Pass d+e option and log size via intel_pt_log_enable(). Allocate a buffer
for log messages and provide intel_pt_log_dump_buf() to dump and reset the
buffer upon decoder errors.
Example:
$ sudo perf record -e intel_pt// sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.094 MB perf.data ]
$ sudo perf config itrace.debug-log-buffer-size=300
$ sudo perf script --itrace=ed+e+o | head -20
Dumping debug log buffer (first line may be sliced)
Other
ffffffff96ca22f6: 48 89 e5 Other
ffffffff96ca22f9: 65 48 8b 05 ff e0 38 69 Other
ffffffff96ca2301: 48 3d c0 a5 c1 98 Other
ffffffff96ca2307: 74 08 Jcc +8
ffffffff96ca2311: 5d Other
ffffffff96ca2312: c3 Ret
ERROR: Bad RET compression (TNT=N) at 0xffffffff96ca2312
End of debug log buffer dump
instruction trace error type 1 time 15913.537143482 cpu 5 pid 36292 tid 36292 ip 0xffffffff96ca2312 code 6: Trace doesn't match instruction
Dumping debug log buffer (first line may be sliced)
Other
ffffffff96ce7fe9: f6 47 2e 20 Other
ffffffff96ce7fed: 74 11 Jcc +17
ffffffff96ce7fef: 48 8b 87 28 0a 00 00 Other
ffffffff96ce7ff6: 5d Other
ffffffff96ce7ff7: 48 8b 40 18 Other
ffffffff96ce7ffb: c3 Ret
ERROR: Bad RET compression (TNT=N) at 0xffffffff96ce7ffb
Warning:
8 instruction trace errors
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220905073424.3971-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220509152400.376613-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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 <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20220124084201.2699795-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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:
<quote>
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.
</quote>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20220124084201.2699795-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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: f4aa081949 ("perf tools: Add Intel PT decoder")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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 <acme@redhat.com>
To pick up some tools/perf/ patches that went via tip/perf/core, such
as:
tools/perf: Add mem_hops field in perf_mem_data_src structure
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Normally, for cycle-acccurate mode, IPC values are an exact number of
instructions and cycles. Due to the granularity of timestamps, that happens
only when a CYC packet correlates to the event.
Support the itrace 'A' option, to use instead, the number of cycles
associated with the current timestamp. This provides IPC information for
every change of timestamp, but at the expense of accuracy. Due to the
granularity of timestamps, the actual number of cycles increases even
though the cycles reported does not. The number of instructions is known,
but if IPC is reported, cycles can be too low and so IPC is too high. Note
that inaccuracy decreases as the period of sampling increases i.e. if the
number of cycles is too low by a small amount, that becomes less
significant if the number of cycles is large.
Furthermore, it can be used in conjunction with dlfilter-show-cycles.so
to provide higher granularity cycle information.
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20211027080334.365596-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use get_unaligned() instead of memcpy() to access potentially unaligned
memory, which, when accessed through a pointer, leads to undefined
behavior. get_unaligned() describes much better what is happening there
anyway even if memcpy() does the job.
In addition, since perf tool builds with -Werror, it would fire with:
util/intel-pt-decoder/../../../arch/x86/lib/insn.c: In function '__insn_get_emulate_prefix':
tools/include/../include/asm-generic/unaligned.h:10:15: error: packed attribute is unnecessary [-Werror=packed]
10 | const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
because -Werror=packed would complain if the packed attribute would have
no effect on the layout of the structure.
In this case, that is intentional so disable the warning only for that
compilation unit.
That part is Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
No functional changes.
Fixes: 5ba1071f75 ("x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/YVSsIkj9Z29TyUjE@zn.tnic
The Intel PT decoder limits the number of unconditional branches (e.g.
jmps) decoded without consuming any trace packets. Generally, a loop
needs a conditional branch which generates a TNT packet, whereas a "ret"
instruction will generate a TIP or TNT packet. So exceeding the limit is
assumed to be a never-ending loop, which can happen if there has been a
decoding error putting the decoder at the wrong place in the code.
Up until now, the limit of 10000 has been enough but some analytic
purposes have been reported to exceed that.
Increase the limit to 100000, and make it configurable via perf config
intel-pt.max-loops. Also amend the "Never-ending loop" message to
mention the configuration entry.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20210701175132.3977-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
VM Time Correlation means determining if each TSC packet belongs to a VM
Guest or the Host. When the trace is "in context" that is indicated by
the NR flag in the PIP packet. However, when tracing kernel-only,
userspace only, or using address filters, the trace can be "out of context"
in which case timing packets are produced but not PIP packets.
Nevertheless, it is very unlikely the VM Guest timestamps will be in
the same range as the Host timestamps. Host time ranges are established
by a starting side-band event timestamp, and subsequently by the buffer
timestamp, written when the buffer is copied to the perf.data file.
This patch supports updating the VM Guest timestamp packets, assuming an
unchanging (during perf record) VMX TSC Offset and no VMX TSC scaling.
Furthermore, it is possible to determine what the VMX TSC Offset is,
although not necessarily at the start. The dry-run option lets that
information be determined so that the user can pass it to a subsequent
run. For more detail, refer to the example in the Intel PT documentation
in a subsequent patch.
VM Time Correlation is also performed on the TSC value in PEBs-via-PT
records.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210430070309.17624-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Even when VMX TSC Offset is not changing (during perf record), different
virtual machines can have different TSC Offsets. There is a Virtual Machine
Control Structure (VMCS) for each virtual CPU, the address of which is
reported to Intel PT in the VMCS packet. We do not know which VMCS belongs
to which virtual machine, so use a tree to keep track of VMCS information.
Then the decoder will be able to use the current VMCS value to look up the
current TSC Offset.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210430070309.17624-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The PIP packet NR (non-root) flag indicates whether or not a virtual
machine is being traced (NR=1 => VM). Add support for tracking its value.
In particular note that the PIP packet (outside of PSB+) will be
associated with a TIP packet from which address the NR value takes
effect. At that point, there is a branch from_ip, to_ip with
corresponding from_nr and to_nr.
In the event of VM-Entry failure, there should still PIP and TIP packets
that can be followed in the same way.
Also note that this assumes that a host VMM is not employing VMX controls
that affect Intel PT, e.g. to hide the host from a guest using Intel PT.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210218095801.19576-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A single q option decodes ip from only FUP/TIP packets. Make it so that
repeating the q option (i.e. qq) decodes only PSB+, getting ip if there
is a FUP packet within PSB+ (i.e. between PSB and PSBEND).
Example:
$ perf record -e intel_pt//u grep -rI pudding drivers
[ perf record: Woken up 52 times to write data ]
[ perf record: Captured and wrote 57.870 MB perf.data ]
$ time perf script --itrace=bi | wc -l
58948289
real 1m23.863s
user 1m23.251s
sys 0m7.452s
$ time perf script --itrace=biq | wc -l
3385694
real 0m4.453s
user 0m4.455s
sys 0m0.328s
$ time perf script --itrace=biqq | wc -l
1883
real 0m0.047s
user 0m0.043s
sys 0m0.009s
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-13-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use the new itrace 'q' option to add support for a mode of decoding that
ignores TNT, does not walk object code, but gets the ip from FUP and TIP
packets.
Example:
$ perf record -e intel_pt//u grep -rI pudding drivers
[ perf record: Woken up 52 times to write data ]
[ perf record: Captured and wrote 57.870 MB perf.data ]
$ time perf script --itrace=bi | wc -l
58948289
real 1m23.863s
user 1m23.251s
sys 0m7.452s
$ time perf script --itrace=biq | wc -l
3385694
real 0m4.453s
user 0m4.455s
sys 0m0.328s
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now that there's a common version of the decoder for all tools, use it
instead of the local copy.
Also use perf's check-headers.sh script to diff the decoder files to
make sure they remain in sync with the kernel version. Objtool has a
similar check.
Committer notes:
Had to keep this all pointing explicitely to x86 headers/files, i.e.
instead of asm/isnn.h we had to use ../include/asm/insn.h when the files
were in differemt dirs, or just replace "<asm/foo.h>" with "foo.h".
This way we continue to be able to process perf.data files with Intel PT
traces in distros other than x86.
Also fixed up the awk script paths to use $(srcdir)/tools/arch instead
or relative directories so that we keep detached tarballs (make help |
grep perf) working.
For now the include lines in these headers are being ignored so as not
to flag false reports of kernel/tools out of sync.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/8a37e615d2880f039505d693d1e068a009358a2b.1567118001.git.jpoimboe@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The core-to-bus ratio (CBR) provides the CPU frequency. With branches
enabled, the decoder was outputting CBR changes only when there was a
branch. That loses the correct time of the change if the trace is not in
context (e.g. not tracing kernel space). Change to output the CBR change
immediately.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190622093248.581-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add 3 new packets to supports PEBS via PT, namely Block Begin Packet
(BBP), Block Item Packet (BIP) and Block End Packet (BEP). PEBS data is
encoded into multiple BIP packets that come between BBP and BEP. The BEP
packet might be associated with a FUP packet. That is indicated by using
a separate packet type (INTEL_PT_BEP_IP) similar to other packets types
with the _IP suffix.
Refer to the Intel SDM for more information about PEBS via PT:
https://software.intel.com/en-us/articles/intel-sdm
May 2019 version: Vol. 3B 18.5.5.2 PEBS output to Intel® Processor Trace
Decoding of BIP packets conflicts with single-byte TNT packets. Since
BIP packets only occur in the context of a block (i.e. between BBP and
BEP), that context must be recorded and passed to the packet decoder.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190610072803.10456-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
