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2018-02-17x86/xen: Calculate __max_logical_packages on PV domainsPrarit Bhargava
The kernel panics on PV domains because native_smp_cpus_done() is only called for HVM domains. Calculate __max_logical_packages for PV domains. Fixes: b4c0a7326f5d ("x86/smpboot: Fix __max_logical_packages estimate") Signed-off-by: Prarit Bhargava <prarit@redhat.com> Tested-and-reported-by: Simon Gaiser <simon@invisiblethingslab.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: xen-devel@lists.xenproject.org Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13xen/vcpu: Handle xen_vcpu_setup() failure at bootAnkur Arora
On PVH, PVHVM, at failure in the VCPUOP_register_vcpu_info hypercall we limit the number of cpus to to MAX_VIRT_CPUS. However, if this failure had occurred for a cpu beyond MAX_VIRT_CPUS, we continue to function with > MAX_VIRT_CPUS. This leads to problems at the next save/restore cycle when there are > MAX_VIRT_CPUS threads going into stop_machine() but coming back up there's valid state for only the first MAX_VIRT_CPUS. This patch pulls the excess CPUs down via cpu_down(). Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02x86/xen: split off smp_pv.cVitaly Kuznetsov
Basically, smp.c is renamed to smp_pv.c and some code moved out to common smp.c. struct xen_common_irq delcaration ended up in smp.h. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02x86/xen: split off smp_hvm.cVitaly Kuznetsov
Move PVHVM related code to smp_hvm.c. Drop 'static' qualifier from xen_smp_send_reschedule(), xen_smp_send_call_function_ipi(), xen_smp_send_call_function_single_ipi(), these functions will be moved to common smp code when smp_pv.c is split. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02x86/xen: split xen_cpu_die()Vitaly Kuznetsov
Split xen_cpu_die() into xen_pv_cpu_die() and xen_hvm_cpu_die() to support further splitting of smp.c. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02x86/xen: split xen_smp_prepare_boot_cpu()Vitaly Kuznetsov
Split xen_smp_prepare_boot_cpu() into xen_pv_smp_prepare_boot_cpu() and xen_hvm_smp_prepare_boot_cpu() to support further splitting of smp.c. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02x86/xen: split xen_smp_intr_init()/xen_smp_intr_free()Vitaly Kuznetsov
xen_smp_intr_init() and xen_smp_intr_free() have PV-specific code and as a praparatory change to splitting smp.c we need to split these fucntions. Create xen_smp_intr_init_pv()/xen_smp_intr_free_pv(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2017-03-16x86: Remap GDT tables in the fixmap sectionThomas Garnier
Each processor holds a GDT in its per-cpu structure. The sgdt instruction gives the base address of the current GDT. This address can be used to bypass KASLR memory randomization. With another bug, an attacker could target other per-cpu structures or deduce the base of the main memory section (PAGE_OFFSET). This patch relocates the GDT table for each processor inside the fixmap section. The space is reserved based on number of supported processors. For consistency, the remapping is done by default on 32 and 64-bit. Each processor switches to its remapped GDT at the end of initialization. For hibernation, the main processor returns with the original GDT and switches back to the remapping at completion. This patch was tested on both architectures. Hibernation and KVM were both tested specially for their usage of the GDT. Thanks to Boris Ostrovsky <boris.ostrovsky@oracle.com> for testing and recommending changes for Xen support. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@suse.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Luis R . Rodriguez <mcgrof@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rafael J . Wysocki <rjw@rjwysocki.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: kasan-dev@googlegroups.com Cc: kernel-hardening@lists.openwall.com Cc: kvm@vger.kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-pm@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/20170314170508.100882-2-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/nmi.h> We are going to move softlockup APIs out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. <linux/nmi.h> already includes <linux/sched.h>. Include the <linux/nmi.h> header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-07xen/x86: Remove PVH supportBoris Ostrovsky
We are replacing existing PVH guests with new implementation. We are keeping xen_pvh_domain() macro (for now set to zero) because when we introduce new PVH implementation later in this series we will reuse current PVH-specific code (xen_pvh_gnttab_setup()), and that code is conditioned by 'if (xen_pvh_domain())'. (We will also need a noop xen_pvh_domain() for !CONFIG_XEN_PVH). Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-12-13x86/smpboot: Make logical package management more robustThomas Gleixner
The logical package management has several issues: - The APIC ids provided by ACPI are not required to be the same as the initial APIC id which can be retrieved by CPUID. The APIC ids provided by ACPI are those which are written by the BIOS into the APIC. The initial id is set by hardware and can not be changed. The hardware provided ids contain the real hardware package information. Especially AMD sets the effective APIC id different from the hardware id as they need to reserve space for the IOAPIC ids starting at id 0. As a consequence those machines trigger the currently active firmware bug printouts in dmesg, These are obviously wrong. - Virtual machines have their own interesting of enumerating APICs and packages which are not reliably covered by the current implementation. The sizing of the mapping array has been tweaked to be generously large to handle systems which provide a wrong core count when HT is disabled so the whole magic which checks for space in the physical hotplug case is not needed anymore. Simplify the whole machinery and do the mapping when the CPU starts and the CPUID derived physical package information is available. This solves the observed problems on AMD machines and works for the virtualization issues as well. Remove the extra call from XEN cpu bringup code as it is not longer required. Fixes: d49597fd3bc7 ("x86/cpu: Deal with broken firmware (VMWare/XEN)") Reported-and-tested-by: Borislav Petkov <bp@suse.de> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: M. Vefa Bicakci <m.v.b@runbox.com> Cc: xen-devel <xen-devel@lists.xen.org> Cc: Charles (Chas) Williams <ciwillia@brocade.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Alok Kataria <akataria@vmware.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1612121102260.3429@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-06xen/x86: Update topology map for PV VCPUsBoris Ostrovsky
Early during boot topology_update_package_map() computes logical_pkg_ids for all present processors. Later, when processors are brought up, identify_cpu() updates these values based on phys_pkg_id which is a function of initial_apicid. On PV guests the latter may point to a non-existing node, causing logical_pkg_ids to be set to -1. Intel's RAPL uses logical_pkg_id (as topology_logical_package_id()) to index its arrays and therefore in this case will point to index 65535 (since logical_pkg_id is a u16). This could lead to either a crash or may actually access random memory location. As a workaround, we recompute topology during CPU bringup to reset logical_pkg_id to a valid value. (The reason for initial_apicid being bogus is because it is initial_apicid of the processor from which the guest is launched. This value is CPUID(1).EBX[31:24]) Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-09-30xen: Remove event channel notification through Xen PCI platform deviceKarimAllah Ahmed
Ever since commit 254d1a3f02eb ("xen/pv-on-hvm kexec: shutdown watches from old kernel") using the INTx interrupt from Xen PCI platform device for event channel notification would just lockup the guest during bootup. postcore_initcall now calls xs_reset_watches which will eventually try to read a value from XenStore and will get stuck on read_reply at XenBus forever since the platform driver is not probed yet and its INTx interrupt handler is not registered yet. That means that the guest can not be notified at this moment of any pending event channels and none of the per-event handlers will ever be invoked (including the XenStore one) and the reply will never be picked up by the kernel. The exact stack where things get stuck during xenbus_init: -xenbus_init -xs_init -xs_reset_watches -xenbus_scanf -xenbus_read -xs_single -xs_single -xs_talkv Vector callbacks have always been the favourite event notification mechanism since their introduction in commit 38e20b07efd5 ("x86/xen: event channels delivery on HVM.") and the vector callback feature has always been advertised for quite some time by Xen that's why INTx was broken for several years now without impacting anyone. Luckily this also means that event channel notification through INTx is basically dead-code which can be safely removed without impacting anybody since it has been effectively disabled for more than 4 years with nobody complaining about it (at least as far as I'm aware of). This commit removes event channel notification through Xen PCI platform device. Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Julien Grall <julien.grall@citrix.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Ross Lagerwall <ross.lagerwall@citrix.com> Cc: xen-devel@lists.xenproject.org Cc: linux-kernel@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-08-24xen/x86: Move irq allocation from Xen smp_op.cpu_up()Boris Ostrovsky
Commit ce0d3c0a6fb1 ("genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now") reverted irq locking introduced by commit a89941816726 ("hotplug: Prevent alloc/free of irq descriptors during cpu up/down") because of Xen allocating irqs in both of its cpu_up ops. We can move those allocations into CPU notifiers so that original patch can be reinstated. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-25xen/pvhvm: run xen_vcpu_setup() for the boot CPUVitaly Kuznetsov
Historically we didn't call VCPUOP_register_vcpu_info for CPU0 for PVHVM guests (while we had it for PV and ARM guests). This is usually fine as we can use vcpu info in the shared_info page but when we try booting on a vCPU with Xen's vCPU id > 31 (e.g. when we try to kdump after crashing on this CPU) we're not able to boot. Switch to always doing VCPUOP_register_vcpu_info for the boot CPU. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-07-25x86/xen: use xen_vcpu_id mapping for HYPERVISOR_vcpu_opVitaly Kuznetsov
HYPERVISOR_vcpu_op() passes Linux's idea of vCPU id as a parameter while Xen's idea is expected. In some cases these ideas diverge so we need to do remapping. Convert all callers of HYPERVISOR_vcpu_op() to use xen_vcpu_nr(). Leave xen_fill_possible_map() and xen_filter_cpu_maps() intact as they're only being called by PV guests before perpu areas are initialized. While the issue could be solved by switching to early_percpu for xen_vcpu_id I think it's not worth it: PV guests will probably never get to the point where their idea of vCPU id diverges from Xen's. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-03-29xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()Boris Ostrovsky
This call has always been missing from xen_play dead() but until recently this was rather benign. With new cpu hotplug framework (commit 8df3e07e7f21 ("cpu/hotplug: Let upcoming cpu bring itself fully up"). however this call is required, otherwise a hot-plugged CPU will not be properly brough up (by never calling cpuhp_online_idle()) Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-03-01arch/hotplug: Call into idle with a proper stateThomas Gleixner
Let the non boot cpus call into idle with the corresponding hotplug state, so the hotplug core can handle the further bringup. That's a first step to convert the boot side of the hotplugged cpus to do all the synchronization with the other side through the state machine. For now it'll only start the hotplug thread and kick the full bringup of the cpu. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Rik van Riel <riel@redhat.com> Cc: Rafael Wysocki <rafael.j.wysocki@intel.com> Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/20160226182341.614102639@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-08xen: Use correctly the Xen memory terminologiesJulien Grall
Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN is meant, I suspect this is because the first support for Xen was for PV. This resulted in some misimplementation of helpers on ARM and confused developers about the expected behavior. For instance, with pfn_to_mfn, we expect to get an MFN based on the name. Although, if we look at the implementation on x86, it's returning a GFN. For clarity and avoid new confusion, replace any reference to mfn with gfn in any helpers used by PV drivers. The x86 code will still keep some reference of pfn_to_mfn which may be used by all kind of guests No changes as been made in the hypercall field, even though they may be invalid, in order to keep the same as the defintion in xen repo. Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a name to close to the KVM function gfn_to_page. Take also the opportunity to simplify simple construction such as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up will come in follow-up patches. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-08-20xen/PMU: Initialization code for Xen PMUBoris Ostrovsky
Map shared data structure that will hold CPU registers, VPMU context, V/PCPU IDs of the CPU interrupted by PMU interrupt. Hypervisor fills this information in its handler and passes it to the guest for further processing. Set up PMU VIRQ. Now that perf infrastructure will assume that PMU is available on a PV guest we need to be careful and make sure that accesses via RDPMC instruction don't cause fatal traps by the hypervisor. Provide a nop RDPMC handler. For the same reason avoid issuing a warning on a write to APIC's LVTPC. Both of these will be made functional in later patches. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-04-14Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes from Ingo Molnar: "The main changes in this cycle were: - changes permitting use of call_rcu() and friends very early in boot, for example, before rcu_init() is invoked. - add in-kernel API to enable and disable expediting of normal RCU grace periods. - improve RCU's handling of (hotplug-) outgoing CPUs. - NO_HZ_FULL_SYSIDLE fixes. - tiny-RCU updates to make it more tiny. - documentation updates. - miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) cpu: Provide smpboot_thread_init() on !CONFIG_SMP kernels as well cpu: Defer smpboot kthread unparking until CPU known to scheduler rcu: Associate quiescent-state reports with grace period rcu: Yet another fix for preemption and CPU hotplug rcu: Add diagnostics to grace-period cleanup rcutorture: Default to grace-period-initialization delays rcu: Handle outgoing CPUs on exit from idle loop cpu: Make CPU-offline idle-loop transition point more precise rcu: Eliminate ->onoff_mutex from rcu_node structure rcu: Process offlining and onlining only at grace-period start rcu: Move rcu_report_unblock_qs_rnp() to common code rcu: Rework preemptible expedited bitmask handling rcu: Remove event tracing from rcu_cpu_notify(), used by offline CPUs rcutorture: Enable slow grace-period initializations rcu: Provide diagnostic option to slow down grace-period initialization rcu: Detect stalls caused by failure to propagate up rcu_node tree rcu: Eliminate empty HOTPLUG_CPU ifdef rcu: Simplify sync_rcu_preempt_exp_init() rcu: Put all orphan-callback-related code under same comment rcu: Consolidate offline-CPU callback initialization ...
2015-04-02x86/cpu: Factor out common CPU initialization code, fix 32-bit Xen PV guestsBoris Ostrovsky
Some of x86 bare-metal and Xen CPU initialization code is common between the two and therefore can be factored out to avoid code duplication. As a side effect, doing so will also extend the fix provided by commit a7fcf28d431e ("x86/asm/entry: Replace this_cpu_sp0() with current_top_of_stack() to x86_32") to 32-bit Xen PV guests. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: konrad.wilk@oracle.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1427897534-5086-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-24x86/asm/entry: Get rid of KERNEL_STACK_OFFSETDenys Vlasenko
PER_CPU_VAR(kernel_stack) was set up in a way where it points five stack slots below the top of stack. Presumably, it was done to avoid one "sub $5*8,%rsp" in syscall/sysenter code paths, where iret frame needs to be created by hand. Ironically, none of them benefits from this optimization, since all of them need to allocate additional data on stack (struct pt_regs), so they still have to perform subtraction. This patch eliminates KERNEL_STACK_OFFSET. PER_CPU_VAR(kernel_stack) now points directly to top of stack. pt_regs allocations are adjusted to allocate iret frame as well. Hopefully we can merge it later with 32-bit specific PER_CPU_VAR(cpu_current_top_of_stack) variable... Net result in generated code is that constants in several insns are changed. This change is necessary for changing struct pt_regs creation in SYSCALL64 code path from MOV to PUSH instructions. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1426785469-15125-2-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-11x86: Use common outgoing-CPU-notification codePaul E. McKenney
This commit removes the open-coded CPU-offline notification with new common code. Among other things, this change avoids calling scheduler code using RCU from an offline CPU that RCU is ignoring. It also allows Xen to notice at online time that the CPU did not go offline correctly. Note that Xen has the surviving CPU carry out some cleanup operations, so if the surviving CPU times out, these cleanup operations might have been carried out while the outgoing CPU was still running. It might therefore be unwise to bring this CPU back online, and this commit avoids doing so. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: <x86@kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: <xen-devel@lists.xenproject.org>
2015-01-26x86,xen: use current->state helpersDavidlohr Bueso
Call __set_current_state() instead of assigning the new state directly. These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping track of who changed the state. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-11-10x86/core, x86/xen/smp: Use 'die_complete' completion when taking CPU downBoris Ostrovsky
Commit 2ed53c0d6cc9 ("x86/smpboot: Speed up suspend/resume by avoiding 100ms sleep for CPU offline during S3") introduced completions to CPU offlining process. These completions are not initialized on Xen kernels causing a panic in play_dead_common(). Move handling of die_complete into common routines to make them available to Xen guests. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: tianyu.lan@intel.com Cc: konrad.wilk@oracle.com Cc: xen-devel@lists.xenproject.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414770572-7950-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-10-13Merge branch 'x86-boot-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 bootup updates from Ingo Molnar: "The changes in this cycle were: - Fix rare SMP-boot hang (mostly in virtual environments) - Fix build warning with certain (rare) toolchains" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/relocs: Make per_cpu_load_addr static x86/smpboot: Initialize secondary CPU only if master CPU will wait for it
2014-10-06x86/xen: Set EFER.NX and EFER.SCE in PVH guestsMukesh Rathor
This fixes two bugs in PVH guests: - Not setting EFER.NX means the NX bit in page table entries is ignored on Intel processors and causes reserved bit page faults on AMD processors. - After the Xen commit 7645640d6ff1 ("x86/PVH: don't set EFER_SCE for pvh guest") PVH guests are required to set EFER.SCE to enable the SYSCALL instruction. Secondary VCPUs are started with pagetables with the NX bit set so EFER.NX must be set before using any stack or data segment. xen_pvh_cpu_early_init() is the new secondary VCPU entry point that sets EFER before jumping to cpu_bringup_and_idle(). Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-09-16x86/smpboot: Initialize secondary CPU only if master CPU will wait for itIgor Mammedov
Hang is observed on virtual machines during CPU hotplug, especially in big guests with many CPUs. (It reproducible more often if host is over-committed). It happens because master CPU gives up waiting on secondary CPU and allows it to run wild. As result AP causes locking or crashing system. For example as described here: https://lkml.org/lkml/2014/3/6/257 If master CPU have sent STARTUP IPI successfully, and AP signalled to master CPU that it's ready to start initialization, make master CPU wait indefinitely till AP is onlined. To ensure that AP won't ever run wild, make it wait at early startup till master CPU confirms its intention to wait for AP. If AP doesn't respond in 10 seconds, the master CPU will timeout and cancel AP onlining. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1403266991-12233-1-git-send-email-imammedo@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-15x86/xen: Fix 32-bit PV guests's usage of kernel_stackBoris Ostrovsky
Commit 198d208df4371734ac4728f69cb585c284d20a15 ("x86: Keep thread_info on thread stack in x86_32") made 32-bit kernels use kernel_stack to point to thread_info. That change missed a couple of updates needed by Xen's 32-bit PV guests: 1. kernel_stack needs to be initialized for secondary CPUs 2. GET_THREAD_INFO() now uses %fs register which may not be the kernel's version when executing xen_iret(). With respect to the second issue, we don't need GET_THREAD_INFO() anymore: we used it as an intermediate step to get to per_cpu xen_vcpu and avoid referencing %fs. Now that we are going to use %fs anyway we may as well go directly to xen_vcpu. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-01-21xen/pvh: Set X86_CR0_WP and others in CR0 (v2)Roger Pau Monne
otherwise we will get for some user-space applications that use 'clone' with CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID end up hitting an assert in glibc manifested by: general protection ip:7f80720d364c sp:7fff98fd8a80 error:0 in libc-2.13.so[7f807209e000+180000] This is due to the nature of said operations which sets and clears the PID. "In the successful one I can see that the page table of the parent process has been updated successfully to use a different physical page, so the write of the tid on that page only affects the child... On the other hand, in the failed case, the write seems to happen before the copy of the original page is done, so both the parent and the child end up with the same value (because the parent copies the page after the write of the child tid has already happened)." (Roger's analysis). The nature of this is due to the Xen's commit of 51e2cac257ec8b4080d89f0855c498cbbd76a5e5 "x86/pvh: set only minimal cr0 and cr4 flags in order to use paging" the CR0_WP was removed so COW features of the Linux kernel were not operating properly. While doing that also update the rest of the CR0 flags to be inline with what a baremetal Linux kernel would set them to. In 'secondary_startup_64' (baremetal Linux) sets: X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | X86_CR0_PG The hypervisor for HVM type guests (which PVH is a bit) sets: X86_CR0_PE | X86_CR0_ET | X86_CR0_TS For PVH it specifically sets: X86_CR0_PG Which means we need to set the rest: X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM to have full parity. Signed-off-by: Roger Pau Monne <roger.pau@citrix.com> Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [v1: Took out the cr4 writes to be a seperate patch] [v2: 0-DAY kernel found xen_setup_gdt to be missing a static]
2014-01-06xen/pvh: Secondary VCPU bringup (non-bootup CPUs)Mukesh Rathor
The VCPU bringup protocol follows the PV with certain twists. From xen/include/public/arch-x86/xen.h: Also note that when calling DOMCTL_setvcpucontext and VCPU_initialise for HVM and PVH guests, not all information in this structure is updated: - For HVM guests, the structures read include: fpu_ctxt (if VGCT_I387_VALID is set), flags, user_regs, debugreg[*] - PVH guests are the same as HVM guests, but additionally use ctrlreg[3] to set cr3. All other fields not used should be set to 0. This is what we do. We piggyback on the 'xen_setup_gdt' - but modify a bit - we need to call 'load_percpu_segment' so that 'switch_to_new_gdt' can load per-cpu data-structures. It has no effect on the VCPU0. We also piggyback on the %rdi register to pass in the CPU number - so that when we bootup a new CPU, the cpu_bringup_and_idle will have passed as the first parameter the CPU number (via %rdi for 64-bit). Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-11-15Merge tag 'stable/for-linus-3.13-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen updates from Konrad Rzeszutek Wilk: "This has tons of fixes and two major features which are concentrated around the Xen SWIOTLB library. The short <blurb> is that the tracing facility (just one function) has been added to SWIOTLB to make it easier to track I/O progress. Additionally under Xen and ARM (32 & 64) the Xen-SWIOTLB driver "is used to translate physical to machine and machine to physical addresses of foreign[guest] pages for DMA operations" (Stefano) when booting under hardware without proper IOMMU. There are also bug-fixes, cleanups, compile warning fixes, etc. The commit times for some of the commits is a bit fresh - that is b/c we wanted to make sure we have the Ack's from the ARM folks - which with the string of back-to-back conferences took a bit of time. Rest assured - the code has been stewing in #linux-next for some time. Features: - SWIOTLB has tracing added when doing bounce buffer. - Xen ARM/ARM64 can use Xen-SWIOTLB. This work allows Linux to safely program real devices for DMA operations when running as a guest on Xen on ARM, without IOMMU support. [*1] - xen_raw_printk works with PVHVM guests if needed. Bug-fixes: - Make memory ballooning work under HVM with large MMIO region. - Inform hypervisor of MCFG regions found in ACPI DSDT. - Remove deprecated IRQF_DISABLED. - Remove deprecated __cpuinit. [*1]: "On arm and arm64 all Xen guests, including dom0, run with second stage translation enabled. As a consequence when dom0 programs a device for a DMA operation is going to use (pseudo) physical addresses instead machine addresses. This work introduces two trees to track physical to machine and machine to physical mappings of foreign pages. Local pages are assumed mapped 1:1 (physical address == machine address). It enables the SWIOTLB-Xen driver on ARM and ARM64, so that Linux can translate physical addresses to machine addresses for dma operations when necessary. " (Stefano)" * tag 'stable/for-linus-3.13-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (32 commits) xen/arm: pfn_to_mfn and mfn_to_pfn return the argument if nothing is in the p2m arm,arm64/include/asm/io.h: define struct bio_vec swiotlb-xen: missing include dma-direction.h pci-swiotlb-xen: call pci_request_acs only ifdef CONFIG_PCI arm: make SWIOTLB available xen: delete new instances of added __cpuinit xen/balloon: Set balloon's initial state to number of existing RAM pages xen/mcfg: Call PHYSDEVOP_pci_mmcfg_reserved for MCFG areas. xen: remove deprecated IRQF_DISABLED x86/xen: remove deprecated IRQF_DISABLED swiotlb-xen: fix error code returned by xen_swiotlb_map_sg_attrs swiotlb-xen: static inline xen_phys_to_bus, xen_bus_to_phys, xen_virt_to_bus and range_straddles_page_boundary grant-table: call set_phys_to_machine after mapping grant refs arm,arm64: do not always merge biovec if we are running on Xen swiotlb: print a warning when the swiotlb is full swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/device xen: introduce xen_dma_map/unmap_page and xen_dma_sync_single_for_cpu/device tracing/events: Fix swiotlb tracepoint creation swiotlb-xen: use xen_alloc/free_coherent_pages xen: introduce xen_alloc/free_coherent_pages ...
2013-11-06x86/xen: remove deprecated IRQF_DISABLEDMichael Opdenacker
This patch proposes to remove the IRQF_DISABLED flag from x86/xen code. It's a NOOP since 2.6.35 and it will be removed one day. Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-10-10xen: Fix possible user space selector corruptionFrediano Ziglio
Due to the way kernel is initialized under Xen is possible that the ring1 selector used by the kernel for the boot cpu end up to be copied to userspace leading to segmentation fault in the userspace. Xen code in the kernel initialize no-boot cpus with correct selectors (ds and es set to __USER_DS) but the boot one keep the ring1 (passed by Xen). On task context switch (switch_to) we assume that ds, es and cs already point to __USER_DS and __KERNEL_CSso these selector are not changed. If processor is an Intel that support sysenter instruction sysenter/sysexit is used so ds and es are not restored switching back from kernel to userspace. In the case the selectors point to a ring1 instead of __USER_DS the userspace code will crash on first memory access attempt (to be precise Xen on the emulated iret used to do sysexit will detect and set ds and es to zero which lead to GPF anyway). Now if an userspace process call kernel using sysenter and get rescheduled (for me it happen on a specific init calling wait4) could happen that the ring1 selector is set to ds and es. This is quite hard to detect cause after a while these selectors are fixed (__USER_DS seems sticky). Bisecting the code commit 7076aada1040de4ed79a5977dbabdb5e5ea5e249 appears to be the first one that have this issue. Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
2013-09-09xen/smp: Update pv_lock_ops functions before alternative code starts under PVHVMKonrad Rzeszutek Wilk
Before this patch we would patch all of the pv_lock_ops sites using alternative assembler. Then later in the bootup cycle change the unlock_kick and lock_spinning to the Xen specific - without re patching. That meant that for the core of the kernel we would be running with the baremetal version of unlock_kick and lock_spinning while for modules we would have the proper Xen specific slowpaths. As most of the module uses some API from the core kernel that ended up with slowpath lockers waiting forever to be kicked (b/c they would be using the Xen specific slowpath logic). And the kick never came b/c the unlock path that was taken was the baremetal one. On PV we do not have the problem as we initialise before the alternative code kicks in. The fix is to make the updating of the pv_lock_ops function be done before the alternative code starts patching. Note that this patch fixes issues discovered by commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23. ("xen: disable PV spinlocks on HVM") wherein it mentioned PV spinlocks cannot possibly work with the current code because they are enabled after pvops patching has already been done, and because PV spinlocks use a different data structure than native spinlocks so we cannot switch between them dynamically. The first problem is solved by this patch. The second problem has been solved by commit 816434ec4a674fcdb3c2221a6dffdc8f34020550 (Merge branch 'x86-spinlocks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip) P.S. There is still the commit 70dd4998cb85f0ecd6ac892cc7232abefa432efb (xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM) to revert but that can be done later after all other bugs have been fixed. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2013-09-09xen/spinlock: Fix locking path engaging too soon under PVHVM.Konrad Rzeszutek Wilk
The xen_lock_spinning has a check for the kicker interrupts and if it is not initialized it will spin normally (not enter the slowpath). But for PVHVM case we would initialize the kicker interrupt before the CPU came online. This meant that if the booting CPU used a spinlock and went in the slowpath - it would enter the slowpath and block forever. The forever part because during bootup: the spinlock would be taken _before_ the CPU sets itself to be online (more on this further), and we enter to poll on the event channel forever. The bootup CPU (see commit fc78d343fa74514f6fd117b5ef4cd27e4ac30236 "xen/smp: initialize IPI vectors before marking CPU online" for details) and the CPU that started the bootup consult the cpu_online_mask to determine whether the booting CPU should get an IPI. The booting CPU has to set itself in this mask via: set_cpu_online(smp_processor_id(), true); However, if the spinlock is taken before this (and it is) and it polls on an event channel - it will never be woken up as the kernel will never send an IPI to an offline CPU. Note that the PVHVM logic in sending IPIs is using the HVM path which has numerous checks using the cpu_online_mask and cpu_active_mask. See above mention git commit for details. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
2013-09-09Merge tag 'v3.11-rc7' into stable/for-linus-3.12Konrad Rzeszutek Wilk
Linux 3.11-rc7 As we need the git commit 28817e9de4f039a1a8c1fe1df2fa2df524626b9e Author: Chuck Anderson <chuck.anderson@oracle.com> Date: Tue Aug 6 15:12:19 2013 -0700 xen/smp: initialize IPI vectors befo