Hi, On Mon, Feb 10, 2020 at 11:47:49AM +0800, Wu Hao wrote: > This patch adds support for performance reporting private feature > for FPGA Management Engine (FME). Now it supports several different > performance counters, including 'basic', 'cache', 'fabric', 'vtd' > and 'vtd_sip'. It allows user to use standard linux tools to access > these performance counters. I had a quick look at this, and it mostly looks alright to me. Just a few high-level comments/questions: - I would still prefer for the PMU drivers to live under drivers/perf/ - You should probably give the PMU a better name than "fme%d", for example "intel_fpga_dfl_fme%d". - CPU0 can be hotplugged off on non-x86 systems. How do you cope with that? - readq() will emit 2x32-bit reads on some architectures. What happens in this case? Will