[libvirt] [PATCH 05/10] Convert disk drive over to use -device where available

[Daniel Veillard]

On Tue, Dec 15, 2009 at 03:14:45PM +0000, Daniel P. Berrange wrote:
> The current preferred syntax for disk drives uses
> 
>   -drive file=/vms/plain.qcow,if=virtio,index=0,boot=on,format=qcow
> 
> The new syntax splits this up into a pair of linked args
> 
>   -drive file=/vms/plain.qcow,if=none,id=virtio-0,index=0,format=qcow2
>   -device virtio-blk-pci,drive=virtio-0
> 
> NB, the 'index=0' bit here in the new args is technically wrong.
> This will be fixed when the disk-controller /addressing patches
> merge with this.
> ---
>  src/qemu/qemu_conf.c |   83 ++++++++++++++++++++++++++++++++++++++++++++-----
>  1 files changed, 74 insertions(+), 9 deletions(-)
> 
> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
> index 8c44a93..2480df4 100644
> --- a/src/qemu/qemu_conf.c
> +++ b/src/qemu/qemu_conf.c
> @@ -1373,10 +1373,16 @@ qemuBuildDriveStr(virConnectPtr conn,
>              virBufferVSprintf(&opt, "file=%s,", disk->src);
>          }
>      }
> -    virBufferVSprintf(&opt, "if=%s", bus);
> +    if (qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE) {
> +        virBufferAddLit(&opt, "if=none,");
> +        virBufferVSprintf(&opt, "id=%s-%d", bus, idx);
> +    } else {
> +        virBufferVSprintf(&opt, "if=%s", bus);
> +    }
>      if (disk->device == VIR_DOMAIN_DISK_DEVICE_CDROM)
>          virBufferAddLit(&opt, ",media=cdrom");
> -    virBufferVSprintf(&opt, ",index=%d", idx);
> +    if (!(qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE))
> +        virBufferVSprintf(&opt, ",index=%d", idx);
>      if (bootable &&
>          disk->device == VIR_DOMAIN_DISK_DEVICE_DISK)
>          virBufferAddLit(&opt, ",boot=on");
> @@ -1416,6 +1422,48 @@ error:
>      return -1;
>  }
>  
> +static int
> +qemuBuildDriveDevStr(virConnectPtr conn,
> +                     virDomainDiskDefPtr disk,
> +                     char **str)
> +{
> +    virBuffer opt = VIR_BUFFER_INITIALIZER;
> +    const char *bus = virDomainDiskQEMUBusTypeToString(disk->bus);
> +    int idx = virDiskNameToIndex(disk->dst);
> +
> +    if (idx < 0) {
> +        qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR,
> +                         _("unsupported disk type '%s'"), disk->dst);
> +        goto error;
> +    }
> +
> +    switch (disk->bus) {
> +    case VIR_DOMAIN_DISK_BUS_IDE:
> +        virBufferAddLit(&opt, "ide-drive");
> +        break;
> +    case VIR_DOMAIN_DISK_BUS_SCSI:
> +        virBufferAddLit(&opt, "scsi-disk");
> +        break;
> +    case VIR_DOMAIN_DISK_BUS_VIRTIO:
> +        virBufferAddLit(&opt, "virtio-blk-pci");
> +        break;
> +
> +    default:
> +        qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR,
> +                         _("unsupported disk bus '%s' with device setup"), bus);
> +        goto error;
> +    }
> +    virBufferVSprintf(&opt, ",drive=%s-%d", bus, idx);
> +
> +    *str = virBufferContentAndReset(&opt);
> +    return 0;
> +
> +error:
> +    virBufferFreeAndReset(&opt);
> +    *str = NULL;
> +    return -1;
> +}
> +
>  
>  int
>  qemuBuildNicStr(virConnectPtr conn,
> @@ -2104,6 +2152,7 @@ int qemudBuildCommandLine(virConnectPtr conn,
>              char *optstr;
>              int bootable = 0;
>              virDomainDiskDefPtr disk = def->disks[i];
> +            int withDeviceArg = 0;
>  
>              if (disk->bus == VIR_DOMAIN_DISK_BUS_USB) {
>                  if (disk->device == VIR_DOMAIN_DISK_DEVICE_DISK) {
> @@ -2116,8 +2165,6 @@ int qemudBuildCommandLine(virConnectPtr conn,
>                  continue;
>              }
>  
> -            ADD_ARG_SPACE;
> -
>              switch (disk->device) {
>              case VIR_DOMAIN_DISK_DEVICE_CDROM:
>                  bootable = bootCD;
> @@ -2133,14 +2180,32 @@ int qemudBuildCommandLine(virConnectPtr conn,
>                  break;
>              }
>  
> -            if (qemuBuildDriveStr(conn, disk, bootable, qemuCmdFlags, &optstr) < 0)
> +            /* Unfortunately it is nt possible to use
> +               -device for floppys, or Xen paravirt
> +               devices. Fortunately, those don't need
> +               static PCI addresses, so we don't really
> +               care that we can't use -device */
> +            if ((qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE) &&
> +                (disk->bus != VIR_DOMAIN_DISK_BUS_FDC) &&
> +                (disk->bus != VIR_DOMAIN_DISK_BUS_XEN))
> +                withDeviceArg = 1;
> +
> +            ADD_ARG_LIT("-drive");
> +
> +            if (qemuBuildDriveStr(conn, disk, bootable,
> +                                  (withDeviceArg ? qemuCmdFlags :
> +                                   (qemuCmdFlags & ~QEMUD_CMD_FLAG_DEVICE)),
> +                                  &optstr) < 0)
>                  goto error;
> +            ADD_ARG(optstr);
>  
> -            if ((qargv[qargc++] = strdup("-drive")) == NULL) {
> -                VIR_FREE(optstr);
> -                goto no_memory;
> +            if (withDeviceArg) {
> +                ADD_ARG_LIT("-device");
> +
> +                if (qemuBuildDriveDevStr(conn, disk, &optstr) < 0)
> +                    goto error;
> +                ADD_ARG(optstr);
>              }
> -            ADD_ARG(optstr);
>          }
>      } else {
>          for (i = 0 ; i < def->ndisks ; i++) {

  ACK, the number of different cases get scary

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/