I observed ~5% emulation slowdown ... thinking about possible mitigations
this fixes TLB issue with SMAP and SMEP features.
these features introduce a new behavior when page can be inaccessible by System (CPL=0).
Current behavior is accessBits was not supporting it but legacy (from Bochs 2.3.6) was.
The wrong behavior can be observed if user access a user page and system access the same page later.
user access is fine and pass SMEP/SMA checks and stores the translation in TLB.
the system access will hit the TLB and nobody could detect that system cannot access that page.
Bugfix: VMX: VmEntry should do TPR Virtualization (TPR Shadow + APIC Access Virtualization case is affected) and even could possibly cause TPR Threshold VMEXIT
fixed enabling of ADX extensions in generic CPUID when enabled through .bochsrc
Small code cleanups on the way to implementation of APIC Registers Virtualization features disclosed in recent Intel SDM rev043
Added phenom_8650_toliman <AMD Phenom X3 8650 (Toliman)> comment into .bochsrc example with all other supported CPU configs.
Added missed SVM definitions into Toliman CPUDB module
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Implemented SVN nested paging support - the Virtual Box boots perfectly with Nested Paging guest !
A lot of code duplication was added for now - major cleanup will follow later.
! Added AMD Phenom X3 8650 (Toliman) configuration to the CPUDB - this configuration has Nested Paging enabled.
Some CPUID modules rework done to enable Toliman configuration.
Ckean up 'executable' attribute from all CPU source files.
- VMX: EPT reserved bits set should cause EPT misconfiguration and not EPT violation
- VMX: EPT walk for guest CR3 address should be considered as 'page walk'
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.
