From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33411) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yx1UC-0004rU-06 for qemu-devel@nongnu.org; Mon, 25 May 2015 19:08:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yx1U8-0004x3-Pu for qemu-devel@nongnu.org; Mon, 25 May 2015 19:08:43 -0400 Received: from mail-pd0-x236.google.com ([2607:f8b0:400e:c02::236]:33631) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yx1U8-0004wp-He for qemu-devel@nongnu.org; Mon, 25 May 2015 19:08:40 -0400 Received: by pdbqa5 with SMTP id qa5so76956410pdb.0 for ; Mon, 25 May 2015 16:08:39 -0700 (PDT) Sender: Richard Henderson Message-ID: <5563AB72.3070601@twiddle.net> Date: Mon, 25 May 2015 16:08:34 -0700 From: Richard Henderson MIME-Version: 1.0 References: <1432511251-22515-1-git-send-email-aurelien@aurel32.net> <1432511251-22515-9-git-send-email-aurelien@aurel32.net> In-Reply-To: <1432511251-22515-9-git-send-email-aurelien@aurel32.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 08/10] target-s390x: implement STFLE instruction List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Aurelien Jarno , qemu-devel@nongnu.org Cc: Alexander Graf On 05/24/2015 04:47 PM, Aurelien Jarno wrote: > Cc: Alexander Graf > Cc: Richard Henderson > Signed-off-by: Aurelien Jarno Sadly, implementing this breaks current kernels. I did this about two years ago and havn't figured out what to do about it. The silly code in head.S doesn't check for just the facilities that it needs, it checks for all facilities that specific processors provide. If we don't e.g. pretend that we have HFP, despite the fact that no one uses it, the kernel won't boot. r~