Re: [Xen-devel] [PATCH v12 for-xen-4.5 09/20] x86/VPMU: Add public xenpmu.h

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 29.09.14 at 17:19, <boris.ostrovsky@xxxxxxxxxx> wrote:
> On 09/29/2014 10:30 AM, Jan Beulich wrote:
>>>>> On 29.09.14 at 16:17, <JBeulich@xxxxxxxx> wrote:
>>>>>> On 25.09.14 at 21:28, <boris.ostrovsky@xxxxxxxxxx> wrote:
>>>> --- a/xen/include/public/arch-x86/xen-x86_64.h
>>>> +++ b/xen/include/public/arch-x86/xen-x86_64.h
>>>> @@ -174,6 +174,14 @@ struct cpu_user_regs {
>>>>   typedef struct cpu_user_regs cpu_user_regs_t;
>>>>   DEFINE_XEN_GUEST_HANDLE(cpu_user_regs_t);
>>>>   
>>>> +struct xen_pmu_regs {
>>>> +    __DECL_REG(ip);
>>>> +    __DECL_REG(sp);
>>> Do you really need __DECL_REG() here? I.e. can't these two fields
>>> be just xen_ulong_t e[is]p and the structure definition then be
>>> shared with 32-bit code (and hence moved altogether into pmu.h)?
>> Otoh - is cs useful at all on 64-bit?
> 
> perf uses user_mode() to figure which mode we are in and that requires CS.

But that won't be complete without also looking at EFLAGS.VM.

Jan


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