The ARMv8.2-TTCNP extension allows an implementation to optimize by
sharing TLB entries between multiple cores, provided that software
declares that it's ready to deal with this by setting a CnP bit in
the TTBRn_ELx. It is mandatory from ARMv8.2 onward.
For QEMU's TLB implementation, sharing TLB entries between different
cores would not really benefit us and would be a lot of work to
implement. So we implement this extension in the "trivial" manner:
we allow the guest to set and read back the CnP bit, but don't change
our behaviour (this is an architecturally valid implementation
choice).
The only code path which looks at the TTBRn_ELx values for the
long-descriptor format where the CnP bit is defined is already doing
enough masking to not get confused when the CnP bit at the bottom of
the register is set, so we can simply add a comment noting why we're
relying on that mask.
Backports commit 41a4bf1feab098da4cd5495cd56a99b0339e2275 from qemu
The v8.4-RCPC extension implements some new instructions:
* LDAPUR, LDAPURB, LDAPURH, LDAPRSB, LDAPRSH, LDAPRSW
* STLUR, STLURB, STLURH
These are all in a new subgroup of encodings that sits below the
top-level "Loads and Stores" group in the Arm ARM.
The STLUR* instructions have standard store-release semantics; the
LDAPUR* have Load-AcquirePC semantics, but (as with LDAPR*) we choose
to implement them as the slightly stronger Load-Acquire.
Backports commit a1229109dec4375259d3fff99f362405aab7917a from qemu
The v8.3-RCPC extension implements three new load instructions
which provide slightly weaker consistency guarantees than the
existing load-acquire operations. For QEMU we choose to simply
implement them with a full LDAQ barrier.
Backports commit 2677cf9f92a5319bb995927f9225940414ce879d from qemu
We had set this for aarch32-only in arm_max_initfn, but
failed to set the same bit for aarch64.
Backports commit dac65ba1d7945c5d58ab63d8769103634adb2b01 from qemu
The ACTLR2 and HACTLR2 AArch32 system registers didn't exist in ARMv7
or the original ARMv8. They were later added as optional registers,
whose presence is signaled by the ID_MMFR4.AC2 field. From ARMv8.2
they are mandatory (ie ID_MMFR4.AC2 must be non-zero).
We implemented HACTLR2 in commit 0e0456ab8895a5e85, but we
incorrectly made it exist for all v8 CPUs, and we didn't implement
ACTLR2 at all.
Sort this out by implementing both registers only when they are
supposed to exist, and setting the ID_MMFR4 bit for -cpu max.
Note that this removes HACTLR2 from our Cortex-A53, -A47 and -A72
CPU models; this is correct, because those CPUs do not implement
this register.
Fixes: 0e0456ab8895a5e85
Backports commit f6287c24c66d6b9187c1c2887e1c7cfa4d304b0c from qemu
The isar_feature_aa32_pan and isar_feature_aa32_ats1e1 functions
are supposed to be testing fields in ID_MMFR3; but a cut-and-paste
error meant we were looking at MVFR0 instead.
Fix the functions to look at the right register; this requires
us to move at least id_mmfr3 to the ARMISARegisters struct; we
choose to move all the ID_MMFRn registers for consistency.
Backports commit 10054016eda1b13bdd8340d100fd029cc8b58f36 from qemu
Set the ID register bits to provide ARMv8.4-PMU (and implicitly
also ARMv8.1-PMU) in the 'max' CPU.
Backports commit 3bec78447a958d4819911252e056f29740ac25e4 from qemu
We're going to want to read the DBGDIDR register from KVM in
a subsequent commit, which means it needs to be in the
ARMISARegisters sub-struct. Move it.
Backports commit 4426d3617d64922d97b74ed22e67e33b6fb7de0a from qemu
Add the 64-bit version of the "is this a v8.1 PMUv3?"
ID register check function, and the _any_ version that
checks for either AArch32 or AArch64 support. We'll use
this in a later commit.
We don't (yet) do any isar_feature checks on ID_AA64DFR1_EL1,
but we move id_aa64dfr1 into the ARMISARegisters struct with
id_aa64dfr0, for consistency.
Backports commit 2a609df87d9b886fd38a190a754dbc241ff707e8 from qemu
Instead of open-coding a check on the ID_DFR0 PerfMon ID register
field, create a standardly-named isar_feature for "does AArch32 have
a v8.1 PMUv3" and use it.
This entails moving the id_dfr0 field into the ARMISARegisters struct.
Backports commit a617953855b65a602d36364b9643f7e5bc31288e from qemu
The ARMv8.1-VMID16 extension extends the VMID from 8 bits to 16 bits:
* the ID_AA64MMFR1_EL1.VMIDBits field specifies whether the VMID is
8 or 16 bits
* the VMID field in VTTBR_EL2 is extended to 16 bits
* VTCR_EL2.VS lets the guest specify whether to use the full 16 bits,
or use the backwards-compatible 8 bits
For QEMU implementing this is trivial:
* we do not track VMIDs in TLB entries, so we never use the VMID field
* we treat any write to VTTBR_EL2, not just a change to the VMID field
bits, as a "possible VMID change" that causes us to throw away TLB
entries, so that code doesn't need changing
* we allow the guest to read/write the VTCR_EL2.VS bit already
So all that's missing is the ID register part: report that we support
VMID16 in our 'max' CPU.
Backports commit dc7a88d0810ad272bdcd2e0869359af78fdd9114 from qemu
ARMv8.2 introduced support for Data Cache Clean instructions
to PoP (point-of-persistence) - DC CVAP and PoDP (point-of-deep-persistence)
- DV CVADP. Both specify conceptual points in a memory system where all writes
that are to reach them are considered persistent.
The support provided considers both to be actually the same so there is no
distinction between the two. If none is available (there is no backing store
for given memory) both will result in Data Cache Clean up to the point of
coherency. Otherwise sync for the specified range shall be performed.
Backports commit 0d57b49992200a926c4436eead97ecfc8cc710be from qemu
While most features are now detected by probing the ID_* registers
kernels can (and do) use MIDR_EL1 for working out of they have to
apply errata. This can trip up warnings in the kernel as it tries to
work out if it should apply workarounds to features that don't
actually exist in the reported CPU type.
Avoid this problem by synthesising our own MIDR value.
Backports commit 2bd5f41c00686a1f847a60824d0375f3df2c26bf from qemu
Cleanup in the boilerplate that each target must define.
Replace arm_env_get_cpu with env_archcpu. The combination
CPU(arm_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 2fc0cc0e1e034582f4718b1a2d57691474ccb6aa from qemu
Use the newly introduced infrastructure for guest random numbers.
Backports commit de390645675966cce113bf5394445bc1f8d07c85 from qemu
(with the actual RNG portion disabled to preserve determinism for the
time being).
These changes were mostly made in upstream unicorn for what I can guess,
was to support old versions of MSVC's compiler.
This is also a pain to maintain, since everything needs to be done
manually and can be a source of errors. It also makes it take more work
than it needs to, to backport changes from qemu.
Because of that, this change restores Qemu's organization of the
coprocessor registers.
Until now, the set_pc logic was unclear, which raised questions about
whether it should be used directly, applying a value to PC or adding
additional checks, for example, set the Thumb bit in Arm cpu. Let's set
the set_pc logic for “Configure the PC, as was done in the ELF file”
and implement synchronize_with_tb hook for preserving PC to cpu_tb_exec.
Backports commit 42f6ed919325413392bea247a1e6f135deb469cd from qemu
This commit doesn't add any supported events, but provides the framework
for adding them. We store the pm_event structs in a simple array, and
provide the mapping from the event numbers to array indexes in the
supported_event_map array. Because the value of PMCEID[01] depends upon
which events are supported at runtime, generate it dynamically.
Backports commit 57a4a11b2b281bb548b419ca81bfafb214e4c77a from qemu
Add 4 attributes that controls the EL1 enable bits, as we may not
always want to turn on pointer authentication with -cpu max.
However, by default they are enabled.
Backports relevant parts of commit
1ae9cfbd470bffb8d9bacd761344e9b5e8adecb6 from qemu.
Provide a trivial implementation with zero limited ordering regions,
which causes the LDLAR and STLLR instructions to devolve into the
LDAR and STLR instructions from the base ARMv8.0 instruction set.
Backports commit 2d7137c10fafefe40a0a049ff8a7bd78b66e661f from qemu
Since the TCR_*.HPD bits were RES0 in ARMv8.0, we can simply
interpret the bits as if ARMv8.1-HPD is present without checking.
We will need a slightly different check for hpd for aarch32.
Backports commit 037c13c5904f5fc67bb0ab7dd91ae07347aedee9 from qemu
At the same time, define the fields for these registers,
and use those defines in arm_pamax().
Backports commit 3dc91ddbc68391f934bf6945853e99cf6810fc00 from qemu
Most of the v8 extensions are self-contained within the ISAR
registers and are not implied by other feature bits, which
makes them the easiest to convert.
Backports commit 962fcbf2efe57231a9f5df0ae0f40c05e35628ba from qemu
This allows the default (and maximum) vector length to be set
from the command-line. Which is extraordinarily helpful in
debugging problems depending on vector length without having to
bake knowledge of PR_SET_SVE_VL into every guest binary.
Backports relevant parts of commit
adf92eab90e3f5f34c285da6d14d48952b7a8e72 from qemu
There is no need to re-set these 9 features already
implied by the call to aarch64_a57_initfn.
Backports commit 156a7065365578deb3d63c2b5b69a4b5999a8fcc from qemu
We've already added the helpers with an SVE patch, all that remains
is to wire up the aa64 and aa32 translators. Enable the feature
within -cpu max for CONFIG_USER_ONLY.
Backports commit 26c470a7bb4233454137de1062341ad48947f252 from qemu
Now we have a working '-cpu max', the linux-user-only
'any' CPU is pretty much the same thing, so implement it
that way.
For the moment we don't add any of the extra feature bits
to the system-emulation "max", because we don't set the
ID register bits we would need to to advertise those
features as present.
Backports commit a0032cc5427d0d396aa0a9383ad9980533448ea4 from qemu
Add support for "-cpu max" for ARM guests. This CPU type behaves
like "-cpu host" when KVM is enabled, and like a system CPU with
the maximum possible feature set otherwise. (Note that this means
it won't be migratable across versions, as we will likely add
features to it in future.)
Backports commit bab52d4bba3f22921a690a887b4bd0342f2754cd from qemu
