How to access performance counter directly?

Question

What I am going to do is programming with hardware performace counters of UltraSPARC T2+ processors in Solaris 10. I programmed a loadable syscall to invoke the hv_niagara_getperf or ultra_getpic, trying to get the counters' data. But there just comes a panic, unresponsive without any text notice, and then reset. I don't know what's the real causes because I am not very familiar with SUN servers.
I did some experiments both in primary domain and logical domain. In primary domain, both hv_niagara_getperf and ultra_getpic lead to panic, and in logical domain, hv_niagara_getperf return the ENOACCESS status and ultra_getpic lead to panic.
My question are:
1, If there is some initialization works or privilege settings to do to prevent panic?
2, If Logical Domain can be set privileges to access hardware performace counters? (I read the Hypervisor api manuals and it says only one domain can access performance counters. But vcpus is divided and allocated to different domains, every vcpu has its performace counters, how can I do to access their own performace counters in different domains?)
3, I know there are methods such as libcpc, cpc module, and pcbe module for users or develpers to get performace data. What I am working at is to make some threads performance tuning on UltraSPARC T2+, Is the overhead acceptable to use these library or modules supported by the OS architecture.
Please help me, indicate my fault and give me some advice or instruction. Thank you very much.

Answer 1

What I am going to do is programming with hardware performace counters of UltraSPARC T2+ processors in Solaris 10. I programmed a loadable syscall to invoke the hv_niagara_getperf or ultra_getpic, trying to get the counters' data. But there just comes a panic, unresponsive without any text notice, and then reset. I don't know what's the real causes because I am not very familiar with SUN servers.
I did some experiments both in primary domain and logical domain. In primary domain, both hv_niagara_getperf and ultra_getpic lead to panic, and in logical domain, hv_niagara_getperf return the ENOACCESS status and ultra_getpic lead to panic.
My question are:
1, If there is some initialization works or privilege settings to do to prevent panic?
2, If Logical Domain can be set privileges to access hardware performace counters? (I read the Hypervisor api manuals and it says only one domain can access performance counters. But vcpus is divided and allocated to different domains, every vcpu has its performace counters, how can I do to access their own performace counters in different domains?)
3, I know there are methods such as libcpc, cpc module, and pcbe module for users or develpers to get performace data. What I am working at is to make some threads performance tuning on UltraSPARC T2+, Is the overhead acceptable to use these library or modules supported by the OS architecture.
Please help me, indicate my fault and give me some advice or instruction. Thank you very much.