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path: root/src/cpu/kvm/timer.cc
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2017-12-04misc: Rename misc.(hh|cc) to logging.(hh|cc)Gabe Black
These files aren't a collection of miscellaneous stuff, they're the definition of the Logger interface, and a few utility macros for calling into that interface (panic, warn, etc.). Change-Id: I84267ac3f45896a83c0ef027f8f19c5e9a5667d1 Reviewed-on: https://gem5-review.googlesource.com/6226 Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2016-11-09style: [patch 1/22] use /r/3648/ to reorganize includesBrandon Potter
2014-02-20kvm: Add support for multi-system simulationAndreas Sandberg
The introduction of parallel event queues added most of the support needed to run multiple VMs (systems) within the same gem5 instance. This changeset fixes up signal delivery so that KVM's control signals are delivered to the thread that executes the CPU's event queue. Specifically: * Timers and counters are now initialized from a separate method (startupThread) that is scheduled as the first event in the thread-specific event queue. This ensures that they are initialized from the thread that is going to execute the CPUs event queue and enables signal delivery to the right thread when exiting from KVM. * The POSIX-timer-based KVM timer (used to force exits from KVM) has been updated to deliver signals to the thread that's executing KVM instead of the process (thread is undefined in that case). This assumes that the timer is instantiated from the thread that is going to execute the KVM vCPU. * Signal masking is now done using pthread_sigmask instead of sigprocmask. The behavior of the latter is undefined in threaded applications. * Since signal masks can be inherited, make sure to actively unmask the control signals when setting up the KVM signal mask. There are currently no facilities to multiplex between multiple KVM CPUs in the same event queue, we are therefore limited to configurations where there is only one KVM CPU per event queue. In practice, this means that multi-system configurations can be simulated, but not multiple CPUs in a shared-memory configuration.
2013-09-19kvm: Fix a case where the run timers weren't armed properlyAndreas Sandberg
There is a possibility that the timespec used to arm a timer becomes zero if the number of ticks used when arming a timer is close to the resolution of the timer. Due to the semantics of POSIX timers, this actually disarms the timer. This changeset fixes this issue by eliminating the rounding error (we always round away from zero now). It also reuses the minimum number of cycles, which were previously only used for cycle-based timers, to calculate a more useful resolution.
2013-06-03kvm: Add handling of EAGAIN when creating timersAndreas Sandberg
timer_create can apparently return -1 and set errno to EAGAIN if the kernel suffered a temporary failure when allocating a timer. This happens from time to time, so we need to handle it.
2013-04-22kvm: Add experimental support for a perf-based execution timerAndreas Sandberg
Add support for using the CPU cycle counter instead of a normal POSIX timer to generate timed exits to gem5. This should, in theory, provide better resolution when requesting timer signals. The perf-based timer requires a fairly recent kernel since it requires a working PERF_EVENT_IOC_PERIOD ioctl. This ioctl has existed in the kernel for a long time, but it used to be completely broken due to an inverted match when the kernel copied things from user space. Additionally, the ioctl does not change the sample period correctly on all kernel versions which implement it. It is currently only known to work reliably on kernel version 3.7 and above on ARM.
2013-04-22kvm: Basic support for hardware virtualized CPUsAndreas Sandberg
This changeset introduces the architecture independent parts required to support KVM-accelerated CPUs. It introduces two new simulation objects: KvmVM -- The KVM VM is a component shared between all CPUs in a shared memory domain. It is typically instantiated as a child of the system object in the simulation hierarchy. It provides access to KVM VM specific interfaces. BaseKvmCPU -- Abstract base class for all KVM-based CPUs. Architecture dependent CPU implementations inherit from this class and implement the following methods: * updateKvmState() -- Update the architecture-dependent KVM state from the gem5 thread context associated with the CPU. * updateThreadContext() -- Update the thread context from the architecture-dependent KVM state. * dump() -- Dump the KVM state using (optional). In order to deliver interrupts to the guest, CPU implementations typically override the tick() method and check for, and deliver, interrupts prior to entering KVM. Hardware-virutalized CPU currently have the following limitations: * SE mode is not supported. * PC events are not supported. * Timing statistics are currently very limited. The current approach simply scales the host cycles with a user-configurable factor. * The simulated system must not contain any caches. * Since cycle counts are approximate, there is no way to request an exact number of cycles (or instructions) to be executed by the CPU. * Hardware virtualized CPUs and gem5 CPUs must not execute at the same time in the same simulator instance. * Only single-CPU systems can be simulated. * Remote GDB connections to the guest system are not supported. Additionally, m5ops requires an architecture specific interface and might not be supported.