Triaging old bug tickets... can you still reproduce this issue with the latest version of QEMU? Or could we close this ticket nowadays?
** Changed in: qemu Status: New => Incomplete -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1318091 Title: Perfctr MSRs not available to Guest OS on AMD Phenom II Status in QEMU: Incomplete Bug description: The AMD Phenom(tm) II X4 965 Processor (family 16, model 4, stepping 3) has the 4 architecturally supported perf counters at MSRs. The selectors are c001000-c001003, and the counters are c001004-c001007. I've verified that the MSRs are there and working by manually setting the MSRs with msr-tools to count cycles. The processor does not support the extended perfctr or the perfctr_nb. These are in cpuid leaf 8000_0001. Qemu also sees that these cpuid flags are not set, when I try launching with -cpu host,perfctr_core,check. However, this flag is only for the extended perfctr MSRs, which also happen to map the original four counters at c0010200. When I run a Guest OS, that OS is unable to use the perf counter registers from c001000-7. rdmsr and wrmsr complete, but the results are always 0. By contrast, a wrmsr to one of the c0010200 registers causes a general protection fault (as it should, since those aren't supported). Kernel: 3.14.0-gentoo Qemu: 2.0.0 (gentoo) and also with 2.0.50 (commit 06b4f00d5) Qemu command: qemu-system-x86_64 -enable-kvm -cpu host -smp 8 -m 1024 -nographic -monitor /dev/pts/4 mnt/hdd.img cat /proc/cpuinfo: processor : 3 vendor_id : AuthenticAMD cpu family : 16 model : 4 model name : AMD Phenom(tm) II X4 965 Processor stepping : 3 cpu MHz : 800.000 cache size : 512 KB physical id : 0 siblings : 4 core id : 3 cpu cores : 4 apicid : 3 initial apicid : 3 fpu : yes fpu_exception : yes cpuid level : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt hw_pstate npt lbrv svm_lock nrip_save bogomips : 6803.79 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 48 bits physical, 48 bits virtual power management: ts ttp tm stc 100mhzsteps hwpstate thanks. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1318091/+subscriptions