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2015-12-28mem: Explicitly check MSHR snoops for cases not dealt withAndreas Hansson
Add a sanity check to make it explicit that we currently do not allow an I/O coherent agent to directly issue writes into the coherent part of the memory system (it has to go via a cache, and get transformed into a read ex, upgrade or invalidation).
2015-12-28mem: Remove unused cache squash functionalityAndreas Hansson
This patch removes the unused squash function from the MSHR queue, and the associated (and also unused) threadNum member from the MSHR.
2015-12-28mem: Avoid unecessary checks when creating HardPFReq in cacheAndreas Hansson
The checks made before sending out a HardPFReq were unecessarily complex, and checked for cases that never occur. This patch tidies it up.
2015-12-28mem: Do not use sender state to track forwarded snoops in cacheAndreas Hansson
This patch changes how the cache tracks which snoops are forwarded, and which ones are created locally. Previously the identification was based on an empty sender state of a specific class, but this method fails to distinguish which cache actually attached the sender state. Instead we use the same mechanism as the crossbar, and keep track of the requests that have outstanding snoops.
2015-12-28mem: Fix cache sender state handling and add clarificationAndreas Hansson
This patch addresses a bug in how the cache attached the MSHR as a sender state. Rather than overwriting any existing sender state it now pushes a new one. The handling of upward snoops is also clarified.
2015-12-18arm: remote GDB: rationalize structure of register offsetsBoris Shingarov
Currently, the wire format of register values in g- and G-packets is modelled using a union of uint8/16/32/64 arrays. The offset positions of each register are expressed as a "register count" scaled according to the width of the register in question. This results in counter- intuitive and error-prone "register count arithmetic", and some formats would even be altogether unrepresentable in such model, e.g. a 64-bit register following a 32-bit one would have a fractional index in the regs64 array. Another difficulty is that the array is allocated before the actual architecture of the workload is known (and therefore before the correct size for the array can be calculated). With this patch I propose a simpler mechanism for expressing the register set structure. In the new code, GdbRegCache is an abstract class; its subclasses contain straightforward structs reflecting the register representation. The determination whether to use e.g. the AArch32 vs. AArch64 register set (or SPARCv8 vs SPARCv9, etc.) is made by polymorphically dispatching getregs() to the concrete subclass. The subclass is not instantiated until it is needed for actual g-/G-packet processing, when the mode is already known. This patch is not meant to be merged in on its own, because it changes the contract between src/base/remote_gdb.* and src/arch/*/remote_gdb.*, so as it stands right now, it would break the other architectures. In this patch only the base and the ARM code are provided for review; once we agree on the structure, I will provide src/arch/*/remote_gdb.* for the other architectures; those patches could then be merged in together. Review Request: http://reviews.gem5.org/r/3207/ Pushed by Joel Hestness <jthestness@gmail.com>
2015-12-18sim: Use the old work item behavior by defaultAndreas Sandberg
When adding an option to forward work items to the Python environment, the new behavior was accidentally enabled by default. Set the value of exit_on_work_items to False by default to revert to the old behavior unless the simulation scripts explicitly requests work item forwarding.
2015-12-17mem: Fix memory allocation bug in deferred snoop handlingAndreas Hansson
This patch fixes a corner case in the deferred snoop handling, where requests ended up being used by multiple packets with different lifetimes, and inadvertently got deleted while they were still in use.
2015-12-14sim: Add an option to forward work items to PythonAndreas Sandberg
There are cases where we want the Python world to handle work items instead of the C++ world. However, that's currently not possible. This changeset adds the forward_work_items option to the System class. Then it is set to True, work items will generate workbegin/workend simulation exists with the work item ID as the exit code and the old C++ handling is completely bypassed. --HG-- extra : rebase_source : 8de637a744fc4b6ff2bc763f00cdf8ddf2bff885
2015-07-20mem: add request types for acquire and releaseDavid Hashe
Add support for acquire and release requests. These synchronization operations are commonly supported by several modern instruction sets.
2015-07-20ruby: more flexible ruby tester supportBrad Beckmann
This patch allows the ruby random tester to use ruby ports that may only support instr or data requests. This patch is similar to a previous changeset (8932:1b2c17565ac8) that was unfortunately broken by subsequent changesets. This current patch implements the support in a more straight-forward way. Since retries are now tested when running the ruby random tester, this patch splits up the retry and drain check behavior so that RubyPort children, such as the GPUCoalescer, can perform those operations correctly without having to duplicate code. Finally, the patch also includes better DPRINTFs for debugging the tester.
2015-12-10dev: Add missing SConscript in src/dev/i2cAndreas Sandberg
2015-12-10dev: Move storage devices to src/dev/storage/Andreas Sandberg
Move the IDE controller and the disk implementations to src/dev/storage. --HG-- rename : src/dev/DiskImage.py => src/dev/storage/DiskImage.py rename : src/dev/Ide.py => src/dev/storage/Ide.py rename : src/dev/SimpleDisk.py => src/dev/storage/SimpleDisk.py rename : src/dev/disk_image.cc => src/dev/storage/disk_image.cc rename : src/dev/disk_image.hh => src/dev/storage/disk_image.hh rename : src/dev/ide_atareg.h => src/dev/storage/ide_atareg.h rename : src/dev/ide_ctrl.cc => src/dev/storage/ide_ctrl.cc rename : src/dev/ide_ctrl.hh => src/dev/storage/ide_ctrl.hh rename : src/dev/ide_disk.cc => src/dev/storage/ide_disk.cc rename : src/dev/ide_disk.hh => src/dev/storage/ide_disk.hh rename : src/dev/ide_wdcreg.h => src/dev/storage/ide_wdcreg.h rename : src/dev/simple_disk.cc => src/dev/storage/simple_disk.cc rename : src/dev/simple_disk.hh => src/dev/storage/simple_disk.hh
2015-12-10dev: Move network devices to src/dev/net/Andreas Sandberg
--HG-- rename : src/dev/Ethernet.py => src/dev/net/Ethernet.py rename : src/dev/etherbus.cc => src/dev/net/etherbus.cc rename : src/dev/etherbus.hh => src/dev/net/etherbus.hh rename : src/dev/etherdevice.cc => src/dev/net/etherdevice.cc rename : src/dev/etherdevice.hh => src/dev/net/etherdevice.hh rename : src/dev/etherdump.cc => src/dev/net/etherdump.cc rename : src/dev/etherdump.hh => src/dev/net/etherdump.hh rename : src/dev/etherint.cc => src/dev/net/etherint.cc rename : src/dev/etherint.hh => src/dev/net/etherint.hh rename : src/dev/etherlink.cc => src/dev/net/etherlink.cc rename : src/dev/etherlink.hh => src/dev/net/etherlink.hh rename : src/dev/etherobject.hh => src/dev/net/etherobject.hh rename : src/dev/etherpkt.cc => src/dev/net/etherpkt.cc rename : src/dev/etherpkt.hh => src/dev/net/etherpkt.hh rename : src/dev/ethertap.cc => src/dev/net/ethertap.cc rename : src/dev/ethertap.hh => src/dev/net/ethertap.hh rename : src/dev/i8254xGBe.cc => src/dev/net/i8254xGBe.cc rename : src/dev/i8254xGBe.hh => src/dev/net/i8254xGBe.hh rename : src/dev/i8254xGBe_defs.hh => src/dev/net/i8254xGBe_defs.hh rename : src/dev/multi_etherlink.cc => src/dev/net/multi_etherlink.cc rename : src/dev/multi_etherlink.hh => src/dev/net/multi_etherlink.hh rename : src/dev/multi_iface.cc => src/dev/net/multi_iface.cc rename : src/dev/multi_iface.hh => src/dev/net/multi_iface.hh rename : src/dev/multi_packet.cc => src/dev/net/multi_packet.cc rename : src/dev/multi_packet.hh => src/dev/net/multi_packet.hh rename : src/dev/ns_gige.cc => src/dev/net/ns_gige.cc rename : src/dev/ns_gige.hh => src/dev/net/ns_gige.hh rename : src/dev/ns_gige_reg.h => src/dev/net/ns_gige_reg.h rename : src/dev/pktfifo.cc => src/dev/net/pktfifo.cc rename : src/dev/pktfifo.hh => src/dev/net/pktfifo.hh rename : src/dev/sinic.cc => src/dev/net/sinic.cc rename : src/dev/sinic.hh => src/dev/net/sinic.hh rename : src/dev/sinicreg.hh => src/dev/net/sinicreg.hh rename : src/dev/tcp_iface.cc => src/dev/net/tcp_iface.cc rename : src/dev/tcp_iface.hh => src/dev/net/tcp_iface.hh
2015-12-10dev: Move i2c functionality to src/dev/i2c/Andreas Sandberg
--HG-- rename : src/dev/I2C.py => src/dev/i2c/I2C.py rename : src/dev/i2cbus.cc => src/dev/i2c/bus.cc rename : src/dev/i2cbus.hh => src/dev/i2c/bus.hh rename : src/dev/i2cdev.hh => src/dev/i2c/device.hh
2015-12-10dev: Move the CopyEngine class to src/dev/pciAndreas Sandberg
--HG-- rename : src/dev/CopyEngine.py => src/dev/pci/CopyEngine.py rename : src/dev/copy_engine.cc => src/dev/pci/copy_engine.cc rename : src/dev/copy_engine.hh => src/dev/pci/copy_engine.hh rename : src/dev/copy_engine_defs.hh => src/dev/pci/copy_engine_defs.hh
2015-12-10dev: Move existing PCI device functionality to src/dev/pciAndreas Sandberg
Move pcidev.(hh|cc) to src/dev/pci/device.(hh|cc) and update existing devices to use the new header location. This also renames the PCIDEV debug flag to have a capitalization that is consistent with the PCI host and other devices. --HG-- rename : src/dev/Pci.py => src/dev/pci/PciDevice.py rename : src/dev/pcidev.cc => src/dev/pci/device.cc rename : src/dev/pcidev.hh => src/dev/pci/device.hh rename : src/dev/pcireg.h => src/dev/pci/pcireg.h
2015-11-05sim: Disable gzip compression for writefile pseudo instructionSascha Bischoff
The writefile pseudo instruction uses OutputDirectory::create and OutputDirectory::openFile to create the output files. However, by default these will check the file extention for .gz, and create a gzip compressed stream if the file ending matches. When writing out files, we want to write them out exactly as they are in the guest simulation, and never want to compress them with gzio. Additionally, this causes m5 writefile to fail when checking the error flags for the output steam. With this patch we add an additional no_gz argument to OutputDirectory::create and OutputDirectory::openFile which allows us to override the gzip compression. Therefore, for m5 writefile we disable the filename check, and always create a standard ostream.
2015-09-18dev, arm: Add gem5 extensions to support more than 8 coresKarthik Sangaiah
Previous ARM-based simulations were limited to 8 cores due to limitations in GICv2 and earlier. This changeset adds a set of gem5-specific extensions that enable support for up to 256 cores. When the gem5 extensions are enabled, the GIC uses CPU IDs instead of a CPU bitmask in the GIC's register interface. To OS can enable the extensions by setting bit 0x200 in ICDICTR. This changeset is based on previous work by Matt Evans.
2015-12-09mem: remove acq/rel cmds from packet and add mem fence reqTony Gutierrez
2015-12-09syscall_emul: don't check host fd when allocating target fdSteve Reinhardt
There's a well-meaning check in Process::allocFD() to return an invalid target fd (-1) if the incoming host fd is -1. However, this means that emulated drivers, which want to allocate a target fd that doesn't correspond to a host fd, can't use -1 to indicate an intentionally invalid host fd. It turns out the allocFD() check is redundant, as callers always test the host fd for validity before calling. Also, callers never test the return value of allocFD() for validity, so even if the test failed, it would likely have the undesirable result of returning -1 to the target app as a file descriptor without setting errno. Thus the check is pointless and is now getting in the way, so it seems we should just get rid of it.
2015-12-07cpu: Support virtual addr in elastic tracesRadhika Jagtap
This patch adds support to optionally capture the virtual address and asid for load/store instructions in the elastic traces. If they are present in the traces, Trace CPU will set those fields of the request during replay.
2015-12-07cpu: Create record type enum for elastic tracesRadhika Jagtap
This patch replaces the booleans that specified the elastic trace record type with an enum type. The source of change is the proto message for elastic trace where the enum is introduced. The struct definitions in the elastic trace probe listener as well as the Trace CPU replace the boleans with the proto message enum. The patch does not impact functionality, but traces are not compatible with previous version. This is preparation for adding new types of records in subsequent patches.
2015-12-07cpu: Add TraceCPU to playback elastic tracesRadhika Jagtap
This patch defines a TraceCPU that replays trace generated using the elastic trace probe attached to the O3 CPU model. The elastic trace is an execution trace with data dependencies and ordering dependencies annoted to it. It also replays fixed timestamp instruction fetch trace that is also generated by the elastic trace probe. The TraceCPU inherits from BaseCPU as a result of which some methods need to be defined. It has two port subclasses inherited from MasterPort for instruction and data ports. It issues the memory requests deducing the timing from the trace and without performing real execution of micro-ops. As soon as the last dependency for an instruction is complete, its computational delay, also provided in the input trace is added. The dependency-free nodes are maintained in a list, called 'ReadyList', ordered by ready time. Instructions which depend on load stall until the responses for read requests are received thus achieving elastic replay. If the dependency is not found when adding a new node, it is assumed complete. Thus, if this node is found to be completely dependency-free its issue time is calculated and it is added to the ready list immediately. This is encapsulated in the subclass ElasticDataGen. If ready nodes are issued in an unconstrained way there can be more nodes outstanding which results in divergence in timing compared to the O3CPU. Therefore, the Trace CPU also models hardware resources. A sub-class to model hardware resources is added which contains the maximum sizes of load buffer, store buffer and ROB. If resources are not available, the node is not issued. The 'depFreeQueue' structure holds nodes that are pending issue. Modeling the ROB size in the Trace CPU as a resource limitation is arguably the most important parameter of all resources. The ROB occupancy is estimated using the newly added field 'robNum'. We need to use ROB number as sequence number is at times much higher due to squashing and trace replay is focused on correct path modeling. A map called 'inFlightNodes' is added to track nodes that are not only in the readyList but also load nodes that are executed (and thus removed from readyList) but are not complete. ReadyList handles what and when to execute next node while the inFlightNodes is used for resource modelling. The oldest ROB number is updated when any node occupies the ROB or when an entry in the ROB is released. The ROB occupancy is equal to the difference in the ROB number of the newly dependency-free node and the oldest ROB number in flight. If no node dependends on a non load/store node then there is no reason to track it in the dependency graph. We filter out such nodes but count them and add a weight field to the subsequent node that we do include in the trace. The weight field is used to model ROB occupancy during replay. The depFreeQueue is chosen to be FIFO so that child nodes which are in program order get pushed into it in that order and thus issued in the in program order, like in the O3CPU. This is also why the dependents is made a sequential container, std::set to std::vector. We only check head of the depFreeQueue as nodes are issued in order and blocking on head models that better than looping the entire queue. An alternative choice would be to inspect top N pending nodes where N is the issue-width. This is left for future as the timing correlation looks good as it is. At the start of an execution event, first we attempt to issue such pending nodes by checking if appropriate resources have become available. If yes, we compute the execute tick with respect to the time then. Then we proceed to complete nodes from the readyList. When a read response is received, sometimes a dependency on it that was supposed to be released when it was issued is still not released. This occurs because the dependent gets added to the graph after the read was sent. So the check is made less strict and the dependency is marked complete on read response instead of insisting that it should have been removed on read sent. There is a check for requests spanning two cache lines as this condition triggers an assert fail in the L1 cache. If it does then truncate the size to access only until the end of that line and ignore the remainder. Strictly-ordered requests are skipped and the dependencies on such requests are handled by simply marking them complete immediately. The simulated seconds can be calculated as the difference between the final_tick stat and the tickOffset stat. A CountedExitEvent that contains a static int belonging to the Trace CPU class as a down counter is used to implement multi Trace CPU simulation exit.
2015-12-07mem: Add instruction sequence number to requestRadhika Jagtap
This patch adds the instruction sequence number to the request and provides a request constructor that accepts a sequence number for initialization.
2015-12-07proto, probe: Add elastic trace probe to o3 cpuRadhika Jagtap
The elastic trace is a type of probe listener and listens to probe points in multiple stages of the O3CPU. The notify method is called on a probe point typically when an instruction successfully progresses through that stage. As different listener methods mapped to the different probe points execute, relevant information about the instruction, e.g. timestamps and register accesses, are captured and stored in temporary InstExecInfo class objects. When the instruction progresses through the commit stage, the timing and the dependency information about the instruction is finalised and encapsulated in a struct called TraceInfo. TraceInfo objects are collected in a list instead of writing them out to the trace file one a time. This is required as the trace is processed in chunks to evaluate order dependencies and computational delay in case an instruction does not have any register dependencies. By this we achieve a simpler algorithm during replay because every record in the trace can be hooked onto a record in its past. The instruction dependency trace is written out as a protobuf format file. A second trace containing fetch requests at absolute timestamps is written to a separate protobuf format file. If the instruction is not executed then it is not added to the trace. The code checks if the instruction had a fault, if it predicated false and thus previous register values were restored or if it was a load/store that did not have a request (e.g. when the size of the request is zero). In all these cases the instruction is set as executed by the Execute stage and is picked up by the commit probe listener. But a request is not issued and registers are not written. So practically, skipping these should not hurt the dependency modelling. If squashing results in squashing younger instructions, it may happen that the squash probe discards the inst and removes it from the temporary store but execute stage deals with the instruction in the next cycle which results in the execute probe seeing this inst as 'new' inst. A sequence number of the last processed trace record is used to trap these cases and not add to the temporary store. The elastic instruction trace and fetch request trace can be read in and played back by the TraceCPU.
2015-12-07probe: Add probe in Fetch, IEW, Rename and CommitRadhika Jagtap
This patch adds probe points in Fetch, IEW, Rename and Commit stages as follows. A probe point is added in the Fetch stage for probing when a fetch request is sent. Notify is fired on the probe point when a request is sent succesfully in the first attempt as well as on a retry attempt. Probe points are added in the IEW stage when an instruction begins to execute and when execution is complete. This points can be used for monitoring the execution time of an instruction. Probe points are added in the Rename stage to probe renaming of source and destination registers and when there is squashing. These probe points can be used to track register dependencies and remove when there is squashing. A probe point for squashing is added in Commit to probe squashed instructions.
2015-12-05dev: Rewrite PCI host functionalityAndreas Sandberg
The gem5's current PCI host functionality is very ad hoc. The current implementations require PCI devices to be hooked up to the configuration space via a separate configuration port. Devices query the platform to get their config-space address range. Un-mapped parts of the config space are intercepted using the XBar's default port mechanism and a magic catch-all device (PciConfigAll). This changeset redesigns the PCI host functionality to improve code reuse and make config-space and interrupt mapping more transparent. Existing platform code has been updated to use the new PCI host and configured to stay backwards compatible (i.e., no guest-side visible changes). The current implementation does not expose any new functionality, but it can easily be extended with features such as automatic interrupt mapping. PCI devices now register themselves with a PCI host controller. The host controller interface is defined in the abstract base class PciHost. Registration is done by PciHost::registerDevice() which takes the device, its bus position (bus/dev/func tuple), and its interrupt pin (INTA-INTC) as a parameter. The registration interface returns a PciHost::DeviceInterface that the PCI device can use to query memory mappings and signal interrupts. The host device manages the entire PCI configuration space. Accesses to devices decoded into the devices bus position and then forwarded to the correct device. Basic PCI host functionality is implemented in the GenericPciHost base class. Most platforms can use this class as a basic PCI controller. It provides the following functionality: * Configurable configuration space decoding. The number of bits dedicated to a device is a prameter, making it possible to support both CAM, ECAM, and legacy mappings. * Basic interrupt mapping using the interruptLine value from a device's configuration space. This behavior is the same as in the old implementation. More advanced controllers can override the interrupt mapping method to dynamically assign host interrupts to PCI devices. * Simple (base + addr) remapping from the PCI bus's address space to physical addresses for PIO, memory, and DMA.
2015-12-04cpu: fix unitialized variable which may cause assertion failurePau Cabre
The assert in lsq_unit_impl.hh line 963 needs pktPending to be initialized to NULL (I got the assertion failure several times without the fix). Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-12-04sim: Get rid of the non-const serialize() methodAndreas Sandberg
The last SimObject using the legacy serialize API with non-const methods has now been transitioned to the new API. This changeset removes the serializeOld() methods from the serialization base class as they are no longer used.
2015-12-04arm, config: Automatically discover available platformsAndreas Sandberg
Add support for automatically discover available platforms. The Python-side uses functionality similar to what we use when auto-detecting available CPU models. The machine IDs have been updated to match the platform configurations. If there isn't a matching machine ID, the configuration scripts default to -1 which Linux uses for device tree only platforms.
2015-12-04dev, arm: Disable R/B swap in HDLCD by defaultAndreas Sandberg
The HDLCD model implements a workaround that swaps the red and blue channels. This works around an issue in certain old kernels. The new driver doesn't seem to have this behavior, so disable the workaround by default and enable it in the affected platforms.
2015-12-04dev, arm: Split MCC and DCC subsystemsAndreas Sandberg
Devices behind the Versatile Express configuration controllers are currently all lumped into one SimObject. This will make DTB generation challenging since the DTB assumes them to be in different parts of the hierarchy. It also makes it hard to model other CoreTiles without also replicating devices from the motherboard. This changeset splits the VExpressCoreTileCtrl into two subsystems: VExpressMCC for all motherboard-related devices and CoreTile2A15DCC for Core Tile specific devices.
2015-12-04sim: Add support for generating back traces on errorsAndreas Sandberg
Add functionality to generate a back trace if gem5 crashes (SIGABRT or SIGSEGV). The current implementation uses glibc's stack traversal support if available and stubs out the call to print_backtrace() otherwise.
2015-12-03arm: Add support for automatic boot loader selectionAndreas Sandberg
Add support for automatically selecting a boot loader that matches the guest system's kernel. Instead of accepting a single boot loader, the ArmSystem class now accepts a vector of boot loaders. When initializing a system, the we now look for the first boot loader with an architecture that matches the kernel. This changeset makes it possible to use the same system for both 64-bit and 32-bit kernels.
2015-12-03dev, mips: Remove the unused MaltaPChip classAndreas Sandberg
The MaltaPChip class is currently unused and identical (except for the class name) to the TsunamiPChip. If someone decides to implement PCI for Malta, they should make sure to share code with the Tsunami implementation if they are similar.
2015-12-01config: Fix broken SimObject listingAndreas Sandberg
The gem5 option '--list-sim-objects' is supposed to list all available SimObjects and their parameters. It currently chokes on SimObjects with parameters that have an object instance as their default value. This is caused by __str__ in SimObject trying to resolve its complete path. When the path resolution method reaches the parent object (a MetaSimObject since it hasn't been instantiated), it dies with a Python exception. This changeset adds a guard to stop path resolution if the parent object is a MetaSimObject.
2015-11-24dev: Remove unnecessary header includeAndreas Sandberg
--HG-- extra : rebase_source : 64046371962e98413757bc3ab0c0d48dfb11ff1e
2015-11-25mem: Fix search-replace issues in DRAMPower wrapper licenseAndreas Hansson
Fix a number of unintentional insertions of 'const'.
2015-11-22config: Added missing types to JSON/INI Python readerAndrew Bardsley
Added the missing types EthernetAddr and Current to the JSON/INI file reader example configs/example/read_config.py. Also added __str__ to EthernetAddr to make values appear in the same form in JSON an INI files.
2015-11-22arm, dev: Fix flash model serialization code typosGeoffrey Blake
The flash model has typos in its serialization code for unknownPages, locationTable, blockValidEntries, and blockEmptyEntries arrays where it would save each entry in the array under the same name in the checkpoint. This patch fixes these typos.
2015-11-22cpu: Fix base FP and CC register index in o3 insertThread()Nathanael Premillieu
Note that the method is not used, and could possibly be deleted.
2015-11-22arm: Fix fplib 128-bit shift operatorsNathanael Premillieu
Appease clang.
2015-11-22cpu: Fix memory leak in traffic generatorAndreas Hansson
In cases where we discard the packet, make sure to also delete it and the associated request.
2015-11-20cpu: Enforce 1 interrupt controller per threadAndreas Sandberg
Consider it a fatal configuration error if the number of interrupt controllers doesn't match the number of threads in an SMT configuration.
2015-11-16Merged changesets: 47e2adf7fb1a and b65d4e878ed2Nilay Vaish
--HG-- extra : amend_source : c51de9ae5387aba6fae8403677054678beceb2ab
2015-11-16x86: Invalidating TLB entry on page faultSwapnil Haria
As per the x86 architecture specification, matching TLB entries need to be invalidated on a page fault. For instance, after a page fault due to inadequate protection bits on a TLB hit, the TLB entry needs to be invalidated. This behavior is clearly specified in the x86 architecture manuals from both AMD and Intel. This invalidation is missing currently in gem5, due to which linux kernel versions 3.8 and up cannot be simulated efficiently. This is exposed by a linux optimisation in commit e4a1cc56e4d728eb87072c71c07581524e5160b1, which removes a tlb flush on updating page table entries in x86. Testing: Linux kernel versions 3.8 onwards were booting very slowly in FS mode, due to repeated page faults (~300000 before the first print statement in a bash file). Ensured that page fault rate drops drastically and observed reduction in boot time from order of hours to minutes for linux kernel v3.8 and v3.11
2015-11-16x86: cpuid: add family to warn() messageBjoern A. Zeeb
doCpuid() has to identical warn messages about unimplemented functions. Add the family to the log message to make them distinguishable. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-11-16x86: pagetable walker: fix typo in commentBjoern A. Zeeb
2015-11-16sparc: Make remote debugging with gdb workPalle Lyckegaard
Remove sparc V8 TBR register from list of registers since it is not part of sparc V9. This brings the number of registers in sync with what gdb expects Without this patch gdb complains about receoved packet too long. with this patch gdb is able to work properly with gem5 for remote debugging. Note: gdb is version 7.8 Note: gdb is configured with --target=sparc64-sun-solaris2.8 Committed by: Nilay Vaish <nilay@cs.wisc.edu>