Bug 895959

Description of problem:
Upstream QEMU currently uses machine type names like this on x86:

$ qemu-kvm  -M ?
Supported machines are:
none                 empty machine
pc                   Standard PC (alias of pc-1.2)
pc-1.2               Standard PC (default)
pc-1.1               Standard PC
pc-1.0               Standard PC
pc-0.15              Standard PC
pc-0.14              Standard PC
pc-0.13              Standard PC
pc-0.12              Standard PC
pc-0.11              Standard PC, qemu 0.11
pc-0.10              Standard PC, qemu 0.10
isapc                ISA-only PC


This is basically a machine type prefix plus a version suffix.

With recent patch from Gerd, upstream machine type name prefixes are changing to directly reflect the hardware names:

> Starting with release 1.4 we have a fully functional q35 machine type,
> i.e. "qemu -M q35" JustWorks[tm].  Update machine type names to reflect
> that:
>
>  * pc-1.4 becomes pc-i440fx-1.4
>  * q35-next becomes pc-q35-1.4
>
> The pc-1.3 (+older) names are maintained for compatibility reasons.
> For the same reason the "pc" and "q35" aliases are kept.  pc-piix-1.4
> continues to be the default machine type, again for compatibility
> reasons.
>
> Also updated the description (shown by "qemu -M ?") with host bridge
> name, south bridge name and chipset release year.

RHEL-5/6 meanwhile have historically changed both the machine type prefix and the version string:

# qemu-system-x86_64 -M ?
Supported machines are:
pc         RHEL 6.2.0 PC (alias of rhel6.2.0)
rhel6.2.0  RHEL 6.2.0 PC (default)
rhel6.1.0  RHEL 6.1.0 PC
rhel6.0.0  RHEL 6.0.0 PC
rhel5.5.0  RHEL 5.5.0 PC
rhel5.4.4  RHEL 5.4.4 PC
rhel5.4.0  RHEL 5.4.0 PC

This was always unpleasant, but it becomes much worse when we consider the possibility of having two machine types - piix and q35.

RHEL needs to have custom versions to deal with backports, but there is no reason why it should be changing the base name prefix, nor does it need to change the descriptions.

Thus for RHEL-7 we should adjust our policy so that we only change the version suffix. So come rhel-7.3 we would have ended up with something like:

 # qemu-system-x86_64 -M ?
 Supported machines are:
 pc                   Standard PC (Q35 + ICH9, 2009) (alias of  pc-q35-rhel7.3.0)
 pc-i440fx-rhel7.0.0  Standard PC (i440FX + PIIX, 1996)
 pc-i440fx-rhel7.1.0  Standard PC (i440FX + PIIX, 1996)
 pc-i440fx-rhel7.2.0  Standard PC (i440FX + PIIX, 1996)
 pc-i440fx-rhel7.3.0  Standard PC (i440FX + PIIX, 1996)
 pc-q35-rhel7.0.0     Standard PC (Q35 + ICH9, 2009)
 pc-q35-rhel7.1.0     Standard PC (Q35 + ICH9, 2009)
 pc-q35-rhel7.2.0     Standard PC (Q35 + ICH9, 2009)
 pc-q35-rhel7.3.0     Standard PC (Q35 + ICH9, 2009) (default)

Obviously the existing machine types from RHEL-5/6 will need to keep their names for sake of backwards compatibility.

This will make it mean that RHEL machine types once again clearly show what hardware they are associated with. This is also important to libvirt since it needs to look at the name prefix to figure out the default PCI bus topology. This also reduces divergence from upstream, which is always a good thing

Version-Release number of selected component (if applicable):
1.3.0-3