From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34092) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yx1a7-0006EX-JA for qemu-devel@nongnu.org; Mon, 25 May 2015 19:14:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Yx1a2-0006PD-9V for qemu-devel@nongnu.org; Mon, 25 May 2015 19:14:51 -0400 Received: from cantor2.suse.de ([195.135.220.15]:33921 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Yx1a2-0006P7-29 for qemu-devel@nongnu.org; Mon, 25 May 2015 19:14:46 -0400 Message-ID: <5563ACE4.8040400@suse.de> Date: Tue, 26 May 2015 01:14:44 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1432511251-22515-1-git-send-email-aurelien@aurel32.net> <1432511251-22515-9-git-send-email-aurelien@aurel32.net> <5563AB72.3070601@twiddle.net> In-Reply-To: <5563AB72.3070601@twiddle.net> Content-Type: text/plain; charset=windows-1252 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: Richard Henderson , Aurelien Jarno , qemu-devel@nongnu.org On 26.05.15 01:08, Richard Henderson wrote: > 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. It depends on how the kernel is configured too. You can select the minimum CPU type it can run on. But in most distros it's set to something way beyond our current emulation scope. But again, the real solution to this would be to have -cpu available and have TCG available feature masks possible to get outed-out. Alex