If the M-profile low-overhead-branch extension is implemented, FPSCR
bits [18:16] are a new field LTPSIZE. If MVE is not implemented
(currently always true for us) then this field always reads as 4 and
ignores writes.
These bits used to be the vector-length field for the old
short-vector extension, so we need to take care that they are not
misinterpreted as setting vec_len. We do this with a rearrangement
of the vfp_set_fpscr() code that deals with vec_len, vec_stride
and also the QC bit; this obviates the need for the M-profile
only masking step that we used to have at the start of the function.
We provide a new field in CPUState for LTPSIZE, even though this
will always be 4, in preparation for MVE, so we don't have to
come back later and split it out of the vfp.xregs[FPSCR] value.
(This state struct field will be saved and restored as part of
the FPSCR value via the vmstate_fpscr in machine.c.)
Backports 8128c8e8cc9489a8387c74075974f86dc0222e7f
Move the id_pfr0 and id_pfr1 fields into the ARMISARegisters
sub-struct. We're going to want id_pfr1 for an isar_features
check, and moving both at the same time avoids an odd
inconsistency.
Changes other than the ones to cpu.h and kvm64.c made
automatically with:
perl -p -i -e 's/cpu->id_pfr/cpu->isar.id_pfr/' target/arm/*.c hw/intc/armv7m_nvic.c
Backports commit 8a130a7be6e222965641e1fd9469fd3ee752c7d4
The ARM_FEATURE_PXN bit indicates whether the CPU supports the PXN
bit in short-descriptor translation table format descriptors. This
is indicated by ID_MMFR0.VMSA being at least 0b0100. Replace the
feature bit with an ID register check, in line with our preference
for ID register checks over feature bits.
Backports commit 0ae0326b984e77a55c224b7863071bd3d8951231
Set the MVFR1 ID register FPHP and SIMDHP fields to indicate
that our "-cpu max" has v8.2-FP16.
Backports commit 5f07817eb94542e39a419baafa3026b15e8d33f7
Architecturally, Neon FP16 operations use the "standard FPSCR" like
all other Neon operations. However, this is defined in the Arm ARM
pseudocode as "a fixed value, except that FZ16 (and AHP) follow the
FPSCR bits". In QEMU, the softfloat float_status doesn't include
separate flush-to-zero for FP16 operations, so we must keep separate
fp_status for "Neon non-FP16" and "Neon fp16" operations, in the
same way we do already for the non-Neon "fp_status" vs "fp_status_f16".
Add the extra float_status field to the CPU state structure,
ensure it is correctly initialized and updated on FPSCR writes,
and make fpstatus_ptr(FPST_STD_F16) return a pointer to it.
Backports commit aaae563bc73de0598bbc09a102e68f27fafe704a
There are a number of paths by which the TBI is still intact
for user-only in the SVE helpers.
Because we currently always set TBI for user-only, we do not
need to pass down the actual TBI setting from above, and we
can remove the top byte in the inner-most primitives, so that
none are forgotten. Moreover, this keeps the "dirty" pointer
around at the higher levels, where we need it for any MTE checking.
Since the normal case, especially for user-only, goes through
RAM, this clearing merely adds two insns per page lookup, which
will be completely in the noise.
Backports commit c4af8ba19b9d22aac79cab679a20b159af9d6809 from qemu
We can simplify our DC_ZVA if we recognize that the largest BS
that we actually use in system mode is 64. Let us just assert
that it fits within TARGET_PAGE_SIZE.
For DC_GVA and STZGM, we want to be able to write whole bytes
of tag memory, so assert that BS is >= 2 * TAG_GRANULE, or 32.
Backports commit a4157b80242bf1c8aa0ee77aae7458ba79012d5d from qemu
Use the same code as system mode, so that we generate the same
exception + syndrome for the unaligned access.
For the moment, if MTE is enabled so that this path is reachable,
this would generate a SIGSEGV in the user-only cpu_loop. Decoding
the syndrome to produce the proper SIGBUS will be done later.
Backports commit 0d1762e931f8a694f261c604daba605bcda70928 from qemu
Move the common set_feature() and unset_feature() functions
from cpu.c and cpu64.c to cpu.h.
Backports commit 5fda95041d7237ab35733ceb66e0cb89f6107169 from qemu
Since on the aarch64-linux-user build, arm_cpus[] is empty, add
the cpu_count variable and only iterate when it is non-zero.
Backports commit 92b6a659388ab3735e5fbb17ac486923b681f57f from qemu
The ARMv8.2-TTS2UXN feature extends the XN field in stage 2
translation table descriptors from just bit [54] to bits [54:53],
allowing stage 2 to control execution permissions separately for EL0
and EL1. Implement the new semantics of the XN field and enable
the feature for our 'max' CPU.
Backports commit ce3125bed935a12e619a8253c19340ecaa899347 from qemu
We will move this code in the next commit. Clean it up
first to avoid checkpatch.pl errors.
Backports commit 51c510aa5876a681cd0059ed3bacaa17590dc2d5 from qemu
Make cpu_register() (renamed to arm_cpu_register()) available
from internals.h so we can register CPUs also from other files
in the future.
Backports commit 37bcf244454f4efb82e2c0c64bbd7eabcc165a0c from qemu
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
We cannot easily create "any" functions for these, because the
ID_AA64PFR0 fields for FP and SIMD signal "enabled" with zero.
Which means that an aarch32-only cpu will return incorrect results
when testing the aarch64 registers.
To use these, we must either have context or additionally test
vs ARM_FEATURE_AARCH64.
Backports commit 7d63183ff1a61b3f7934dc9b40b10e4fd5e100cd from qemu
Use this in the places that were checking ARM_FEATURE_VFP, and
are obviously testing for the existance of the register set
as opposed to testing for some particular instruction extension.
Backports commit 7fbc6a403a0aab834e764fa61d81ed8586cfe352 from qemu
We are going to convert FEATURE tests to ISAR tests,
so FPSP needs to be set for these cpus, like we have
already for FPDP.
Backports commit 9eb4f58918a851fb46895fd9b7ce579afeac9d02 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
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
We already define FIELD macros for ID_DFR0, so use them in the
one place where we're doing direct bit value manipulation.
Backports commit d52c061e541982a3663ad5c65bd3b518dbe85b87 from qemu
Add FIELD() definitions for the ID_AA64DFR0_EL1 and use them
where we currently have hard-coded bit values.
Backports commit ceb2744b47a1ef4184dca56a158eb3156b6eba36 from qemu
Enforce a convention that an isar_feature function that tests a
32-bit ID register always has _aa32_ in its name, and one that
tests a 64-bit ID register always has _aa64_ in its name.
We already follow this except for three cases: thumb_div,
arm_div and jazelle, which all need _aa32_ adding.
(As noted in the comment, isar_feature_aa32_fp16_arith()
is an exception in that it currently tests ID_AA64PFR0_EL1,
but will switch to MVFR1 once we've properly implemented
FP16 for AArch32.)
Backports commit 873b73c0c891ec20adacc7bd1ae789294334d675 from qemu
The fall through organization of this function meant that we
would raise an interrupt, then might overwrite that with another.
Since interrupt prioritization is IMPLEMENTATION DEFINED, we
can recognize these in any order we choose.
Unify the code to raise the interrupt in a block at the end.
Backports commit d63d0ec59d87a698de5ed843288f90a23470cf2e from qemu
Avoid redundant computation of cpu state by passing it in
from the caller, which has already computed it for itself.
Backports commit be87955687446be152f366af543c9234eab78a7c from qemu
This inline function has one user in cpu.c, and need not be exposed
otherwise. Code movement only, with fixups for checkpatch.
Backports commit 310cedf39dea240a89f90729fd99481ff6158e90 from qemu
The PMU is not optional on cortex-r5 and cortex-r5f (see
the "Features" chapter of the Technical Reference Manual).
Backports commit 90f671581ac601fcc1b840d9e9abe7e3c3e672db from qemu
This is derived from cortex-m4 description, adding DP support and FPv5
instructions with the corresponding flags in isar and mvfr2.
Checked that it could successfully execute
vrinta.f32 s15, s15
while cortex-m4 emulation rejects it with "illegal instruction".
Backports commit cf7beda5072e106ddce875c1996446540c5fe239 from qemu
In Arm v8.0 M-profile CPUs without the Security Extension and also in
v7M CPUs, there is no NSACR register. However, the code we have to handle
the FPU does not always check whether the ARM_FEATURE_M_SECURITY bit
is set before testing whether env->v7m.nsacr permits access to the
FPU. This means that for a CPU with an FPU but without the Security
Extension we would always take a bogus fault when trying to stack
the FPU registers on an exception entry.
We could fix this by adding extra feature bit checks for all uses,
but it is simpler to just make the internal value of nsacr 0xcff
("all non-secure accesses allowed"), since this is not guest
visible when the Security Extension is not present. This allows
us to continue to follow the Arm ARM pseudocode which takes a
similar approach. (In particular, in the v8.1 Arm ARM the register
is documented as reading as 0xcff in this configuration.)
Fixes: https://bugs.launchpad.net/qemu/+bug/1838475
Backports commit 02ac2f7f613b47f6a5b397b20ab0e6b2e7fb89fa from qemu
In arm_cpu_realizefn() we make several assertions about the values of
guest ID registers:
* if the CPU provides AArch32 v7VE or better it must advertise the
ARM_DIV feature
* if the CPU provides AArch32 A-profile v6 or better it must
advertise the Jazelle feature
These are essentially consistency checks that our ID register
specifications in cpu.c didn't accidentally miss out a feature,
because increasingly the TCG emulation gates features on the values
in ID registers rather than using old-style checks of ARM_FEATURE_FOO
bits.
Unfortunately, these asserts can cause problems if we're running KVM,
because in that case we don't control the values of the ID registers
-- we read them from the host kernel. In particular, if the host
kernel is older than 4.15 then it doesn't expose the ID registers via
the KVM_GET_ONE_REG ioctl, and we set up dummy values for some
registers and leave the rest at zero. (See the comment in
target/arm/kvm64.c kvm_arm_get_host_cpu_features().) This set of
dummy values is not sufficient to pass our assertions, and so on
those kernels running an AArch32 guest on AArch64 will assert.
We could provide a more sophisticated set of dummy ID registers in
this case, but that still leaves the possibility of a host CPU which
reports bogus ID register values that would cause us to assert. It's
more robust to only do these ID register checks if we're using TCG,
as that is the only case where this is truly a QEMU code bug.
Backports commit 8f4821d77e465bc2ef77302d47640d5a43d92b30 from qemu
The ARMv5 architecture didn't specify detailed per-feature ID
registers. Now that we're using the MVFR0 register fields to
gate the existence of VFP instructions, we need to set up
the correct values in the cpu->isar structure so that we still
provide an FPU to the guest.
This fixes a regression in the arm926 and arm1026 CPUs, which
are the only ones that both have VFP and are ARMv5 or earlier.
This regression was introduced by the VFP refactoring, and more
specifically by commits 1120827fa182f0e76 and 266bd25c485597c,
which accidentally disabled VFP short-vector support and
double-precision support on these CPUs.
Backports commit cb7cef8b32033f6284a47d797edd5c19c5491698 from qemu
When we converted to using feature bits in 602f6e42cfbf we missed out
the fact (dp && arm_dc_feature(s, ARM_FEATURE_V8)) was supported for
-cpu max configurations. This caused a regression in the GCC test
suite. Fix this by setting the appropriate bits in mvfr1.FPHP to
report ARMv8-A with FP support (but not ARMv8.2-FP16).
Fixes: https://bugs.launchpad.net/qemu/+bug/1836078
Backports commit 45b1a243b81a7c9ae56235937280711dd9914ca7 from qemu
These routines are TCG specific.
The arm_deliver_fault() function is only used within the new
helper. Make it static.
Backports commit e21b551cb652663f2f2405a64d63ef6b4a1042b7 from qemu
At the moment our -cpu max for AArch32 supports VFP short-vectors
because we always implement them, even for CPUs which should
not have them. The following commits are going to switch to
using the correct ID-register-check to enable or disable short
vector support, so we need to turn it on explicitly for -cpu max,
because Cortex-A15 doesn't implement it.
We don't enable this for the AArch64 -cpu max, because the v8A
architecture never supports short-vectors.
Backports commit 973751fd798d41402d34f9f705c0c6d1633d0cda from qemu
The Cortex-R5F initfn was not correctly setting up the MVFR
ID register values. Fill these in, since some subsequent patches
will use ID register checks rather than CPU feature bit checks.
Backports commit 3de79d335c9aa7d726865e3933d9b21781032183 from qemu
We are close to running out of TB flags for AArch32; we could
start using the cs_base word, but before we do that we can
economise on our usage by sharing the same bits for the VFP
VECSTRIDE field and the XScale XSCALE_CPAR field. This
works because no XScale CPU ever had VFP.
Backports commit ea7ac69d124c94c6e5579145e727adec9ccbefef from qemu
The M-profile floating point support has three associated config
registers: FPCAR, FPCCR and FPDSCR. It also makes the registers
CPACR and NSACR have behaviour other than reads-as-zero.
Add support for all of these as simple reads-as-written registers.
We will hook up actual functionality later.
The main complexity here is handling the FPCCR register, which
has a mix of banked and unbanked bits.
Note that we don't share storage with the A-profile
cpu->cp15.nsacr and cpu->cp15.cpacr_el1, though the behaviour
is quite similar, for two reasons:
* the M profile CPACR is banked between security states
* it preserves the invariant that M profile uses no state
inside the cp15 substruct
Backports commit d33abe82c7c9847284a23e575e1078cccab540b5 from qemu
