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Diffstat (limited to 'docs/about/emulation.rst')
| -rw-r--r-- | docs/about/emulation.rst | 49 |
1 files changed, 42 insertions, 7 deletions
diff --git a/docs/about/emulation.rst b/docs/about/emulation.rst index c03033e4e9..eea1261baa 100644 --- a/docs/about/emulation.rst +++ b/docs/about/emulation.rst @@ -207,8 +207,8 @@ Once built a program can be run with multiple plugins loaded each with their own arguments:: $QEMU $OTHER_QEMU_ARGS \ - -plugin contrib/plugin/libhowvec.so,inline=on,count=hint \ - -plugin contrib/plugin/libhotblocks.so + -plugin contrib/plugins/libhowvec.so,inline=on,count=hint \ + -plugin contrib/plugins/libhotblocks.so Arguments are plugin specific and can be used to modify their behaviour. In this case the howvec plugin is being asked to use inline @@ -219,6 +219,14 @@ Linux user-mode emulation also evaluates the environment variable QEMU_PLUGIN="file=contrib/plugins/libhowvec.so,inline=on,count=hint" $QEMU +QEMU plugins avoid to write directly to stdin/stderr, and use the log provided +by the API (see function ``qemu_plugin_outs``). +To show output, you may use this additional parameter:: + + $QEMU $OTHER_QEMU_ARGS \ + -d plugin \ + -plugin contrib/plugins/libhowvec.so,inline=on,count=hint + Example Plugins ~~~~~~~~~~~~~~~ @@ -260,8 +268,7 @@ Behaviour can be tweaked with the following arguments: * - Option - Description * - inline=true|false - - Use faster inline addition of a single counter. Not per-cpu and not - thread safe. + - Use faster inline addition of a single counter. * - idle=true|false - Dump the current execution stats whenever the guest vCPU idles @@ -381,6 +388,15 @@ run:: 160 1 0 135 1 0 +Test inline operations +...................... + +``tests/plugins/inline.c`` + +This plugin is used for testing all inline operations, conditional callbacks and +scoreboard. It prints a per-cpu summary of all events. + + Hot Blocks .......... @@ -394,9 +410,6 @@ with linux-user execution as system emulation tends to generate re-translations as blocks from different programs get swapped in and out of system memory. -If your program is single-threaded you can use the ``inline`` option for -slightly faster (but not thread safe) counters. - Example:: $ qemu-aarch64 \ @@ -736,6 +749,28 @@ The plugin will log the reason of exit, for example:: 0xd4 reached, exiting +Limit instructions per second +............................. + +This plugin can limit the number of Instructions Per Second that are executed:: + + # get number of instructions + $ num_insn=$(./build/qemu-x86_64 -plugin ./build/tests/plugin/libinsn.so -d plugin /bin/true |& grep total | sed -e 's/.*: //') + # limit speed to execute in 10 seconds + $ time ./build/qemu-x86_64 -plugin ./build/contrib/plugins/libips.so,ips=$(($num_insn/10)) /bin/true + real 10.000s + + +.. list-table:: IPS arguments + :widths: 20 80 + :header-rows: 1 + + * - Option + - Description + * - ips=N + - Maximum number of instructions per cpu that can be executed in one second. + The plugin will sleep when the given number of instructions is reached. + Other emulation features ------------------------ |