From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Knorr Subject: Re: xen on suse 9.3 and software raid Date: Thu, 12 May 2005 16:28:18 +0200 Message-ID: <20050512142818.GA32316@bytesex> References: <4271F381.4010303@microbus.com> <42720A1B.3010905@microbus.com> <8764xri5h0.fsf@bytesex.org> <428218F7.1070605@microbus.com> <20050512135235.GC31317@bytesex> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20050512135235.GC31317@bytesex> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-users-bounces@lists.xensource.com Errors-To: xen-users-bounces@lists.xensource.com To: Robbie Dinn Cc: xen-devel@lists.xensource.com, xen-users@lists.xensource.com, agruen@suse.de List-Id: xen-devel@lists.xenproject.org [ adding xen-devel to Cc: ] > Just loading the raid6 module in a xen domain makes my > machine oops, log below. I'd guess it's because the > module attempts to use mmx within the kernel, which is > a bit tricky because you have to save/restore userspace > fp state for that. Could be a corner case which simply > doesn't work with xen. Confirmed, the faulting instruction is a attempt to access cr0, right here: static inline unsigned long raid6_get_fpu(void) { unsigned long cr0; preempt_disable(); asm volatile("mov %%cr0,%0 ; clts" : "=r" (cr0)); return cr0; } (which is called by raid6_before_mmx, which in turn is called by raid6_mmx1_gen_syndrome, both calls not visible in the trace because they are inlined). Ideas how to fix that? Other than just disabling raid6? Can that code be replaced with xen hypercalls? fsave & frestore are also used btw. It's all in drivers/md/raid6x86.h Gerd -- -mm seems unusually stable at present. -- akpm about 2.6.12-rc3-mm3