> On Thu, Aug 17, 2017 at 02:17:23PM -0400, [email protected] wrote:
> > diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
> > index a322fed..f0e8d9c 100644
> > --- a/arch/x86/events/intel/ds.c
> > +++ b/arch/x86/events/intel/ds.c
> > @@ -1065,6 +1065,35 @@ static inline u64 intel_hsw_transaction(struct
> pebs_record_skl *pebs)
> >     return txn;
> >  }
> >
> > +static u64 dla_to_phys(u64 dla)
> > +{
> > +   u64 phys_addr = 0;
> > +   struct page *p = NULL;
> > +
> > +   if (dla >= TASK_SIZE) {
> > +           /* If it's vmalloc()d memory, leave phys_addr as 0 */
> > +           if (virt_addr_valid(dla) &&
> > +               !(dla >= VMALLOC_START && dla < VMALLOC_END))
> > +                   phys_addr = (u64)virt_to_phys((void *)(uintptr_t)dla);
> > +   } else {
> > +           /*
> > +            * Walking the pages tables for user address.
> > +            * Interrupts are disabled, so it prevents any tear down
> > +            * of the page tables.
> > +            * Try IRQ-safe __get_user_pages_fast first.
> > +            * If failed, leave phys_addr as 0.
> > +            */
> > +           if ((current->mm != NULL) &&
> > +               (__get_user_pages_fast(dla, 1, 0, &p) == 1))
> > +                   phys_addr = page_to_phys(p) + dla % PAGE_SIZE;
> > +
> > +           if (p)
> > +                   put_page(p);
> > +   }
> > +
> > +   return phys_addr;
> > +}
> 
> Is this in any way x86 specific? AFAICT this should work in generic code as
> long as data->addr is provided.

No, it's not X86 specific. I think it can be used as generic code to convert
virtual address to physical address.

Thanks,
Kan
> 
> >  static void setup_pebs_sample_data(struct perf_event *event,
> >                                struct pt_regs *iregs, void *__pebs,
> >                                struct perf_sample_data *data, @@ -
> 1179,6 +1208,9 @@ static
> > void setup_pebs_sample_data(struct perf_event *event,
> >         x86_pmu.intel_cap.pebs_format >= 1)
> >             data->addr = pebs->dla;
> >
> > +   if ((sample_type & PERF_SAMPLE_PHYS_ADDR) && (data->addr != 0))
> > +           data->phys_addr = dla_to_phys(data->addr);
> > +
> >     if (x86_pmu.intel_cap.pebs_format >= 2) {
> >             /* Only set the TSX weight when no memory weight. */
> >             if ((sample_type & PERF_SAMPLE_WEIGHT) && !fll)
> 

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