Setting the physical_vnets_channels parameter enables the emulation of
the bandwidth impact of having multiple physical channels for each
virtual network. This is implemented by computing bandwidth in a
per-vnet/channel basis within Throttle objects. The size of the
message buffers are also scaled according to this setting (when buffer
are not unlimited).
The physical_vnets_bandwidth can be used to override the channel width
set for each link and assign different widths for each virtual network.
The --simple-physical-channels option can be used with the generic
configuration scripts to automatically assign a single physical channel
to each virtual network defined in the protocol.
JIRA: https://gem5.atlassian.net/browse/GEM5-920
Change-Id: Ia8c9ec8651405eac8710d3f4d67f637a8054a76b
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/41854
Reviewed-by: Meatboy 106 <garbage2collector@gmail.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
The 'max_dequeue_rate' parameter limits the rate at which messages can
be dequeued in a single cycle. When set, 'isReady' returns false if
after max_dequeue_rate is reached.
This can be used to fine tune the performance of cache controllers.
For the record, other ways of achieving a similar effect could be:
1) Modifying the SLICC compiler to limit message consumption in the
generated wakeup() function
2) Set the buffer size to max_dequeue_rate. This can potentially cut the
the expected throughput in half. For instance if a producer can
enqueue every cycle, and a consumer can dequeue every cycle, a
message can only be actually enqueued every two (assuming
buffer_size=1) since the buffer entries available after dequeue
are only visible in the next cycle (even if the consumer executes
before the producer).
JIRA: https://gem5.atlassian.net/browse/GEM5-920
Change-Id: I3a446c7276b80a0e3f409b4fbab0ab65ff5c1f81
Signed-off-by: Tiago Mück <tiago.muck@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/41862
Reviewed-by: Meatboy 106 <garbage2collector@gmail.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
The 7th parameter of breakpoint_set_code is dontStop. It seems the
fastmodel would prefetch something or do some evaluation ahead with the
flag set. This behavior prevents the instruction stepping feature of
gdb. The implementation of the feature is creating a breakpoint on the
next instruction and contining the simulation. Without stopping on the
breakpoint, it wouldn't invoke the breakpoint callback, since it may
evaulate the code we just want it to stop already. We should set the
dontStop to false to fix this issue.
Change-Id: Iaf8acd3235fa9625c1423ef34606e1fa5d0c531a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55484
Reviewed-by: Earl Ou <shunhsingou@google.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Ported from https://gem5-review.googlesource.com/c/public/gem5/+/48019:
Certain DS insts are classfied as Loads, but don't actually go through
the memory pipeline. However, any instruction classified as a load
marks its destination registers as free in the memory pipeline.
Because these instructions didn't use the memory pipeline, they
never freed their destination registers, which led to a deadlock.
This patch explicitly calls the function used to free the destination
registers in the execute() method of those Load instructions that
don't use the memory pipeline.
Change-Id: I8231217a79661ca6acc837b2ab4931b946049a1a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55463
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
There are two entities setting up the IOAPIC when the simulation is
started, the IOAPIC itsef, and the PC platform object. It's probably not
a good idea (and definitely confusing) to have this initialization
happening in two places.
For now at least, lets make the PC platform object mask the IOAPIC lines
at startup like the IOAPIC is doing. This will help prevent spurious
interrupts from being delivered to the CPU during startup.
Change-Id: I10f455d8e0fca28ddaf772c224a32c1f5f2dd37b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55452
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These are mapped to instruction definitions like MOV_R_R, even though
one or more of the Rs might have come from a fixed value. Because
MOV_R_R (for instance) is only defined once, using a fixed text constant
there won't work because that can only have one value.
Instead, use a variable which will have the value of that constant so
that the same disassembly code will work no matter what fixed value was
used.
Change-Id: Ie45181c6becce80ad44fa30fc3323757ef713d7c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55444
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
This command can trigger count latching for any of the PIT channels
together with a single command, and can also latch a status byte. The
status byte is not implemented here, but there is already functionality
for latching the count which this can use.
Change-Id: Ic2ad7c73d0c521fdd6fe5f62cb478c6718f3b90c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55283
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
When performing a real mode far jump, we were computing the offset into
the segment more or less correctly, but then when we tried to actually
set the PC using it, we used the second of the two wrip microop
arguments. The first argument is an unsigned value and is intended to be
a base to work from when figuring out the new IP, and the second
argument is a signed offset which can be used to implement relative
jumps/branches. When we used the second operand for our new value,
setting the first operand to t0 (the zero register on x86), we would
inadvertantly sign extend it since the wrip instruction would treat it
as a signed value.
Instead, we can just switch the two operands so that the wrip microop
treats the desired value as the unsigned base, and then adds a signed t0
to it, which will still be 0 one way or the other.
Also, while researching this bug, I found that the size used for
computing the new IP is always the operand size, and never the address
size. This CL fixes that problem as well by removing the faulty
override.
Change-Id: I96ac9effd37b40161dd8d0b634c5869e767a8873
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55243
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This file populated the "cxx_config_directory" map from type names to
directory entry generating types. It used a comprehensive list of
includes of all SimObject headers, and a comprehensive list of the
generating types to fill everything in.
Instead, this change creates a new singleton helper class which, when
instantiated as a static member of a CxxConfigParams subclass, will
install a pointer to a CxxConfigDirectoryEntry to that map during global
object construction time.
Also, this change renames the map to cxxConfigDirectory which is in
compliance with the style guide, and puts it behind an accessor which
returns a static variable which is the actual map. This avoids any
problems that might come from global object construction order.
Change-Id: Iaa913fbe5af1b11d90ca618e29420eeb7cb0faed
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49455
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The BaseCPU type had been specializing itself based on the value of
TARGET_ISA, which is not compatible with building more than one ISA at a
time.
This change refactors the CPU models so that the BaseCPU is more
general, and the ISA specific components are added to the CPU when the
CPU types are fully specialized. For instance, The AtomicSimpleCPU has a
version called X86AtomicSimpleCPU which installs the X86 specific
aspects of the CPU.
This specialization is done in three ways.
1. The mmu parameter is assigned an instance of the architecture
specific MMU type. This provides a reasonable default, but also avoids
having having to use the ISA specific type when the parameter is
created.
2. The ISA specific types are made available as class attributes, and
the utility functions (including __init__!) in the BaseCPU class can
refer to them to get the types they need to set up the CPU at run time.
Because SimObjects have strange, unhelpful semantics as far as assigning
to their attributes, these types need to be set up in a non-SimObject
class, which is then brought in as a base of the actual SimObject type.
Because the metaclass of this other type is just "type", things work
like you would expect. The SimObject doesn't do any special processing
of base classes if they aren't also SimObjects, so these attributes
survive and are accessible using normal lookup in the BaseCPU class.
3. There are some methods like addCheckerCPU and properties like
needsTSO which have ISA specific values or behaviors. These are set in
the ISA specific subclass, where they are inherently specific to an ISA
and don't need to check TARGET_ISA.
Also, the DummyChecker which was set up for the BaseSimpleCPU which
doesn't actually do anything in either C++ or python was not carried
forward. The CPU type still exists, but it isn't installed in the
simple CPUs.
To provide backward compatibility, each ISA implements a .py file which
matches the original .py for a CPU, and the original is renamed with a
Base prefix. The ISA specific version creates an alias with the old CPU
name which maps to the ISA specific type. This way, old scripts which
refer to, for example, AtomicSimpleCPU, will get the X86AtomicSimpleCPU
if the x86 version was compiled in, the ArmAtomicSimpleCPU on arm, etc.
Unfortunately, because of how tags on PySource and by extension SimObjects
are implemented right now, if you set the tags on two SimObjects or
PySources which have the same module path, the later will overwrite the
former whether or not they both would be included. There are some
changes in review which would revamp this and make it work like you
would expect, without this central bookkeeping which has the conflict.
Since I can't use that here, I fell back to checking TARGET_ISA to
decide whether to tell SCons about those files at all.
In the long term, this mechanism should be revamped so that these
compatibility types are only available if there is exactly one ISA
compiled into gem5. After the configs have been updated and no longer
assume they can use AtomicSimpleCPU in all cases, then these types can
be deleted.
Also, because ISAs can now either provide subclasses for a CPU or not,
the CPU_MODELS variable has been removed, meaning the non-ISA
specialized versions of those CPU models will always be included in
gem5, except when building the NULL ISA.
In the future, a more granular config mechanism will hopefully be
implemented for *all* of gem5 and not just the CPUs, and these can be
conditional again in case you only need certain models, and want to
reduce build time or binary size by excluding the others.
Change-Id: I02fc3f645c551678ede46268bbea9f66c3f6c74b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52490
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Currently, an access to an invalid address will cause GEM5 to exit with
a `!pkt.isError()` assertion failure. I was seeing this assertion while
running a baremetal RISC-V binary that faulted before the trap vector
had been configured and therefore tried to jump to address zero. With
this change we now print the invalid address and the type of access
(ifetch/load/store/amo) which makes debugging such a problem much easier.
For example, my faulting program now prints the following:
`panic: Instruction fetch ([0:0x4]) failed: BadAddressError [0:3] IF`
I also saw this assertion with a program that was dereferencing a NULL
pointer, which now prints a more helpful message:
`panic: Data fetch ([0x10:0x11]) failed: BadAddressError [10:10]`
Change-Id: Id983b74bf4688711f47308c6c7c15f49662ac495
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55203
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
