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2014-04-24KVM: x86: Fix wrong/stuck PMU when guest does not use PMINadav Amit1-2/+5
If a guest enables a performance counter but does not enable PMI, the hypervisor currently does not reprogram the performance counter once it overflows. As a result the host performance counter is kept with the original sampling period which was configured according to the value of the guest's counter when the counter was enabled. Such behaviour can cause very bad consequences. The most distrubing one can cause the guest not to make any progress at all, and keep exiting due to host PMI before any guest instructions is exeucted. This situation occurs when the performance counter holds a very high value when the guest enables the performance counter. As a result the host's sampling period is configured to be very short. The host then never reconfigures the sampling period and get stuck at entry->PMI->exit loop. We encountered such a scenario in our experiments. The solution is to reprogram the counter even if the guest does not use PMI. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-07-19perf, kvm: Support the in_tx/in_tx_cp modifiers in KVM arch perfmon emulation v5Andi Kleen1-5/+20
[KVM maintainers: The underlying support for this is in perf/core now. So please merge this patch into the KVM tree.] This is not arch perfmon, but older CPUs will just ignore it. This makes it possible to do at least some TSX measurements from a KVM guest v2: Various fixes to address review feedback v3: Ignore the bits when no CPUID. No #GP. Force raw events with TSX bits. v4: Use reserved bits for #GP v5: Remove obsolete argument Acked-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-04-02pmu: prepare for migration supportPaolo Bonzini1-3/+11
In order to migrate the PMU state correctly, we need to restore the values of MSR_CORE_PERF_GLOBAL_STATUS (a read-only register) and MSR_CORE_PERF_GLOBAL_OVF_CTRL (which has side effects when written). We also need to write the full 40-bit value of the performance counter, which would only be possible with a v3 architectural PMU's full-width counter MSRs. To distinguish host-initiated writes from the guest's, pass the full struct msr_data to kvm_pmu_set_msr. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2012-07-26Merge branch 'queue' into nextAvi Kivity1-1/+1
Merge patches queued during the run-up to the merge window. * queue: (25 commits) KVM: Choose better candidate for directed yield KVM: Note down when cpu relax intercepted or pause loop exited KVM: Add config to support ple or cpu relax optimzation KVM: switch to symbolic name for irq_states size KVM: x86: Fix typos in pmu.c KVM: x86: Fix typos in lapic.c KVM: x86: Fix typos in cpuid.c KVM: x86: Fix typos in emulate.c KVM: x86: Fix typos in x86.c KVM: SVM: Fix typos KVM: VMX: Fix typos KVM: remove the unused parameter of gfn_to_pfn_memslot KVM: remove is_error_hpa KVM: make bad_pfn static to kvm_main.c KVM: using get_fault_pfn to get the fault pfn KVM: MMU: track the refcount when unmap the page KVM: x86: remove unnecessary mark_page_dirty KVM: MMU: Avoid handling same rmap_pde in kvm_handle_hva_range() KVM: MMU: Push trace_kvm_age_page() into kvm_age_rmapp() KVM: MMU: Add memslot parameter to hva handlers ... Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-20KVM: x86: Fix typos in pmu.cGuo Chao1-1/+1
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-05perf/x86: Rename Intel specific macrosRobert Richter1-11/+11
There are macros that are Intel specific and not x86 generic. Rename them into INTEL_*. This patch removes X86_PMC_IDX_GENERIC and does: $ sed -i -e 's/X86_PMC_MAX_/INTEL_PMC_MAX_/g' \ arch/x86/include/asm/kvm_host.h \ arch/x86/include/asm/perf_event.h \ arch/x86/kernel/cpu/perf_event.c \ arch/x86/kernel/cpu/perf_event_p4.c \ arch/x86/kvm/pmu.c $ sed -i -e 's/X86_PMC_IDX_FIXED/INTEL_PMC_IDX_FIXED/g' \ arch/x86/include/asm/perf_event.h \ arch/x86/kernel/cpu/perf_event.c \ arch/x86/kernel/cpu/perf_event_intel.c \ arch/x86/kernel/cpu/perf_event_intel_ds.c \ arch/x86/kvm/pmu.c $ sed -i -e 's/X86_PMC_MSK_/INTEL_PMC_MSK_/g' \ arch/x86/include/asm/perf_event.h \ arch/x86/kernel/cpu/perf_event.c Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1340217996-2254-2-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-04-10KVM: PMU emulation: GLOBAL_CTRL MSR should be enabled on resetGleb Natapov1-9/+9
On reset all MPU counters should be enabled in GLOBAL_CTRL MSR. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-05KVM: PMU: Fix integer constant is too large warning in kvm_pmu_set_msr()Sasikantha babu1-1/+1
Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: PMU: add proper support for fixed counter 2Gleb Natapov1-1/+2
Currently pmu emulation emulates fixed counter 2 as bus cycles architectural counter, but since commit 9c1497ea591b25d perf has pseudo encoding for it. Use it. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: PMU: Fix raw event checkGleb Natapov1-1/+1
If eventsel has EDGE, INV or CMASK set we should create raw counter for it, but the check is done on a wrong variable. Fix it. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: PMU: warn when pin control is set in eventsel msrGleb Natapov1-0/+3
Print warning once if pin control bit is set in eventsel msr since emulation does not support it yet. Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-08KVM: x86 emulator: correctly mask pmc index bits in RDPMC instruction emulationGleb Natapov1-1/+1
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 Natapov1-0/+533
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>