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2019-07-25x86/apic: Add static key to Control IPI shorthandsThomas Gleixner4-1/+33
The IPI shorthand functionality delivers IPI/NMI broadcasts to all CPUs in the system. This can have similar side effects as the MCE broadcasting when CPUs are waiting in the BIOS or are offlined. The kernel tracks already the state of offlined CPUs whether they have been brought up at least once so that the CR4 MCE bit is set to make sure that MCE broadcasts can't brick the machine. Utilize that information and compare it to the cpu_present_mask. If all present CPUs have been brought up at least once then the broadcast side effect is mitigated by disabling regular interrupt/IPI delivery in the APIC itself and by the cpu offline check at the begin of the NMI handler. Use a static key to switch between broadcasting via shorthands or sending the IPI/NMI one by one. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105220.386410643@linutronix.de
2019-07-25x86/apic: Move no_ipi_broadcast() out of 32bitThomas Gleixner3-29/+27
For the upcoming shorthand support for all APIC incarnations the command line option needs to be available for 64 bit as well. While at it, rename the control variable, make it static and mark it __ro_after_init. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105220.278327940@linutronix.de
2019-07-25x86/apic: Add NMI_VECTOR wait to IPI shorthandThomas Gleixner1-1/+4
To support NMI shorthand broadcasts add the safe wait for ICR idle for NMI vector delivery. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105220.185838026@linutronix.de
2019-07-25x86/apic: Remove dest argument from __default_send_IPI_shortcut()Thomas Gleixner4-14/+11
The SDM states: "The destination shorthand field of the ICR allows the delivery mode to be by-passed in favor of broadcasting the IPI to all the processors on the system bus and/or back to itself (see Section 10.6.1, Interrupt Command Register (ICR)). Three destination shorthands are supported: self, all excluding self, and all including self. The destination mode is ignored when a destination shorthand is used." So there is no point to supply the destination mode to the shorthand delivery function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105220.094613426@linutronix.de
2019-07-25x86/hotplug: Silence APIC and NMI when CPU is deadThomas Gleixner4-12/+34
In order to support IPI/NMI broadcasting via the shorthand mechanism side effects of shorthands need to be mitigated: Shorthand IPIs and NMIs hit all CPUs including unplugged CPUs Neither of those can be handled on unplugged CPUs for obvious reasons. It would be trivial to just fully disable the APIC via the enable bit in MSR_APICBASE. But that's not possible because clearing that bit on systems based on the 3 wire APIC bus would require a hardware reset to bring it back as the APIC would lose track of bus arbitration. On systems with FSB delivery APICBASE could be disabled, but it has to be guaranteed that no interrupt is sent to the APIC while in that state and it's not clear from the SDM whether it still responds to INIT/SIPI messages. Therefore stay on the safe side and switch the APIC into soft disabled mode so it won't deliver any regular vector to the CPU. NMIs are still propagated to the 'dead' CPUs. To mitigate that add a check for the CPU being offline on early nmi entry and if so bail. Note, this cannot use the stop/restart_nmi() magic which is used in the alternatives code. A dead CPU cannot invoke nmi_enter() or anything else due to RCU and other reasons. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907241723290.1791@nanos.tec.linutronix.de
2019-07-25x86/cpu: Move arch_smt_update() to a neutral placeThomas Gleixner3-1/+12
arch_smt_update() will be used to control IPI/NMI broadcasting via the shorthand mechanism. Keeping it in the bugs file and calling the apic function from there is possible, but not really intuitive. Move it to a neutral place and invoke the bugs function from there. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.910317273@linutronix.de
2019-07-25x86/apic/uv: Make x2apic_extra_bits staticThomas Gleixner2-3/+1
Not used outside of the UV apic source. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.725264153@linutronix.de
2019-07-25x86/apic: Consolidate the apic local headersThomas Gleixner12-119/+83
Now there are three small local headers. Some contain functions which are only used in one source file. Move all the inlines and declarations into a single local header and the inlines which are only used in one source file into that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.618612624@linutronix.de
2019-07-25x86/apic: Move apic_flat_64 header into apic directoryThomas Gleixner3-2/+2
Only used locally. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.526508168@linutronix.de
2019-07-25x86/apic: Move ipi header into apic directoryThomas Gleixner8-14/+13
Only used locally. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.434738036@linutronix.de
2019-07-25x86/apic: Cleanup the include mazeThomas Gleixner9-110/+24
All of these APIC files include the world and some more. Remove the unneeded cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.342631201@linutronix.de
2019-07-25x86/apic: Move IPI inlines into ipi.cThomas Gleixner2-22/+13
No point in having them in an header file. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.252225936@linutronix.de
2019-07-25x86/apic: Make apic_pending_intr_clear() more robustThomas Gleixner1-43/+62
In course of developing shorthand based IPI support issues with the function which tries to clear eventually pending ISR bits in the local APIC were observed. 1) O-day testing triggered the WARN_ON() in apic_pending_intr_clear(). This warning is emitted when the function fails to clear pending ISR bits or observes pending IRR bits which are not delivered to the CPU after the stale ISR bit(s) are ACK'ed. Unfortunately the function only emits a WARN_ON() and fails to dump the IRR/ISR content. That's useless for debugging. Feng added spot on debug printk's which revealed that the stale IRR bit belonged to the APIC timer interrupt vector, but adding ad hoc debug code does not help with sporadic failures in the field. Rework the loop so the full IRR/ISR contents are saved and on failure dumped. 2) The loop termination logic is interesting at best. If the machine has no TSC or cpu_khz is not known yet it tries 1 million times to ack stale IRR/ISR bits. What? With TSC it uses the TSC to calculate the loop termination. It takes a timestamp at entry and terminates the loop when: (rdtsc() - start_timestamp) >= (cpu_hkz << 10) That's roughly one second. Both methods are problematic. The APIC has 256 vectors, which means that in theory max. 256 IRR/ISR bits can be set. In practice this is impossible and the chance that more than a few bits are set is close to zero. With the pure loop based approach the 1 million retries are complete overkill. With TSC this can terminate too early in a guest which is running on a heavily loaded host even with only a couple of IRR/ISR bits set. The reason is that after acknowledging the highest priority ISR bit, pending IRRs must get serviced first before the next round of acknowledge can take place as the APIC (real and virtualized) does not honour EOI without a preceeding interrupt on the CPU. And every APIC read/write takes a VMEXIT if the APIC is virtualized. While trying to reproduce the issue 0-day reported it was observed that the guest was scheduled out long enough under heavy load that it terminated after 8 iterations. Make the loop terminate after 512 iterations. That's plenty enough in any case and does not take endless time to complete. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.158847694@linutronix.de
2019-07-25x86/apic: Soft disable APIC before initializing itThomas Gleixner1-0/+8
If the APIC was already enabled on entry of setup_local_APIC() then disabling it soft via the SPIV register makes a lot of sense. That masks all LVT entries and brings it into a well defined state. Otherwise previously enabled LVTs which are not touched in the setup function stay unmasked and might surprise the just booting kernel. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105219.068290579@linutronix.de
2019-07-25x86/apic: Invoke perf_events_lapic_init() after enabling APICThomas Gleixner1-3/+2
If the APIC is soft disabled then unmasking an LVT entry does not work and the write is ignored. perf_events_lapic_init() tries to do so. Move the invocation after the point where the APIC has been enabled. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105218.962517234@linutronix.de
2019-07-25x86/kgbd: Use NMI_VECTOR not APIC_DM_NMIThomas Gleixner1-1/+1
apic->send_IPI_allbutself() takes a vector number as argument. APIC_DM_NMI is clearly not a vector number. It's defined to 0x400 which is outside the vector space. Use NMI_VECTOR instead as that's what it is intended to be. Fixes: 82da3ff89dc2 ("x86: kgdb support") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190722105218.855189979@linutronix.de
2019-07-25x86/reboot: Always use NMI fallback when shutdown via reboot vector IPI failsGrzegorz Halat1-19/+27
A reboot request sends an IPI via the reboot vector and waits for all other CPUs to stop. If one or more CPUs are in critical regions with interrupts disabled then the IPI is not handled on those CPUs and the shutdown hangs if native_stop_other_cpus() is called with the wait argument set. Such a situation can happen when one CPU was stopped within a lock held section and another CPU is trying to acquire that lock with interrupts disabled. There are other scenarios which can cause such a lockup as well. In theory the shutdown should be attempted by an NMI IPI after the timeout period elapsed. Though the wait loop after sending the reboot vector IPI prevents this. It checks the wait request argument and the timeout. If wait is set, which is true for sys_reboot() then it won't fall through to the NMI shutdown method after the timeout period has finished. This was an oversight when the NMI shutdown mechanism was added to handle the 'reboot IPI is not working' situation. The mechanism was added to deal with stuck panic shutdowns, which do not have the wait request set, so the 'wait request' case was probably not considered. Remove the wait check from the post reboot vector IPI wait loop and enforce that the wait loop in the NMI fallback path is invoked even if NMI IPIs are disabled or the registration of the NMI handler fails. That second wait loop will then hang if not all CPUs shutdown and the wait argument is set. [ tglx: Avoid the hard to parse line break in the NMI fallback path, add comments and massage the changelog ] Fixes: 7d007d21e539 ("x86/reboot: Use NMI to assist in shutting down if IRQ fails") Signed-off-by: Grzegorz Halat <ghalat@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Don Zickus <dzickus@redhat.com> Link: https://lkml.kernel.org/r/20190628122813.15500-1-ghalat@redhat.com
2019-07-25perf/x86/intel: Mark expected switch fall-throughsGustavo A. R. Silva1-0/+2
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warnings: arch/x86/events/intel/core.c: In function ‘intel_pmu_init’: arch/x86/events/intel/core.c:4959:8: warning: this statement may fall through [-Wimplicit-fallthrough=] arch/x86/events/intel/core.c:5008:8: warning: this statement may fall through [-Wimplicit-fallthrough=] Warning level 3 was used: -Wimplicit-fallthrough=3 This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190624161913.GA32270@embeddedor Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25perf/x86: Apply more accurate check on hypervisor platformZhenzhong Duan1-2/+1
check_msr is used to fix a bug report in guest where KVM doesn't support LBR MSR and cause #GP. The msr check is bypassed on real HW to workaround a false failure, see commit d0e1a507bdc7 ("perf/x86/intel: Disable check_msr for real HW") When running a guest with CONFIG_HYPERVISOR_GUEST not set or "nopv" enabled, current check isn't enough and #GP could trigger. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1564022366-18293-1-git-send-email-zhenzhong.duan@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25perf/x86/intel: Fix invalid Bit 13 for Icelake MSR_OFFCORE_RSP_x registerYunying Sun1-2/+2
The Intel SDM states that bit 13 of Icelake's MSR_OFFCORE_RSP_x register is valid, and used for counting hardware generated prefetches of L3 cache. Update the bitmask to allow bit 13. Before: $ perf stat -e cpu/event=0xb7,umask=0x1,config1=0x1bfff/u sleep 3 Performance counter stats for 'sleep 3': <not supported> cpu/event=0xb7,umask=0x1,config1=0x1bfff/u After: $ perf stat -e cpu/event=0xb7,umask=0x1,config1=0x1bfff/u sleep 3 Performance counter stats for 'sleep 3': 9,293 cpu/event=0xb7,umask=0x1,config1=0x1bfff/u Signed-off-by: Yunying Sun <yunying.sun@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: bp@alien8.de Cc: hpa@zytor.com Cc: jolsa@redhat.com Cc: namhyung@kernel.org Link: https://lkml.kernel.org/r/20190724082932.12833-1-yunying.sun@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25perf/x86/intel: Fix SLOTS PEBS event constraintKan Liang1-1/+1
Sampling SLOTS event and ref-cycles event in a group on Icelake gives EINVAL. SLOTS event is the event stands for the fixed counter 3, not fixed counter 2. Wrong mask was set to SLOTS event in intel_icl_pebs_event_constraints[]. Reported-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6017608936c1 ("perf/x86/intel: Add Icelake support") Link: https://lkml.kernel.org/r/20190723200429.8180-1-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-25x86/speculation/mds: Apply more accurate check on hypervisor platformZhenzhong Duan1-1/+1
X86_HYPER_NATIVE isn't accurate for checking if running on native platform, e.g. CONFIG_HYPERVISOR_GUEST isn't set or "nopv" is enabled. Checking the CPU feature bit X86_FEATURE_HYPERVISOR to determine if it's running on native platform is more accurate. This still doesn't cover the platforms on which X86_FEATURE_HYPERVISOR is unsupported, e.g. VMware, but there is nothing which can be done about this scenario. Fixes: 8a4b06d391b0 ("x86/speculation/mds: Add sysfs reporting for MDS") Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564022349-17338-1-git-send-email-zhenzhong.duan@oracle.com
2019-07-25x86/hpet: Undo the early counter is counting checkThomas Gleixner1-4/+8
Rui reported that on a Pentium D machine which has HPET forced enabled because it is not advertised by ACPI, the early counter is counting check leads to a silent boot hang. The reason is that the ordering of checking the counter first and then reconfiguring the HPET fails to work on that machine. As the HPET is not advertised and presumably not initialized by the BIOS the early enable and the following reconfiguration seems to bring it into a broken state. Adding clocksource=jiffies to the command line results in the following clocksource watchdog warning: clocksource: timekeeping watchdog on CPU1: Marking clocksource 'tsc-early' as unstable because the skew is too large: clocksource: 'hpet' wd_now: 33 wd_last: 33 mask: ffffffff That clearly shows that the HPET is not counting after it got reconfigured and reenabled. If the counter is not working then the HPET timer is not expiring either, which explains the boot hang. Move the counter is counting check after the full configuration again to unbreak these systems. Reported-by: Rui Salvaterra <rsalvaterra@gmail.com> Fixes: 3222daf970f3 ("x86/hpet: Separate counter check out of clocksource register code") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Rui Salvaterra <rsalvaterra@gmail.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907250810530.1791@nanos.tec.linutronix.de
2019-07-25treewide: add "WITH Linux-syscall-note" to SPDX tag of uapi headersMasahiro Yamada4-4/+4
UAPI headers licensed under GPL are supposed to have exception "WITH Linux-syscall-note" so that they can be included into non-GPL user space application code. The exception note is missing in some UAPI headers. Some of them slipped in by the treewide conversion commit b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license"). Just run: $ git show --oneline b24413180f56 -- arch/x86/include/uapi/asm/ I believe they are not intentional, and should be fixed too. This patch was generated by the following script: git grep -l --not -e Linux-syscall-note --and -e SPDX-License-Identifier \ -- :arch/*/include/uapi/asm/*.h :include/uapi/ :^*/Kbuild | while read file do sed -i -e '/[[:space:]]OR[[:space:]]/s/\(GPL-[^[:space:]]*\)/(\1 WITH Linux-syscall-note)/g' \ -e '/[[:space:]]or[[:space:]]/s/\(GPL-[^[:space:]]*\)/(\1 WITH Linux-syscall-note)/g' \ -e '/[[:space:]]OR[[:space:]]/!{/[[:space:]]or[[:space:]]/!s/\(GPL-[^[:space:]]*\)/\1 WITH Linux-syscall-note/g}' $file done After this patch is applied, there are 5 UAPI headers that do not contain "WITH Linux-syscall-note". They are kept untouched since this exception applies only to GPL variants. $ git grep --not -e Linux-syscall-note --and -e SPDX-License-Identifier \ -- :arch/*/include/uapi/asm/*.h :include/uapi/ :^*/Kbuild include/uapi/drm/panfrost_drm.h:/* SPDX-License-Identifier: MIT */ include/uapi/linux/batman_adv.h:/* SPDX-License-Identifier: MIT */ include/uapi/linux/qemu_fw_cfg.h:/* SPDX-License-Identifier: BSD-3-Clause */ include/uapi/linux/vbox_err.h:/* SPDX-License-Identifier: MIT */ include/uapi/linux/virtio_iommu.h:/* SPDX-License-Identifier: BSD-3-Clause */ Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-24Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds6-12/+43
Pull KVM fixes from Paolo Bonzini: "Bugfixes, a pvspinlock optimization, and documentation moving" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: X86: Boost queue head vCPU to mitigate lock waiter preemption Documentation: move Documentation/virtual to Documentation/virt KVM: nVMX: Set cached_vmcs12 and cached_shadow_vmcs12 NULL after free KVM: X86: Dynamically allocate user_fpu KVM: X86: Fix fpu state crash in kvm guest Revert "kvm: x86: Use task structs fpu field for user" KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested
2019-07-24x86/crash: Remove unnecessary comparisonNikolas Nyby1-2/+0
The ret comparison and return are unnecessary as of commit f296f2634920 ("x86/kexec: Remove walk_iomem_res() call with GART type") elf_header_exclude_ranges() returns ret in any case, with or without this comparison. [ tglx: Use a proper commit reference instead of full SHA ] Signed-off-by: Nikolas Nyby <nikolas@gnu.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190724041337.8346-1-nikolas@gnu.org
2019-07-24x86/mm: Avoid redundant interrupt disable in load_mm_cr4()Jan Kiszka4-13/+29
load_mm_cr4() is always called with interrupts disabled from: - switch_mm_irqs_off() - refresh_pce(), which is a on_each_cpu() callback Thus, disabling interrupts in cr4_set/clear_bits() is redundant. Implement cr4_set/clear_bits_irqsoff() helpers, rename load_mm_cr4() to load_mm_cr4_irqsoff() and use the new helpers. The new helpers do not need a lockdep assert as __cr4_set() has one already. The renaming in combination with the checks in __cr4_set() ensure that any changes in the boundary conditions at the call sites will be detected. [ tglx: Massaged change log ] Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/0fbbcb64-5f26-4ffb-1bb9-4f5f48426893@siemens.com
2019-07-24KVM: X86: Boost queue head vCPU to mitigate lock waiter preemptionWanpeng Li1-1/+2
Commit 11752adb (locking/pvqspinlock: Implement hybrid PV queued/unfair locks) introduces hybrid PV queued/unfair locks - queued mode (no starvation) - unfair mode (good performance on not heavily contended lock) The lock waiter goes into the unfair mode especially in VMs with over-commit vCPUs since increaing over-commitment increase the likehood that the queue head vCPU may have been preempted and not actively spinning. However, reschedule queue head vCPU timely to acquire the lock still can get better performance than just depending on lock stealing in over-subscribe scenario. Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM: ebizzy -M vanilla boosting improved 1VM 23520 25040 6% 2VM 8000 13600 70% 3VM 3100 5400 74% The lock holder vCPU yields to the queue head vCPU when unlock, to boost queue head vCPU which is involuntary preemption or the one which is voluntary halt due to fail to acquire the lock after a short spin in the guest. Cc: Waiman Long <longman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-24x86/entry/32: Pass cr2 to do_async_page_fault()Matt Mullins1-4/+9
Commit a0d14b8909de ("x86/mm, tracing: Fix CR2 corruption") added the address parameter to do_async_page_fault(), but does not pass it from the 32-bit entry point. To plumb it through, factor-out common_exception_read_cr2 in the same fashion as common_exception, and uses it from both page_fault and async_page_fault. For a 32-bit KVM guest, this fixes: Run /sbin/init as init process Starting init: /sbin/init exists but couldn't execute it (error -14) Fixes: a0d14b8909de ("x86/mm, tracing: Fix CR2 corruption") Signed-off-by: Matt Mullins <mmullins@fb.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20190724042058.24506-1-mmullins@fb.com
2019-07-24Documentation: move Documentation/virtual to Documentation/virtChristoph Hellwig1-1/+1
Renaming docs seems to be en vogue at the moment, so fix on of the grossly misnamed directories. We usually never use "virtual" as a shortcut for virtualization in the kernel, but always virt, as seen in the virt/ top-level directory. Fix up the documentation to match that. Fixes: ed16648eb5b8 ("Move kvm, uml, and lguest subdirectories under a common "virtual" directory, I.E:") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-23x86/bitops: Use __builtin_constant_p() directly instead of IS_IMMEDIATE()Masahiro Yamada1-4/+3
__builtin_constant_p(nr) is used everywhere now. It does not make much sense to define IS_IMMEDIATE() as its alias. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190723074415.26811-1-yamada.masahiro@socionext.com
2019-07-23x86/build: Remove unneeded uapi asm-generic wrappersMasahiro Yamada10-16/+0
These are listed in include/uapi/asm-generic/Kbuild, so Kbuild will automatically generate them. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190723112646.14046-1-yamada.masahiro@socionext.com
2019-07-22KVM: nVMX: Set cached_vmcs12 and cached_shadow_vmcs12 NULL after freeJan Kiszka1-0/+2
Shall help finding use-after-free bugs earlier. Suggested-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-22KVM: X86: Dynamically allocate user_fpuWanpeng Li4-5/+27
After reverting commit 240c35a3783a (kvm: x86: Use task structs fpu field for user), struct kvm_vcpu is 19456 bytes on my server, PAGE_ALLOC_COSTLY_ORDER(3) is the order at which allocations are deemed costly to service. In serveless scenario, one host can service hundreds/thoudands firecracker/kata-container instances, howerver, new instance will fail to launch after memory is too fragmented to allocate kvm_vcpu struct on host, this was observed in some cloud provider product environments. This patch dynamically allocates user_fpu, kvm_vcpu is 15168 bytes now on my Skylake server. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-22KVM: X86: Fix fpu state crash in kvm guestWanpeng Li1-3/+6
The idea before commit 240c35a37 (which has just been reverted) was that we have the following FPU states: userspace (QEMU) guest --------------------------------------------------------------------------- processor vcpu->arch.guest_fpu >>> KVM_RUN: kvm_load_guest_fpu vcpu->arch.user_fpu processor >>> preempt out vcpu->arch.user_fpu current->thread.fpu >>> preempt in vcpu->arch.user_fpu processor >>> back to userspace >>> kvm_put_guest_fpu processor vcpu->arch.guest_fpu --------------------------------------------------------------------------- With the new lazy model we want to get the state back to the processor when schedule in from current->thread.fpu. Reported-by: Thomas Lambertz <mail@thomaslambertz.de> Reported-by: anthony <antdev66@gmail.com> Tested-by: anthony <antdev66@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Lambertz <mail@thomaslambertz.de> Cc: anthony <antdev66@gmail.com> Cc: stable@vger.kernel.org Fixes: 5f409e20b (x86/fpu: Defer FPU state load until return to userspace) Signed-off-by: Wanpeng Li <wanpengli@tencent.com> [Add a comment in front of the warning. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-22Revert "kvm: x86: Use task structs fpu field for user"Paolo Bonzini2-5/+6
This reverts commit 240c35a3783ab9b3a0afaba0dde7291295680a6b ("kvm: x86: Use task structs fpu field for user", 2018-11-06). The commit is broken and causes QEMU's FPU state to be destroyed when KVM_RUN is preempted. Fixes: 240c35a3783a ("kvm: x86: Use task structs fpu field for user") Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-22KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nestedJan Kiszka1-0/+2
Letting this pend may cause nested_get_vmcs12_pages to run against an invalid state, corrupting the effective vmcs of L1. This was triggerable in QEMU after a guest corruption in L2, followed by a L1 reset. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Cc: stable@vger.kernel.org Fixes: 7f7f1ba33cf2 ("KVM: x86: do not load vmcs12 pages while still in SMM") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-22x86: Remove X86_FEATURE_MFENCE_RDTSCJosh Poimboeuf5-41/+8
AMD and Intel both have serializing lfence (X86_FEATURE_LFENCE_RDTSC). They've both had it for a long time, and AMD has had it enabled in Linux since Spectre v1 was announced. Back then, there was a proposal to remove the serializing mfence feature bit (X86_FEATURE_MFENCE_RDTSC), since both AMD and Intel have serializing lfence. At the time, it was (ahem) speculated that some hypervisors might not yet support its removal, so it remained for the time being. Now a year-and-a-half later, it should be safe to remove. I asked Andrew Cooper about whether it's still needed: So if you're virtualised, you've got no choice in the matter.  lfence is either dispatch-serialising or not on AMD, and you won't be able to change it. Furthermore, you can't accurately tell what state the bit is in, because the MSR might not be virtualised at all, or may not reflect the true state in hardware.  Worse still, attempting to set the bit may not be successful even if there isn't a fault for doing so. Xen sets the DE_CFG bit unconditionally, as does Linux by the looks of things (see MSR_F10H_DECFG_LFENCE_SERIALIZE_BIT).  ISTR other hypervisor vendors saying the same, but I don't have any information to hand. If you are running under a hypervisor which has been updated, then lfence will almost certainly be dispatch-serialising in practice, and you'll almost certainly see the bit already set in DE_CFG.  If you're running under a hypervisor which hasn't been patched since Spectre, you've already lost in many more ways. I'd argue that X86_FEATURE_MFENCE_RDTSC is not worth keeping. So remove it. This will reduce some code rot, and also make it easier to hook barrier_nospec() up to a cmdline disable for performance raisins, without having to need an alternative_3() macro. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/d990aa51e40063acb9888e8c1b688e41355a9588.1562255067.git.jpoimboe@redhat.com
2019-07-22x86/realmode: Remove trampoline_statusPingfan Liu6-17/+0
There is no reader of trampoline_status, it's only written. It turns out that after commit ce4b1b16502b ("x86/smpboot: Initialize secondary CPU only if master CPU will wait for it"), trampoline_status is not needed any more. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/1563266424-3472-1-git-send-email-kernelfans@gmail.com
2019-07-22x86/hyperv: Add functions to allocate/deallocate page for Hyper-VMaya Nakamura2-1/+18
Introduce two new functions, hv_alloc_hyperv_page() and hv_free_hyperv_page(), to allocate/deallocate memory with the size and alignment that Hyper-V expects as a page. Although currently they are not used, they are ready to be used to allocate/deallocate memory on x86 when their ARM64 counterparts are implemented, keeping symmetry between architectures with potentially different guest page sizes. Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.1906272334560.32342@nanos.tec.linutronix.de/ Link: https://lore.kernel.org/lkml/87muindr9c.fsf@vitty.brq.redhat.com/ Link: https://lkml.kernel.org/r/706b2e71eb3e587b5f8801e50f090fae2a00e35d.1562916939.git.m.maya.nakamura@gmail.com
2019-07-22x86/hyperv: Create and use Hyper-V page definitionsMaya Nakamura1-1/+11
Define HV_HYP_PAGE_SHIFT, HV_HYP_PAGE_SIZE, and HV_HYP_PAGE_MASK because the Linux guest page size and hypervisor page size concepts are different, even though they happen to be the same value on x86. Also, replace PAGE_SIZE with HV_HYP_PAGE_SIZE. Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lkml.kernel.org/r/e95111629abf65d016e983f72494cbf110ce605f.1562916939.git.m.maya.nakamura@gmail.com
2019-07-22x86/irq/64: Update stale commentCao jin1-4/+4
Commit e6401c130931 ("x86/irq/64: Split the IRQ stack into its own pages") missed to update one piece of comment as it did to its peer in Xen, which will confuse people who still need to read comment. Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190719081635.26528-1-caoj.fnst@cn.fujitsu.com
2019-07-22x86/sysfb_efi: Add quirks for some devices with swapped width and heightHans de Goede1-0/+46
Some Lenovo 2-in-1s with a detachable keyboard have a portrait screen but advertise a landscape resolution and pitch, resulting in a messed up display if the kernel tries to show anything on the efifb (because of the wrong pitch). Fix this by adding a new DMI match table for devices which need to have their width and height swapped. At first it was tried to use the existing table for overriding some of the efifb parameters, but some of the affected devices have variants with different LCD resolutions which will not work with hardcoded override values. Reference: https://bugzilla.redhat.com/show_bug.cgi?id=1730783 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190721152418.11644-1-hdegoede@redhat.com
2019-07-22x86/stacktrace: Prevent access_ok() warnings in arch_stack_walk_user()Eiichi Tsukata1-1/+1
When arch_stack_walk_user() is called from atomic contexts, access_ok() can trigger the following warning if compiled with CONFIG_DEBUG_ATOMIC_SLEEP=y. Reproducer: // CONFIG_DEBUG_ATOMIC_SLEEP=y # cd /sys/kernel/debug/tracing # echo 1 > options/userstacktrace # echo 1 > events/irq/irq_handler_entry/enable WARNING: CPU: 0 PID: 2649 at arch/x86/kernel/stacktrace.c:103 arch_stack_walk_user+0x6e/0xf6 CPU: 0 PID: 2649 Comm: bash Not tainted 5.3.0-rc1+ #99 RIP: 0010:arch_stack_walk_user+0x6e/0xf6 Call Trace: <IRQ> stack_trace_save_user+0x10a/0x16d trace_buffer_unlock_commit_regs+0x185/0x240 trace_event_buffer_commit+0xec/0x330 trace_event_raw_event_irq_handler_entry+0x159/0x1e0 __handle_irq_event_percpu+0x22d/0x440 handle_irq_event_percpu+0x70/0x100 handle_irq_event+0x5a/0x8b handle_edge_irq+0x12f/0x3f0 handle_irq+0x34/0x40 do_IRQ+0xa6/0x1f0 common_interrupt+0xf/0xf </IRQ> Fix it by calling __range_not_ok() directly instead of access_ok() as copy_from_user_nmi() does. This is fine here because the actual copy is inside a pagefault disabled region. Reported-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Eiichi Tsukata <devel@etsukata.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190722083216.16192-2-devel@etsukata.com
2019-07-22x86/cpufeatures: Enable a new AVX512 CPU featureGayatri Kammela2-0/+2
Add a new AVX512 instruction group/feature for enumeration in /proc/cpuinfo: AVX512_VP2INTERSECT. CPUID.(EAX=7,ECX=0):EDX[bit 8] AVX512_VP2INTERSECT Detailed information of CPUID bits for this feature can be found in the Intel Architecture Intsruction Set Extensions Programming Reference document (refer to Table 1-2). A copy of this document is available at https://bugzilla.kernel.org/show_bug.cgi?id=204215. Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190717234632.32673-3-gayatri.kammela@intel.com
2019-07-22cpu/cpuid-deps: Add a tab to cpuid dependent featuresGayatri Kammela1-48/+48
Improve code readability by adding a tab between the elements of each structure in an array of cpuid-dep struct so longer feature names will fit. Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190717234632.32673-2-gayatri.kammela@intel.com
2019-07-22x86/syscalls: Split the x32 syscalls into their own tableAndy Lutomirski6-26/+73
For unfortunate historical reasons, the x32 syscalls and the x86_64 syscalls are not all numbered the same. As an example, ioctl() is nr 16 on x86_64 but 514 on x32. This has potentially nasty consequences, since it means that there are two valid RAX values to do ioctl(2) and two invalid RAX values. The valid values are 16 (i.e. ioctl(2) using the x86_64 ABI) and (514 | 0x40000000) (i.e. ioctl(2) using the x32 ABI). The invalid values are 514 and (16 | 0x40000000). 514 will enter the "COMPAT_SYSCALL_DEFINE3(ioctl, ...)" entry point with in_compat_syscall() and in_x32_syscall() returning false, whereas (16 | 0x40000000) will enter the native entry point with in_compat_syscall() and in_x32_syscall() returning true. Both are bogus, and both will exercise code paths in the kernel and in any running seccomp filters that really ought to be unreachable. Splitting out the x32 syscalls into their own tables, allows both bogus invocations to return -ENOSYS. I've checked glibc, musl, and Bionic, and all of them appear to call syscalls with their correct numbers, so this change should have no effect on them. There is an added benefit going forward: new syscalls that need special handling on x32 can share the same number on x32 and x86_64. This means that the special syscall range 512-547 can be treated as a legacy wart instead of something that may need to be extended in the future. Also add a selftest to verify the new behavior. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/208024256b764312598f014ebfb0a42472c19354.1562185330.git.luto@kernel.org
2019-07-22x86/syscalls: Disallow compat entries for all types of 64-bit syscallsAndy Lutomirski1-2/+2
A "compat" entry in the syscall tables means to use a different entry on 32-bit and 64-bit builds. This only makes sense for syscalls that exist in the first place in 32-bit builds, so disallow it for anything other than i386. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/4b7565954c5a06530ac01d98cb1592538fd8ae51.1562185330.git.luto@kernel.org
2019-07-22x86/syscalls: Use the compat versions of rt_sigsuspend() and rt_sigprocmask()Andy Lutomirski1-2/+2
I'm working on some code that detects at build time if there's a COMPAT_SYSCALL_DEFINE() that is not referenced in the x86 syscall tables. It catches three offenders: rt_sigsuspend(), rt_sigprocmask(), and sendfile64(). For rt_sigsuspend() and rt_sigprocmask(), the only potential difference between the native and compat versions is that the compat version converts the sigset_t, but, on little endian architectures, the conversion is a no-op. This is why they both currently work on x86. To make the code more consistent, and to make the upcoming patches work, rewire x86 to use the compat vesions. sendfile64() is more complicated, and will be addressed separately. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/51643ac3157b5921eae0e172a8a0b1d953e68ebb.1562185330.git.luto@kernel.org
2019-07-22x86/syscalls: Make __X32_SYSCALL_BIT be unsigned longAndy Lutomirski1-1/+1
Currently, it's an int. This is bizarre. Fortunately, the code using it still works: ~__X32_SYSCALL_BIT is also int, so, if nr is unsigned long, then C kindly sign-extends the ~__X32_SYSCALL_BIT part, and it actually results in the desired value. This is far more subtle than it deserves to be. Syscall numbers are, for all practical purposes, unsigned long, so make __X32_SYSCALL_BIT be unsigned long. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/99b0d83ad891c67105470a1a6b63243fd63a5061.1562185330.git.luto@kernel.org
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