From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50329) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkPXu-0003iP-Bc for qemu-devel@nongnu.org; Wed, 23 Aug 2017 02:53:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dkPXq-0008UD-C2 for qemu-devel@nongnu.org; Wed, 23 Aug 2017 02:53:46 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:35634) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dkPXq-0008Tv-2s for qemu-devel@nongnu.org; Wed, 23 Aug 2017 02:53:42 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7N6qhxi114396 for ; Wed, 23 Aug 2017 02:53:40 -0400 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ch43ptmdw-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 23 Aug 2017 02:53:40 -0400 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 23 Aug 2017 07:53:37 +0100 From: Christian Borntraeger Date: Wed, 23 Aug 2017 08:53:32 +0200 Message-Id: <1503471212-109371-1-git-send-email-borntraeger@de.ibm.com> Subject: [Qemu-devel] [PATCH v2] 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 , Christian Borntraeger , Christian Ehrhardt , Dan Horak 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 configure | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/configure b/configure index dd73cce..0b68b37 100755 --- a/configure +++ b/configure @@ -240,6 +240,11 @@ supported_target() { return 1 } + +ld_has() { + $ld --help 2>/dev/null | grep ".$1" >/dev/null 2>&1 +} + # default parameters source_path=$(dirname "$0") cpu="" @@ -5043,7 +5048,7 @@ fi # Use ASLR, no-SEH and DEP if available if test "$mingw32" = "yes" ; then for flag in --dynamicbase --no-seh --nxcompat; do - if $ld --help 2>/dev/null | grep ".$flag" >/dev/null 2>/dev/null ; then + if ld_had $flag ; then LDFLAGS="-Wl,$flag $LDFLAGS" fi done @@ -6522,6 +6527,20 @@ if test "$target_linux_user" = "yes" -o "$target_bsd_user" = "yes" ; then ldflags="$ldflags $textseg_ldflags" fi +# Newer kernels on s390 check for an S390_PGSTE program header and +# enable the pgste page table extensions in that case. This makes +# the vm.allocate_pgste sysctl unnecessary. We enable this program +# header if +# - we build on s390x +# - we build the system emulation for s390x (qemu-system-s390x) +# - KVM is enabled +# - the linker support --s390-pgste +if test "$TARGET_ARCH" = "s390x" -a "$target_softmmu" = "yes" -a "$ARCH" = "s390x" -a "$kvm" = "yes"; then + if ld_has --s390-pgste ; then + ldflags="-Wl,--s390-pgste $ldflags" + fi +fi + echo "LDFLAGS+=$ldflags" >> $config_target_mak echo "QEMU_CFLAGS+=$cflags" >> $config_target_mak -- 2.7.4