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Diffstat (limited to 'docs/about')
| -rw-r--r-- | docs/about/deprecated.rst | 19 | ||||
| -rw-r--r-- | docs/about/emulation.rst | 44 |
2 files changed, 62 insertions, 1 deletions
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index ed31d4b0b2..c0aa52def5 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -184,6 +184,25 @@ be an effective use of its limited resources, and thus intends to discontinue it. Since all recent x86 hardware from the past >10 years is capable of the 64-bit x86 extensions, a corresponding 64-bit OS should be used instead. +TCG Plugin support not enabled by default on 32-bit hosts (since 9.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +While it is still possible to enable TCG plugin support for 32-bit +hosts there are a number of potential pitfalls when instrumenting +64-bit guests. The plugin APIs typically pass most addresses as +uint64_t but practices like encoding that address in a host pointer +for passing as user-data will lose data. As most software analysis +benefits from having plenty of host memory it seems reasonable to +encourage users to use 64 bit builds of QEMU for analysis work +whatever targets they are instrumenting. + +TCG Plugin support not enabled by default with TCI (since 9.2) +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +While the TCG interpreter can interpret the TCG ops used by plugins it +is going to be so much slower it wouldn't make sense for any serious +instrumentation. Due to implementation differences there will also be +anomalies in things like memory instrumentation. System emulator CPUs -------------------- diff --git a/docs/about/emulation.rst b/docs/about/emulation.rst index 05f54d3f27..3028d5fff7 100644 --- a/docs/about/emulation.rst +++ b/docs/about/emulation.rst @@ -268,6 +268,36 @@ Behaviour can be tweaked with the following arguments: * - idle=true|false - Dump the current execution stats whenever the guest vCPU idles +Basic Block Vectors +................... + +``contrib/plugins/bbv.c`` + +The bbv plugin allows you to generate basic block vectors for use with the +`SimPoint <https://cseweb.ucsd.edu/~calder/simpoint/>`__ analysis tool. + +.. list-table:: Basic block vectors arguments + :widths: 20 80 + :header-rows: 1 + + * - Option + - Description + * - interval=N + - The interval to generate a basic block vector specified by the number of + instructions (Default: N = 100000000) + * - outfile=PATH + - The path to output files. + It will be suffixed with ``.N.bb`` where ``N`` is a vCPU index. + +Example:: + + $ qemu-aarch64 \ + -plugin contrib/plugins/libbbv.so,interval=100,outfile=sha1 \ + tests/tcg/aarch64-linux-user/sha1 + SHA1=15dd99a1991e0b3826fede3deffc1feba42278e6 + $ du sha1.0.bb + 23128 sha1.0.bb + Instruction ........... @@ -384,6 +414,19 @@ run:: 160 1 0 135 1 0 +Behaviour can be tweaked with the following arguments: + +.. list-table:: Syscall plugin arguments + :widths: 20 80 + :header-rows: 1 + + * - Option + - Description + * - print=true|false + - Print the number of times each syscall is called + * - log_writes=true|false + - Log the buffer of each write syscall in hexdump format + Test inline operations ...................... @@ -773,4 +816,3 @@ Other emulation features When running system emulation you can also enable deterministic execution which allows for repeatable record/replay debugging. See :ref:`Record/Replay<replay>` for more details. - |