From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36475) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBAl0-0006Oo-Mj for qemu-devel@nongnu.org; Wed, 17 May 2017 22:01:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBAkw-00073r-Pu for qemu-devel@nongnu.org; Wed, 17 May 2017 22:01:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47778) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dBAkw-00073h-GB for qemu-devel@nongnu.org; Wed, 17 May 2017 22:01:34 -0400 References: <1495035337-13337-1-git-send-email-thuth@redhat.com> <20170517162642.ebmrhawmfdde5vsz@aurel32.net> From: Thomas Huth Message-ID: <4d64a1a0-71dd-5ea0-6d2f-e2fa547cfbe3@redhat.com> Date: Thu, 18 May 2017 04:01:27 +0200 MIME-Version: 1.0 In-Reply-To: <20170517162642.ebmrhawmfdde5vsz@aurel32.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH] target/s390x/cpu_models: Set some additional feature bits for the "qemu" CPU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Aurelien Jarno Cc: qemu-devel@nongnu.org, Richard Henderson , Alexander Graf , David Hildenbrand , mmarek@suse.com, mbenes@suse.cz On 17.05.2017 18:26, Aurelien Jarno wrote: > On 2017-05-17 17:35, Thomas Huth wrote: >> Currently we only present the plain z900 feature bits to the guest, >> but QEMU already emulates some additional features (but not all of >> the next CPU generation, so we can not use the next CPU level as >> default yet). Since newer Linux kernels are checking the feature bits >> and refuse to work if a required feature is missing, we should present >> as much of the supported features as possible when we are running >> with the default "qemu" CPU. >> This patch now adds the "stfle", "extended immediate" and "stckf" >> facility bits to the "qemu" CPU, which are already supported facilities. >> It is unfortunately still not enough to run e.g. recent Fedora kernels, >> but at least it's a first step into the right direction. > > This indeed looks like a step in a good direction. At least it makes the > recently added STFLE emulation useful :-). > >> Signed-off-by: Thomas Huth >> --- >> target/s390x/cpu_models.c | 29 ++++++++++++++++++++++++++--- >> 1 file changed, 26 insertions(+), 3 deletions(-) >> >> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c >> index 8d27363..18789ab 100644 >> --- a/target/s390x/cpu_models.c >> +++ b/target/s390x/cpu_models.c >> @@ -658,6 +658,24 @@ static void check_compatibility(const S390CPUModel *max_model, >> "available in the configuration: "); >> } >> >> +/** >> + * The base TCG CPU model "qemu" is based on the z900. However, we already >> + * can also emulate some additional features of later CPU generations, so >> + * we add these additional feature bits here. >> + */ >> +static void add_qemu_cpu_model_features(S390FeatBitmap fbm) >> +{ >> + int i, feats[] = { >> + S390_FEAT_STFLE, >> + S390_FEAT_EXTENDED_IMMEDIATE, >> + S390_FEAT_STORE_CLOCK_FAST > > According to my list, QEMU also fully implements the following > facilities: > > S390_FEAT_LONG_DISPLACEMENT > S390_FEAT_GENERAL_INSTRUCTIONS_EXT > S390_FEAT_EXECUTE_EXT > S390_FEAT_STFLE_45 Ok, thanks, I'll respin and add them to the list! >> + }; >> + >> + for (i = 0; i < ARRAY_SIZE(feats); i++) { >> + set_bit(feats[i], fbm); >> + } >> +} >> + >> static S390CPUModel *get_max_cpu_model(Error **errp) >> { >> static S390CPUModel max_model; >> @@ -670,10 +688,11 @@ static S390CPUModel *get_max_cpu_model(Error **errp) >> if (kvm_enabled()) { >> kvm_s390_get_host_cpu_model(&max_model, errp); >> } else { >> - /* TCG emulates a z900 */ >> + /* TCG emulates a z900 (with some additional features) */ >> max_model.def = &s390_cpu_defs[0]; >> bitmap_copy(max_model.features, max_model.def->default_feat, >> S390_FEAT_MAX); >> + add_qemu_cpu_model_features(max_model.features); >> } >> if (!*errp) { >> cached = true; >> @@ -925,11 +944,15 @@ static void s390_host_cpu_model_initfn(Object *obj) >> >> static void s390_qemu_cpu_model_initfn(Object *obj) >> { >> + static S390CPUDef s390_qemu_cpu_defs; >> S390CPU *cpu = S390_CPU(obj); >> >> cpu->model = g_malloc0(sizeof(*cpu->model)); >> - /* TCG emulates a z900 */ >> - cpu->model->def = &s390_cpu_defs[0]; >> + /* TCG emulates a z900 (with some additional features) */ >> + memcpy(&s390_qemu_cpu_defs, &s390_cpu_defs[0], sizeof(s390_qemu_cpu_defs)); >> + add_qemu_cpu_model_features(s390_qemu_cpu_defs.default_feat); >> + add_qemu_cpu_model_features(s390_qemu_cpu_defs.full_feat); >> + cpu->model->def = &s390_qemu_cpu_defs; >> bitmap_copy(cpu->model->features, cpu->model->def->default_feat, >> S390_FEAT_MAX); >> } > > Otherwise it looks fine to me. > > Reviewed-by: Aurelien Jarno Thanks! Thomas