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path: root/drivers/kvm/lapic.c
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2007-10-22KVM: Improve local apic timer wraparound handlingKevin Pedretti
Better handle wrap-around cases when reading the APIC CCR (current count register). Also, if ICR is 0, CCR should also be 0... previously reading CCR before setting ICR would result in a large kinda-random number. Signed-off-by: Kevin Pedretti <kevin.pedretti@gmail.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22KVM: Fix local apic timer divide by zeroKevin Pedretti
kvm_lapic_reset() was initializing apic->timer.divide_count to 0, which could potentially lead to a divide by zero error in apic_get_tmcct(). Any guest that reads the APIC's CCR (current count) register before setting DCR (divide configuration) would trigger a divide by zero exception in the host kernel, leading to a host-OS crash. This patch results in apic->timer.divide_count being initialized to 2 at reset, eliminating the bug (DCR=0 at reset, meaning divide by 2). Signed-off-by: Kevin Pedretti <kevin.pedretti@gmail.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: enable in-kernel APIC INIT/SIPI handlingHe, Qing
This patch enables INIT/SIPI handling using in-kernel APIC by introducing a ->mp_state field to emulate the SMP state transition. [avi: remove smp_processor_id() warning] Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Xin Li <xin.b.li@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: round robin for APIC lowest priority delivery modeHe, Qing
Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: deliver PIC interrupt only to vcpu0Qing He
This patch changes the PIC interrupts delivery. Now it is only delivered to vcpu0 when either condition is met (on vcpu0): 1. local APIC is hardware disabled 2. LVT0 is unmasked and configured to delivery mode ExtInt It fixes the 2x faster wall clock on x86_64 and SMP i386 Linux guests Signed-off-by: Eddie (Yaozu) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Migrate lapic hrtimer when vcpu moves to another cpuEddie Dong
This reduces overhead by accessing cachelines from the wrong node, as well as simplifying locking. [Qing: fix for inactive or expired one-shot timer] Signed-off-by: Yaozu (Eddie) Dong <Eddie.Dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Keep track of missed timer irq injectionsEddie Dong
APIC timer IRQ is set every time when a certain period expires at host time, but the guest may be descheduled at that time and thus the irq be overwritten by later fire. This patch keep track of firing irq numbers and decrease only when the IRQ is injected to guest or buffered in APIC. Signed-off-by: Yaozu (Eddie) Dong <Eddie.Dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: VMX: Use shadow TPR/cr8 for 64-bits guestsYang, Sheng
This patch enables TPR shadow of VMX on CR8 access. 64bit Windows using CR8 access TPR frequently. The TPR shadow can improve the performance of access TPR by not causing vmexit. Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: in-kernel LAPIC save and restore supportEddie Dong
This patch adds a new vcpu-based IOCTL to save and restore the local apic registers for a single vcpu. The kernel only copies the apic page as a whole, extraction of registers is left to userspace side. On restore, the APIC timer is restarted from the initial count, this introduces a little delay, but works fine. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Emulate local APIC in kernelEddie Dong
Because lightweight exits (exits which don't involve userspace) are many times faster than heavyweight exits, it makes sense to emulate high usage devices in the kernel. The local APIC is one such device, especially for Windows and for SMP, so we add an APIC model to kvm. It also allows in-kernel host-side drivers to inject interrupts without going through userspace. [compile fix on i386 from Jindrich Makovicka] Signed-off-by: Yaozu (Eddie) Dong <Eddie.Dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>