Re: TSC Frequency

2019-11-01 Thread Jan Kiszka
1997Ghz in that field. > The difference is so small that I don't have a good way to evaluate it. > > It does sometimes make the process of maintain a proper systick > frequency in custom RTOS painful. The forwarding of the Linux-measured TSC frequency is an offer to the inmates, not a must-use. You ca

Re: TSC Frequency

2019-10-31 Thread Chung-Fan Yang
I also noticed this. I am working on a Broadwell machine with 2.2Ghz of core frequency. Jailhouse get set the cpu_khz in comm region with the frequency probed by Linux during boot. I got somthing like ~2.1997Ghz in that field. The difference is so small that I don't have a good way to evaluate

Re: TSC Frequency

2019-10-31 Thread michael . g . hinton
I guess I should clarify (for my future sake, at least) that the Jailhouse driver automatically passes this Linux-derived frequency into each cell's config, while I'm planning on measuring frequency information from the MSRs directly within an inmate. -- You received this message because you

TSC Frequency

2019-10-31 Thread michael . g . hinton
Hello, I notice that on my machine (Coffee Lake architecture, Intel 8th Generation), apparently Linux detects a TSC frequency of 3,696,003,000 Hz. However, the Intel SDM Vol. 4 Table 2-20, under bits 8-15 of the PLATFORM_INFO_MSR (0xCE), says that the invariant TSC runs at the Maximum Non