From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42659) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dX9wx-0003WE-NM for qemu-devel@nongnu.org; Mon, 17 Jul 2017 13:36:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dX9wv-0002Nw-3D for qemu-devel@nongnu.org; Mon, 17 Jul 2017 13:36:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48688) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dX9wu-0002NY-Qa for qemu-devel@nongnu.org; Mon, 17 Jul 2017 13:36:49 -0400 From: David Hildenbrand References: <1500028867-134709-1-git-send-email-borntraeger@de.ibm.com> <1500028867-134709-36-git-send-email-borntraeger@de.ibm.com> <344b342f-7aaa-22d8-37b6-c96d2840c20b@redhat.com> Message-ID: Date: Mon, 17 Jul 2017 19:36:44 +0200 MIME-Version: 1.0 In-Reply-To: <344b342f-7aaa-22d8-37b6-c96d2840c20b@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL 35/40] s390x/cpumodel: we are always in zarchitecture mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger , Peter Maydell Cc: Thomas Huth , Cornelia Huck , qemu-devel , Alexander Graf , "Jason J. Herne" , Richard Henderson On 17.07.2017 19:33, David Hildenbrand wrote: > On 14.07.2017 12:41, Christian Borntraeger wrote: >> From: "Jason J. Herne" >> >> In QEMU, a guest VCPU always started in and never was able to leave >> z/Architecture mode. Now we have an architected way of showing this >> condition. >> >> The SIGP SET ARCHITECTURE instruction is simply rejected. Linux as guest >> seems to not care about the return value, which is a good thing >> The new handling is just like already being in z/Architecture mode. >> >> We'll not try to fake absence of this facility, but still not indicate >> the facility in case some strange CPU model turned z/Architecture off >> completely (which doesn't work either way but let's us see how a >> guest would react on a lack of this facility). >> >> Signed-off-by: Jason J. Herne >> Acked-by: Christian Borntraeger >> Acked-by: Cornelia Huck >> Signed-off-by: Christian Borntraeger >> --- >> target/s390x/cpu_features.c | 5 +++-- >> target/s390x/kvm.c | 38 +++++++++++--------------------------- >> 2 files changed, 14 insertions(+), 29 deletions(-) >> >> diff --git a/target/s390x/cpu_features.c b/target/s390x/cpu_features.c >> index e5a3f71..fa887d9 100644 >> --- a/target/s390x/cpu_features.c >> +++ b/target/s390x/cpu_features.c >> @@ -337,8 +337,9 @@ void s390_fill_feat_block(const S390FeatBitmap features, S390FeatType type, >> int bit_nr; >> >> if (type == S390_FEAT_TYPE_STFL && test_bit(S390_FEAT_ZARCH, features)) { >> - /* z/Architecture is always active if around */ >> - data[0] |= 0x20; >> + /* Features that are always active */ >> + data[0] |= 0x20; /* z/Architecture */ >> + data[17] |= 0x20; /* Configuration-z-architectural-mode */ >> } > > This also requires changes in TCG , no? (set architecture there is left > untouched) > > Never mind, just realized we do our own block creation in do_stfle.... -- Thanks, David