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2018-01-19arch, mem, sim: Consolidate and rename the SE mode page table classes.Gabe Black
Now that Nothing inherits from PageTableBase directly, it can be merged into FuncPageTable. This change also takes the opportunity to rename the combined class to EmulationPageTable which lets you know that it's specifically for SE mode. Also remove the page table entry cache since it doesn't seem to actually improve performance. The TLBs likely absorb the majority of the locality, essentially acting like a cache like they would in real hardware. Change-Id: If1bcb91aed08686603bf7bee37298c0eee826e13 Reviewed-on: https://gem5-review.googlesource.com/7342 Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-11arch,mem: Move page table construction into the arch classes.Gabe Black
This gets rid of an awkward NoArchPageTable class, and also gives the arch a place to inject ISA specific parameters (specifically page size) without having to have TheISA:: in the generic version of these types. Change-Id: I1412f303460d5c43dafdb9b3cd07af81c908a441 Reviewed-on: https://gem5-review.googlesource.com/6981 Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-07-17sim, x86: Make clone a virtual functionSean Wilson
This fixes the function call to clone in syscall_emul.hh where the x86 version should be called before the base implementation of clone. Change-Id: Iccd2f680ff6e3a5536037d688a80ab3f236bbd98 Signed-off-by: Sean Wilson <spwilson2@wisc.edu> Reviewed-on: https://gem5-review.googlesource.com/3902 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2017-05-25x86: sim: Make 32 bit x86 processes work again.Gabe Black
When the LiveProcess class was renamed to be just Process, the CL author also changed the syscall function from a virtual function into a regular one. Unfortunately, the I386Process class overrode the syscall function to adjust the return address so that control would return to the right place. Without that adjustment, 32 bit x86 process would segfault and die immediately after their first system call. This change reinstates the virtual specifier on the base syscall function, and adds an override keyword on the I386Process's version so that it won't be orphaned again in the future. It also fixes some small style issues the style checker script complained about. Change-Id: I0d1178ea0eda6676050c8fc043820a2bb4d99c0d Reviewed-on: https://gem5-review.googlesource.com/3500 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2017-03-17syscall-emul: change NULL to nullptr in Process filesBrandon Potter
Change-Id: I9ff21092876593237f919e9f7fb7283bd865ba2e Reviewed-on: https://gem5-review.googlesource.com/2421 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Brandon Potter <Brandon.Potter@amd.com>
2017-03-09syscall-emul: Move memState into its own fileBrandon Potter
The Process class is full of implementation details and structures related to SE Mode. This changeset factors out an internal class from Process and moves it into a separate file. The purpose behind doing this is to clean up the code and make it a bit more modular. Change-Id: Ic6941a1657751e8d51d5b6b1dcc04f1195884280 Reviewed-on: https://gem5-review.googlesource.com/2263 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2017-03-06syscall-emul: Remove unused class and memberBrandon Potter
The WaitRec structure in the Process class is unnecessary. There is a member declaration inside of the Process class, waitList, that uses the WaitRec definition. However, waitList is unused so they are both dead bits of code. This changeset removes both the WaitRec struct and waitList member from Process. Change-Id: Ia6ee7488b9f47fd0f0ae29c818fba6ea0710699c Reviewed-on: https://gem5-review.googlesource.com/2262 Reviewed-by: Tony Gutierrez <anthony.gutierrez@amd.com> Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2017-02-27syscall_emul: [PATCH 15/22] add clone/execve for threading and multiprocess ↵Brandon Potter
simulations Modifies the clone system call and adds execve system call. Requires allowing processes to steal thread contexts from other processes in the same system object and the ability to detach pieces of process state (such as MemState) to allow dynamic sharing.
2017-02-27syscall_emul: [patch 14/22] adds identifier system callsBrandon Potter
This changeset add fields to the process object and adds the following three system calls: setpgid, gettid, getpid.
2015-07-20syscall_emul: [patch 13/22] add system call retry capabilityBrandon Potter
This changeset adds functionality that allows system calls to retry without affecting thread context state such as the program counter or register values for the associated thread context (when system calls return with a retry fault). This functionality is needed to solve problems with blocking system calls in multi-process or multi-threaded simulations where information is passed between processes/threads. Blocking system calls can cause deadlock because the simulator itself is single threaded. There is only a single thread servicing the event queue which can cause deadlock if the thread hits a blocking system call instruction. To illustrate the problem, consider two processes using the producer/consumer sharing model. The processes can use file descriptors and the read and write calls to pass information to one another. If the consumer calls the blocking read system call before the producer has produced anything, the call will block the event queue (while executing the system call instruction) and deadlock the simulation. The solution implemented in this changeset is to recognize that the system calls will block and then generate a special retry fault. The fault will be sent back up through the function call chain until it is exposed to the cpu model's pipeline where the fault becomes visible. The fault will trigger the cpu model to replay the instruction at a future tick where the call has a chance to succeed without actually going into a blocking state. In subsequent patches, we recognize that a syscall will block by calling a non-blocking poll (from inside the system call implementation) and checking for events. When events show up during the poll, it signifies that the call would not have blocked and the syscall is allowed to proceed (calling an underlying host system call if necessary). If no events are returned from the poll, we generate the fault and try the instruction for the thread context at a distant tick. Note that retrying every tick is not efficient. As an aside, the simulator has some multi-threading support for the event queue, but it is not used by default and needs work. Even if the event queue was completely multi-threaded, meaning that there is a hardware thread on the host servicing a single simulator thread contexts with a 1:1 mapping between them, it's still possible to run into deadlock due to the event queue barriers on quantum boundaries. The solution of replaying at a later tick is the simplest solution and solves the problem generally.
2016-11-09syscall_emul: [patch 10/22] refactor fdentry and add fdarray classBrandon Potter
Several large changes happen in this patch. The FDEntry class is rewritten so that file descriptors now correspond to types: 'File' which is normal file-backed file with the file open on the host machine, 'Pipe' which is a pipe that has been opened on the host machine, and 'Device' which does not have an open file on the host yet acts as a pseudo device with which to issue ioctls. Other types which might be added in the future are directory entries and sockets (off the top of my head). The FDArray class was create to hold most of the file descriptor handling that was stuffed into the Process class. It uses shared pointers and the std::array type to hold the FDEntries mentioned above. The changes to these two classes needed to be propagated out to the rest of the code so there were quite a few changes for that. Also, comments were added where I thought they were needed to help others and extend our DOxygen coverage.
2016-11-09syscall_emul: [patch 8/22] refactor process classBrandon Potter
Moves aux_vector into its own .hh and .cc files just to get it out of the already crowded Process files. Arguably, it could stay there, but it's probably better just to move it and give it files. The changeset looks ugly around the Process header file, but the goal here is to move methods and members around so that they're not defined randomly throughout the entire header file. I expect this is likely one of the reasons why I several unused variables related to this class. So, the methods are declared first followed by members. I've tried to aggregate them together so that similar entries reside near one another. There are other changes coming to this code so this is by no means the final product.
2016-11-09syscall_emul: [patch 7/22] remove numCpus methodBrandon Potter
The numCpus method is misleading in that it's not really a measure of how many CPUs might be executing a process, but how many thread contexts are assigned to the process at any given point in time. It's nice to highlight this distinction because thread contexts are never reused in the same way that a CPU can be reused for multiple processes. The reason that there is no reuse is that there is no CPU scheduler for SE. The tru64 code intends to use this method and the accompanying contextIDs field to support SMT and track the number of threads with some system calls. With the up coming clone and exec patches, this paradigm must change. There needs to be a 1:1 mapping between the thread contexts and processes so that the process state between threads is allowed to vary when needed by Linux. This should not break SMT for tru64 if the Process class is refactored so that multiple Processes can share state between themselves. The following patches will do the refactoring incrementally as features are added.
2016-11-09syscall_emul: [patch 6/22] remove unused fields from Process classBrandon Potter
It looks like tru64 has some nxm* system calls, but the two fields that are defined in the Process class are unused by any of the code. There doesn't appear to be any reference in the tru64 code.
2016-11-09syscall_emul: [patch 5/22] remove LiveProcess class and use Process insteadBrandon Potter
The EIOProcess class was removed recently and it was the only other class which derived from Process. Since every Process invocation is also a LiveProcess invocation, it makes sense to simplify the organization by combining the fields from LiveProcess into Process.
2016-11-09syscall_emul: [patch 4/22] remove redundant M5_pid field from processBrandon Potter
2016-11-09style: [patch 3/22] reduce include dependencies in some headersBrandon Potter
Used cppclean to help identify useless includes and removed them. This involved erroneously included headers, but also cases where forward declarations could have been used rather than a full include.
2016-11-09syscall_emul: [patch 2/22] move SyscallDesc into its own .hh and .ccBrandon Potter
The class was crammed into syscall_emul.hh which has tons of forward declarations and template definitions. To clean it up a bit, moved the class into separate files and commented the class with doxygen style comments. Also, provided some encapsulation by adding some accessors and a mutator. The syscallreturn.hh file was renamed syscall_return.hh to make it consistent with other similarly named files in the src/sim directory. The DPRINTF_SYSCALL macro was moved into its own header file with the include the Base and Verbose flags as well. --HG-- rename : src/sim/syscallreturn.hh => src/sim/syscall_return.hh
2016-03-17base: add symbol support for dynamic librariesBrandon Potter
Libraries are loaded into the process address space using the mmap system call. Conveniently, this happens to be a good time to update the process symbol table with the library's incoming symbols so we handle the table update from within the system call. This works just like an application's normal symbols. The only difference between a dynamic library and a main executable is when the symbol table update occurs. The symbol table update for an executable happens at program load time and is finished before the process ever begins executing. Since dynamic linking happens at runtime, the symbol loading happens after the library is first loaded into the process address space. The library binary is examined at this time for a symbol section and that section is parsed for symbol types with specific bindings (global, local, weak). Subsequently, these symbols are added to the table and are available for use by gem5 for things like trace generation. Checkpointing should work just as it did previously. The address space (and therefore the library) will be recorded and the symbol table will be entirely recorded. (It's not possible to do anything clever like checkpoint a program and then load the program back with different libraries with LD_LIBRARY_PATH, because the library becomes part of the address space after being loaded.)
2016-03-17base: support dynamic loading of Linux ELF objects in SE modeBrandon Potter
2016-03-17syscall_emul: move mmapGrowsDown() to LiveProcessSteve Reinhardt
The mmapGrowsDown() method was a static method on the OperatingSystem class (and derived classes), which worked OK for the templated syscall emulation methods, but made it hard to access elsewhere. This patch moves the method to be a virtual function on the LiveProcess method, where it can be overridden for specific platforms (for now, Alpha). This patch also changes the value of mmapGrowsDown() from being false by default and true only on X86Linux32 to being true by default and false only on Alpha, which seems closer to reality (though in reality most people use ASLR and this doesn't really matter anymore). In the process, also got rid of the unused mmap_start field on LiveProcess and OperatingSystem mmapGrowsUp variable.
2015-10-12misc: Add explicit overrides and fix other clang >= 3.5 issuesAndreas Hansson
This patch adds explicit overrides as this is now required when using "-Wall" with clang >= 3.5, the latter now part of the most recent XCode. The patch consequently removes "virtual" for those methods where "override" is added. The latter should be enough of an indication. As part of this patch, a few minor issues that clang >= 3.5 complains about are also resolved (unused methods and variables).
2015-10-12misc: Remove redundant compiler-specific definesAndreas Hansson
This patch moves away from using M5_ATTR_OVERRIDE and the m5::hashmap (and similar) abstractions, as these are no longer needed with gcc 4.7 and clang 3.1 as minimum compiler versions.
2015-09-29syscall_emul: Bandage readlink /proc/self/exeJoel Hestness
The recent changeset to readlink() to handle reading the /proc/self/exe link introduces a number of problems. This patch fixes two: 1) Because readlink() called on /proc/self/exe now uses LiveProcess::progName() to find the binary path, it will only get the zeroth parameter of the simulated system command line. However, if a config script also specifies the process' executable, the executable parameter is used to create the LiveProcess rather than the zeroth command line parameter. Thus, the zeroth command line parameter is not necessarily the correct path to the binary executing in the simulated system. To fix this, add a LiveProcess data member, 'executable', which is correctly set during instantiation and returned from progName(). 2) If a config script allows a user to pass a relative path as the zeroth simulated system command line parameter or process executable, readlink() will incorrecly return a relative path when called on '/proc/self/exe'. /proc/self/exe is always set to a full path, so running benchmarks can fail if a relative path is returned. To fix this, clean up the handling of LiveProcess::progName() within readlink() to get the full binary path. NOTE: This patch still leaves the potential problem that host full path to the binary bleeds into the simulated system, potentially causing the appearance of non-deterministic simulated system execution.
2015-08-07base: Declare a type for context IDsAndreas Sandberg
Context IDs used to be declared as ad hoc (usually as int). This changeset introduces a typedef for ContextIDs and a constant for invalid context IDs.
2015-07-24style: change Process function calls to use camelCaseBrandon Potter
The Process class methods were using an improper style and this subsequently bled into the system call code. The following regular expressions should be helpful if someone transitions private system call patches on top of these changesets: s/alloc_fd/allocFD/ s/sim_fd(/simFD(/ s/sim_fd_obj/getFDEntry/ s/fix_file_offsets/fixFileOffsets/ s/find_file_offsets/findFileOffsets/
2015-07-24base: refactor process class (specifically FdMap and friends)Brandon Potter
This patch extends the previous patch's alterations around fd_map. It cleans up some of the uglier code in the process file and replaces it with a more concise C++11 version. As part of the changes, the FdMap class is pulled out of the Process class and receives its own file.
2015-07-24syscall_emul: file descriptor interface changesBrandon Potter
This patch gets rid of unused Process::dup_fd method and does minor refactoring in the process class files. The file descriptor max has been changed to be the number of file descriptors since this clarifies the loop boundary condition and cleans up the code a bit. The fd_map field has been altered to be dynamically allocated as opposed to being an array; the intention here is to build on this is subsequent patches to allow processes to share their file descriptors with the clone system call.
2015-07-07sim: Refactor and simplify the drain APIAndreas Sandberg
The drain() call currently passes around a DrainManager pointer, which is now completely pointless since there is only ever one global DrainManager in the system. It also contains vestiges from the time when SimObjects had to keep track of their child objects that needed draining. This changeset moves all of the DrainState handling to the Drainable base class and changes the drain() and drainResume() calls to reflect this. Particularly, the drain() call has been updated to take no parameters (the DrainManager argument isn't needed) and return a DrainState instead of an unsigned integer (there is no point returning anything other than 0 or 1 any more). Drainable objects should return either DrainState::Draining (equivalent to returning 1 in the old system) if they need more time to drain or DrainState::Drained (equivalent to returning 0 in the old system) if they are already in a consistent state. Returning DrainState::Running is considered an error. Drain done signalling is now done through the signalDrainDone() method in the Drainable class instead of using the DrainManager directly. The new call checks if the state of the object is DrainState::Draining before notifying the drain manager. This means that it is safe to call signalDrainDone() without first checking if the simulator has requested draining. The intention here is to reduce the code needed to implement draining in simple objects.
2015-07-07sim: Refactor the serialization base classAndreas Sandberg
Objects that are can be serialized are supposed to inherit from the Serializable class. This class is meant to provide a unified API for such objects. However, so far it has mainly been used by SimObjects due to some fundamental design limitations. This changeset redesigns to the serialization interface to make it more generic and hide the underlying checkpoint storage. Specifically: * Add a set of APIs to serialize into a subsection of the current object. Previously, objects that needed this functionality would use ad-hoc solutions using nameOut() and section name generation. In the new world, an object that implements the interface has the methods serializeSection() and unserializeSection() that serialize into a named /subsection/ of the current object. Calling serialize() serializes an object into the current section. * Move the name() method from Serializable to SimObject as it is no longer needed for serialization. The fully qualified section name is generated by the main serialization code on the fly as objects serialize sub-objects. * Add a scoped ScopedCheckpointSection helper class. Some objects need to serialize data structures, that are not deriving from Serializable, into subsections. Previously, this was done using nameOut() and manual section name generation. To simplify this, this changeset introduces a ScopedCheckpointSection() helper class. When this class is instantiated, it adds a new /subsection/ and subsequent serialization calls during the lifetime of this helper class happen inside this section (or a subsection in case of nested sections). * The serialize() call is now const which prevents accidental state manipulation during serialization. Objects that rely on modifying state can use the serializeOld() call instead. The default implementation simply calls serialize(). Note: The old-style calls need to be explicitly called using the serializeOld()/serializeSectionOld() style APIs. These are used by default when serializing SimObjects. * Both the input and output checkpoints now use their own named types. This hides underlying checkpoint implementation from objects that need checkpointing and makes it easier to change the underlying checkpoint storage code.
2015-04-13sim: Use NULL instead of None for testing filenames.Nilay Vaish
The filenames are initialized with NULL. So the test should be checking for them to be == NULL instead == None.
2014-11-23mem: Page Table map api modificationAlexandru Dutu
This patch adds uncacheable/cacheable and read-only/read-write attributes to the map method of PageTableBase. It also modifies the constructor of TlbEntry structs for all architectures to consider the new attributes.
2014-11-23x86: Segment initialization to support KvmCPU in SEAlexandru Dutu
This patch sets up low and high privilege code and data segments and places them in the following order: cs low, ds low, ds, cs, in the GDT. Additionally, a syscall and page fault handler for KvmCPU in SE mode are defined. The order of the segment selectors in GDT is required in this manner for interrupt handling to work properly. Segment initialization is done for all the thread contexts.
2014-10-22syscall_emul: add EmulatedDriver objectSteve Reinhardt
Fake SE-mode device drivers can now be added by deriving from this abstract object.
2014-08-28mem: adding architectural page table support for SE modeAlexandru
This patch enables the use of page tables that are stored in system memory and respect x86 specification, in SE mode. It defines an architectural page table for x86 as a MultiLevelPageTable class and puts a placeholder class for other ISAs page tables, giving the possibility for future implementation.
2014-04-01mem: adding a multi-level page table classAlexandru
This patch defines a multi-level page table class that stores the page table in system memory, consistent with ISA specifications. In this way, cpu models that use the actual hardware to execute (e.g. KvmCPU), are able to traverse the page table.
2012-08-06process: add progName() virtual functionSteve Reinhardt
This replaces a (potentially uninitialized) string field with a virtual function so that we can have a safe interface without requiring changes to the eio code.
2012-07-10Add hook to call map() on Process from python.Steve Reinhardt
This enables configuration scripts to set up mappings from process virtual addresses to specific physical addresses in SE mode. This feature is needed to support modeling of user-accessible memories or devices in SE mode, avoiding the complexities of FS mode and the need to write a device driver.
2012-02-24MEM: Make port proxies use references rather than pointersAndreas Hansson
This patch is adding a clearer design intent to all objects that would not be complete without a port proxy by making the proxies members rathen than dynamically allocated. In essence, if NULL would not be a valid value for the proxy, then we avoid using a pointer to make this clear. The same approach is used for the methods using these proxies, such as loadSections, that now use references rather than pointers to better reflect the fact that NULL would not be an acceptable value (in fact the code would break and that is how this patch started out). Overall the concept of "using a reference to express unconditional composition where a NULL pointer is never valid" could be done on a much broader scale throughout the code base, but for now it is only done in the locations affected by the proxies.
2012-01-31Merge with head, hopefully the last time for this batch.Gabe Black
2012-01-31clang: Enable compiling gem5 using clang 2.9 and 3.0Koan-Sin Tan
This patch adds the necessary flags to the SConstruct and SConscript files for compiling using clang 2.9 and later (on Ubuntu et al and OSX XCode 4.2), and also cleans up a bunch of compiler warnings found by clang. Most of the warnings are related to hidden virtual functions, comparisons with unsigneds >= 0, and if-statements with empty bodies. A number of mismatches between struct and class are also fixed. clang 2.8 is not working as it has problems with class names that occur in multiple namespaces (e.g. Statistics in kernel_stats.hh). clang has a bug (http://llvm.org/bugs/show_bug.cgi?id=7247) which causes confusion between the container std::set and the function Packet::set, and this is currently addressed by not including the entire namespace std, but rather selecting e.g. "using std::vector" in the appropriate places.
2012-01-28Merge with the main repo.Gabe Black
--HG-- rename : src/mem/vport.hh => src/mem/fs_translating_port_proxy.hh rename : src/mem/translating_port.cc => src/mem/se_translating_port_proxy.cc rename : src/mem/translating_port.hh => src/mem/se_translating_port_proxy.hh
2012-01-17MEM: Add port proxies instead of non-structural portsAndreas Hansson
Port proxies are used to replace non-structural ports, and thus enable all ports in the system to correspond to a structural entity. This has the advantage of accessing memory through the normal memory subsystem and thus allowing any constellation of distributed memories, address maps, etc. Most accesses are done through the "system port" that is used for loading binaries, debugging etc. For the entities that belong to the CPU, e.g. threads and thread contexts, they wrap the CPU data port in a port proxy. The following replacements are made: FunctionalPort > PortProxy TranslatingPort > SETranslatingPortProxy VirtualPort > FSTranslatingPortProxy --HG-- rename : src/mem/vport.cc => src/mem/fs_translating_port_proxy.cc rename : src/mem/vport.hh => src/mem/fs_translating_port_proxy.hh rename : src/mem/translating_port.cc => src/mem/se_translating_port_proxy.cc rename : src/mem/translating_port.hh => src/mem/se_translating_port_proxy.hh
2012-01-07Merge with main repository.Gabe Black
2011-10-30SE/FS: Build the base process class in FS.Gabe Black
2011-10-22SE: move page allocation from PageTable to ProcessSteve Reinhardt
PageTable supported an allocate() call that called back through the Process to allocate memory, but did not have a method to map addresses without allocating new pages. It makes more sense for Process to do the allocation, so this method was renamed allocateMem() and moved to Process, and uses a new map() call on PageTable. The remaining uses of the process pointer in PageTable were only to get the name and the PID, so by passing these in directly in the constructor, we can make PageTable completely independent of Process.
2011-09-09Stack: Tidy up some comments, a warning, and make stack extension consistent.Gabe Black
Do some minor cleanup of some recently added comments, a warning, and change other instances of stack extension to be like what's now being done for x86.
2011-05-23sim: style fixes in sim/process.hhSteve Reinhardt
2010-08-17sim: revamp unserialization procedureSteve Reinhardt
Replace direct call to unserialize() on each SimObject with a pair of calls for better control over initialization in both ckpt and non-ckpt cases. If restoring from a checkpoint, loadState(ckpt) is called on each SimObject. The default implementation simply calls unserialize() if there is a corresponding checkpoint section, so we get backward compatibility for existing objects. However, objects can override loadState() to get other behaviors, e.g., doing other programmed initializations after unserialize(), or complaining if no checkpoint section is found. (Note that the default warning for a missing checkpoint section is now gone.) If not restoring from a checkpoint, we call the new initState() method on each SimObject instead. This provides a hook for state initializations that are only required when *not* restoring from a checkpoint. Given this new framework, do some cleanup of LiveProcess subclasses and X86System, which were (in some cases) emulating initState() behavior in startup via a local flag or (in other cases) erroneously doing initializations in startup() that clobbered state loaded earlier by unserialize().
2010-07-05process: get rid of some unused code & varsSteve Reinhardt