[libvirt] [PATCH] qemu: Don't use -enable-nesting with qemu 1.2.0+

[Cole Robinson]

On 10/20/2012 03:49 PM, Eric Blake wrote:
> On 10/20/2012 01:28 PM, Cole Robinson wrote:
>> Since the option doesn't exist. Fixes booting with
>> cpu mode='host-model' and qemu 1.2.0
>> ---
>>  src/qemu/qemu_capabilities.c | 1 -
>>  1 file changed, 1 deletion(-)
>>
>> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
>> index c9a4ab7..d691d51 100644
>> --- a/src/qemu/qemu_capabilities.c
>> +++ b/src/qemu/qemu_capabilities.c
>> @@ -2162,7 +2162,6 @@ qemuCapsInitQMPBasic(qemuCapsPtr caps)
>>      qemuCapsSet(caps, QEMU_CAPS_NODEFCONFIG);
>>      qemuCapsSet(caps, QEMU_CAPS_BOOT_MENU);
>>      qemuCapsSet(caps, QEMU_CAPS_FSDEV);
>> -    qemuCapsSet(caps, QEMU_CAPS_NESTING);
> 
> This passed 'make check', so I'm half-inclined to give ACK.  But what
> hardware were you testing on?  Was it one that allows nested virt?

Nowadays any virt CPU should support nested virt AFAIK.

  None
> of my ready-access machines allow nested virt, so I'm having a hard time
> reproducing the scenario, and I wonder if this is a case where older
> qemu was conditionally exposing the -help output based on what hardware
> it was running on, and where your patch now causes a regression on
> hardware that allows nesting.  If so, then we still need some way to set
> the bit when appropriate - did qemu give us a counterpart QMP query-*
> command that we can use to determine when nested virt is supported by
> qemu, if we can't blindly assume it is always supported in 1.2.0+?
> 

In qemu-kvm.git

commit 02885019915d7df85b0e8200aa305dfbe2942443
Author: Jan Kiszka <jan.kiszka at siemens.com>
Date:   Mon Jun 27 20:19:46 2011 +0200

    qemu-kvm: Drop -enable-nesting command line switch

    As in upstream, this feature can be controlled via -cpu ...,+/-svm.


So the command line switch doesn't actually exist in qemu-1.2.0+ which is what
qemuCapsInitQMPBasic is supposed to representing.

- Cole