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| -rw-r--r-- | docs/devel/tcg-plugins.rst | 137 |
1 files changed, 133 insertions, 4 deletions
diff --git a/docs/devel/tcg-plugins.rst b/docs/devel/tcg-plugins.rst index 8b40b2a606..9740a70406 100644 --- a/docs/devel/tcg-plugins.rst +++ b/docs/devel/tcg-plugins.rst @@ -145,12 +145,141 @@ Example Plugins There are a number of plugins included with QEMU and you are encouraged to contribute your own plugins plugins upstream. There is a -``contrib/plugins`` directory where they can go. +``contrib/plugins`` directory where they can go. There are also some +basic plugins that are used to test and exercise the API during the +``make check-tcg`` target in ``tests\plugins``. -- tests/plugins +- tests/plugins/empty.c -These are some basic plugins that are used to test and exercise the -API during the ``make check-tcg`` target. +Purely a test plugin for measuring the overhead of the plugins system +itself. Does no instrumentation. + +- tests/plugins/bb.c + +A very basic plugin which will measure execution in course terms as +each basic block is executed. By default the results are shown once +execution finishes:: + + $ qemu-aarch64 -plugin tests/plugin/libbb.so \ + -d plugin ./tests/tcg/aarch64-linux-user/sha1 + SHA1=15dd99a1991e0b3826fede3deffc1feba42278e6 + bb's: 2277338, insns: 158483046 + +Behaviour can be tweaked with the following arguments: + + * inline=true|false + + Use faster inline addition of a single counter. Not per-cpu and not + thread safe. + + * idle=true|false + + Dump the current execution stats whenever the guest vCPU idles + +- tests/plugins/insn.c + +This is a basic instruction level instrumentation which can count the +number of instructions executed on each core/thread:: + + $ qemu-aarch64 -plugin tests/plugin/libinsn.so \ + -d plugin ./tests/tcg/aarch64-linux-user/threadcount + Created 10 threads + Done + cpu 0 insns: 46765 + cpu 1 insns: 3694 + cpu 2 insns: 3694 + cpu 3 insns: 2994 + cpu 4 insns: 1497 + cpu 5 insns: 1497 + cpu 6 insns: 1497 + cpu 7 insns: 1497 + total insns: 63135 + +Behaviour can be tweaked with the following arguments: + + * inline=true|false + + Use faster inline addition of a single counter. Not per-cpu and not + thread safe. + + * sizes=true|false + + Give a summary of the instruction sizes for the execution + + * match=<string> + + Only instrument instructions matching the string prefix. Will show + some basic stats including how many instructions have executed since + the last execution. For example:: + + $ qemu-aarch64 -plugin tests/plugin/libinsn.so,match=bl \ + -d plugin ./tests/tcg/aarch64-linux-user/sha512-vector + ... + 0x40069c, 'bl #0x4002b0', 10 hits, 1093 match hits, Δ+1257 since last match, 98 avg insns/match + 0x4006ac, 'bl #0x403690', 10 hits, 1094 match hits, Δ+47 since last match, 98 avg insns/match + 0x4037fc, 'bl #0x4002b0', 18 hits, 1095 match hits, Δ+22 since last match, 98 avg insns/match + 0x400720, 'bl #0x403690', 10 hits, 1096 match hits, Δ+58 since last match, 98 avg insns/match + 0x4037fc, 'bl #0x4002b0', 19 hits, 1097 match hits, Δ+22 since last match, 98 avg insns/match + 0x400730, 'bl #0x403690', 10 hits, 1098 match hits, Δ+33 since last match, 98 avg insns/match + 0x4037ac, 'bl #0x4002b0', 12 hits, 1099 match hits, Δ+20 since last match, 98 avg insns/match + ... + +For more detailed execution tracing see the ``execlog`` plugin for +other options. + +- tests/plugins/mem.c + +Basic instruction level memory instrumentation:: + + $ qemu-aarch64 -plugin tests/plugin/libmem.so,inline=true \ + -d plugin ./tests/tcg/aarch64-linux-user/sha1 + SHA1=15dd99a1991e0b3826fede3deffc1feba42278e6 + inline mem accesses: 79525013 + +Behaviour can be tweaked with the following arguments: + + * inline=true|false + + Use faster inline addition of a single counter. Not per-cpu and not + thread safe. + + * callback=true|false + + Use callbacks on each memory instrumentation. + + * hwaddr=true|false + + Count IO accesses (only for system emulation) + +- tests/plugins/syscall.c + +A basic syscall tracing plugin. This only works for user-mode. By +default it will give a summary of syscall stats at the end of the +run:: + + $ qemu-aarch64 -plugin tests/plugin/libsyscall \ + -d plugin ./tests/tcg/aarch64-linux-user/threadcount + Created 10 threads + Done + syscall no. calls errors + 226 12 0 + 99 11 11 + 115 11 0 + 222 11 0 + 93 10 0 + 220 10 0 + 233 10 0 + 215 8 0 + 214 4 0 + 134 2 0 + 64 2 0 + 96 1 0 + 94 1 0 + 80 1 0 + 261 1 0 + 78 1 0 + 160 1 0 + 135 1 0 - contrib/plugins/hotblocks.c |