Hi Marc, On 2020/7/14 19:34, Marc Zyngier wrote: > Hi Keqian, > > On 2020-07-14 03:20, zhukeqian wrote: >> Hi all, >> >> We are studying Enhanced Counter Virtualization (introduced by ARMv8.6 >> extension), and here is a question >> raised by Biaoxiang Ye <yebiaoxiang@xxxxxxxxxx>: >> >> Described in the ARMv8.6 Extension Specification: >> Note: the scaling factor CNTSCALE is designed as a 2.62 bit fixed >> point number, so permitting a scaling up by >> (nearly) a factor 4. The scaling factor CNTISCALE is signed as an 8.56 >> number for the scaling of the values >> written into the timers for comparison with the actual count. This >> implies that the greatest scaling down of the >> counter supported in (nearly) a factor of *512*. >> >> We think the number "512" should be "256" (2^8), or do we miss something? > > This register doesn't seem to be described in ARM DDI 0487F.b, > which is the official documentation and does contain the ARMv8.6 > material, including ARMv8.6-ECV. > > Either you are looking at confidential information (and nobody > can answer you in public), or obsolete information (and nobody > knows what this is about). > Well, it's alpha release version :( . Many thanks! Thanks, Keqian > In any case, this is most probably a question for ARM's support > team, and not the kernel mailing lists. > > Thanks, > > M. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
