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Diffstat (limited to 'qemu-doc.texi')
| -rw-r--r-- | qemu-doc.texi | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/qemu-doc.texi b/qemu-doc.texi index e60c46b5c9..227c2b0b45 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -2629,6 +2629,7 @@ so should only be used with trusted guest OS. @menu * Supported Operating Systems :: +* Features:: * Linux User space emulator:: * BSD User space emulator :: @end menu @@ -2645,6 +2646,39 @@ Linux (referred as qemu-linux-user) BSD (referred as qemu-bsd-user) @end itemize +@node Features +@section Features + +QEMU user space emulation has the following notable features: + +@table @strong +@item System call translation: +QEMU includes a generic system call translator. This means that +the parameters of the system calls can be converted to fix +endianness and 32/64-bit mismatches between hosts and targets. +IOCTLs can be converted too. + +@item POSIX signal handling: +QEMU can redirect to the running program all signals coming from +the host (such as @code{SIGALRM}), as well as synthesize signals from +virtual CPU exceptions (for example @code{SIGFPE} when the program +executes a division by zero). + +QEMU relies on the host kernel to emulate most signal system +calls, for example to emulate the signal mask. On Linux, QEMU +supports both normal and real-time signals. + +@item Threading: +On Linux, QEMU can emulate the @code{clone} syscall and create a real +host thread (with a separate virtual CPU) for each emulated thread. +Note that not all targets currently emulate atomic operations correctly. +x86 and ARM use a global lock in order to preserve their semantics. +@end table + +QEMU was conceived so that ultimately it can emulate itself. Although +it is not very useful, it is an important test to show the power of the +emulator. + @node Linux User space emulator @section Linux User space emulator |