Re: kern/50332 (AVX instructions don't work but OSXSAVE flag is set)

[Jaromír Doleček <jaromir.dolecek%gmail.com@localhost>]

The following reply was made to PR port-xen/50332; it has been noted by GNATS.

From: =?UTF-8?B?SmFyb23DrXIgRG9sZcSNZWs=?= <jaromir.dolecek%gmail.com@localhost>
To: "gnats-bugs%NetBSD.org@localhost" <gnats-bugs%netbsd.org@localhost>, Manuel Bouyer <bouyer%antioche.eu.org@localhost>
Cc: 
Subject: Re: kern/50332 (AVX instructions don't work but OSXSAVE flag is set)
Date: Tue, 19 Jun 2018 00:55:27 +0200

 I'm working on this, have some local hacks in xen/cpu.c with which the
 AVX test program passes. It seems we could just test for OSXSAVE being
 already set in Xen case. For Xen, NetBSD kernel does not modify this
 option. On my machine, that flag is set when I boot DOMU with default
 options, and not set when I add no-xsave. So perhaps we could have
 conditional on this only.
 
 Manuel, you observed that panic after max's commits in 2017-11-07
 which led to fixes in rev 1.26 and 1.27 of arch/x86/x86/fpu.c
 
 I've checked on releng.netbsd.org, that machine has this flag also
 off, but it's DOMU. Can you please confirm to me whether cpuctl
 identify returns OSXSAVE on the appropriate DOM0, under which you run
 that DOMU anita run which panicced?
 
 Jaromir