Greetings. I have an image I've created with a bunch of chost flags which works on my machine when it comes to native boot. if I take that same image into a vm managed via libvirt, I get kernel panic. I'd assume that something is missing from my vm config, question is what and what I can do about it? here is the flags part of lscpu in native and vm: https://dpaste.com/3TR8QJ5G8 and the vm's xml: https://dpaste.com/984JX4LUQ if I build the image with the default flags (march=x86-64), the vm boots well. my new chost is -O2 -pipe -march=skylake -mabm -mno-adx -mno-avx -mno-avx2 -mno-bmi -mno-bmi2 -mno-f16c -mno-fma -mno-xsave -mno-xsavec -mno-xsaveopt -mno-xsaves -mno-sgx the cpu is Intel(R) Pentium(R) CPU G4560 @ 3.50GHz

thoughts? Thanks, Dagg.

Greetings Martin, > Sent: Thursday, November 19, 2020 at 11:23 PM > From: "Martin Kletzander" <mkletzan(a)redhat.com&gt; > To: "daggs" <daggs(a)gmx.com&gt; > Cc: "libvirt-usersredhat.com" <libvirt-users(a)redhat.com&gt; > Subject: Re: image works in native but not in vm when cpu mode='host-passthrough' is set > > On Tue, Nov 17, 2020 at 11:32:29AM +0100, daggs wrote: > ... > Not sure, but there might be some flags that are not passed through even with > host-passthrough. Virtualisation ones are definitely one of those that need to > be enabled on top of host-passthrough. The easiest thing to check that I can > think of would be booting some live distro and checking the flags in > /proc/cpuinfo and how are they different from your host. > I don't need livecd, I can diff both native and vm, see https://dpaste.com/ARETBEPCL from what I can see, the vm is missing these flags: dts acpi tm pbe art pebs bts nonstop_tsc aperfmperf dtes64 monitor ds_cpl est tm2 sdbg xtpr pdcm epb intel_pt dtherm pln pts hwp hwp_notify hwp_act_window hwp_epp and have these flags: tsc_known_freq hypervisor umip arch_capabilities beside the acpi flag which I found strange to be messing, I can't think of any other flag which might be needed.

Dagg.

Greetings Martin, > Sent: Monday, November 23, 2020 at 4:08 PM > From: "Martin Kletzander" <mkletzan(a)redhat.com&gt; > To: "daggs" <daggs(a)gmx.com&gt; > Cc: "libvirt-usersredhat.com" <libvirt-users(a)redhat.com&gt; > Subject: Re: image works in native but not in vm when cpu mode='host-passthrough' is set > > I'm sorry to say that, but nobody else here provides expertise, maybe extracting > the qemu command-lines from the logs and asking on qemu-users might be the best > next step. Sorry I cannot help you more as I do not see anything immediately > obvious here. > > Martin > seems like it, thanks for the help, I'll try over the qemu-users ml.