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2013-05-28x86: Increase precision of x86_platform.get/set_wallclock()David Vrabel1-6/+3
All the virtualized platforms (KVM, lguest and Xen) have persistent wallclocks that have more than one second of precision. read_persistent_wallclock() and update_persistent_wallclock() allow for nanosecond precision but their implementation on x86 with x86_platform.get/set_wallclock() only allows for one second precision. This means guests may see a wallclock time that is off by up to 1 second. Make set_wallclock() and get_wallclock() take a struct timespec parameter (which allows for nanosecond precision) so KVM and Xen guests may start with a more accurate wallclock time and a Xen dom0 can maintain a more accurate wallclock for guests. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-03-04Merge branch 'master' into queueMarcelo Tosatti1-2/+2
* master: (15791 commits) Linux 3.9-rc1 btrfs/raid56: Add missing #include <linux/vmalloc.h> fix compat_sys_rt_sigprocmask() SUNRPC: One line comment fix ext4: enable quotas before orphan cleanup ext4: don't allow quota mount options when quota feature enabled ext4: fix a warning from sparse check for ext4_dir_llseek ext4: convert number of blocks to clusters properly ext4: fix possible memory leak in ext4_remount() jbd2: fix ERR_PTR dereference in jbd2__journal_start metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP ... Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Conflicts: arch/x86/kernel/kvmclock.c
2013-02-27x86: kvmclock: Do not setup kvmclock vsyscall in the absence of that clockJan Kiszka1-1/+8
This fixes boot lockups with "no-kvmclock", when the host is not exposing this particular feature (QEMU: -cpu ...,-kvmclock) or when the kvmclock initialization failed for whatever reason. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-02-24Merge tag 'kvm-3.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-5/+6
Pull KVM updates from Marcelo Tosatti: "KVM updates for the 3.9 merge window, including x86 real mode emulation fixes, stronger memory slot interface restrictions, mmu_lock spinlock hold time reduction, improved handling of large page faults on shadow, initial APICv HW acceleration support, s390 channel IO based virtio, amongst others" * tag 'kvm-3.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (143 commits) Revert "KVM: MMU: lazily drop large spte" x86: pvclock kvm: align allocation size to page size KVM: nVMX: Remove redundant get_vmcs12 from nested_vmx_exit_handled_msr x86 emulator: fix parity calculation for AAD instruction KVM: PPC: BookE: Handle alignment interrupts booke: Added DBCR4 SPR number KVM: PPC: booke: Allow multiple exception types KVM: PPC: booke: use vcpu reference from thread_struct KVM: Remove user_alloc from struct kvm_memory_slot KVM: VMX: disable apicv by default KVM: s390: Fix handling of iscs. KVM: MMU: cleanup __direct_map KVM: MMU: remove pt_access in mmu_set_spte KVM: MMU: cleanup mapping-level KVM: MMU: lazily drop large spte KVM: VMX: cleanup vmx_set_cr0(). KVM: VMX: add missing exit names to VMX_EXIT_REASONS array KVM: VMX: disable SMEP feature when guest is in non-paging mode KVM: Remove duplicate text in api.txt Revert "KVM: MMU: split kvm_mmu_free_page" ...
2013-02-18x86: pvclock kvm: align allocation size to page sizeMarcelo Tosatti1-5/+6
To match whats mapped via vsyscalls to userspace. Reported-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2013-01-25x86, kvm: Fix kvm's use of __pa() on percpu areasDave Hansen1-2/+2
In short, it is illegal to call __pa() on an address holding a percpu variable. This replaces those __pa() calls with slow_virt_to_phys(). All of the cases in this patch are in boot time (or CPU hotplug time at worst) code, so the slow pagetable walking in slow_virt_to_phys() is not expected to have a performance impact. The times when this actually matters are pretty obscure (certain 32-bit NUMA systems), but it _does_ happen. It is important to keep KVM guests working on these systems because the real hardware is getting harder and harder to find. This bug manifested first by me seeing a plain hang at boot after this message: CPU 0 irqstacks, hard=f3018000 soft=f301a000 or, sometimes, it would actually make it out to the console: [ 0.000000] BUG: unable to handle kernel paging request at ffffffff I eventually traced it down to the KVM async pagefault code. This can be worked around by disabling that code either at compile-time, or on the kernel command-line. The kvm async pagefault code was injecting page faults in to the guest which the guest misinterpreted because its "reason" was not being properly sent from the host. The guest passes a physical address of an per-cpu async page fault structure via an MSR to the host. Since __pa() is broken on percpu data, the physical address it sent was bascially bogus and the host went scribbling on random data. The guest never saw the real reason for the page fault (it was injected by the host), assumed that the kernel had taken a _real_ page fault, and panic()'d. The behavior varied, though, depending on what got corrupted by the bad write. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130122212435.4905663F@kernel.stglabs.ibm.com Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-27x86: kvm guest: pvclock vsyscall supportMarcelo Tosatti1-12/+42
Hook into generic pvclock vsyscall code, with the aim to allow userspace to have visibility into pvclock data. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-11-27x86: kvmclock: allocate pvclock shared memory areaMarcelo Tosatti1-11/+47
We want to expose the pvclock shared memory areas, which the hypervisor periodically updates, to userspace. For a linear mapping from userspace, it is necessary that entire page sized regions are used for array of pvclock structures. There is no such guarantee with per cpu areas, therefore move to memblock_alloc based allocation. Acked-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-06-11x86: kvmclock: remove check_and_clear_guest_paused warningMarcelo Tosatti1-5/+0
CPU offline path calls the hrtimer interrupt handler with interrupts disabled, without touching preempt_count, triggering this warning. Remove the warning since it is supposed to be used from hrtimer interrupt context only. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-04-08kvmclock: remove unneeded EXPORT macroEric B Munson1-1/+0
check_and_clear_guest_paused does not need to be exported as it isn't used by any modules, remove the export. Signed-off-by: Eric B Munson <emunson@mgebm.net> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-04-08kvmclock: Add functions to check if the host has stopped the vmEric B Munson1-0/+21
When a host stops or suspends a VM it will set a flag to show this. The watchdog will use these functions to determine if a softlockup is real, or the result of a suspended VM. Signed-off-by: Eric B Munson <emunson@mgebm.net> asm-generic changes Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-20x86: kvmclock: abstract save/restore sched_clock_stateMarcelo Tosatti1-0/+11
Upon resume from hibernation, CPU 0's hvclock area contains the old values for system_time and tsc_timestamp. It is necessary for the hypervisor to update these values with uptodate ones before the CPU uses them. Abstract TSC's save/restore sched_clock_state functions and use restore_state to write to KVM_SYSTEM_TIME MSR, forcing an update. Also move restore_sched_clock_state before __restore_processor_state, since the later calls CONFIG_LOCK_STAT's lockstat_clock (also for TSC). Thanks to Igor Mammedov for tracking it down. Fixes suspend-to-disk with kvmclock. Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-05x86: Introduce x86_cpuinit.early_percpu_clock_init hookIgor Mammedov1-3/+1
When kvm guest uses kvmclock, it may hang on vcpu hot-plug. This is caused by an overflow in pvclock_get_nsec_offset, u64 delta = tsc - shadow->tsc_timestamp; which in turn is caused by an undefined values from percpu hv_clock that hasn't been initialized yet. Uninitialized clock on being booted cpu is accessed from start_secondary -> smp_callin -> smp_store_cpu_info -> identify_secondary_cpu -> mtrr_ap_init -> mtrr_restore -> stop_machine_from_inactive_cpu -> queue_stop_cpus_work ... -> sched_clock -> kvm_clock_read which is well before x86_cpuinit.setup_percpu_clockev call in start_secondary, where percpu clock is initialized. This patch introduces a hook that allows to setup/initialize per_cpu clock early and avoid overflow due to reading - undefined values - old values if cpu was offlined and then onlined again Another possible early user of this clock source is ftrace that accesses it to get timestamps for ring buffer entries. So if mtrr_ap_init is moved from identify_secondary_cpu to past x86_cpuinit.setup_percpu_clockev in start_secondary, ftrace may cause the same overflow/hang on cpu hot-plug anyway. More complete description of the problem: https://lkml.org/lkml/2012/2/2/101 Credits to Marcelo Tosatti <mtosatti@redhat.com> for hook idea. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-11-20KVM guest: prevent tracing recursion with kvmclockAvi Kivity1-2/+3
Prevent tracing of preempt_disable() in get_cpu_var() in kvm_clock_read(). When CONFIG_DEBUG_PREEMPT is enabled, preempt_disable/enable() are traced and this causes the function_graph tracer to go into an infinite recursion. By open coding the preempt_disable() around the get_cpu_var(), we can use the notrace version which prevents preempt_disable/enable() from being traced and prevents the recursion. Based on a similar patch for Xen from Jeremy Fitzhardinge. Tested-by: Gleb Natapov <gleb@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-07-24KVM guest: KVM Steal time registrationGlauber Costa1-0/+2
This patch implements the kvm bits of the steal time infrastructure. The most important part of it, is the steal time clock. It is an continuous clock that shows the accumulated amount of steal time since vcpu creation. It is supposed to survive cpu offlining/onlining. [marcelo: fix build with CONFIG_KVM_GUEST=n] Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Eric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Peter Zijlstra <peterz@infradead.org> CC: Avi Kivity <avi@redhat.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-02-21x86: Convert remaining x86 clocksources to clocksource_register_hz/khzJohn Stultz1-5/+1
This converts the remaining x86 clocksources to use clocksource_register_hz/khz. CC: jacob.jun.pan@intel.com CC: Glauber Costa <glommer@redhat.com> CC: Dimitri Sivanich <sivanich@sgi.com> CC: Rusty Russell <rusty@rustcorp.com.au> CC: Jeremy Fitzhardinge <jeremy@xensource.com> CC: Chris McDermott <lcm@us.ibm.com> CC: Thomas Gleixner <tglx@linutronix.de> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen] Signed-off-by: John Stultz <johnstul@us.ibm.com>
2011-01-12KVM paravirt: Move kvm_smp_prepare_boot_cpu() from kvmclock.c to kvm.c.Gleb Natapov1-12/+1
Async PF also needs to hook into smp_prepare_boot_cpu so move the hook into generic code. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24KVM guest: Move a printk that's using the clock before it's readyArjan Koers1-2/+4
Fix a hang during SMP kernel boot on KVM that showed up after commit 489fb490dbf8dab0249ad82b56688ae3842a79e8 (2.6.35) and 59aab522154a2f17b25335b63c1cf68a51fb6ae0 (2.6.34.1). The problem only occurs when CONFIG_PRINTK_TIME is set. KVM-Stable-Tag. Signed-off-by: Arjan Koers <0h61vkll2ly8@xutrox.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-19x86, paravirt: don't compute pvclock adjustments if we trust the tscGlauber Costa1-0/+3
If the HV told us we can fully trust the TSC, skip any correction Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-19x86: KVM guest: Try using new kvm clock msrsGlauber Costa1-21/+32
We now added a new set of clock-related msrs in replacement of the old ones. In theory, we could just try to use them and get a return value indicating they do not exist, due to our use of kvm_write_msr_save. However, kvm clock registration happens very early, and if we ever try to write to a non-existant MSR, we raise a lethal #GP, since our idt handlers are not in place yet. So this patch tests for a cpuid feature exported by the host to decide which set of msrs are supported. Signed-off-by: Glauber Costa <glommer@redhat.com> Acked-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2009-09-18Merge branch 'x86-platform-for-linus' of ↵Linus Torvalds1-4/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits) x86: Move get/set_wallclock to x86_platform_ops x86: platform: Fix section annotations x86: apic namespace cleanup x86: Distangle ioapic and i8259 x86: Add Moorestown early detection x86: Add hardware_subarch ID for Moorestown x86: Add early platform detection x86: Move tsc_init to late_time_init x86: Move tsc_calibration to x86_init_ops x86: Replace the now identical time_32/64.c by time.c x86: time_32/64.c unify profile_pc x86: Move calibrate_cpu to tsc.c x86: Make timer setup and global variables the same in time_32/64.c x86: Remove mca bus ifdef from timer interrupt x86: Simplify timer_ack magic in time_32.c x86: Prepare unification of time_32/64.c x86: Remove do_timer hook x86: Add timer_init to x86_init_ops x86: Move percpu clockevents setup to x86_init_ops x86: Move xen_post_allocator_init into xen_pagetable_setup_done ... Fix up conflicts in arch/x86/include/asm/io_apic.h
2009-09-16x86: Move get/set_wallclock to x86_platform_opsFeng Tang1-2/+2
get/set_wallclock() have already a set of platform dependent implementations (default, EFI, paravirt). MRST will add another variant. Moving them to platform ops simplifies the existing code and minimizes the effort to integrate new variants. Signed-off-by: Feng Tang <feng.tang@intel.com> LKML-Reference: <new-submission> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-09-10KVM guest: fix bogus wallclock physical address calculationGlauber Costa1-2/+2
The use of __pa() to calculate the address of a C-visible symbol is wrong, and can lead to unpredictable results. See arch/x86/include/asm/page.h for details. It should be replaced with __pa_symbol(), that does the correct math here, by taking relocations into account. This ensures the correct wallclock data structure physical address is passed to the hypervisor. Cc: stable@kernel.org Signed-off-by: Glauber Costa <glommer@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-08-31x86: Move tsc_calibration to x86_init_opsThomas Gleixner1-1/+1
TSC calibration is modified by the vmware hypervisor and paravirt by separate means. Moorestown wants to add its own calibration routine as well. So make calibrate_tsc a proper x86_init_ops function and override it by paravirt or by the early setup of the vmware hypervisor. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-08-31x86: Move percpu clockevents setup to x86_init_opsThomas Gleixner1-1/+4
paravirt overrides the setup of the default apic timers as per cpu timers. Moorestown needs to override that as well. Move it to x86_init_ops setup and create a separate x86_cpuinit struct which holds the function for the secondary evtl. hotplugabble CPUs. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-04-21clocksource: pass clocksource to read() callbackMagnus Damm1-1/+6
Pass clocksource pointer to the read() callback for clocksources. This allows us to share the callback between multiple instances. [hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods] [akpm@linux-foundation.org: cleanup] Signed-off-by: Magnus Damm <damm@igel.co.jp> Acked-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-23x86: refactor x86_quirks supportIngo Molnar1-1/+0
Impact: cleanup Make x86_quirks support more transparent. The highlevel methods are now named: extern void x86_quirk_pre_intr_init(void); extern void x86_quirk_intr_init(void); extern void x86_quirk_trap_init(void); extern void x86_quirk_pre_time_init(void); extern void x86_quirk_time_init(void); This makes it clear that if some platform extension has to do something here that it is considered ... weird, and is discouraged. Also remove arch_hooks.h and move it into setup.h (and other header files where appropriate). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-31x86: KVM guest: kvm_get_tsc_khz: return khz, not lpjEduardo Habkost1-4/+4
kvm_get_tsc_khz() currently returns the previously-calculated preset_lpj value, but it is in loops-per-jiffy, not kHz. The current code works correctly only when HZ=1000. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31x86: KVM guest: sign kvmclock as paravirtGlauber Costa1-0/+2
Currently, we only set the KVM paravirt signature in case of CONFIG_KVM_GUEST. However, it is possible to have it turned off, while CONFIG_KVM_CLOCK is turned on. This is also a paravirt case, and should be shown accordingly. Signed-off-by: Glauber Costa <glommer@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-11-30kvm_setup_secondary_clock() is cpuinitAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-11x86: KVM guest: fix section mismatch warning in kvmclock.cRakib Mullick1-1/+1
WARNING: arch/x86/kernel/built-in.o(.text+0x1722c): Section mismatch in reference from the function kvm_setup_secondary_clock() to the function .devinit.text:setup_secondary_APIC_clock() The function kvm_setup_secondary_clock() references the function __devinit setup_secondary_APIC_clock(). This is often because kvm_setup_secondary_clock lacks a __devinit annotation or the annotation of setup_secondary_APIC_clock is wrong. Signed-off-by: Md.Rakib H. Mullick <rakib.mullick@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15x86: KVM guest: use paravirt function to calculate cpu khzGlauber Costa1-0/+30
We're currently facing timing problems in guests that do calibration under heavy load, and then the load vanishes. This means we'll have a much lower lpj than we actually should, and delays end up taking less time than they should, which is a nasty bug. Solution is to pass on the lpj value from host to guest, and have it preset. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-07-20x86: KVM guest: make kvm_smp_prepare_boot_cpu() staticAdrian Bunk1-1/+1
This patch makes the needlessly global kvm_smp_prepare_boot_cpu() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24x86: KVM guest: Use the paravirt clocksource structs and functionsGerd Hoffmann1-56/+33
This patch updates the kvm host code to use the pvclock structs and functions, thereby making it compatible with Xen. The patch also fixes an initialization bug: on SMP systems the per-cpu has two different locations early at boot and after CPU bringup. kvmclock must take that in account when registering the physical address within the host. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-23namespacecheck: automated fixesIngo Molnar1-2/+2
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-04x86: KVM geust: make setup_secondary_clock definition dependent on local apicGlauber Costa1-0/+4
Since the pv_apic_ops are only present if CONFIG_X86_LOCAL_APIC is compiled in, kvmclock failed to build without this option. This patch fixes this. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27x86: KVM guest: disable clock before rebooting.Glauber Costa1-0/+27
This patch writes 0 (actually, what really matters is that the LSB is cleared) to the system time msr before shutting down the machine for kexec. Without it, we can have a random memory location being written when the guest comes back It overrides the functions shutdown, used in the path of kernel_kexec() (sys.c) and crash_shutdown, used in the path of crash_kexec() (kexec.c) Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27x86: KVM guest: paravirtualized clocksourceGlauber de Oliveira Costa1-0/+160
This is the guest part of kvm clock implementation It does not do tsc-only timing, as tsc can have deltas between cpus, and it did not seem worthy to me to keep adjusting them. We do use it, however, for fine-grained adjustment. Other than that, time comes from the host. [randy dunlap: add missing include] [randy dunlap: disallow on Voyager or Visual WS] Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
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