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path: root/arch/x86/kvm/cpuid.c
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2012-12-05KVM: x86: Make register state after reset conform to specificationJulian Stecklina
VMX behaves now as SVM wrt to FPU initialization. Code has been moved to generic code path. General-purpose registers are now cleared on reset and INIT. SVM code properly initializes EDX. Signed-off-by: Julian Stecklina <jsteckli@os.inf.tu-dresden.de> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-11-30KVM: x86: Emulate IA32_TSC_ADJUST MSRWill Auld
CPUID.7.0.EBX[1]=1 indicates IA32_TSC_ADJUST MSR 0x3b is supported Basic design is to emulate the MSR by allowing reads and writes to a guest vcpu specific location to store the value of the emulated MSR while adding the value to the vmcs tsc_offset. In this way the IA32_TSC_ADJUST value will be included in all reads to the TSC MSR whether through rdmsr or rdtsc. This is of course as long as the "use TSC counter offsetting" VM-execution control is enabled as well as the IA32_TSC_ADJUST control. However, because hardware will only return the TSC + IA32_TSC_ADJUST + vmsc tsc_offset for a guest process when it does and rdtsc (with the correct settings) the value of our virtualized IA32_TSC_ADJUST must be stored in one of these three locations. The argument against storing it in the actual MSR is performance. This is likely to be seldom used while the save/restore is required on every transition. IA32_TSC_ADJUST was created as a way to solve some issues with writing TSC itself so that is not an option either. The remaining option, defined above as our solution has the problem of returning incorrect vmcs tsc_offset values (unless we intercept and fix, not done here) as mentioned above. However, more problematic is that storing the data in vmcs tsc_offset will have a different semantic effect on the system than does using the actual MSR. This is illustrated in the following example: The hypervisor set the IA32_TSC_ADJUST, then the guest sets it and a guest process performs a rdtsc. In this case the guest process will get TSC + IA32_TSC_ADJUST_hyperviser + vmsc tsc_offset including IA32_TSC_ADJUST_guest. While the total system semantics changed the semantics as seen by the guest do not and hence this will not cause a problem. Signed-off-by: Will Auld <will.auld@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-09-05KVM: x86: minor size optimizationMathias Krause
Some fields can be constified and/or made static to reduce code and data size. Numbers for a 32 bit build: text data bss dec hex filename before: 3351 80 0 3431 d67 cpuid.o after: 3391 0 0 3391 d3f cpuid.o Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-20KVM: x86: Fix typos in cpuid.cGuo Chao
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-12KVM: VMX: Implement PCID/INVPCID for guests with EPTMao, Junjie
This patch handles PCID/INVPCID for guests. Process-context identifiers (PCIDs) are a facility by which a logical processor may cache information for multiple linear-address spaces so that the processor may retain cached information when software switches to a different linear address space. Refer to section 4.10.1 in IA32 Intel Software Developer's Manual Volume 3A for details. For guests with EPT, the PCID feature is enabled and INVPCID behaves as running natively. For guests without EPT, the PCID feature is disabled and INVPCID triggers #UD. Signed-off-by: Junjie Mao <junjie.mao@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-09KVM: Split cpuid register access from computationAvi Kivity
Introduce kvm_cpuid() to perform the leaf limit check and calculate register values, and let kvm_emulate_cpuid() just handle reading and writing the registers from/to the vcpu. This allows us to reuse kvm_cpuid() in a context where directly reading and writing registers is not desired. Signed-off-by: Avi Kivity <avi@redhat.com>
2012-06-25KVM: host side for eoi optimizationMichael S. Tsirkin
Implementation of PV EOI using shared memory. This reduces the number of exits an interrupt causes as much as by half. The idea is simple: there's a bit, per APIC, in guest memory, that tells the guest that it does not need EOI. We set it before injecting an interrupt and clear before injecting a nested one. Guest tests it using a test and clear operation - this is necessary so that host can detect interrupt nesting - and if set, it can skip the EOI MSR. There's a new MSR to set the address of said register in guest memory. Otherwise not much changed: - Guest EOI is not required - Register is tested & ISR is automatically cleared on exit For testing results see description of previous patch 'kvm_para: guest side for eoi avoidance'. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-06KVM: fix cpuid eax for KVM leafMichael S. Tsirkin
cpuid eax should return the max leaf so that guests can find out the valid range. This matches Xen et al. Update documentation to match. Tested with -cpu host. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08KVM: x86: expose Intel cpu new features (HLE, RTM) to guestLiu, Jinsong
Intel recently release 2 new features, HLE and RTM. Refer to http://software.intel.com/file/41417. This patch expose them to guest. Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05KVM: SVM: Add support for AMD's OSVW feature in guestsBoris Ostrovsky
In some cases guests should not provide workarounds for errata even when the physical processor is affected. For example, because of erratum 400 on family 10h processors a Linux guest will read an MSR (resulting in VMEXIT) before going to idle in order to avoid getting stuck in a non-C0 state. This is not necessary: HLT and IO instructions are intercepted and therefore there is no reason for erratum 400 workaround in the guest. This patch allows us to present a guest with certain errata as fixed, regardless of the state of actual hardware. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: Expose the architectural performance monitoring CPUID leafGleb Natapov
Provide a CPUID leaf that describes the emulated PMU. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: Expose a version 2 architectural PMU to a guestsGleb Natapov
Use perf_events to emulate an architectural PMU, version 2. Based on PMU version 1 emulation by Avi Kivity. [avi: adjust for cpuid.c] [jan: fix anonymous field initialization for older gcc] Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: x86: Do not rely on implicit inclusionsJan Kiszka
Works so far by change, but it is not guaranteed to stay like this. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-27KVM: Refactor and simplify kvm_dev_ioctl_get_supported_cpuidSasha Levin
This patch cleans and simplifies kvm_dev_ioctl_get_supported_cpuid by using a table instead of duplicating code as Avi suggested. This patch also fixes a bug where kvm_dev_ioctl_get_supported_cpuid would return -E2BIG when amount of entries passed was just right. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: expose latest Intel cpu new features (BMI1/BMI2/FMA/AVX2) to guestLiu, Jinsong
Intel latest cpu add 6 new features, refer http://software.intel.com/file/36945 The new feature cpuid listed as below: 1. FMA CPUID.EAX=01H:ECX.FMA[bit 12] 2. MOVBE CPUID.EAX=01H:ECX.MOVBE[bit 22] 3. BMI1 CPUID.EAX=07H,ECX=0H:EBX.BMI1[bit 3] 4. AVX2 CPUID.EAX=07H,ECX=0H:EBX.AVX2[bit 5] 5. BMI2 CPUID.EAX=07H,ECX=0H:EBX.BMI2[bit 8] 6. LZCNT CPUID.EAX=80000001H:ECX.LZCNT[bit 5] This patch expose these features to guest. Among them, FMA/MOVBE/LZCNT has already been defined, MOVBE/LZCNT has already been exposed. This patch defines BMI1/AVX2/BMI2, and exposes FMA/BMI1/AVX2/BMI2 to guest. Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-27KVM: Move cpuid code to new fileAvi Kivity
The cpuid code has grown; put it into a separate file. Signed-off-by: Avi Kivity <avi@redhat.com>