[libvirt] [PATCH] qemu: Forbid "sgio" support for SCSI generic host device

[Jiri Denemark]

On Fri, Mar 07, 2014 at 22:23:26 +0800, Osier Yang wrote:
> The kernel didn't support the unprivileged SGIO for SCSI generic
> device finally, and since it's unknow whether the way to support
> unprivileged SGIO for SCSI generic device will be similar as for
> SCSI block device or not, even it's simliar (I.e. via sysfs, for
> SCSI block device, it's /sys/dev/block/8\:0/queue/unpriv_sgio,
> for example), the file name might be different, So it's better not
> guess what it should be like currently.
> 
> This patch removes the related code (mainly about the "shareable"
> checking on the "sgio" setting, it's not supported at all, why
> we leave checking code there? :-), and error out if "sgio" is
> specified in the domain config.
> ---
>  src/qemu/qemu_conf.c | 87 ++++++++++++----------------------------------------
>  1 file changed, 20 insertions(+), 67 deletions(-)
> 
> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
> index 2c397b0..ad6348d 100644
> --- a/src/qemu/qemu_conf.c
> +++ b/src/qemu/qemu_conf.c
...
> @@ -1135,22 +1102,15 @@ qemuSetUnprivSGIO(virDomainDeviceDefPtr dev)
>      } else if (dev->type == VIR_DOMAIN_DEVICE_HOSTDEV) {
>          hostdev = dev->data.hostdev;
>  
> -        if (!hostdev->shareable ||
> -            !(hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
> -              hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI))
> -            return 0;

In the follow-up patch, you recovered just the

    hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI

part. Shouldn't the other checks in this condition remain?

> -
> -        if (!(hostdev_name = virSCSIDeviceGetDevName(NULL,
> -                                                     hostdev->source.subsys.u.scsi.adapter,
> -                                                     hostdev->source.subsys.u.scsi.bus,
> -                                                     hostdev->source.subsys.u.scsi.target,
> -                                                     hostdev->source.subsys.u.scsi.unit)))
> -            goto cleanup;
> -
> -        if (virAsprintf(&hostdev_path, "/dev/%s", hostdev_name) < 0)
> +        if (hostdev->source.subsys.u.scsi.sgio) {

In other words, should this be something like

    if (hostdev->shareable &&
        hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
        hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI &&
        hostdev->source.subsys.u.scsi.sgio) {

> +            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                           _("'sgio' is not supported for SCSI "
> +                             "generic device yet "));
> +            ret = -1;
>              goto cleanup;
> +        }
>  
> -        path = hostdev_path;
> +        return 0;
>      } else {
>          return 0;
>      }

Jirka