linux-dev/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c, branch linus/master

perf intel-pt: Add support for emulated ptwrite

2022-05-17T14:55:49Z

ptwrite is an Intel x86 instruction that writes arbitrary values into an Intel PT trace. It is not supported on all hardware, so provide an alternative that makes use of TNT packets to convey the payload data. TNT packets encode Taken/Not-taken conditional branch information, so taking branches based on the payload value will encode the value into the TNT packet. Refer to the changes to the documentation file perf-intel-pt.txt in this patch for an example. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Link: https://lore.kernel.org/r/20220509152400.376613-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: decoder: Add MODE.Exec IFLAG processing

2022-02-15T20:08:03Z

As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new Intel PT feature called Event Trace which adds a bit to the existing MODE.Exec packet to record the interrupt flag. Previously, the MODE.Exec packet did not generate any events, so the new processing required is practically the same as a new packet. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Link: https://lore.kernel.org/r/20220124084201.2699795-9-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: decoder: Add CFE (Control Flow Event) and EVD (Event Data) processing

2022-02-15T20:07:23Z

As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new Intel PT feature called Event Trace which requires 2 new packets CFE (Control Flow Event) and EVD (Event Data). Each Event Trace event is represented by a CFE packet that is preceded by zero or more EVD packets. It may be bound to a following FUP (Flow Update) packet that provides the IP. Event Trace exposes details about asynchronous events. The CFE packet contains a type field to identify one of the following: 1 INTR interrupt, fault, exception, NMI 2 IRET interrupt return 3 SMI system management interrupt 4 RSM resume from system management mode 5 SIPI startup interprocessor interrupt 6 INIT INIT signal 7 VMENTRY VM-Entry 8 VMEXIT VM-Entry 9 VMEXIT_INTR VM-Exit due to interrupt 10 SHUTDOWN Shutdown For more details, refer to the Intel SDM, Intel Processor Trace chapter. Add processing to the decoder for the new packets. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Link: https://lore.kernel.org/r/20220124084201.2699795-8-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: decoder: Factor out clearing of FUP (Flow Update) event variables

2022-02-15T20:06:58Z

Factor out clearing of FUP (Flow Update) event variables, to avoid code duplication. Committer Notes: From the Intel documentation: Flow Update Packets (FUP): FUPs provide the source IP addresses for asynchronous events (interrupt and exceptions), as well as other cases where the source address cannot be determined from the binary. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Link: https://lore.kernel.org/r/20220124084201.2699795-7-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: pkt-decoder: Add CFE and EVD packets

2022-02-15T20:05:44Z

As of Intel SDM (https://www.intel.com/sdm) version 076, there is a new Intel PT feature called Event Trace which requires 2 new packets CFE and EVD. Add them to the packet decoder and packet decoder test. Committer notes: I got the "Intel® 64 and IA-32 architectures software developer’s manual combined volumes: 1, 2A, 2B, 2C, 2D, 3A, 3B, 3C, 3D, and 4" PDF at: https://cdrdv2.intel.com/v1/dl/getContent/671200 And these new packets are described in page 3951: 32.2.4 Event Trace is a capability that exposes details about the asynchronous events, when they are generated, and when their corresponding software event handler completes execution. These include: o Interrupts, including NMI and SMI, including the interrupt vector when defined. o Faults, exceptions including the fault vector. — Page faults additionally include the page fault address, when in context. o Event handler returns, including IRET and RSM. o VM exits and VM entries.¹ — VM exits include the values written to the “exit reason” and “exit qualification” VMCS fields. INIT and SIPI events. o TSX aborts, including the abort status returned for the RTM instructions. o Shutdown. Additionally, it provides indication of the status of the Interrupt Flag (IF), to indicate when interrupts are masked. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Link: https://lore.kernel.org/r/20220124084201.2699795-4-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix missing 'instruction' events with 'q' option

2021-12-11T11:19:47Z

FUP packets contain IP information, which makes them also an 'instruction' event in 'hop' mode i.e. the itrace 'q' option. That wasn't happening, so restructure the logic so that FUP events are added along with appropriate 'instruction' and 'branch' events. Fixes: 7c1b16ba0e26e6 ("perf intel-pt: Add support for decoding FUP/TIP only") Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org # v5.15+ Link: https://lore.kernel.org/r/20211210162303.2288710-7-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix next 'err' value, walking trace

2021-12-11T11:19:47Z

Code after label 'next:' in intel_pt_walk_trace() assumes 'err' is zero, but it may not be, if arrived at via a 'goto'. Ensure it is zero. Fixes: 7c1b16ba0e26e6 ("perf intel-pt: Add support for decoding FUP/TIP only") Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org # v5.15+ Link: https://lore.kernel.org/r/20211210162303.2288710-6-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix state setting when receiving overflow (OVF) packet

2021-12-11T11:19:47Z

An overflow (OVF packet) is treated as an error because it represents a loss of trace data, but there is no loss of synchronization, so the packet state should be INTEL_PT_STATE_IN_SYNC not INTEL_PT_STATE_ERR_RESYNC. To support that, some additional variables must be reset, and the FUP packet that may follow OVF is treated as an FUP event. Fixes: f4aa081949e7b6 ("perf tools: Add Intel PT decoder") Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org # v5.15+ Link: https://lore.kernel.org/r/20211210162303.2288710-5-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix intel_pt_fup_event() assumptions about setting state type

2021-12-11T11:19:47Z

intel_pt_fup_event() assumes it can overwrite the state type if there has been an FUP event, but this is an unnecessary and unexpected constraint on callers. Fix by touching only the state type flags that are affected by an FUP event. Fixes: a472e65fc490a ("perf intel-pt: Add decoder support for ptwrite and power event packets") Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org # v5.15+ Link: https://lore.kernel.org/r/20211210162303.2288710-4-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix sync state when a PSB (synchronization) packet is found

2021-12-11T11:19:47Z

When syncing, it may be that branch packet generation is not enabled at that point, in which case there will not immediately be a control-flow packet, so some packets before a control flow packet turns up, get ignored. However, the decoder is in sync as soon as a PSB is found, so the state should be set accordingly. Fixes: f4aa081949e7b6 ("perf tools: Add Intel PT decoder") Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org # v5.15+ Link: https://lore.kernel.org/r/20211210162303.2288710-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo