2016-05-27 09:49+0300, kmeaw@xxxxxxxxxxxxxx: > 26.05.2016, 23:44, "Gabriel L. Somlo" <gsomlo@xxxxxxxxx>: >> On Thu, May 26, 2016 at 10:39:31PM +0200, Radim Krčmář wrote: >>> 2016-05-26 10:32+0300, kmeaw@xxxxxxxxxxxxxx: >>> > This patch implements a dummy handler for MSR_IA32_PERF_CTL to avoid the >>> > crashes. Most notably it fixes an issue with MacOS X 10.10 kernel. >>> Does MacOS X write it too? >> >> After setting /sys/module/kvm/parameters/ignore_msrs, all I get in >> dmesg after firing up OS X is: >> >> vcpu0 ignored rdmsr: 0x199 >> >> So no, I don't think it would try to write it. > > That's right, OS X does not issue an wrmsr to 0x199. More specifically, I have not > observed that on my KVM instances. Should I remove the "wrmsr" portion from the > patch? Yes, please. Silently ignoring the write is worse than #GP and #GP is not a problem, so I wouldn't bother with a phony implementation. Returning 0 on read is ok as seems to mean P-state=0, which is within expectations. (I wonder why MacOS X doesn't read IA32_PERF_STATUS, though.) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
