[libvirt] [PATCH v3 1/4] qemu: add qemu vga devices caps and one cap to mark them usable

[Eric Blake]

On 12/13/2012 02:06 AM, Guannan Ren wrote:
> QEMU_CAPS_DEVICE_QXL          -device qxl
> QEMU_CAPS_DEVICE_VGA          -device VGA
> QEMU_CAPS_DEVICE_CIRRUS_VGA   -device cirrus-vga
> QEMU_CAPS_DEVICE_VMWARE_SVGA  -device vmware-svga
> 
> QEMU_CAPS_1DOT20_PLUS        /* safe to use -device XXX
>                                  for primary video device */

NACK to this name; see my complaints on the cover letter.  We'll need a
v4 that picks a name more appropriate to the actual feature being
tested, rather than a name that merely reflects our current
implementation of why we decided the feature is available.

Hmm, maybe I misunderstood what the actual feature is when I suggested
QEMU_CAPS_SECONDARY_DISPLAY; based on the comment you used here, maybe a
better name is QEMU_CAPS_PRIMARY_DISPLAY_DEVICE.

> +
> +              "VGA", /* 120 */
> +              "cirrus-vga",
> +              "vmware-svga",
> +              "qemu1.20+"

Again, this XML name does not reflect the feature; we need something nicer.

>      );
>  
>  struct _qemuCaps {
> @@ -1177,6 +1183,9 @@ qemuCapsComputeCmdFlags(const char *help,
>  
>      if (version >= 11000)
>          qemuCapsSet(caps, QEMU_CAPS_CPU_HOST);
> +
> +    if (version >= 1002000)
> +        qemuCapsSet(caps, QEMU_CAPS_1DOT20_PLUS);
>      return 0;

And here, what I envision if Red Hat decides to backport this feature
into their qemu 0.12.1.x monster, the Red Hat specific backport patch
would look like:

+
+    if (version >= 1002000)
+        qemuCapsSet(caps, QEMU_CAPS_PRIMARY_DISPLAY_DEVICE);
+#if BACKPORT_ONLY
+    else if (version is 12001 but feature is backported)
+        qemuCapsSet(caps, QEMU_CAPS_PRIMARY_DISPLAY_DEVICE);
+#endif

Remember, RHEL 6.x qemu will NOT be version 1.2 or later, it will stay
at version 0.12.1 + lots of backports.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 619 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20121213/55fa6833/attachment-0001.sig>