Messages in this thread | | | Date | Thu, 26 May 2022 11:56:33 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 06/13] perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR using IBS_DC_PHYSADDR |
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On Thu, May 26, 2022 at 02:16:28PM +0530, Ravi Bangoria wrote: > On 25-May-22 4:51 PM, Peter Zijlstra wrote: > > On Wed, May 25, 2022 at 03:09:31PM +0530, Ravi Bangoria wrote: > >> IBS_DC_PHYSADDR provides the physical data address for the tagged load/ > >> store operation. Populate perf sample physical address using it. > >> > >> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> > >> --- > >> arch/x86/events/amd/ibs.c | 26 +++++++++++++++++++++++++- > >> 1 file changed, 25 insertions(+), 1 deletion(-) > >> > >> diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c > >> index b57736357e25..c719020c0e83 100644 > >> --- a/arch/x86/events/amd/ibs.c > >> +++ b/arch/x86/events/amd/ibs.c > >> @@ -986,13 +986,35 @@ static void perf_ibs_get_data_addr(struct perf_event *event, > >> data->addr = ibs_data->regs[ibs_op_msr_idx(MSR_AMD64_IBSDCLINAD)]; > >> } > >> > >> +static void perf_ibs_get_phy_addr(struct perf_event *event, > >> + struct perf_ibs_data *ibs_data, > >> + struct perf_sample_data *data) > >> +{ > >> + union perf_mem_data_src *data_src = &data->data_src; > >> + u64 op_data3 = ibs_data->regs[ibs_op_msr_idx(MSR_AMD64_IBSOPDATA3)]; > >> + u64 phy_addr_valid = op_data3 & IBS_DC_PHY_ADDR_VALID_MASK; > >> + > >> + if (!(event->attr.sample_type & PERF_SAMPLE_DATA_SRC)) > >> + perf_ibs_get_mem_op(op_data3, data); > >> + > >> + if ((data_src->mem_op != PERF_MEM_OP_LOAD && > >> + data_src->mem_op != PERF_MEM_OP_STORE) || > >> + !phy_addr_valid) { > >> + data->phys_addr = 0x0; > >> + return; > >> + } > >> + > >> + data->phys_addr = ibs_data->regs[ibs_op_msr_idx(MSR_AMD64_IBSDCPHYSAD)]; > >> +} > > > > perf_prepare_sample() will unconditionally overwrite data->phys_addr. > > There is currently no facility to let the driver set this field. > > Thanks for pointing it Peter. Would you mind if I add:
I think it's best if you extend/mimic the __PERF_SAMPLE_CALLCHAIN_EARLY hack. It's more or less the same problem and then at least the solution is consistent.
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