From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46301) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WsaBb-00018i-Pv for qemu-devel@nongnu.org; Thu, 05 Jun 2014 12:06:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WsaBW-0001Ts-P8 for qemu-devel@nongnu.org; Thu, 05 Jun 2014 12:06:39 -0400 Sender: Richard Henderson Message-ID: <5390957C.3010405@twiddle.net> Date: Thu, 05 Jun 2014 09:06:20 -0700 From: Richard Henderson MIME-Version: 1.0 References: <1401961383-28601-1-git-send-email-agraf@suse.de> In-Reply-To: <1401961383-28601-1-git-send-email-agraf@suse.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] linux-user: Tell guest about big host page sizes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf , qemu-ppc@nongnu.org Cc: Riku Voipio , qemu-devel@nongnu.org On 06/05/2014 02:43 AM, Alexander Graf wrote: > We tell the guest its page size via AUX vectors. The guest process then uses > this page size as information on which boundaries it can mmap() things. > > However, if the host has a bigger page size granularity than the guest, it can > not fulfill these mmap() requests - which falls apart when MAP_FIXED is passed > to mmap. > > So in that case, let the guest know that we're running on a bigger page size > granularity than the target would require. > > This fixes running qemu-ppc (TARGET_PAGE_SIZE=4k) on a 64k page size ppc64 host > for me. > > Signed-off-by: Alexander Graf > --- > linux-user/elfload.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Woot. Obviously this won't fix all guests, only those that expect a variable page size to begin. But it's certainly a step forward. Reviewed-by: Richard Henderson r~