There are cases where a system's byte order isn't well-defined from an
ISA. For example, Arm implementations can be either big or little
endian, sometimes depending on a boot parameter. Decouple the CPU byte
order from the System's default byte order by exposing the System's
byte order as a parameter that defaults to big endian for SPARC and
POWER and little endian for everything else.
Change-Id: I24f87ea3a61b05042ede20dea6bb056af071d2c0
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33175
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
When the system call happens during the execution of the system call
instruction, it can be ambiguous what state takes precedence, the state
update from the instruction or the system call. These may be tracked
differently and found in an unpredictable order in, for example, the O3
CPU. An instruction can avoid updating any state explicitly, but
implicitly updated state (specifically the PC) will always update,
whether the instruction wants it to or not.
If the system call can be deferred by using a Fault object, then it's no
longer ambiguous. The PC update will be discarded, and the system call
can set the PC however it likes. Because there is no implicit PC update,
the PC needs to be walked forward, either to what it would have been
anyway, or to what the system call set in NPC.
In addition, because of the existing semantics around handling Faults,
the instruction no longer needs to be marked as serializing,
non-speculative, etc.
The "normal", aka architectural, aka FS version of the system call
instructions don't return a Fault artificially.
Change-Id: I72011a16a89332b1dcfb01c79f2f0d75c55ab773
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33281
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
isa_traits.hh used to have much more in it, but now it only has
PageShift, PageBytes, and (for now) the guest endianness. These values
should only be retrieved from the System class generally speaking, so
only the system class should include arch/isa_traits.hh.
Some gpu compute related files need PageBytes or PageShift. Even though
those files don't advertise their ISA dependence, they are tied to x86.
In those files, they can include arch/x86/isa_traits.hh.
The only other file which legitimately needs arch/isa_traits.hh is the
decoder cache since it uses PageBytes to size an array.
Change-Id: I12686368715623e3140a68a7027c136bd52567b1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33203
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This is no longer willing to implicitly cast between the locally defined
Linux::fd_set type and the system fd_set type. That's pretty reasonable
since those types are really independent of one another, and we
shouldn't be using them interchangeably in the first place. That's a
pre-existing condition though, and I just want to get the existing code
to compile for now.
Change-Id: I41d5f3695dfe5f0e406d074d31d13c6e3282df64
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33415
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
In sim/vma.hh, the include was indirectly getting the definition of
DPRINTF. It was replaced with an include of base/trace.hh which actually
provides that definition.
In the indirect branch predictor, it was being used to get the
definition of TheISA::PCState. This should come from arch/types.hh
instead.
Change-Id: I6de08f196499c85b54edde09d654902cc766c2eb
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33195
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Before this commit:
* SEV events were not waking neither WFE (wrong) nor futex WAIT (correct)
* locked memory events (LLSC) due to LDXR and STXR were waking up both
WFE (correct) and futex WAIT (wrong)
This commit fixes all wrong behaviours mentioned above.
The fact that LLSC events were waking up futexes leads to deadlocks,
as shown in the test case described at:
https://gem5.atlassian.net/browse/GEM5-537
because threads woken up by SVE are not removed from the waiter list
for the futex address they are sleeping on.
A previous fix atttempt was done at:
1531b56d605d47252dc0620bb3e755b7cf84df97
in which only sleeping threads are woken up. But that is not sufficient,
because the futex sleeping thread that was being wrongly woken up on SEV
can start to sleep on a second futex.
As an example, consider the case where 4 threads are fighting over two
critical sections protected by futex1 and futex2 addresses. In this case,
one thread wakes up the other thread after it is done with the section.
Suppose the following sequence of events:
* thread1 is awake and all others are suspended on futex1
* thread1 SEV wakes thread2 from the futex1 while in the critical region 1.
This is the wrong behaviour that this patch prevents, because
now thread2 is still in the sleeper list for futex1
* thread1 then futex wakes tread3, then proceeds to critical region 2.
* thread3 wakes up, but because thread2 has critical region, it sleeps
again.
* thread2 finishes its work, futex wakes thread3, and then proceeds to
futex2
When it reaches futex2, thread1 is still working there, so it sleeps on
futex2.
* thread3 futex wakes thread2, because it is still wrongly on the sleeper
list of futex1. But thread2 is in futex2 now.
If it weren't for this mistake, it should have awaken the final thread4
instead.
Outcome: thread4 sleeps forever, no other thread ever wakes it, because all
other threads have woken from futex1 and awoken another thread.
The problem is fixed by adding the waitingTcs unordered_set FutexMap,
which is basically an inverse map to FutexMap, which tracks (addr,
tgid) -> ThreadContext. This allows us allow to quickly check
if a given ThreadContext is waiting on a futex in any address.
Then the SEV wakeup code path
now checks if the thread is k
Change-Id: Icec5e30b041f53e5aa3b6e0d291e77bc0e865984
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29777
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Both methods do basically the same, especially since they don't handle the
timeout which is basically the only difference between both modes of the
syscall (one uses absolute and the other relative time).
Remove the WaiterState::WaiterState(ThreadContext* _tc) constructor,
since the only calls were from FutexMap::suspend which does not use them
anymore. Instead, set the magic 0xffffffff constant as a parameter to
suspend_bitset.
Change-Id: I69d86bad31d63604657a3c71cf07e5623f0ea639
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29776
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Add checkpoint parameters (together with corresponding serialization
and unserialization) for VMA list of class MemState into a separate
section named 'vmalist'.
Without these VMA list parameters, a page table fault will occur when
running with --restore-simpoint-checkpoint, because of an empty VMA
list. For example:
$ ./build/RISCV/gem5.debug --debug-flags=Exec configs/example/se.py \
-c tests/test-progs/hello/bin/riscv/linux/hello \
--cpu-type=NonCachingSimpleCPU --restore-simpoint-checkpoint \
--checkpoint-dir m5out/ -r 2
...
2404000: system.switch_cpus: T0 : @_int_malloc+3392 : sd a5, 8(a0) \
: MemWrite : D=0x000000000001ed21 A=0x862e8
panic: Page table fault when accessing virtual address 0x862e8
...
Example checkpoint output:
[system.cpu.workload.vmalist]
size=3
[system.cpu.workload.vmalist.Vma0]
name=stack
addrRangeStart=...
addrRangeEnd=...
[system.cpu.workload.vmalist.Vma1]
name=heap
addrRangeStart=...
addrRangeEnd=...
[system.cpu.workload.vmalist.Vma2]
...
Change-Id: Ib2fa7ad2c34fe667ce95bc4b10a1affcf60d9c1f
Signed-off-by: Ian Jiang <ianjiang.ict@gmail.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/31875
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This very simple and mostly useless operation has no side effects, and
can be used to verify that arguments are making it into gem5, being
operated on, and then that a result can be returned into the simulation.
Change-Id: I29bce824078526ff77513c80365f8fad88fef128
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27557
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch adds the ability for a host-OS process external to gem5
to access the backing store via POSIX shared memory.
The new param shared_backstore of the System object is the filename
of the shared memory (i.e., the first argument to shm_open()).
Change-Id: I98c948a32a15049a4515e6c02a14595fb5fe379f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30994
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Adds support for device memories in the system and RubySystem classes.
Devices may register memory ranges with the system class and packets
which originate from the device MasterID will update the device memory
in Ruby. In RubySystem functional access is updated to keep the packets
within the Ruby network they originated from.
Change-Id: I47850df1dc1994485d471ccd9da89e8d88eb0d20
JIRA: https://gem5.atlassian.net/browse/GEM5-470
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29653
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch adds a faulting flag to InstRecord.
This allows tracers to identify that the traced instruction has
faulted, when ExecFaulting is enabled. It can be set with
InstRecord::setFaulting() and read with Instrecord::getFaulting().
Change-Id: I390392d59de930533eab101e96dc4d3c76500748
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30134
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Initialize _stackSize and _stackMin to the maximum stack size values.
The are setup in each arch's Process::initState and may be uninitialized
until then. If a stack fixup occurs before these are setup, addresses
which are not in the stack might be allocated on the stack. This
prevents that until they are initialized in Process::initState. If an
access occurs before that with these initial values, the stack fixup
will simply allocate a page of memory in the stack space. However, it
will not print the typical info messages about growing the stack during
this time.
Change-Id: I9f9316734f4bf1f773fc538922e83b867731c684
JIRA: https://gem5.atlassian.net/browse/GEM5-629
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30394
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These are the stats in the base class, not in any derived classes. Only
Alpha has an additional stats. These were not really "kernel"
statistics, they were just applicable primarily in FS. They are
potentially applicable to any simulation, but will probably not be
incremented in SE simulations.
Also this merges these stats from being per thread to being per
workload, ie operating system instance. This is probably more relevant
since exactly what thread within a workload runs which particular
instruction is not very important/predictable, but the aggregate
behavior is. If necessary, this could be adjusted in the future to
split things back out again into stats per thread while keeping them
inside the single workload object.
Change-Id: I130e11a9022bdfcadcfb02c7995871503114cd53
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25147
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
If a port is unbound, trying to call its peer will likely cause a
segfault. Rather than check if a port is bound every time you go to use
it, we can instead bind to a default peer which just throws an exception
back to the caller. The caller can catch the exception and report the
error.
This change adds a common new class to throw as the exception, and also
a small utility function which reports the error and dies.
Change-Id: Ia58a2030922c73e2fd7d139822bce38d9b0f2171
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30295
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The System class has a few different arrays of values which each
correspond to a thread of execution based on their position. This
change collects them together into a single class to make managing them
easier and less error prone. It also collects methods for manipulating
those threads as an API for that class.
This class acts as a collection point for thread based state which the
System class can look into to get at all its state. It also acts as an
interface for interacting with threads for other classes. This forces
external consumers to use the API instead of accessing the individual
arrays which improves consistency.
Change-Id: Idc4575c5a0b56fe75f5c497809ad91c22bfe26cc
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25144
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Instead of calling into object files after the fact and asking them to
put symbols into a target symbol table, this change makes object files
fill in a symbol table themselves at construction. Then, that table can
be retrieved and used to fill in aggregate tables, masked, moved,
and/or filtered to have only one type of symbol binding.
This simplifies the symbol management API of the object file types
significantly, and makes it easier to deal with symbol tables alongside
binaries in the FS workload classes.
Change-Id: Ic9006ca432033d72589867c93d9c5f8a1d87f73c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24787
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
All other considerations aside, DTRACE probably fits best in trace.hh
where it is now, but unfortunately that creates an awkward dependence
between that file and eventq.hh and eventq_impl.hh. DTRACE only depends
on flags in the Debug namespace and a universal macro TRACING_ON, so
even though it won't be alongside the things it's most logically
associated with, it will be alongside all of its dependencies.
An alternative would be to re-implement DTRACE in eventq_impl.hh which
wouldn't be too big of a problem because it's so simple, but it's
cleaner and less error prone to still keep a single definition.
Because base/trace.hh includes base/debug.hh, any consumers expecting to
find DTRACE in base/trace.hh will still get that definition, even though
it's no longer direct.
Change-Id: I0dac83295891630686c3a8038eb54138cf40ab44
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29411
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
This uses a "name()" method which is not defined by the Ticked class,
and isn't a global method. This was probably originally supposed to be
the name() method of the Serializable class that Ticked inherits from,
but a while ago that was removed. It's not clear how this has been
compiling.
Instead, use the name() method of the ClockedObject which is the first
constructor argument.
Change-Id: Icfb71732c58ea9984ef7343bbaa46097a25abf28
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29406
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This constant isn't in normalized units, ie doesn't scale when the time
value of a Tick changes, is global, has an extremely generic name even
though it's only used by a few ethernet devices, and has an arbitrary
value.
Get rid of it, and replace it with 1ns, what it would typically be
equivalent to when using the default 1ps time scale.
Change-Id: I31d9dad438f854b4152cd53c9a7042a25d13e0a6
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29398
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This singleton object is used thruoughout the simulator. There is
really no reason not to have it statically allocated, except that
whether it was allocated seems to sometimes be used as a signal that
something already put symbols in it, specifically in SE mode.
To keep that functionality for the moment, this change adds an "empty"
method to the SymbolTable class to make it easy to check if the symbol
table is empty, or if someone already populated it.
Change-Id: Ia93510082d3f9809fc504bc5803254d8c308d572
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24785
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
