This also allows checkpointing of a Kvm GIC via the Pl390 model.
Change-Id: Ic85d81cfefad630617491b732398f5e6a5f34c0b
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2444
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Weiping Liao <weipingliao@google.com>
Instructions that use the coprocessor interface check the current
program status to determine whether the current context has the
priviledges to read from/write to the coprocessor. Some modes allow
the execution of coprocessor instructions, some others do not allow it,
while some other modes are unexpected (e.g., executing an AArch32
instruction while being in an AArch64 mode).
Previously we would unconditionally trigger a panic if we were in an
unexpected mode. This change removes the panic and replaces it
with an Undefined Instruction fault that triggers if and when a
coprocessor instruction commits in an unexpected mode. This allows
speculative coprocessor instructions from unexpected modes to execute
but prevents them from gettting committed.
Change-Id: If2776d5bae2471cdbaf76d0e1ae655f501bfbf01
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Rekai Gonzalez Alberquilla <rekai.gonzalezalberquilla@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2281
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Weiping Liao <weipingliao@google.com>
A completed write to a memory location that is Write-Through Cacheable
has to be visible to an external observer without the need of explicit
cache maintenance. This change adds support for Write-Through
Cacheable Normal memory and treats it as Non-cacheable. This incurs a
small penalty as accesses to the memory do not fill in the cache but
does not violate the properties of the memory type.
Change-Id: Iee17ef9d952a550be9ad660b1e60e9f6c4ef2c2d
Reviewed-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2280
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
The kernel and gem5 derive MPIDR values from CPU IDs in slightly
different ways. This means that guests running in a multi-CPU setup
sometimes fail to bring up secondary CPUs. Fix this by overriding the
MPIDR value in virtual CPUs just after they have been instantiated.
Change-Id: I916d44978a9c855ab89c80a083af45b0cea6edac
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2461
Reviewed-by: Weiping Liao <weipingliao@google.com>
In arch/arm/faults.hh, template the static member vals require explicit
specialisation to avoid compiler warnings.
Change-Id: Ie404ccaa43269cb1bb819e33153e776abbf3a79b
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.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>
The gem5 stores flags separately from other fields CPSR, so we need to
split them out and recombine on trips to/from KVM.
Change-Id: I28ed00eb6f0e2a1436adfbc51b6ccf056958afeb
Reviewed-on: https://gem5-review.googlesource.com/2260
Reviewed-by: Rahul Thakur <rjthakur@google.com>
Maintainer: Rahul Thakur <rjthakur@google.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.
CPU models (e.g., O3CPU) issue instruction fetches for the whole cache
block rather than a specific instruction. Consequently the TLB lookups
translate the cache block virtual address. When the TLB lookup fails,
however, the Prefetch Abort must be raised for the PC of the
instruction that caused the fault rather than for the address of the
block.
This change fixes the way we instantiate the PrefetchAbort faults to
use the PC of the request rather the address of the instruction fetch
request.
Change-Id: I8e45549da1c3be55ad204a060029c95ce822a851
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Rekai Gonzalez Alberquilla <rekai.gonzalezalberquilla@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
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.
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.
KvmGic functionality has been subsumed within the new MuxingKvmGic
model, which has Pl390 fallback when not using KVM for fast emulation.
This simplifies configuration and will enable checkpointing between
KVM emulation and full-system simulation.
Change-Id: Ie61251720064c512843015c075e4ac419a4081e8
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
This device allows us to, when KVM support is detected and compiled in,
instantiate the same Gic device whether the actual simulation is with
KVM cores or simulated cores. Checkpointing is not yet supported.
Change-Id: I67e4e0b6fb7ab5058e52c933f4f3d8e7ab24981e
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
A KVM VM is typically a child of the System object already, but for
solving future issues with configuration graph resolution, the most
logical way to keep track of this object is for it to be an actual
parameter of the System object.
Change-Id: I965ded22203ff8667db9ca02de0042ff1c772220
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Trying to read MISCREG_CTR_EL0 on AArch64 returned 0 as is was not
implmemented. With that an operating system relying on the cache line
sizes reported in order to manage the caches would (a) panic given the
returned value 0 is not valid (high bit is RES1) or (b) worst case would
assume a cache line size of 4 doing a tremendous amount of extra
instruction work (including fetching). Return the same values as for ARMv7
as the fields seem to be the same, or RES0/1 seem to be reported
accordingly for AArch64
In collaboration with: Andrew Turner
Testing Done: Checked on FreeBSD boots with extra printfs; also observed a
reduction of a factor of about 10 in instruction fetches for a simple
micro-test.
Reviewed at http://reviews.gem5.org/r/3667/
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
The headers declared in export_method_cxx_predecls are redundant since a
SimObject's main header is automatically included.
Change-Id: Ied9e84630b36960e54efe91d16f8c66fba7e0da0
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Joe Gross <joseph.gross@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Compute the proper values of the aforementioned registers from
the system configuration rather than configuring the values themselves.
Change-Id: If9774b6610a29568b80ae4866107b9a6a5b5be0f
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Compute the proper values of the aforementioned registers from
the system configuration rather than configuring the values themselves.
Change-Id: Ie7685b5d8b5f2dd9d6380b4af74f16d596b2bfd1
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Modify the opClass assigned to AArch64 FP instructions from SimdFloat* to
Float*. Also create the FloatMemRead and FloatMemWrite opClasses, which
distinguishes writes to the INT and FP register banks.
Change the latency of (Simd)FloatMultAcc to 5, based on the Cortex-A72,
where the "latency" of FMADD is 3 if the next instruction is a FMADD and
has only the augend to destination dependency, otherwise it's 7 cycles.
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Introduce and use a lookup table.
Using fetchDescriptor() rather than DMA cleanly handles nested paging.
Change-Id: I69ec762f176bd752ba1040890e731826b58d15a6
During host bootup, KVM reads/writes to CNTHCTL_EL2. Because this
miscreg has not been implemented, the simulation would end there. This
patch causes the simulation to warn about the read/write instead of fail.
Change-Id: If034bfd0818a9a5e50c5fe86609e945258c96fa3
This fixes a bug where stage 2 lookups used the AArch32
permissions rules even if we were executing in AArch64 mode.
Change-Id: Ia40758f0599667ca7ca15268bd3bf051342c24c1
This patch restricts trapping to hypervisor only if we are in the
correct exception level for the trap to happen.
Change-Id: I0a382b6a572ef835ea36d2702b8a81b633bd3df0
Faults that could potentially be routed to the hypervisor checked
whether or not they were in a secure state without checking if security
was enabled or not. This caused faults not to be routed correctly. This
patch causes secure state checking to first ask if security is enabled.
Change-Id: I179e9b181b27f552734c9bab2b18d05ac579a119
We recompute if we are doing a stage 2 walk inside of the table walker
but we have already figured it out in the tlb. Pass the information in
to the walk instead of recomputing it.
Change-Id: I39637ce99309b2ddbc30344d45ac9ebf6a203401
The functional case is already handled within the fetchDescriptor()
function. We can thus use that function for both atomic and functional
mode when we start the table walk.
Change-Id: Iacaed28cd9024d259fd37a58150efd00ff94d86e
This patch adds the option for faults to be routed to the hypervisor
using the pre-existing routeToHyp() functions that are present in each
fault type.
Change-Id: I9735512c094457636b9870456a5be5432288e004
During address translation instructions (such as AT S1E1R_Xt) the exception
level can be different than the current exception level. This patch fixes
how the TLB determines what EL to use during these instructions.
Change-Id: Ia9ce229404de9e284bc1f7479fd2c580efd55f8f
This patch adds the AArch64 instruction hvc which raises an exception
from EL1 into EL2. The host OS uses this instruction to world switch
into the guest.
Change-Id: I930ee43f4f0abd4b35a68eb2a72e44e3ea6570be
