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authorStefan Hajnoczi2022-10-06 13:11:56 +0200
committerStefan Hajnoczi2022-10-06 13:11:56 +0200
commitf1d33f55c47dfdaf8daacd618588ad3ae4c452d1 (patch)
treec759a5deb49756097f301652837b14ffc91ef6b2 /docs/devel
parentMerge tag 'pull-hex-20221003' of https://github.com/quic/qemu into staging (diff)
parentplugins: add [pre|post]fork helpers to linux-user (diff)
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Merge tag 'pull-testing-gdbstub-plugins-gitdm-061022-3' of https://github.com/stsquad/qemu into staging
testing, gdbstub, plugin and gitdm updates - cleanup scripts/ci/setup in advance of ppc64 runner - ensure detected gdb reported to TCG tests - update hexagon container with build deps - move alpine container to tagged release - fix overflow during qos-test test tree iteration - allow bios blobs to be built with test cross compilers - introduce monitor_puts for plain strings - share disas code between monitor and plugins - fix bug in execlog plugin - add more tcg plugin documentation, reorg - fix link to semihosting spec - re-factor gdbstub to use AccelClass/Ops - many gitdm updates - fix race with plugin mutex lock and linux-user fork() # -----BEGIN PGP SIGNATURE----- # # iQEzBAABCgAdFiEEZoWumedRZ7yvyN81+9DbCVqeKkQFAmM+s+YACgkQ+9DbCVqe # KkSDwgf/Qj0OScOr5Bfw3/KAV0/SFL1vHISb2r5qZVG4DvdY/c/sitPBHPJ8N5jQ # 918M8AiI3+4Mb/GwkdYBEyWgVZ5ELOkJTObypa5pwmF1K/xDUlG7ZRmJ9+xkJ44Q # TmrVLQyw6d907B2u+DfqX68AYYnto1yQT/eUo6TiLdIJ5NXIYRn5u34snG9qWHja # b/Dp7DxnoJMS1EhlMhukekCHGGNUeYn4ewIKbsG1EouH5PndzrvP8LRAcWyxv0m4 # tD2bEAHCMKqTqefkNgG7GCO3HND1JBfWdckx3OD4hBnMnuNtsZBL23QN7MDytgnv # 0JnYSwkWZCuMIt7oKCOXLUbCjQG97Q== # =1vZ4 # -----END PGP SIGNATURE----- # gpg: Signature made Thu 06 Oct 2022 06:54:30 EDT # gpg: using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44 # gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [unknown] # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: 6685 AE99 E751 67BC AFC8 DF35 FBD0 DB09 5A9E 2A44 * tag 'pull-testing-gdbstub-plugins-gitdm-061022-3' of https://github.com/stsquad/qemu: (52 commits) plugins: add [pre|post]fork helpers to linux-user contrib/gitdm: add Université Grenoble Alpes contrib/gitdm: add Simon to individual contributors contrib/gitdm: add China Telecom to the domain map contrib/gitdm: add ISCAS to the academics group contrib/gitdm: add WANG Xuerui to individual contributers contrib/gitdm: add Paul to individual contributors contrib/gitdm: add mapping for Loongson Technology accel/kvm: move kvm_update_guest_debug to inline stub gdbstub: move guest debug support check to ops gdbstub: move breakpoint logic to accel ops gdbstub: move sstep flags probing into AccelClass gdbstub: move into its own sub directory semihosting: update link to spec docs/devel: document the test plugins contrib/plugins: reset skip when matching in execlog docs/devel: move API to end of tcg-plugins.rst docs/devel: clean-up qemu invocations in tcg-plugins plugins: Assert mmu_idx in range before use in qemu_plugin_get_hwaddr plugins: extend execlog to filter matches ... Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'docs/devel')
-rw-r--r--docs/devel/tcg-plugins.rst175
-rw-r--r--docs/devel/writing-monitor-commands.rst2
2 files changed, 159 insertions, 18 deletions
diff --git a/docs/devel/tcg-plugins.rst b/docs/devel/tcg-plugins.rst
index a7cc44aa20..9740a70406 100644
--- a/docs/devel/tcg-plugins.rst
+++ b/docs/devel/tcg-plugins.rst
@@ -110,11 +110,6 @@ details are opaque to plugins. The plugin is able to query select
details of instructions and system configuration only through the
exported *qemu_plugin* functions.
-API
-~~~
-
-.. kernel-doc:: include/qemu/qemu-plugin.h
-
Internals
---------
@@ -150,12 +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/empty.c
+
+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>
-- tests/plugins
+ Only instrument instructions matching the string prefix. Will show
+ some basic stats including how many instructions have executed since
+ the last execution. For example::
-These are some basic plugins that are used to test and exercise the
-API during the ``make check-tcg`` target.
+ $ 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
@@ -172,7 +296,7 @@ slightly faster (but not thread safe) counters.
Example::
- ./aarch64-linux-user/qemu-aarch64 \
+ $ qemu-aarch64 \
-plugin contrib/plugins/libhotblocks.so -d plugin \
./tests/tcg/aarch64-linux-user/sha1
SHA1=15dd99a1991e0b3826fede3deffc1feba42278e6
@@ -186,7 +310,7 @@ Example::
Similar to hotblocks but this time tracks memory accesses::
- ./aarch64-linux-user/qemu-aarch64 \
+ $ qemu-aarch64 \
-plugin contrib/plugins/libhotpages.so -d plugin \
./tests/tcg/aarch64-linux-user/sha1
SHA1=15dd99a1991e0b3826fede3deffc1feba42278e6
@@ -220,7 +344,7 @@ counted. You can give a value to the ``count`` argument for a class of
instructions to break it down fully, so for example to see all the system
registers accesses::
- ./aarch64-softmmu/qemu-system-aarch64 $(QEMU_ARGS) \
+ $ qemu-system-aarch64 $(QEMU_ARGS) \
-append "root=/dev/sda2 systemd.unit=benchmark.service" \
-smp 4 -plugin ./contrib/plugins/libhowvec.so,count=sreg -d plugin
@@ -288,10 +412,10 @@ for the plugin is a path for the socket the two instances will
communicate over::
- ./sparc-softmmu/qemu-system-sparc -monitor none -parallel none \
+ $ qemu-system-sparc -monitor none -parallel none \
-net none -M SS-20 -m 256 -kernel day11/zImage.elf \
-plugin ./contrib/plugins/liblockstep.so,sockpath=lockstep-sparc.sock \
- -d plugin,nochain
+ -d plugin,nochain
which will eventually report::
@@ -346,9 +470,9 @@ The execlog tool traces executed instructions with memory access. It can be used
for debugging and security analysis purposes.
Please be aware that this will generate a lot of output.
-The plugin takes no argument::
+The plugin needs default argument::
- qemu-system-arm $(QEMU_ARGS) \
+ $ qemu-system-arm $(QEMU_ARGS) \
-plugin ./contrib/plugins/libexeclog.so -d plugin
which will output an execution trace following this structure::
@@ -364,13 +488,20 @@ which will output an execution trace following this structure::
0, 0xd34, 0xf9c8f000, "bl #0x10c8"
0, 0x10c8, 0xfff96c43, "ldr r3, [r0, #0x44]", load, 0x200000e4, RAM
+the output can be filtered to only track certain instructions or
+addresses using the ``ifilter`` or ``afilter`` options. You can stack the
+arguments if required::
+
+ $ qemu-system-arm $(QEMU_ARGS) \
+ -plugin ./contrib/plugins/libexeclog.so,ifilter=st1w,afilter=0x40001808 -d plugin
+
- contrib/plugins/cache.c
Cache modelling plugin that measures the performance of a given L1 cache
configuration, and optionally a unified L2 per-core cache when a given working
set is run::
- qemu-x86_64 -plugin ./contrib/plugins/libcache.so \
+ $ qemu-x86_64 -plugin ./contrib/plugins/libcache.so \
-d plugin -D cache.log ./tests/tcg/x86_64-linux-user/float_convs
will report the following::
@@ -441,3 +572,13 @@ The plugin has a number of arguments, all of them are optional:
associativity of the L2 cache, respectively. Setting any of the L2
configuration arguments implies ``l2=on``.
(default: N = 2097152 (2MB), B = 64, A = 16)
+
+API
+---
+
+The following API is generated from the inline documentation in
+``include/qemu/qemu-plugin.h``. Please ensure any updates to the API
+include the full kernel-doc annotations.
+
+.. kernel-doc:: include/qemu/qemu-plugin.h
+
diff --git a/docs/devel/writing-monitor-commands.rst b/docs/devel/writing-monitor-commands.rst
index 4aa2bb904d..2fefedcd98 100644
--- a/docs/devel/writing-monitor-commands.rst
+++ b/docs/devel/writing-monitor-commands.rst
@@ -716,7 +716,7 @@ message. Here's the implementation of the "info roms" HMP command::
if (hmp_handle_error(mon, err)) {
return;
}
- monitor_printf(mon, "%s", info->human_readable_text);
+ monitor_puts(mon, info->human_readable_text);
}
Also, you have to add the function's prototype to the hmp.h file.