Add a non-standard extension to the RSP protocol: the "." command
requests a dump of the simulated page table.
The dump consists of concatenated records, one record per page table
entry. Each record contains the entry's "virtual" value written as
hex, followed by a colon (:), followed by the entry's "physical" value
written as hex, followed by a semicolon (;).
At the time of writing, one practical use of this feature (in
combination with the "shared_backstore" parameter) is extremely fast
Miranda-Ingalls simulation of JIT compilers.
Change-Id: I333ed11d4ce671251d0b93cddae3bbcea44ea4ca
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47719
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Apply the gem5 namespace to the codebase.
Some anonymous namespaces could theoretically be removed,
but since this change's main goal was to keep conflicts
at a minimum, it was decided not to modify much the
general shape of the files.
A few missing comments of the form "// namespace X" that
occurred before the newly added "} // namespace gem5"
have been added for consistency.
std out should not be included in the gem5 namespace, so
they weren't.
ProtoMessage has not been included in the gem5 namespace,
since I'm not familiar with how proto works.
Regarding the SystemC files, although they belong to gem5,
they actually perform integration between gem5 and SystemC;
therefore, it deserved its own separate namespace.
Files that are automatically generated have been included
in the gem5 namespace.
The .isa files currently are limited to a single namespace.
This limitation should be later removed to make it easier
to accomodate a better API.
Regarding the files in util, gem5:: was prepended where
suitable. Notice that this patch was tested as much as
possible given that most of these were already not
previously compiling.
Change-Id: Ia53d404ec79c46edaa98f654e23bc3b0e179fe2d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46323
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This change replaces the __attribute__ syntax with the now standard [[]]
syntax. It also reorganizes compiler.hh so that all special macros have
some explanatory text saying what they do, and each attribute which has a
standard version can use that if available and what version of c++ it's
standard in is put in a comment.
Also, the requirements as far as where you put [[]] style attributes are
a little more strict than the old school __attribute__ style. The use of
the attribute macros was updated to fit these new, more strict
requirements.
Change-Id: Iace44306a534111f1c38b9856dc9e88cd9b49d2a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35219
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
In checkpoint output files, the parameters for page table including
size and entries are organized not very clearly. For example:
[system.cpu.workload]
...
ptable.size=...
[system.cpu.workload.Entry0]
vaddr=...
paddr=...
flags=...
[system.cpu.workload.Entry1]
...
This commit moves these parameters into a separate section named
'ptable'. For example:
[system.cpu.workload.ptable]
size=...
[system.cpu.workload.ptable.Entry0]
vaddr=...
paddr=...
flags=...
[system.cpu.workload.ptable.Entry1]
...
Change-Id: Iaa4129b3f4f090e8c3651bde90524abba0999c7f
Signed-off-by: Ian Jiang <ianjiang.ict@gmail.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31874
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch is changing the underlying type for RequestPtr from Request*
to shared_ptr<Request>. Having memory requests being managed by smart
pointers will simplify the code; it will also prevent memory leakage and
dangling pointers.
Change-Id: I7749af38a11ac8eb4d53d8df1252951e0890fde3
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/10996
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Since b8b13206c8, the '.fast' build has failed to compile with an error
caused by a variable and an assert.
As a reminder, assert macros are optimized out of the build for '.fast'.
If an assert check requires a variable that is unused anywhere else in
the code, the compiler complains that the variable is unused and the
scons build fails. The solution is to add a M5_VAR_USED specifier to
tell the compiler to ignore the variable.
Change-Id: I38f6bbed1e4c0506c5bbc1206c21f1f7e3d8dfe6
Reviewed-on: https://gem5-review.googlesource.com/8462
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
When moving a memory region the target region should be unmapped.
The assertion does reflect this, but the following line accesses
the invalid pointer regardless. This commit replaces the pointer
access with an emplace.
Change-Id: I85f9be4e6c223eab447c75043e593ed3f90017e1
Reviewed-on: https://gem5-review.googlesource.com/8261
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Rather than store the actual TLB entry that corresponds to a mapping,
we can just store some abstracted information (address, a few flags)
and then let the caller turn that into the appropriate entry. There
could potentially be some small amount of overhead from creating
entries vs. storing them and just installing them, but it's likely
pretty minimal since that only happens on a TLB miss (ideally rare),
and, if it is problematic, there could be some preallocated TLB
entries which are just minimally filled in as necessary.
This has the nice effect of finally making the page tables ISA
agnostic.
Change-Id: I11e630f60682f0a0029b0683eb8ff0135fbd4317
Reviewed-on: https://gem5-review.googlesource.com/7350
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>
This avoids having a copy in the lookup function itself, and the
declaration of a lot of temporary TLB entry pointers in callers. The
gpu TLB seems to have had the most dependence on the original signature
of the lookup function, partially because it was relying on a somewhat
unsafe copy to a TLB entry using a base class pointer type.
Change-Id: I8b1cf494468163deee000002d243541657faf57f
Reviewed-on: https://gem5-review.googlesource.com/7343
Reviewed-by: Gabe Black <gabeblack@google.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>
Using the architectural page table on x86 and the functional page table
on ARM, both with the twolf benchmark in SE mode, there was no
performance penalty for doing so, and again possibly a performance
improvement. By using a pointer instead of an inline instance, it's
possible for the actual type of the TLB entry to be hidden somewhat,
taking a step towards abstracting away another aspect of the ISAs.
Since the TLB entries are no longer overwritten and now need to be
allocated and freed, this change introduces return types from the
updateCache and eraseCacheEntry functions. These functions will return
the pointer to any entry which has been displaced from the cache which
the caller can either free or ignore, depending on whether the entry
has a purpose outside of the cache.
Because the functional page table stores its entries over a longer time
period, it will generally not delete the pointer returned from those
functions. The "architechtural" page table, ie the one which is backed
by memory, doesn't have any other use for the TlbEntrys and will delete
them. That leads to more news and deletes than there used to be.
To address that, and also to speed up the architectural page table in
general, it would be a good idea to augment the functional page table
with an image of the table in memory, instead of replacing it with one.
The functional page table would provide quick lookups and also avoid
having to translate page table entries to TLB entries, making
performance essentially equivalent to the functional case. The backing
page tables, which are primarily for consumption by the physical
hardware when in KVM, can be updated when mappings change but otherwise
left alone.
If we end up doing that, we could just let the ISA specific process
classes enable whatever additional TLB machinery they need, likely
a backing copy in memory, without any knowledge or involvement from
the ISA agnostic class. We would be able to get rid of the useArchPT
setting and the bits of code in the configs which set it.
Change-Id: I2e21945cd852bb1b3d0740fe6a4c5acbfd9548c5
Reviewed-on: https://gem5-review.googlesource.com/6983
Maintainer: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.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.
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.
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.
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.
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.
The existing implementation can read uninitialized data or stale information
from the cached PageTable entries.
1) Add a valid bit for the cache entries. Simply using zero for the virtual
address to signify invalid entries is not sufficient. Speculative, wrong-path
accesses frequently access page zero. The current implementation would return
a uninitialized TLB entry when address zero was accessed and the PageTable
cache entry was invalid.
2) When unmapping/mapping/remaping a page, invalidate the corresponding
PageTable cache entry if one already exists.
This patch is the result of static analysis identifying a number of
memory leaks. The leaks are all benign as they are a result of not
deallocating memory in the desctructor. The fix still has value as it
removes false positives in the static analysis.
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.
At the same time, rename the trace flags to debug flags since they
have broader usage than simply tracing. This means that
--trace-flags is now --debug-flags and --trace-help is now --debug-help
Also move the "Fault" reference counted pointer type into a separate file,
sim/fault.hh. It would be better to name this less similarly to sim/faults.hh
to reduce confusion, but fault.hh matches the name of the type. We could change
Fault to FaultPtr to match other pointer types, and then changing the name of
the file would make more sense.
1) Move alpha-specific code out of page_table.cc:serialize().
2) Begin serializing M5_pid and unserializing it, but adding an function to do optional paramIn so that old checkpoints don't need to be fixed up.
3) Fix up alpha startup code so that the unserialized M5_pid value is properly written to DTB_IPR_ASN.
4) Fix the memory unserialize that I forgot somehow in the last changeset.
5) Add in an agg_se.py to handle aggregated checkpoints. --bench foo-bar plus positional arguments foo bar are the only changes in usage from se.py.
Note this aggregation stuff has only been tested for Alpha and nothing else, though it should take a very minimal amount of work to get it to work with another ISA.
The page table now stores actual page table entries. It is still a templated
class here, but this will be corrected in the near future.
--HG--
extra : convert_revision : 804dcc6320414c2b3ab76a74a15295bd24e1d13d
creation and initialization now happens in python. Parameter objects
are generated and initialized by python. The .ini file is now solely for
debugging purposes and is not used in construction of the objects in any
way.
--HG--
extra : convert_revision : 7e722873e417cb3d696f2e34c35ff488b7bff4ed
Makes page table cache scheme actually work
src/mem/page_table.cc:
src/mem/page_table.hh:
fix caching scheme to actually work and improve performance
--HG--
extra : convert_revision : 443a8d8acbee540b26affcfdfbf107b8e735d1bd
