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path: root/arch/x86/kvm/i8254.h
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2012-04-27KVM: x86: Run PIT work in own kthreadJan Kiszka
We can't run PIT IRQ injection work in the interrupt context of the host timer. This would allow the user to influence the handler complexity by asking for a broadcast to a large number of VCPUs. Therefore, this work was pushed into workqueue context in 9d244caf2e. However, this prevents prioritizing the PIT injection over other task as workqueues share kernel threads. This replaces the workqueue with a kthread worker and gives that thread a name in the format "kvm-pit/<owner-process-pid>". That allows to identify and adjust the kthread priority according to the VM process parameters. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-05-11KVM: remove useless function declaration kvm_inject_pit_timer_irqs()Duan Jiong
Just remove useless function define kvm_inject_pit_timer_irqs() from file arch/x86/kvm/i8254.h Signed-off-by:Duan Jiong<djduanjiong@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11KVM: Remove base_addresss in kvm_pit since it is unusedJustin P. Mattock
The patch below removes unsigned long base_addresss; in i8254.h since it is unused. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01KVM: x86: Introduce a workqueue to deliver PIT timer interruptsChris Lalancette
We really want to "kvm_set_irq" during the hrtimer callback, but that is risky because that is during interrupt context. Instead, offload the work to a workqueue, which is a bit safer and should provide most of the same functionality. Signed-off-by: Chris Lalancette <clalance@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-03-01KVM: Convert i8254/i8259 locks to raw_spinlocksThomas Gleixner
The i8254/i8259 locks need to be real spinlocks on preempt-rt. Convert them to raw_spinlock. No change for !RT kernels. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10KVM: PIT support for HPET legacy modeBeth Kon
When kvm is in hpet_legacy_mode, the hpet is providing the timer interrupt and the pit should not be. So in legacy mode, the pit timer is destroyed, but the *state* of the pit is maintained. So if kvm or the guest tries to modify the state of the pit, this modification is accepted, *except* that the timer isn't actually started. When we exit hpet_legacy_mode, the current state of the pit (which is up to date since we've been accepting modifications) is used to restart the pit timer. The saved_mode code in kvm_pit_load_count temporarily changes mode to 0xff in order to destroy the timer, but then restores the actual value, again maintaining "current" state of the pit for possible later reenablement. [avi: add some reserved storage in the ioctl; make SET_PIT2 IOW] [marcelo: fix memory corruption due to reserved storage] Signed-off-by: Beth Kon <eak@us.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-09-10KVM: Allow PIT emulation without speaker portJan Kiszka
The in-kernel speaker emulation is only a dummy and also unneeded from the performance point of view. Rather, it takes user space support to generate sound output on the host, e.g. console beeps. To allow this, introduce KVM_CREATE_PIT2 which controls in-kernel speaker port emulation via a flag passed along the new IOCTL. It also leaves room for future extensions of the PIT configuration interface. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10KVM: unify part of generic timer handlingMarcelo Tosatti
Hide the internals of vcpu awakening / injection from the in-kernel emulated timers. This makes future changes in this logic easier and decreases the distance to more generic timer handling. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10KVM: PIT: remove unused scheduled variableMarcelo Tosatti
Unused. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: Reset PIT irq injection logic when the PIT IRQ is unmaskedAvi Kivity
While the PIT is masked the guest cannot ack the irq, so the reinject logic will never allow the interrupt to be injected. Fix by resetting the reinjection counters on unmask. Unbreaks Xen. Signed-off-by: Avi Kivity <avi@redhat.com>
2009-03-24KVM: PIT: provide an option to disable interrupt reinjectionMarcelo Tosatti
Certain clocks (such as TSC) in older 2.6 guests overaccount for lost ticks, causing severe time drift. Interrupt reinjection magnifies the problem. Provide an option to disable it. [avi: allow room for expansion in case we want to disable reinjection of other timers] Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-28KVM: Fix guest shared interrupt with in-kernel irqchipSheng Yang
Every call of kvm_set_irq() should offer an irq_source_id, which is allocated by kvm_request_irq_source_id(). Based on irq_source_id, we identify the irq source and implement logical OR for shared level interrupts. The allocated irq_source_id can be freed by kvm_free_irq_source_id(). Currently, we support at most sizeof(unsigned long) different irq sources. [Amit: - rebase to kvm.git HEAD - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file - move kvm_request_irq_source_id to the update_irq ioctl] [Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests] Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-10-15KVM: PIT: fix injection logic and countMarcelo Tosatti
The PIT injection logic is problematic under the following cases: 1) If there is a higher priority vector to be delivered by the time kvm_pit_timer_intr_post is invoked ps->inject_pending won't be set. This opens the possibility for missing many PIT event injections (say if guest executes hlt at this point). 2) ps->inject_pending is racy with more than two vcpus. Since there's no locking around read/dec of pt->pending, two vcpu's can inject two interrupts for a single pt->pending count. Fix 1 by using an irq ack notifier: only reinject when the previous irq has been acked. Fix 2 with appropriate locking around manipulation of pending count and irq_ack by the injection / ack paths. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27KVM: Add reset support for in kernel PITSheng Yang
Separate the reset part and prepare for reset support. Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27KVM: Add save/restore supporting of in kernel PITSheng Yang
Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-04-27KVM: In kernel PIT modelSheng Yang
The patch moves the PIT model from userspace to kernel, and increases the timer accuracy greatly. [marcelo: make last_injected_time per-guest] Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Tested-and-Acked-by: Alex Davis <alex14641@yahoo.com> Signed-off-by: Avi Kivity <avi@qumranet.com>