December 2018 - Devel - libvirt List Archives

[libvirt] [PATCH v2] qemu: Introduce caching whether /dev/kvm is accessible
by Marc Hartmayer 21 Dec '18

21 Dec '18

Introduce caching whether /dev/kvm is usable as the QEMU user:QEMU group. This reduces the overhead of the QEMU capabilities cache lookup. Before this patch there were many fork() calls used for checking whether /dev/kvm is accessible. Now we store the result whether /dev/kvm is accessible or not and we only need to re-run the virFileAccessibleAs check if the ctime of /dev/kvm has changed. Suggested-by: Daniel P. Berrangé <berrange(a)redhat.com> Signed-off-by: Marc Hartmayer <mhartmay(a)linux.ibm.com> --- src/qemu/qemu_capabilities.c | 54 ++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index e228f52ec0bb..85516954149b 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -3238,6 +3238,10 @@ struct _virQEMUCapsCachePriv { virArch hostArch; unsigned int microcodeVersion; char *kernelVersion; + + /* cache whether /dev/kvm is usable as runUid:runGuid */ + virTristateBool kvmUsable; + time_t kvmCtime; }; typedef struct _virQEMUCapsCachePriv virQEMUCapsCachePriv; typedef virQEMUCapsCachePriv *virQEMUCapsCachePrivPtr; @@ -3824,6 +3828,52 @@ virQEMUCapsSaveFile(void *data, } +/* Determine whether '/dev/kvm' is usable as QEMU user:QEMU group. */ +static bool +virQEMUCapsKVMUsable(virQEMUCapsCachePrivPtr priv) +{ + struct stat sb; + static const char *kvm_device = "/dev/kvm"; + virTristateBool value; + virTristateBool cached_value = priv->kvmUsable; + time_t kvm_ctime; + time_t cached_kvm_ctime = priv->kvmCtime; + + if (stat(kvm_device, &sb) < 0) { + virReportSystemError(errno, + _("Failed to stat %s"), kvm_device); + return false; + } + kvm_ctime = sb.st_ctime; + + if (kvm_ctime != cached_kvm_ctime) { + VIR_DEBUG("%s has changed (%lld vs %lld)", kvm_device, + (long long)kvm_ctime, (long long)cached_kvm_ctime); + cached_value = VIR_TRISTATE_BOOL_ABSENT; + } + + if (cached_value != VIR_TRISTATE_BOOL_ABSENT) + return cached_value == VIR_TRISTATE_BOOL_YES; + + if (virFileAccessibleAs(kvm_device, R_OK | W_OK, + priv->runUid, priv->runGid) == 0) { + value = VIR_TRISTATE_BOOL_YES; + } else { + value = VIR_TRISTATE_BOOL_NO; + } + + /* There is a race window between 'stat' and + * 'virFileAccessibleAs'. However, since we're only interested in + * detecting changes *after* the virFileAccessibleAs check, we can + * neglect this here. + */ + priv->kvmCtime = kvm_ctime; + priv->kvmUsable = value; + + return value == VIR_TRISTATE_BOOL_YES; +} + + static bool virQEMUCapsIsValid(void *data, void *privData) @@ -3872,8 +3922,7 @@ virQEMUCapsIsValid(void *data, return true; } - kvmUsable = virFileAccessibleAs("/dev/kvm", R_OK | W_OK, - priv->runUid, priv->runGid) == 0; + kvmUsable = virQEMUCapsKVMUsable(priv); if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM) && kvmUsable) { @@ -4684,6 +4733,7 @@ virQEMUCapsCacheNew(const char *libDir, priv->runUid = runUid; priv->runGid = runGid; priv->microcodeVersion = microcodeVersion; + priv->kvmUsable = VIR_TRISTATE_BOOL_ABSENT; if (uname(&uts) == 0 && virAsprintf(&priv->kernelVersion, "%s %s", uts.release, uts.version) < 0) -- 2.17.0

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[libvirt] [PATCH 0/2] Fix a couple of security_selinux issues
by John Ferlan 21 Dec '18

21 Dec '18

Both found by Coverity... Please, be kind if this send is messed up - I have a new laptop and I'm slowly finding out all the things that I don't have on it that I used to have on the old one. John Ferlan (2): security: Resolve possible memory leak security: Fix comparison for virSecuritySELinuxRecallLabel src/security/security_selinux.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) -- 2.19.2

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[libvirt] [jenkins-ci PATCH 0/7] guests: Use Python 3 for Ansible
by Andrea Bolognani 21 Dec '18

21 Dec '18

The initial trigger for working on this was the fact that Fedora Rawhide no longer contains the python2-dnf package, breaking our update procedure; while looking into it, however, I ended up cleaning up some other stuff and dropping some code which is no longer needed with modern Ansible versions. Andrea Bolognani (7): guests: Store OS details as strings guests: Remove casts for OS details guests: Install Python 3 during bootstrap guests: Use ansible_python_interpreter everywhere guests: Don't dynamically look for Python binary guests: Drop package module bootstrap step guests: Drop SELinux file editing enablement guests/host_vars/libvirt-centos-7/main.yml | 8 ++++--- guests/host_vars/libvirt-debian-8/main.yml | 8 ++++--- guests/host_vars/libvirt-debian-9/main.yml | 8 ++++--- guests/host_vars/libvirt-debian-sid/main.yml | 8 ++++--- guests/host_vars/libvirt-fedora-28/main.yml | 8 ++++--- guests/host_vars/libvirt-fedora-29/main.yml | 8 ++++--- .../host_vars/libvirt-fedora-rawhide/main.yml | 8 ++++--- guests/host_vars/libvirt-freebsd-11/main.yml | 10 ++++---- guests/host_vars/libvirt-freebsd-12/main.yml | 10 ++++---- .../libvirt-freebsd-current/main.yml | 10 ++++---- guests/host_vars/libvirt-ubuntu-16/main.yml | 8 ++++--- guests/host_vars/libvirt-ubuntu-18/main.yml | 8 ++++--- guests/lcitool | 2 +- guests/playbooks/update/tasks/base.yml | 24 ------------------- guests/playbooks/update/tasks/bootstrap.yml | 21 +++++++++++++--- guests/playbooks/update/tasks/packages.yml | 4 ++-- guests/playbooks/update/tasks/paths.yml | 15 ------------ guests/playbooks/update/templates/bashrc.j2 | 2 +- 18 files changed, 82 insertions(+), 88 deletions(-) -- 2.19.2

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[libvirt] [PATCH v2 0/2] qemu: fix misc noisy logs for optional storage sources
by Nikolay Shirokovskiy 21 Dec '18

21 Dec '18

John, I still did not add anything to formatdomain.html.in because when I gave this a thought it looks odd to add something like "we don't get stats for missing storage source" - it is obvious because such getting stats is simply not possible. It you feel there is need to add something to the docs then please help me formulate it and we include it in the patch(es) on pushing. Nikolay Diff from v1: ============ - add error logs examples to commit messages - add notices at INFO level of handling optional disks with missing sources in a special way - comment why handling such cases in a special manner in code - check for cold_boot flag in qemuProcessPrepareHostStorage Nikolay Shirokovskiy (2): qemu: don't log error for missing optional storage sources on stats qemu: don't log error for missing optional storage sources on start src/qemu/qemu_domain.c | 9 +++++++++ src/qemu/qemu_domain.h | 3 +++ src/qemu/qemu_driver.c | 14 ++++++++++++++ src/qemu/qemu_process.c | 10 +++++++++- 4 files changed, 35 insertions(+), 1 deletion(-) -- 1.8.3.1

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[libvirt] CfP for VHPC ‘19: HPC Virtualization Paper Registration due January 25, 2019 - 14th Virtualization in High-Performance Cloud Computing Workshop@ISC
by VHPC 19 20 Dec '18

20 Dec '18

Please accept our apologies if you receive multiple copies of this Call for Papers ==================================================================== CALL FOR PAPERS 14th Workshop on Virtualization in High-Performance Cloud Computing (VHPC '19) held in conjunction with the International Supercomputing Conference - High Performance, June 16-20, 2019, Frankfurt, Germany. (Springer LNCS Proceedings) ==================================================================== Date: June 20, 2019 Workshop URL: http://vhpc.org Abstract Submission Deadline: January 25, 2019 Springer LNCS, rolling abstract submission Abstract/Paper Submission Link: https://edas.info/newPaper.php?c=25685 Call for Papers Containers and virtualization technologies constitute key enabling factors for flexible resource management in modern data centers, and particularly in cloud environments. Cloud providers need to manage complex infrastructures in a seamless fashion to support the highly dynamic and heterogeneous workloads and hosted applications customers deploy. Similarly, HPC environments have been increasingly adopting techniques that enable flexible management of vast computing and networking resources, close to marginal provisioning cost, which is unprecedented in the history of scientific and commercial computing. Various virtualization-containerization technologies contribute to the overall picture in different ways: machine virtualization, with its capability to enable consolidation of multiple underutilized servers with heterogeneous software and operating systems (OSes), and its capability to live-migrate a fully operating virtual machine (VM) with a very short downtime, enables novel and dynamic ways to manage physical servers; OS-level virtualization (i.e., containerization), with its capability to isolate multiple user-space environments and to allow for their coexistence within the same OS kernel, promises to provide many of the advantages of machine virtualization with high levels of responsiveness and performance; lastly, unikernels provide for many virtualization benefits with a minimized OS/library surface. I/O Virtualization in turn allows physical network interfaces to take traffic from multiple VMs or containers; network virtualization, with its capability to create logical network overlays that are independent of the underlying physical topology is furthermore enabling virtualization of HPC infrastructures. Publication Accepted papers will be published in a Springer LNCS proceedings volume. Topics of Interest The VHPC program committee solicits original, high-quality submissions related to virtualization across the entire software stack with a special focus on the intersection of HPC, containers-virtualization and the cloud. Major Topics: - HPC on Containers and VMs - Containerized applications with OS-level virtualization - Lightweight applications with Unikernels - HP-as-a-Service each major topic encompassing design/architecture, management, performance management, modeling and configuration/tooling: Design / Architecture: - Containers and OS-level virtualization (LXC, Docker, rkt, Singularity, Shifter, i.a.) - Hypervisor support for heterogeneous resources (GPUs, co-processors, FPGAs, etc.) - Hypervisor extensions to mitigate side-channel attacks ([micro-]architectural timing attacks, privilege escalation) - VM & Container trust and security models - Multi-environment coupling, system software supporting in-situ analysis with HPC simulation - Cloud reliability, fault-tolerance and high-availability - Energy-efficient and power-aware virtualization - Containers inside VMs with hypervisor isolation - Virtualization support for emerging memory technologies - Lightweight/specialized operating systems in conjunction with virtual machines - Hypervisor support for heterogeneous resources (GPUs, co-processors, FPGAs, etc.) - Novel unikernels and use cases for virtualized HPC environments - ARM-based hypervisors, ARM virtualization extensions Management: - Container and VM management for HPC and cloud environments - HPC services integration, services to support HPC - Service and on-demand scheduling & resource management - Dedicated workload management with VMs or containers - Workflow coupling with VMs and containers - Unikernel, lightweight VM application management - Environments and tools for operating containerized environments (batch, orchestration) - Novel models for non-HPC workload provisioning on HPC resources Performance Measurements and Modeling: - Performance improvements for or driven by unikernels - Optimizations of virtual machine monitor platforms and hypervisors - Scalability analysis of VMs and/or containers at large scale - Performance measurement, modeling and monitoring of virtualized/cloud workloads - Virtualization in supercomputing environments, HPC clusters, HPC in the cloud Configuration / Tooling: - Tool support for unikernels: configuration/build environments, debuggers, profilers - Job scheduling/control/policy and container placement in virtualized environments - Operating MPI in containers/VMs and Unikernels - Software defined networks and network virtualization - GPU virtualization operationalization The Workshop on Virtualization in High-Performance Cloud Computing (VHPC) aims to bring together researchers and industrial practitioners facing the challenges posed by virtualization in order to foster discussion, collaboration, mutual exchange of knowledge and experience, enabling research to ultimately provide novel solutions for virtualized computing systems of tomorrow. The workshop will be one day in length, composed of 20 min paper presentations, each followed by 10 min discussion sections, plus lightning talks that are limited to 5 minutes. Presentations may be accompanied by interactive demonstrations. Important Dates January 25, 2019 - Abstract Registration deadline Apr 19th, 2019 - Paper submission deadline (Springer LNCS) May 3, 2019 - Acceptance notification June 20th, 2019 - Workshop Day July 10th, 2019 - Camera-ready version due Chair Michael Alexander (chair), University of Vienna, Austria Anastassios Nanos (co-chair), SunLight.io, UK Andrew Younge (co-chair), Sandia National Laboratories Program committee Stergios Anastasiadis, University of Ioannina, Greece Jakob Blomer, CERN, Europe Eduardo César, Universidad Autonoma de Barcelona, Spain Stephen Crago, USC ISI, USA Tommaso Cucinotta, St. Anna School of Advanced Studies, Italy Christoffer Dall, Columbia University, USA Patrick Dreher, MIT, USA Kyle Hale, Northwestern University, USA Brian Kocoloski, Washington University, USA John Lange, University of Pittsburgh, USA Giuseppe Lettieri, University of Pisa, Italy Qing Liu, Oak Ridge National Laboratory, USA Nikos Parlavantzas, IRISA, France Kevin Pedretti, Sandia National Laboratories, USA Amer Qouneh, Western New England University, USA Carlos Reaño, Queen’s University Belfast, UK Borja Sotomayor, University of Chicago, USA Joe Stubbs, Texas Advanced Computing Center, USA Anata Tiwari, San Diego Supercomputer Center, USA Kurt Tutschku, Blekinge Institute of Technology, Sweden Yasuhiro Watashiba, Osaka University, Japan Chao-Tung Yang, Tunghai University, Taiwan Na Zhang, VMware, USA Paper Submission-Publication Papers submitted to the workshop will be reviewed by at least two members of the program committee and external reviewers. Submissions should include abstract, keywords, the e-mail address of the corresponding author, and must not exceed 10 pages, including tables and figures at a main font size no smaller than 11 point. Submission of a paper should be regarded as a commitment that, should the paper be accepted, at least one of the authors will register and attend the conference to present the work. Accepted papers will be published in a Springer LNCS volume. The format must be according to the Springer LNCS Style. Initial submissions are in PDF; authors of accepted papers will be requested to provide source files. Format Guidelines: ftp://ftp.springernature.com/cs-proceeding/llncs/llncs2e.zip Abstract, Paper Submission Link: https://edas.info/newPaper.php?c=25685 Lightning Talks Lightning Talks are non-paper track, synoptical in nature and are strictly limited to 5 minutes. They can be used to gain early feedback on ongoing research, for demonstrations, to present research results, early research ideas, perspectives and positions of interest to the community. Submit abstract via the main submission link. General Information The workshop is one day in length and will be held in conjunction with the International Supercomputing Conference - High Performance (ISC) 2019, June 16-20, Frankfurt, Germany.

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[libvirt] [PULL v3 30/44] hw/i386: Remove deprecated machines pc-0.10 and pc-0.11
by Michael S. Tsirkin 20 Dec '18

20 Dec '18

From: Thomas Huth <thuth(a)redhat.com> They've been deprecated for two releases and nobody complained that they are still required anymore, so it's time to remove these now. And while we're at it, mark the other remaining old 0.x machine types as deprecated (since they can not properly be used for live-migration anyway). Signed-off-by: Thomas Huth <thuth(a)redhat.com> Reviewed-by: Michael S. Tsirkin <mst(a)redhat.com> Signed-off-by: Michael S. Tsirkin <mst(a)redhat.com> Reviewed-by: Eduardo Habkost <ehabkost(a)redhat.com> --- hw/i386/pc_piix.c | 70 ++----------------------------------------- tests/cpu-plug-test.c | 4 +-- qemu-deprecated.texi | 2 +- 3 files changed, 4 insertions(+), 72 deletions(-) diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c index e000c7511a..7f1cb527b5 100644 --- a/hw/i386/pc_piix.c +++ b/hw/i386/pc_piix.c @@ -368,7 +368,7 @@ static void pc_compat_1_2(MachineState *machine) x86_cpu_change_kvm_default("kvm-pv-eoi", NULL); } -/* PC compat function for pc-0.10 to pc-0.13 */ +/* PC compat function for pc-0.12 and pc-0.13 */ static void pc_compat_0_13(MachineState *machine) { pc_compat_1_2(machine); @@ -834,6 +834,7 @@ static void pc_i440fx_0_15_machine_options(MachineClass *m) { pc_i440fx_1_0_machine_options(m); m->hw_version = "0.15"; + m->deprecation_reason = "use a newer machine type instead"; SET_MACHINE_COMPAT(m, PC_COMPAT_0_15); } @@ -951,73 +952,6 @@ static void pc_i440fx_0_12_machine_options(MachineClass *m) DEFINE_I440FX_MACHINE(v0_12, "pc-0.12", pc_compat_0_13, pc_i440fx_0_12_machine_options); - -#define PC_COMPAT_0_11 \ - PC_CPU_MODEL_IDS("0.11") \ - {\ - .driver = "virtio-blk-pci",\ - .property = "vectors",\ - .value = stringify(0),\ - },{\ - .driver = TYPE_PCI_DEVICE,\ - .property = "rombar",\ - .value = stringify(0),\ - },{\ - .driver = "ide-drive",\ - .property = "ver",\ - .value = "0.11",\ - },{\ - .driver = "scsi-disk",\ - .property = "ver",\ - .value = "0.11",\ - }, - -static void pc_i440fx_0_11_machine_options(MachineClass *m) -{ - pc_i440fx_0_12_machine_options(m); - m->hw_version = "0.11"; - m->deprecation_reason = "use a newer machine type instead"; - SET_MACHINE_COMPAT(m, PC_COMPAT_0_11); -} - -DEFINE_I440FX_MACHINE(v0_11, "pc-0.11", pc_compat_0_13, - pc_i440fx_0_11_machine_options); - - -#define PC_COMPAT_0_10 \ - PC_CPU_MODEL_IDS("0.10") \ - {\ - .driver = "virtio-blk-pci",\ - .property = "class",\ - .value = stringify(PCI_CLASS_STORAGE_OTHER),\ - },{\ - .driver = "virtio-serial-pci",\ - .property = "class",\ - .value = stringify(PCI_CLASS_DISPLAY_OTHER),\ - },{\ - .driver = "virtio-net-pci",\ - .property = "vectors",\ - .value = stringify(0),\ - },{\ - .driver = "ide-drive",\ - .property = "ver",\ - .value = "0.10",\ - },{\ - .driver = "scsi-disk",\ - .property = "ver",\ - .value = "0.10",\ - }, - -static void pc_i440fx_0_10_machine_options(MachineClass *m) -{ - pc_i440fx_0_11_machine_options(m); - m->hw_version = "0.10"; - SET_MACHINE_COMPAT(m, PC_COMPAT_0_10); -} - -DEFINE_I440FX_MACHINE(v0_10, "pc-0.10", pc_compat_0_13, - pc_i440fx_0_10_machine_options); - typedef struct { uint16_t gpu_device_id; uint16_t pch_device_id; diff --git a/tests/cpu-plug-test.c b/tests/cpu-plug-test.c index f4a677d238..668f00144e 100644 --- a/tests/cpu-plug-test.c +++ b/tests/cpu-plug-test.c @@ -157,9 +157,7 @@ static void add_pc_test_case(const char *mname) (strcmp(mname, "pc-0.15") == 0) || (strcmp(mname, "pc-0.14") == 0) || (strcmp(mname, "pc-0.13") == 0) || - (strcmp(mname, "pc-0.12") == 0) || - (strcmp(mname, "pc-0.11") == 0) || - (strcmp(mname, "pc-0.10") == 0)) { + (strcmp(mname, "pc-0.12") == 0)) { path = g_strdup_printf("cpu-plug/%s/init/%ux%ux%u&maxcpus=%u", mname, data->sockets, data->cores, data->threads, data->maxcpus); diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi index e362d37225..c3735b698e 100644 --- a/qemu-deprecated.texi +++ b/qemu-deprecated.texi @@ -134,7 +134,7 @@ their usecases. @section System emulator machines -@subsection pc-0.10 and pc-0.11 (since 3.0) +@subsection pc-0.12, pc-0.13, pc-0.14 and pc-0.15 (since 4.0) These machine types are very old and likely can not be used for live migration from old QEMU versions anymore. A newer machine type should be used instead. -- MST

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[libvirt] [jenkins-ci PATCH] guests: Stop using squash_actions
by Andrea Bolognani 20 Dec '18

20 Dec '18

The feature is deprecated, and modern Ansible versions complain about it. Pass the list of packages to install to the corresponding module directly instead. Signed-off-by: Andrea Bolognani <abologna(a)redhat.com> --- guests/ansible.cfg | 1 - guests/playbooks/update/tasks/packages.yml | 4 +--- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/guests/ansible.cfg b/guests/ansible.cfg index 6b18c57..344646d 100644 --- a/guests/ansible.cfg +++ b/guests/ansible.cfg @@ -4,7 +4,6 @@ forks = 16 inventory = ./inventory log_path = ./log nocows = 1 -squash_actions = package [ssh_connection] pipelining = True diff --git a/guests/playbooks/update/tasks/packages.yml b/guests/playbooks/update/tasks/packages.yml index a725b07..8cebb5f 100644 --- a/guests/playbooks/update/tasks/packages.yml +++ b/guests/playbooks/update/tasks/packages.yml @@ -66,7 +66,5 @@ - name: '{{ project }}: Install/remove packages (state={{ state }})' package: - name: '{{ item }}' + name: '{{ flattened|sort }}' state: '{{ state }}' - with_items: - '{{ flattened|sort }}' -- 2.19.2

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[libvirt] [PATCH] news: Document original owner remembering
by Michal Privoznik 20 Dec '18

20 Dec '18

Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- docs/news.xml | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/docs/news.xml b/docs/news.xml index e9b6bb7c65..09a34d1705 100644 --- a/docs/news.xml +++ b/docs/news.xml @@ -79,6 +79,19 @@ qemu: Add support for ARMv6l guests </summary> </change> + <change> + <summary> + Remember original owners and SELinux labels of files + </summary> + <description> + When a domain is starting up libvirt changes DAC and + SELinux labels so that domain can access it. However, + it never remembered the original labels and therefore + the file was returned back to root:root. With this + release, the original labels are remembered and + restored properly. + </description> + </change> </section> <section title="Bug fixes"> </section> -- 2.19.2

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[libvirt] [designer PATCH 0/6] Various fixes
by Pino Toscano 20 Dec '18

20 Dec '18

Including making it build again. Pino Toscano (6): Fix typo in autogen.sh Bump libvirt-config & libvirt-gobject requirements to 0.1.9 Add missing break in gvir_designer_domain_add_graphics Use g_list_free_full Update .gitignore Switch away from osinfo_entity_get_param_value .gitignore | 64 ++++++++++++---------- autogen.sh | 4 +- configure.ac | 4 +- examples/virt-designer.c | 15 ++--- libvirt-designer/libvirt-designer-domain.c | 11 ++-- 5 files changed, 49 insertions(+), 49 deletions(-) -- 2.17.2

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Re: [libvirt] [PATCH 2/4] q35: set split kernel irqchip as default
by Eduardo Habkost 20 Dec '18

20 Dec '18

On Wed, Dec 19, 2018 at 09:12:55PM +0100, Paolo Bonzini wrote: > On 19/12/18 09:50, Peter Xu wrote: > > Starting from QEMU 4.0, let's specify "split" as the default value for > > kernel-irqchip. > > > > So for QEMU>=4.0 we'll have: allowed=Y,required=N,split=Y > > for QEMU<=3.1 we'll have: allowed=Y,required=N,split=N > > (omitting all the "kernel_irqchip_" prefix) > > > > Note that this "split" is optional - we'll first try to enable split > > kernel irqchip, and we'll fall back to complete kernel irqchip if we > > found that the kernel capability is missing. > > Please just fail completely and require a new kernel for the 4.0 machine > type. There are subtle differences between kernel and QEMU irqchip, I > don't think we want to open that can of worms. This would make existing VMs that are runnable with pc-q35-3.1.0 not runnable by only updating the machine-type. The good news is that we can make this a non-issue by clearly documenting that QEMU needs a more recent kernel (just like we'll do for RDTSCP[1]). [1] https://lore.kernel.org/lkml/20181210181328.GA762@zn.tnic/ -- Eduardo

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