From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35932) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkUqd-00011Y-F7 for qemu-devel@nongnu.org; Wed, 23 Aug 2017 08:33:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dkUqX-0007GE-L8 for qemu-devel@nongnu.org; Wed, 23 Aug 2017 08:33:27 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:55049 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dkUqX-0007Fy-G5 for qemu-devel@nongnu.org; Wed, 23 Aug 2017 08:33:21 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7NCSqSh119967 for ; Wed, 23 Aug 2017 08:33:20 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ch4ker1ay-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 23 Aug 2017 08:33:20 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 23 Aug 2017 13:33:18 +0100 References: <1503483383-199649-1-git-send-email-borntraeger@de.ibm.com> <20170823143128.7cc7ae68.cohuck@redhat.com> From: Christian Borntraeger Date: Wed, 23 Aug 2017 14:33:13 +0200 MIME-Version: 1.0 In-Reply-To: <20170823143128.7cc7ae68.cohuck@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Message-Id: Subject: Re: [Qemu-devel] [PATCH v3] configure: enable --s390-pgste linker option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Cornelia Huck Cc: qemu-devel , Alexander Graf , Thomas Huth , David Hildenbrand , Janosch Frank , Paolo Bonzini , Christian Ehrhardt , Dan Horak On 08/23/2017 02:31 PM, Cornelia Huck wrote: > On Wed, 23 Aug 2017 12:16:23 +0200 > Christian Borntraeger wrote: > >> KVM guests on s390 need a different page table layout than normal >> processes (2kb page table + 2kb page status extensions vs 2kb page table >> only). As of today this has to be enabled via the vm.allocate_pgste >> sysctl. >> >> Newer kernels (>= 4.12) on s390 check for an S390_PGSTE program header >> and enable the pgste page table extensions in that case. This makes the >> vm.allocate_pgste sysctl unnecessary. We enable this program header for >> the s390 system emulation (qemu-system-s390x) if we build on s390 >> - for s390 system emulation >> - the linker supports --s390-pgste (binutils >= 2.29) >> - KVM is enabled >> >> This will allow distributions to disable the global vm.allocate_pgste >> sysctl, which will improve the page table allocation for non KVM >> processes as only 2kb chunks are necessary. >> >> Cc: Christian Ehrhardt >> Cc: Alexander Graf >> Cc: Dan Horak >> Cc: David Hildenbrand >> Signed-off-by: Christian Borntraeger >> Acked-by: Janosch Frank >> --- >> V1->V2: >> - provide ld_has function >> - use ld_has to replace some open coded variants >> - check target arch and arch for s390 >> - check for s390x before calling the linker >> V2->V3: >> - fix typos >> configure | 21 ++++++++++++++++++++- >> 1 file changed, 20 insertions(+), 1 deletion(-) > > Looks sane. > > I guess I'll wait for some more Acks or R-bs and then queue it to > s390-next. Sure. Looks like I forgot to add Thomas/Davids R-bs, so please add those.