NetBSD Problem Report #55955

From  Sun Jan 24 13:51:48 2021
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Date: Sun, 24 Jan 2021 13:51:46 +0000 (UTC)
Subject: guest NetBSD 9.1 does not boot in qemu-kvm with "-cpu host" on Phenom II X4 970 CPU on ubuntu 20.04
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>Number:         55955
>Category:       port-amd64
>Synopsis:       guest NetBSD 9.1 does not boot in qemu-kvm with "-cpu host" on Phenom II X4 970 CPU on ubuntu 20.04
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jan 24 13:55:00 +0000 2021
>Last-Modified:  Sun Jan 24 14:01:06 +0000 2021
>Originator:     Vadim
>Release:        9.1
host OS: linux ubuntu 20.04
host uname -a: Linux **** 5.4.0-62-generic #70-Ubuntu SMP Tue Jan 12 12:45:47 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
qemu: 5.2.0 (compiled from sources) or 4.2.1 (from ubuntu-supplied packages)
When I start qemu 5.2.0 like:

./qemu-system-x86_64 -accel kvm -hda NetBSD-9.1-i386-install.img -cpu host

Boot process does not go behind a very first string with 6 numbers, rebooting the guest machine quietly and immediately.

This no-boot happens also with "-cpu Phenom" and "-cpu Opteron_G3" but not with other "Opteron_Gn", n=1,2,4,5 (they do boot).

This also happens with other install images: NetBSD-9.1-amd64-install.img, NetBSD-9.1-i386.iso and NetBSD-9.1-amd64.iso.

Exactly same also happens when using "qemu-system-i386", obviously only for "i386" images.

The same no-boot happened with 9.0 install images, although I've not tested them thoroughfully.

When I try to boot my host machine off an USB stick with NetBSD-9.1-i386-install.img on it, it boots (at least) up to the keyboard selection menu.

NetBSD-8.2-amd64.iso install image seems to boot OK in qemu under the same circumstances.

1. get host machine with the mentioned CPU and ubuntu 20.04 on it

2. get and compile qemu-5.2.0 with KVM support. (although qemu-4.2.1 from ubuntu packages also shows that bug)

3. run NetBSD install images as described.

Do not use "-cpu host" or "-cpu Phenom" or "-cpu Opteron_G3" option, which however does not allow guest OS to see host CPUID flags.

"-cpu host" is the default option in ubuntu-provided "virt manager" virtualization software.



Responsible-Changed-From-To: install-manager->port-amd64-maintainer
Responsible-Changed-When: Sun, 24 Jan 2021 14:01:06 +0000
x86 specific issue


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