https://bugzilla.kernel.org/show_bug.cgi?id=206579 --- Comment #32 from Suravee Suthikulpanit (suravee.suthikulpanit@xxxxxxx) --- (In reply to Anthony from comment #28) > Created attachment 287685 [details] > avic_inhibit_reasons-anthony > > Hi I also just wanted to give my observations I have found when testing the > patches. > > I confirm I also don't have don't have crashes relating to the original > report. > > I have been trying out the SVM AVIC patches since around the first patch > that was submitted but never got round to documentation my testing until > recently. > > I can't remember the specific patch set/kernel version I tried but I > remember having avic apparently working with when synic + stimer where > enabled but not without. If my understanding is correctly this shouldn't be > the case as synic is meant to be a case when avic is permanently disabled. > > This is still the case with current patchset. > > In summary I can get avic reporting it's working according to perf stat and > trace logs when synic is on but not working when synic is off. Using > EPYC-IBPB or passthrough doesn't change the avic_inhibit_reasons. > > With Synic I get avic_inhibit_reasons - 10 > With Synic+Stimer off I get - 0 > > > To note I am using arch linux + qemu 4.2 + linux-mainline-5.6.0-rc2. > > Please see a small trace log of synic on vs off, domain capabilities, perf > stat and patches used. > > These were recording once the VM was launched and sitting at the login > screen. > > Please let me know if there is any other info I get provide to help. Thanks for the observation info, and your observation makes sense. AVIC is also deactivated w/ synic enabled. (https://elixir.bootlin.com/linux/v5.6-rc3/source/arch/x86/kvm/hyperv.c#L773) Thanks, Suravee -- You are receiving this mail because: You are watching the assignee of the bug.
