Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933310AbbBQOZF (ORCPT ); Tue, 17 Feb 2015 09:25:05 -0500 Received: from e06smtp14.uk.ibm.com ([195.75.94.110]:47298 "EHLO e06smtp14.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756760AbbBQOZA (ORCPT ); Tue, 17 Feb 2015 09:25:00 -0500 From: Michael Mueller To: qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Gleb Natapov , Alexander Graf , Christian Borntraeger , "Jason J. Herne" , Cornelia Huck , Paolo Bonzini , Andreas Faerber , Richard Henderson , Michael Mueller Subject: [RFC PATCH v2 00/15] QEMU: s390: cpu model implementation Date: Tue, 17 Feb 2015 15:23:58 +0100 Message-Id: <1424183053-4310-1-git-send-email-mimu@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.4 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15021714-0017-0000-0000-000003116616 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5915 Lines: 132 This patch set in combination with its kernel kvm patch set proposes an implementation of S390 cpu models. The origin of this item is to provide a means for management interfaces like libvirt to draw decisions if life guest migration to a target hypervisor is reasonable. A migration constraint is that a target hypervisor is capable to run a guest with the same S390 cpu model as the source hypervisor does. To verify this condition, the administration interface employes the existing QMP command "query-cpu-definitions" which returns a list of all currently supported S390 cpu models of a given host system. Together with the newly defined QMP command "query-cpu-model", which returns the current active S390 cpu model of a guest, a conclusion can be drawn if a migration is possible. A S390 cpu model is defined as a triple of machine type, cpu facility set and IBC value. Each historic, current and future triple receives a name composed of the machine type and its general availability counter. This name forms the cpu model name (e.g.: "2817-ga2".) With means of the Instruction Blocking Control feature (IBC), the instruction set available to a given guest is limitable. Details: - The QMP command query-cpu-model returns the active cpu model and the accellerator it is using: {"name":"2066-ga1","accelerator":"kvm"} Or just the empty model in case an accelerator does not implement cpu models yet: {} - A management instance like libvirt may probe by means of the QMP command query-cpu-definitions which models are defined and usable for all supporting accelerators. To implement this the cpu definition info type gets an optional field named 'accelerators' which holds a list defining which cpu model is 'runnable' and in addition which one the 'default' cpu model is (i.e. the model to be used in the 'host' case). [{"name":"2964-ga1", "accelerators":[{"name":"kvm","runnable":false,"default":false}]} Or just 'host' in case an accelerator does not implement cpu models yet: [{"name":"host"}] - For accel=kvm the cpu model initialization takes place in kvm_arch_init() What's currently a little bit unclear to me is how to best initialize the various accelerators for machine 'none'. I played around with different options and finally came up with the following sugguestion: Introduce a QEMU "probe mode" that gets entered in case the current machine is "none" and no specific accelerator is requested on the cmd line. When in that mode, loop trough a list of acellerators in configure_accelerator and invoke all their init methods once. The last accelerator to init shall be tcg. In cpu model context that allows to initialize the S390 CPU classes for each single accelertor which supports it. Whence the callback for qemu-cpu-definitions allows to populate its answer string according to the above sketched extended CpuDefinitionInfo type for multiplaccelerators. v1-v2: - QEMU-side facility list mask introduced: this allows to enable guest facilities that are handled by instruction interception handlers implemented on qemu side. Similar to the facilities enabled by means of the KVM side facility list mask which are handled by kvm/kernel. - Concept of soft facilities has been dropped - Result type of QMP command query-cpu-definitions extended to hold additional information beside the cpu model name including which cpu model is runnable in current accelerator and machine context. Michael Mueller (15): cpu-model: Introduce probe mode for machine none cpu-model: Introduce option --probe to switch into probe mode cpu-model: Introduce stub routine cpu_desc_avail cpu-model/s390: Introduce S390 CPU models cpu-model/s390: Introduce S390 CPU facilities cpu-model/s390: Define cpu model specific facility lists cpu-model/s390: Add cpu model alias definition routines cpu-model/s390: Update linux-headers/asm-s390/kvm.h cpu-model/s390: Add KVM VM attribute interface routines cpu-model/s390: Add cpu class initialization routines cpu-model/s390: Add QMP command query-cpu-model cpu-model/s390: Extend QMP command query-cpu-definitions cpu-model/s390: Add processor property routines cpu-model/s390: Add cpu model selection routine cpu-model/s390: Enable S390 cpu model accel.c | 36 +- hw/s390x/s390-virtio.c | 6 + include/hw/boards.h | 1 + include/qemu-common.h | 2 + include/sysemu/accel.h | 2 +- include/sysemu/arch_init.h | 1 + include/sysemu/kvm.h | 10 + kvm-all.c | 3 + linux-headers/asm-s390/kvm.h | 20 ++ qapi-schema.json | 55 ++- qemu-options.hx | 8 + qmp-commands.hx | 6 + qmp.c | 5 + stubs/Makefile.objs | 2 + stubs/arch-query-cpu-mod.c | 9 + stubs/cpu-desc-avail.c | 6 + target-s390x/Makefile.objs | 1 + target-s390x/cpu-facilities.h | 76 +++++ target-s390x/cpu-models.c | 754 ++++++++++++++++++++++++++++++++++++++++++ target-s390x/cpu-models.h | 339 +++++++++++++++++++ target-s390x/cpu-qom.h | 22 ++ target-s390x/cpu.c | 154 ++++++++- target-s390x/helper.c | 3 +- target-s390x/kvm.c | 104 ++++++ trace-events | 6 + vl.c | 9 +- 26 files changed, 1621 insertions(+), 19 deletions(-) create mode 100644 stubs/arch-query-cpu-mod.c create mode 100644 stubs/cpu-desc-avail.c create mode 100644 target-s390x/cpu-facilities.h create mode 100644 target-s390x/cpu-models.c create mode 100644 target-s390x/cpu-models.h -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/