[libvirt] [PATCH] qemu: support bootindex on vfio-ccw mdev device

[Peter Krempa]

On Fri, Aug 02, 2019 at 15:15:59 +0200, Boris Fiuczynski wrote:
> Add support to specify a boot order on vfio-ccw passthrough devices.
> 
> Signed-off-by: Boris Fiuczynski <fiuczy at linux.ibm.com>
> Acked-by: Jason J. Herne <jjherne at linux.ibm.com>
> Reviewed-by: Marc Hartmayer <mhartmay at linux.ibm.com>
> ---
>  src/qemu/qemu_command.c                       | 27 +++++++++++++----
>  .../hostdev-subsys-mdev-vfio-ccw-boot.args    | 29 +++++++++++++++++++
>  .../hostdev-subsys-mdev-vfio-ccw-boot.xml     | 23 +++++++++++++++
>  tests/qemuxml2argvtest.c                      |  4 +++
>  4 files changed, 78 insertions(+), 5 deletions(-)
>  create mode 100644 tests/qemuxml2argvdata/hostdev-subsys-mdev-vfio-ccw-boot.args
>  create mode 100644 tests/qemuxml2argvdata/hostdev-subsys-mdev-vfio-ccw-boot.xml

Note that I don't currently have enough information to verify that the
mdev claim is correct (e.g. why it's only with CCW devices?), but I have
two formal comments:

> 
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index fee51158a9..36138e2ccf 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -5613,6 +5613,9 @@ qemuBuildHostdevMediatedDevStr(const virDomainDef *def,
>      if (qemuBuildDeviceAddressStr(&buf, def, dev->info, qemuCaps) < 0)
>          goto cleanup;
>  
> +    if (dev->info->bootIndex)
> +        virBufferAsprintf(&buf, ",bootindex=%u", dev->info->bootIndex);
> +
>      if (virBufferCheckError(&buf) < 0)
>          goto cleanup;
>  
> @@ -5624,6 +5627,22 @@ qemuBuildHostdevMediatedDevStr(const virDomainDef *def,
>      return ret;
>  }
>  
> +static bool
> +qemuHostdevSupportsBoot(virDomainHostdevDefPtr hostdev)

Refactor to this function should be separate from the logic change
below.

> +{
> +    if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS) {
> +        virDomainHostdevSubsysPtr subsys = &hostdev->source.subsys;
> +        if (subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI ||
> +            subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB ||
> +            subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI ||
> +            (subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV &&
> +            subsys->u.mdev.model == VIR_MDEV_MODEL_TYPE_VFIO_CCW)) {

This line is misaligned. Please make sure that it's clear that the above
line belongs to the term in the brackets.


> +            return true;
> +        }
> +    }
> +    return false;
> +}
> +
>  static int
>  qemuBuildHostdevCommandLine(virCommandPtr cmd,
>                              const virDomainDef *def,
> @@ -5638,13 +5657,11 @@ qemuBuildHostdevCommandLine(virCommandPtr cmd,
>          char *devstr;
>  
>          if (hostdev->info->bootIndex) {
> -            if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
> -                (subsys->type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
> -                 subsys->type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB &&
> -                 subsys->type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI)) {
> +            if (!qemuHostdevSupportsBoot(hostdev)) {
>                  virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>                                 _("booting from assigned devices is only "
> -                                 "supported for PCI, USB and SCSI devices"));
> +                                 "supported for PCI, USB, SCSI and MDEV "
> +                                 "of model vfio-ccw devices"));

Ideally this validation will be done in the validation callback rather
than in the command line generator. (pre-existing so I don't require you
to refactor this at this time).

Also this error can be probably stashed into qemuHostdevSupportsBoot.
(and name it like qemuHostdevValidateBoot).
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20190802/7d6ebd2b/attachment-0001.sig>