The only functional difference between them was that the SE one might
have optionally fixed up missing translations for demand paging.
This lets us get rid of some code recreating the proxy ports in
setProcessPtr since the SE translating port no longer keeps a copy of
the process object pointer.
Change-Id: Id97df1874f1de138ffd4f2dbb5846dda79d9e4ac
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26550
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
The logic that determines which syscall to call was built into the
implementation of faults/exceptions or even into the instruction
decoder, but that logic can depend on what OS is being used, and
sometimes even what version, for example 32bit vs. 64bit.
This change pushes that logic up into the Process objects since those
already handle a lot of the aspects of emulating the guest OS. Instead,
the ISA or fault implementations just notify the rest of the system
that a nebulous syscall has happened, and that gets propogated upward
until the process does something with it. That's very analogous to how
a system call would work on a real machine.
When a system call happens, the low level component which detects that
should call tc->syscall(&fault), where tc is the relevant thread (or
execution) context, and fault is a Fault which can ultimately be set
by the system call implementation.
The TC implementor (probably a CPU) will then have a chance to do
whatever it needs to to handle a system call. Currently only O3 does
anything special here. That implementor will end up calling the
Process's syscall() method.
Once in Process::syscall, the process object will use it's contextual
knowledge to determine what system call is being requested. It then
calls Process::doSyscall with the right syscall number, where doSyscall
centralizes the common mechanism for actually retrieving and calling
into the system call implementation.
Jira Issue: https://gem5.atlassian.net/browse/GEM5-187
Change-Id: I937ec1ef0576142c2a182ff33ca508d77ad0e7a1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23176
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
A memory image can be described by an object file, but an object file
is more than a memory image. Also, it makes sense to manipulate a
memory image to, for instance, change how it's loaded into memory. That
takes on larger implications (relocations, the entry point, symbols,
etc.) when talking about the whole object file, and also modifies
aspects which may not need to change. For instance if an image needs
to be loaded into memory at addresses different from what's in the
object file, but other things like symbols need to stay unmodified.
Change-Id: Ia360405ffb2c1c48e0cc201ac0a0764357996a54
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21466
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Set the default release to that single value for all ISAs.
glibc has checks for the kernel version based on uname, and refuses
to start any syscall emulation programs if those checks don't pass with
error:
FATAL: kernel too old
The ideal solution to this problem is to actually implement all missing
system calls for the required kernel version and bumping the release
accordingly.
However, it is very hard to implement all missing syscalls and verify
compliance.
Previously, we have simply bumped the version manually from time to
time when major glibc versions started breaking.
This commit alleviates the problem in two ways.
Firstly, having a single kernel version for all versions means that it is
easier to bump all versions at once.
Secondly, it makes it is possible to set the release with a parameter,
which in turn can be set from the command line with:
se.py --param 'system.cpu[:].workload[:].release = "4.18.0"'
Change-Id: I9e3c31073bfe68735f7b0775c8e299aa62b98222
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17849
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The system calls had four parameters. One of the parameters
is ThreadContext and another is Process. The ThreadContext
holds the value of the current process so the Process parameter
is redundant since the system call functions already have
indirect access.
With the old API, it is possible to call into the functions with
the wrong supplied Process which could end up being a confusing
error.
This patch removes the redundancy by forcing access through the
ThreadContext field within each system call.
Change-Id: Ib43d3f65824f6d425260dfd9f67de1892b6e8b7c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12299
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This gets rid of the big mass of #if-s around headers and around the
code which creates an object file.
As a nice side bonus, this also means that in addition to supporting
multiple OS/arch combinations simultaneously, the object file loader
could support multiple ISAs simultaneously as well, since each could
load and set up its object file loaders indepedently and without the
base process classes knowledge/involvement.
Change-Id: I0a19ad06e30e9062a96d27f00b66756eb3a595ba
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18631
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
54c77aa055 introduced a bug which manifests as cyclical
dependency on a member initialization for the Process
class.
The current working directory (cwd) parameter is passed into
Process to initialize both the target and host versions of the
cwd. (The target and host versions may differ if the faux
filesystem is used.) The host cwd init invoked methods which
rely on the host cwd already being initialized. To avoid the
bug, the code will now rely on using the targets cwd version,
but will issue checks against the redirect paths.
Change-Id: I4ab644a3e00737dbf249f5d6faf20a26ceb04248
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18448
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This change introduces the concept of a faux-filesystem.
The faux-filesystem creates a directory structure in m5out
(or whatever output dir the user specifies) where system calls
may be redirected.
This is useful to avoid non-determinism when reading files
with varying path names (e.g., variations from run-to-run if
the simulation is scheduled on a cluster where paths may change).
Also, this changeset allows circumventing host pseudofiles which
have information specific to the host processor (such as cache
hierarchy or processor information). Bypassing host pseudofiles
can be useful when executing runtimes in the absence of an
operating system kernel since runtimes may try to query standard
files (i.e. /proc or /sys) which are not relevant to an
application executing in syscall emulation mode.
Change-Id: I90821b3b403168b904a662fa98b85def1628621c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/12119
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This changeset enables clone to work with X86KvmCPU model, which
will allow running multi-threaded applications at near hardware
speeds. Even though the application is multi-threaded, the KvmCPU
model uses one event queue, therefore, only one hardware thread
will be used, through KVM, to simulate multiple application threads.
Change-Id: I2b2a7b1edb1c56eeb9c4fa0553cd236029cd53f8
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18268
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These types are IntReg, FloatReg, FloatRegBits, and MiscReg. There are
some remaining types, specifically the vector registers and the CCReg.
I'm less familiar with these new types of registers, and so will look
at getting rid of them at some later time.
Change-Id: Ide8f76b15c531286f61427330053b44074b8ac9b
Reviewed-on: https://gem5-review.googlesource.com/c/13624
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
The new version extracts all the x86 specific aspects of the class,
and builds the interface around a variable collection of template
arguments which are classes that represent the different levels of the
page table. The multilevel page table class is now much more ISA
independent.
Change-Id: Id42e168a78d0e70f80ab2438480cb6e00a3aa636
Reviewed-on: https://gem5-review.googlesource.com/7347
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
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>
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>
The clone system call added in 236719892 relies on header files
from Linux systems. Obviously, this prevents compilation for
anyone using FreeBSD or Mac to compile the simulator. This
changeset is meant as a temporary fix to allow builds on
non-Linux systems until a proper solution is found.
Change-Id: I404cc41c588ed193dd2c1ca0c1aea35b0786fe4e
Reviewed-on: https://gem5-review.googlesource.com/2420
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
The changeset does a major refactor on the exit, exit_group, and
futex system calls regarding exit functionality.
A FutexMap class and related structures are added into a new
file. This increases code clarity by encapsulating the futex
operations and the futex state into an object.
Several exit conditions were added to allow the simulator to end
processes under certain conditions. Also, the simulation only
exits now when all processes have finished executing.
Change-Id: I1ee244caa9b5586fe7375e5b9b50fd3959b9655e
Reviewed-on: https://gem5-review.googlesource.com/2269
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
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>
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.
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.
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.
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.
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.
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.
Seeing build breakage after brandon@11801:
[ CXX] X86/sim/process.cc -> .o build/X86/sim/process.cc:137:64:
error: field '_pid' is uninitialized when used here
[-Werror,-Wuninitialized] static_cast<PageTableBase *>(new
ArchPageTable(name(), _pid, system)) : ^ build/X86/sim/process.cc:138:64:
error: field '_pid' is uninitialized when used here
[-Werror,-Wuninitialized] static_cast<PageTableBase *>(new
FuncPageTable(name(), _pid))), ^ 2 errors generated.
Testing Done: Compiles now on FreeBSD 10 with clang.
Reviewed at http://reviews.gem5.org/r/3804/
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
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.
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
When restoring from a checkpoint, the simulation used to use file handles from
the checkpoint. This disallows multiple separate restore simulations from using
separate input and output files and directories, and plays havoc when the
checkpointed file locations may have changed. Add handling to allow the command
line specified files to be used as input/output for the restored simulation
(Note: this is the similar functionality to FS mode for output and error).
First of five patches adding RISC-V to GEM5. This patch introduces the
base 64-bit ISA (RV64I) in src/arch/riscv for use with syscall emulation.
The multiply, floating point, and atomic memory instructions will be added
in additional patches, as well as support for more detailed CPU models.
The loader is also modified to be able to parse RISC-V ELF files, and a
"Hello world\!" example for RISC-V is added to test-progs.
Patch 2 will implement the multiply extension, RV64M; patch 3 will implement
the floating point (single- and double-precision) extensions, RV64FD;
patch 4 will implement the atomic memory instructions, RV64A, and patch 5
will add support for timing, minor, and detailed CPU models that is missing
from the first four patches (such as handling locked memory).
[Removed several unused parameters and imports from RiscvInterrupts.py,
RiscvISA.py, and RiscvSystem.py.]
[Fixed copyright information in RISC-V files copied from elsewhere that had
ARM licenses attached.]
[Reorganized instruction definitions in decoder.isa so that they are sorted
by opcode in preparation for the addition of ISA extensions M, A, F, D.]
[Fixed formatting of several files, removed some variables and
instructions that were missed when moving them to other patches, fixed
RISC-V Foundation copyright attribution, and fixed history of files
copied from other architectures using hg copy.]
[Fixed indentation of switch cases in isa.cc.]
[Reorganized syscall descriptions in linux/process.cc to remove large
number of repeated unimplemented system calls and added implmementations
to functions that have received them since it process.cc was first
created.]
[Fixed spacing for some copyright attributions.]
[Replaced the rest of the file copies using hg copy.]
[Fixed style check errors and corrected unaligned memory accesses.]
[Fix some minor formatting mistakes.]
Signed-off by: Alec Roelke
Signed-off by: Jason Lowe-Power <jason@lowepower.com>
We want to extend the stats of objects hierarchically and thus it is necessary
to register the statistics of the base-class(es), as well. For now, these are
empty, but generic stats will be added there.
Patch originally provided by Akash Bagdia at ARM Ltd.
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.)
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.
