Bochs instruction emulation handlers won't refer to direct fields of instructions like MODRM.NNN or MODRM.RM anymore.
Use generic source/destination indications like SRC1, SRC2 and DST.
All handlers are modified to support new notation. In addition fetchDecode module was modified to assign sources to instructions properly.
Immediate benefits:
- Removal of several duplicated handlers (FMA3 duplicated with FMA4 is a trivial example)
- Simpler to understand fetch-decode code
Future benefits:
- Integration of disassembler into Bochs CPU module, ability to disasm bx_instruction_c instance (planned)
Huge patch. Almost all source files wre modified.
but in case you want a few %% of extra emulation performance - it is still possible to disable it with configure option.
most guests I saw do not use it !
for CPU emulation performance reasons, the alignment check compilation
still can be enabled using configure option --enable-alignment-check.
There is no software in the world which enable #AC exception checking, this
x86 feature is completely legacy but its emulation support costs up to 3-5%
emulation speed.
The checking for #AC exception enable still will be done, if
CPL == 3, EFLAGS.AC = 1 and CR0.AM = 1
but the alignment check is not compiled in, the Bochs will PANIC with corresponding message.
You can press 'always continue' and ignore the PANIC, the simulation will continue as if alignment checking is not enabled.
I am merging the code in order to start making shortcuts between VMX emulation and SVM emulation.
Of course SVM emulation is incomplete, completely untested and not expected to work.
But someone could already take a look one the code and give some suggestions.
Also looking for anybody with existing SVM kernels - as simple as possible - for testing.
Status:
- exceptions intercept is not implemented yet
- IO intercept is not implemented yet
- MSR intercept is not implemented yet
- virtual interrupts are not implemented yet
- CPUID is not implemented yet
No advanced SVM featurez planned - I am implementing the very basic 'Pacifica' document from 2005 using QEMU code as reference.
32-bit CPU using Bochs binary compiled with x86-64 support.
The commit also fixes some init.cc issues with initialization of SYSCALL/SYSRET MSR in AMD hosts and also includes code reorg.
- SYSCALL/SYSRET: SYSCALL/SYSRET instructions are not supported in legacy mode for Intel processors
- CPUID: CPUID.0x80000001.EDX[11] SYSCALL/SYSRET support should not be reported outside long64 mode if legacy mode SYSCALL/SYSRET is not supported
- Added new CPUDB entry - AMD K6-2 3D proc3essor (Chomper)
Change CPUID to generic interface which could be chosen from .bochsrc.
Bochs CPU emulation will enable/disable features (like instruction sets) according to CPUID that is selected.
TODO: Add database of CPUID from real hardware CPUs
