Re: [Xen-devel] [PATCH v5 0/6] xen/PMU: PMU support for Xen PV(H) guests

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 08/07/2015 11:50 AM, Julien Grall wrote:
> Hi,
>
> On 07/08/15 16:35, David Vrabel wrote:
>> On 02/07/15 15:53, Boris Ostrovsky wrote:
>>> I haven't posted Linux part of PV(H) VPMU support in a while but now
>>> that (hopefully) the hypervisor part is getting close to be done I
>>> think it's time to post it again.
>>>
>>> There are very few differences compared to the last version, mostly due
>>> to updates in shared structures layouts. Patches 1 and 4 have no changes
>>> at all and patch 5 has minor changes due to rebasing so I kept David's
>>> Reviewed-by tag.
>> This breaks the arm and arm64 builds.
>>
>> In file included from
>> /local/davidvr/work/k.org/tip/drivers/xen/sys-hypervisor.c:23:0:
>> /local/davidvr/work/k.org/tip/include/xen/interface/xenpmu.h:91:22:
>> error: field ‘pmu’ has incomplete type
>>    struct xen_pmu_arch pmu;
>>                        ^
>> /local/davidvr/work/k.org/tip/drivers/xen/sys-hypervisor.c: In function
>> ‘pmu_mode_store’:
>> /local/davidvr/work/k.org/tip/drivers/xen/sys-hypervisor.c:403:2: error:
>> implicit declaration of function ‘HYPERVISOR_xenpmu_op’
>> [-Werror=implicit-function-declaration]
>>    ret = HYPERVISOR_xenpmu_op(XENPMU_mode_set, &xp);
>>    ^
> There is no PMU support for the moment on ARM and this hypercall is only
> used for x86. I would introduce a new CONFIG (CONFIG_XEN_PMMU) which is
> enabled for x86 and disabled for ARM.

CONFIG_XEN_VPMU, but yes.


>
>> cc1: some warnings being treated as errors
>> /local/davidvr/work/k.org/tip/scripts/Makefile.build:258: recipe for
>> target 'drivers/xen/sys-hypervisor.o' failed
>> make[3]: *** [drivers/xen/sys-hypervisor.o] Error 1
>> make[3]: *** Waiting for unfinished jobs....
>> /local/davidvr/work/k.org/tip/drivers/xen/xenfs/xensyms.c: In function
>> ‘xensyms_next_sym’:
>> /local/davidvr/work/k.org/tip/drivers/xen/xenfs/xensyms.c:34:2: error:
>> implicit declaration of function ‘HYPERVISOR_dom0_op’
>> [-Werror=implicit-function-declaration]
>>    ret = HYPERVISOR_dom0_op(&xs->op);
>>    ^
> DOM0 op doesn't exists for ARM and xensyms is not even plumbed. I would
> make sure that XEN_SYMS is not enabled for ARM maybe adding the line
> below in the kconfig?
>
> depends on X86 && XEN_DOM0 && XENFS

Yes. Sorry for breakage. I usually build the hypervisor for ARM but 
clearly didn't do this for Linux.

-boris