Messages in this thread | | | Subject | Re: [PATCH 4/7] drivers/perf: hisi_pcie: Check the target filter properly | From | Yicong Yang <> | Date | Wed, 21 Feb 2024 17:46:07 +0800 |
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On 2024/2/8 20:29, Jonathan Cameron wrote: > On Sun, 4 Feb 2024 15:45:24 +0800 > Yicong Yang <yangyicong@huawei.com> wrote: > >> From: Junhao He <hejunhao3@huawei.com> >> >> The PMU can monitor traffic of certain target Root Port or downstream >> target Endpoint. User can specify the target filter by the "port" or >> "bdf" option respectively. The PMU can only monitor the Root Port or >> Endpoint on the same PCIe core so the value of "port" or "bdf" should >> be valid and will be checked by the driver. >> >> Currently at least and only one of "port" and "bdf" option must be set. >> If "port" filter is not set or is set explicitly to zero (default), >> driver will regard the user specifies a "bdf" option since "port" option >> is a bitmask of the target Root Ports and zero is not a valid >> value. >> >> If user not explicitly set "port" or "bdf" filter, the driver uses "bdf" >> default value (zero) to set target filter, but driver will skip the >> check of bdf=0, although it's a valid value (meaning 0000:000:00.0). >> Then the user just gets zero. >> >> Therefore, we need to check if both "port" and "bdf" are invalid, then >> return failure and report warning. >> >> Testing: >> before the patch: >> 0 hisi_pcie0_core1/rx_mrd_flux/ >> 0 hisi_pcie0_core1/rx_mrd_flux,port=0/ >> 24,124 hisi_pcie0_core1/rx_mrd_flux,port=1/ >> 0 hisi_pcie0_core1/rx_mrd_flux,bdf=0/ >> <not supported> hisi_pcie0_core1/rx_mrd_flux,bdf=1/ > > Nice to include an example that works for bdf > hisi_pcie0_core1/rx_mrd_flux,bdf=1,port=0 > or something like that? >> >> after the patch: >> <not supported> hisi_pcie0_core1/rx_mrd_flux/ >> <not supported> hisi_pcie0_core1/rx_mrd_flux,port=0/ >> 24,153 hisi_pcie0_core1/rx_mrd_flux,port=1/ >> <not supported> hisi_pcie0_core1/rx_mrd_flux,bdf=0/ >> <not supported> hisi_pcie0_core1/rx_mrd_flux,bdf=1/ >> >> Signed-off-by: Junhao He <hejunhao3@huawei.com> >> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> > > Clearly the current situation is wrong, but perhaps we can > have a more intuitive scheme (could be added as a follow up patch) > and have the driver figure out which port the bdf lies below? > > Maybe that's a job for userspace tooling rather than the driver, but > the driver already has verification code and it wouldn't be hard > to not just check the rp is ours, but also set the filter to specify > that rp, or maybe just set the mask to include them all? >
To do a check should be simple, we can decode the bdf and find the target endpoint and related root port for doing the check.
Another example is what we've done in hisi_ptt that we maintian a list of supported root ports and endpoints, but that will be a bit more complex.
> Jonathan > > >> --- >> drivers/perf/hisilicon/hisi_pcie_pmu.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c >> index 83be3390686c..b91f03c02c57 100644 >> --- a/drivers/perf/hisilicon/hisi_pcie_pmu.c >> +++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c >> @@ -306,10 +306,10 @@ static bool hisi_pcie_pmu_valid_filter(struct perf_event *event, >> if (hisi_pcie_get_trig_len(event) > HISI_PCIE_TRIG_MAX_VAL) >> return false; >> >> - if (requester_id) { >> - if (!hisi_pcie_pmu_valid_requester_id(pcie_pmu, requester_id)) >> - return false; >> - } >> + /* Need to explicitly set filter of "port" or "bdf" */ >> + if (!hisi_pcie_get_port(event) && >> + !hisi_pcie_pmu_valid_requester_id(pcie_pmu, requester_id)) >> + return false; >> >> return true; >> } > > . >
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