similar to: [PATCH v4 3/7] X86: MPX IA32_BNDCFGS msr handle

X86: implement PCID/INVPCID for hvm This patch handle PCID/INVPCID for hvm: For hap hvm, we enable PCID/INVPCID, since no need to intercept INVPCID, and we just set INVPCID non-root behavior as running natively; For shadow hvm, we disable PCID/INVPCID, otherwise we need to emulate INVPCID at vmm by setting INVPCID non-root behavior as vmexit. Signed-off-by: Liu, Jinsong

[VMX] Add support for Pause-Loop Exiting New NHM processors will support Pause-Loop Exiting by adding 2 VM-execution control fields: PLE_Gap - upper bound on the amount of time between two successive executions of PAUSE in a loop. PLE_Window - upper bound on the amount of time a guest is allowed to execute in a PAUSE loop If the time, between this execution of PAUSE

The "APIC-register virtualization" and "virtual-interrupt deliver" VM-execution control has no effect on the behavior of RDMSR/WRMSR if the "virtualize x2APIC mode" VM-execution control is 0. When guest uses x2APIC mode, we should enable "virtualize x2APIC mode" for APICV first. Signed-off-by: Jiongxi Li <jiongxi.li@intel.com> diff --git

Changes from v2 to v3: - Use pfn_to_paddr() to get the address from frame number instead of doing shift directly. - Remove some unnecessary initialization code and add "static" to vmentry_fields and gpdptr_fields. - Enable the VMREAD/VMWRITE bitmap only if nested hvm is enabled. - Use clear_page() to set all 0 to the page instead of memset(). - Use domheap to allocate the

I am a newcomer to Centos and could benefit from some help. I am repurposing an older server and installed Centos 6.7 on a Tyan Tiger MPX 2466 motherboard. The installation went flawlessly but the graphics chip on the motherboard is obviously quite old, a Matrix Millennium MGA 2064W, and the slow default driver (VESA?) was installed. Is a faster video driver available? It would be nice to be

> First, is MPX hardware available now? I wouldn't mind getting my hands on > one. It is available at least in the mobile versions of the recent Intel Skylake CPUs. I am currently playing with Alienware 15 R2 with the following CPU: Intel(R) Core(TM) i7-6820HK. Interestingly, my preliminary experiments indicate that adding MPX bounds checking via Pointer Checker in gcc is usually

Hello, As far as I know, there is no MPX pass in LLVM (though the x86-64 backend already declares MPX registers and instructions). I wonder if anyone is currently working on the LLVM pass for MPX instrumentation, similar to Pointer Checker in gcc. If yes, could anyone elaborate on the status and accessability to other researchers? And if any help is needed? Prof. Santosh Nagarakatte, the author

On Thu, Feb 4, 2016 at 4:59 AM, Dmitrii Kuvaiskii < Dmitrii.Kuvaiskii at tu-dresden.de> wrote: > >> Recently I played with MPX support on Intel C/C++ Compiler (icc). This > >> implementation looks *much* better, with the following example > >> overheads: 1.2X on "raytrace", 1.25X on "bodytrack", 1.08X on > >> "streamcluster".

On Wed, Feb 3, 2016 at 6:27 AM, Dmitrii Kuvaiskii < Dmitrii.Kuvaiskii at tu-dresden.de> wrote: > I continue playing with Intel MPX and its support in modern compilers. > All experiments were done on the Alienware (Dell) 15 R2, Ubuntu 15.10 > (linux 4.2.0), gcc version is 5.2.1, icc version 2016.1.150. The > benchmark suite is PARSEC 3.0, all versions with 1 thread and default

Dmitrii, all, Please note, that GCC 5.3 had a significant update to the MPX code quality - please, use this version as reference. Regards, Sergos On Tue, Feb 9, 2016 at 12:49 AM, Kostya Serebryany via llvm-dev < llvm-dev at lists.llvm.org> wrote: > > > On Thu, Feb 4, 2016 at 10:40 AM, Kostya Serebryany <kcc at google.com> wrote: > >> >> >> On Thu, Feb

Intercepting this MSR is pointless - The swapgs instruction does not cause a vmexit, so the cached result of this is potentially stale after the next guest instruction. It is correctly saved and restored on vcpu context switch. Furthermore, 64bit Windows writes to this MSR on every thread context switch, so interception causes a substantial performance hit. From: Paul Durrant

I've recently played with the GCC implementation of pointer checker on a real hardware, my recent impressions are here: https://github.com/google/sanitizers/wiki/AddressSanitizerIntelMemoryProtectionExtensions (there is also some old pre-hardware content). In short, I totally agree with what David says above: MPX is a disaster. (Usual disclaimer: my opinion here is too biased) I am glad

SVI should be restored in case guest is processing virtual interrupt while saveing a domain state. Otherwise SVI would be missed when virtual interrupt delivery is enabled. Signed-off-by: Jiongxi Li <jiongxi.li@intel.com> diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c index ee2294c..38ff216 100644 --- a/xen/arch/x86/hvm/vlapic.c +++ b/xen/arch/x86/hvm/vlapic.c @@

On 2/7/2017 20:02, Kostya Serebryany wrote: > ... > > My understanding is that BNDCU is the cheapest possible instruction, > just like XOR or ADD, > so the overhead should be relatively small. > Still my guesstimate would be >= 5% since stores are very numerous. > And such overhead will be on top of whatever overhead SafeStack has. > Do you have any measurements to

hvm: clear vmxe if vmxoff The current Xen code keeps X86_CR4_VMXE set even if VMXON has not been executed. The stop_vmx() code assumes that it is possible to call VMXOFF if X86_CR4_VMXE is set which is not always true. Calling VMXOFF without VMXON results in an illegal opcode trap, and to avoid this condition this patch makes sure that X86_CR4_VMXE is only set when VMXON has been called.

Hello everyone, I'm a newbie of llvm. I'm trying to insert Intel MPX instruction BNDCU with BuildMI. I add my machinefunctionpass at addPreEmitPass2. Here is the code of insertion: BuildMI(MBB, MI, DL, TII->get(X86::BNDCU64rr)).addReg(X86::BND2, RegState::Define).addReg(X86::R10); And here is to stack track when I compiler program with modified llc:

This applies to both SVM and VMX. Signed-off-by: Jan Beulich <jbeulich@suse.com> --- a/xen/arch/x86/hvm/svm/vmcb.c +++ b/xen/arch/x86/hvm/svm/vmcb.c @@ -310,7 +310,7 @@ static struct keyhandler vmcb_dump_keyha .desc = "dump AMD-V VMCBs" }; -void setup_vmcb_dump(void) +void __init setup_vmcb_dump(void) { register_keyhandler(''v'',

TPR shadow/threshold feature is important to speedup the boot time for Windows guest. Besides, it is a must feature for certain VMM. We map virtual APIC page address and TPR threshold from L1 VMCS, and synch it into shadow VMCS in virtual vmentry. If TPR_BELOW_THRESHOLD VM exit is triggered by L2 guest, we inject it into L1 VMM for handling. Besides, this commit fixes an issue for apic access

Change from v2: re-written code in ''vmx_intr_assist'' into if()/else if() sequence to make code change easy to review. Virtual interrupt delivery avoids Xen to inject vAPIC interrupts manually, which is fully taken care of by the hardware. This needs some special awareness into existing interrupr injection path: For pending interrupt from vLAPIC, instead of direct injection, we

I recently realized that the original way of dealing with the DebugCtl MSR on VMX failed to make use of the dedicated guest VMCS field. This is being fixed with this patch. What is puzzling me to a certain degree is that while there is a guest VMCS field for this MSR, there''s no equivalent host load field, but there''s also no indication that the MSR would be cleared during a