#include <linux/uuid.h>
>
>  #define ACRN_IO_REQUEST_MAX            16
>
> @@ -186,7 +185,7 @@ struct acrn_ioreq_notify {
>   * @reserved0:         Reserved and must be 0
>   * @vcpu_num:          Number of vCPU in the VM. Return from hypervisor.
>   * @reserved1:         Reserved and must be 0
> - * @uuid:              UUID of the VM. Pass to hypervisor directly.
> + * @uuid:              Reserved (used to be UUID of the VM)
>   * @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.
> @@ -198,7 +197,7 @@ struct acrn_vm_creation {
>         __u16   reserved0;
>         __u16   vcpu_num;
>         __u16   reserved1;
> -       guid_t  uuid;
> +       __u8    uuid[16];
>         __u64   vm_flag;
>         __u64   ioreq_buf;
>         __u64   cpu_affinity;
> diff --git a/samples/acrn/vm-sample.c b/samples/acrn/vm-sample.c
> index b2dad47a77a0..7abd68b20153 100644
> --- a/samples/acrn/vm-sample.c
> +++ b/samples/acrn/vm-sample.c
> @@ -29,8 +29,6 @@ static struct acrn_io_request *io_req_buf = (struct acrn_io_request *)io_request
>
>  __u16 vcpu_num;
>  __u16 vmid;
> -/* POST_STANDARD_VM_UUID1, refer to https://github.com/projectacrn/acrn-hypervisor/blob/master/hypervisor/include/common/vm_uuids.h */
> -guid_t vm_uuid = GUID_INIT(0x385479d2, 0xd625, 0xe811, 0x86, 0x4e, 0xcb, 0x7a, 0x18, 0xb3, 0x46, 0x43);
>
>  int hsm_fd;
>  int is_running = 1;
> @@ -63,7 +61,6 @@ int main(int argc, char **argv)
>         }
>         hsm_fd = open("/dev/acrn_hsm", O_RDWR|O_CLOEXEC);
>
> -       memcpy(&create_vm.uuid, &vm_uuid, 16);
>         create_vm.ioreq_buf = (__u64)io_req_buf;
>         ret = ioctl(hsm_fd, ACRN_IOCTL_CREATE_VM, &create_vm);
>         printf("Created VM! [%d]\n", ret);
> --
> 2.35.1
>