The "background region" for a v8M MPU is a default which will be used
(if enabled, and if the access is privileged) if the access does
not match any specific MPU region. We were incorrectly using it
always (by putting the condition at the wrong nesting level). This
meant that we would always return the default background permissions
rather than the correct permissions for a specific region, and also
that we would not return the right information in response to a
TT instruction.
Move the check for the background region to the same place in the
logic as the equivalent v8M MPUCheck() pseudocode puts it.
This in turn means we must adjust the condition we use to detect
matches in multiple regions to avoid false-positives.
Backports commit cff21316c666c8053b1f425577e324038d0ca30d from qemu
Fortunately, the functions affected are so far only called from SVE,
so there is no tail to be cleared. But as we convert more of AdvSIMD
to gvec, this will matter.
Backports commit d8efe78e8039511b95c23d75bb48eca6873fbb0f from qemu
For same-sign saturation, we have tcg vector operations. We can
compute the QC bit by comparing the saturated value against the
unsaturated value.
Backports commit 89e68b575e138d0af1435f11a8ffcd8779c237bd from qemu
Change the representation of this field such that it is easy
to set from vector code.
Backports commit a4d5846245c5e029e5aa3945a9bda1de1c3fedbf from qemu
Given that we mask bits properly on set, there is no reason
to mask them again on get. We failed to clear the exception
status bits, 0x9f, which means that the wrong value would be
returned on get. Except in the (probably normal) case in which
the set clears all of the bits.
Simplify the code in set to also clear the RES0 bits.
Backports commit 18aaa59c622208743565307668a2100ab24f7de9 from qemu
Minimize the code within a macro by splitting out a helper function.
Use deposit32 instead of manual bit manipulation.
Backports commit 55a889456ef78f3f9b8eae9846c2f1453b1dd77b from qemu
The 32-bit PMIN/PMAX has been decomposed to scalars,
and so can be trivially expanded inline.
Backports commit 9ecd3c5c1651fa7f9adbedff4806a2da0b50490c from qemu
Since we're now handling a == b generically, we no longer need
to do it by hand within target/arm/.
Backports commit 2900847ff4c862887af750935a875059615f509a from qemu
There are a whole bunch more registers in the CPUID space which are
currently not used but are exposed as RAZ. To avoid too much
duplication we expand ARMCPRegUserSpaceInfo to understand glob
patterns so we only need one entry to tweak whole ranges of registers.
Backports commit d040242effe47850060d2ef1c461ff637d88a84d from qemu
As this is a single register we could expose it with a simple ifdef
but we use the existing modify_arm_cp_regs mechanism for consistency.
Backports commit 522641660c3de64ed8322b8636c58625cd564a3f from qemu
A number of CPUID registers are exposed to userspace by modern Linux
kernels thanks to the "ARM64 CPU Feature Registers" ABI. For QEMU's
user-mode emulation we don't need to emulate the kernels trap but just
return the value the trap would have done. To avoid too much #ifdef
hackery we process ARMCPRegInfo with a new helper (modify_arm_cp_regs)
before defining the registers. The modify routine is driven by a
simple data structure which describes which bits are exported and
which are fixed.
Backports commit 6c5c0fec29bbfe36c64eca1edfd8455be46b77c6 from qemu
Although technically not visible to userspace the kernel does make
them visible via a trap and emulate ABI. We provide a new permission
mask (PL0U_R) which maps to PL0_R for CONFIG_USER builds and adjust
the minimum permission check accordingly.
Backports commit b5bd7440422bb66deaceb812bb9287a6a3cdf10c from qemu
The lo,hi order is different from the comments. And in commit
1ec182c33379 ("target/arm: Convert to HAVE_CMPXCHG128"), it changes
the original code logic. So just restore the old code logic before this
commit:
do_paired_cmpxchg64_be():
cmpv = int128_make128(env->exclusive_high, env->exclusive_val);
newv = int128_make128(new_hi, new_lo);
This fixes a bug that would only be visible for big-endian
AArch64 guest code.
Fixes: 1ec182c33379 ("target/arm: Convert to HAVE_CMPXCHG128")
Backports commit abd5abc58c5d4c9bd23427b0998a44eb87ed47a2 from qemu
HACR_EL2 is a register with IMPDEF behaviour, which allows
implementation specific trapping to EL2. Implement it as RAZ/WI,
since QEMU's implementation has no extra traps. This also
matches what h/w implementations like Cortex-A53 and A57 do.
Backports commit 831a2fca343ebcd6651eab9102bd7a36b77da65d from qemu
This bug was introduced in:
commit 5ecdd3e47cadae83a62dc92b472f1fe163b56f59
target/arm: Finish implementation of PM[X]EVCNTR and PM[X]EVTYPER
Backports commit 62c7ec3488fe0dcbabffd543f458914e27736115 from qemu
The {IOE, DZE, OFE, UFE, IXE, IDE} bits in the FPSCR/FPCR are for
enabling trapped IEEE floating point exceptions (where IEEE exception
conditions cause a CPU exception rather than updating the FPSR status
bits). QEMU doesn't implement this (and nor does the hardware we're
modelling), but for implementations which don't implement trapped
exception handling these control bits are supposed to be RAZ/WI.
This allows guest code to test for whether the feature is present
by trying to write to the bit and checking whether it sticks.
QEMU is incorrectly making these bits read as written. Make them
RAZ/WI as the architecture requires.
In particular this was causing problems for the NetBSD automatic
test suite.
Backports commit a15945d98d3a3390c3da344d1b47218e91e49d8b from qemu
This has been enabled in the linux kernel since v3.11
(commit d50240a5f6cea, 2013-09-03,
"arm64: mm: permit use of tagged pointers at EL0").
Backports commit f6a148fef63698826e69ca91cc11877ab1ed786f from qemu
This will allow TBI to be used in user-only mode, as well as
avoid ping-ponging the softmmu TLB when TBI is in use. It
will also enable other armv8 extensions.
Backports commit 3a471103ac1823bafc907962dcaf6bd4fc0942a2 from qemu
Split out gen_top_byte_ignore in preparation of handling these
data accesses; the new tbflags field is not yet honored.
Backports commit 4a9ee99db38ba513bf1e8f43665b79c60accd017 from qemu
The branch target exception for guarded pages has high priority,
and only 8 instructions are valid for that case. Perform this
check before doing any other decode.
Clear BTYPE after all insns that neither set BTYPE nor exit via
exception (DISAS_NORETURN).
Not yet handled are insns that exit via DISAS_NORETURN for some
other reason, like direct branches.
Backports commit 51bf0d7aa91a9d4e2563240a42e6cb705cef84aa from qemu
Caching the bit means that we will not have to re-walk the
page tables to look up the bit during translation.
Backports commit 1bafc2ba7e6bfe89fff3503fdac8db39c973de48 from qemu
Place this in its own field within ENV, as that will
make it easier to reset from within TCG generated code.
With the change to pstate_read/write, exception entry
and return are automatically handled.
Backports commit f6e52eaac13b6947f4406c127e3090c898e439c9 from qemu
A flawed test lead to the instructions always being treated as
unallocated encodings.
Fixes: https://bugs.launchpad.net/bugs/1813460
Backports commit 1cf86a8618644beb860951ff4383457ee88a7f4a from qemu
Since QEMU does not support the ARMv8.2-LVA, Large Virtual Address,
extension (yet), the VA address space is 48-bits plus a sign bit. User
mode can only handle the positive half of the address space, so that
makes a limit of 48 bits.
(With LVA, it would be 53 and 52 bits respectively.)
The incorrectly large address space conflicts with PAuth instructions,
which use bits 48-54 and 56-63 for the pointer authentication code. This
also conflicts with (as yet unsupported by QEMU) data tagging and with
the ARMv8.5-MTE extension.
Backports commit f6768aa1b4c6a80448eabd22bb9b4123c709caea from qemu
Drop the pac properties. This approach cannot work as written
because the properties are applied before arm_cpu_reset, which
zeros SCTLR_EL1 (amongst everything else).
We can re-introduce the properties if they turn out to be useful.
But since linux 5.0 enables all of the keys, they may not be.
Backports commit 276c6e813719568bdc9743e87ff8f42115006206 from qemu
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
Whenever we notice that a counter overflow has occurred, send an
interrupt. This is made more reliable with the addition of a timer in a
follow-on commit.
Backports commit f4efb4b2a17528837cb445f9bdfaef8df4a5acf7 from qemu
In disas_simd_indexed(), for the case of "complex fp", each indexable
element is a complex pair, so the total size is twice that indicated
in the 'size' field in the encoding. We were trying to do this
"double the size" operation with a left shift by 1, but this is
incorrect because the 'size' field is a MO_8/MO_16/MO_32/MO_64
value, and doubling the size should be done by a simple increment.
This meant we were mishandling FCMLA (by element) of values where
the real and imaginary parts are 32-bit floats, and would incorrectly
UNDEF this encoding. (No other insns take this code path, and for
16-bit floats it happens that 1 << 1 and 1 + 1 are both the same).
Backports commit eaefb97a8b97dbf42c016fe65b68b92f99a346f6 from qemu
The FCMLA (by element) instruction exists in the
"vector x indexed element" encoding group, but not in
the "scalar x indexed element" group. Correctly UNDEF
the unallocated encodings.
Backports commit 4dfabb6d568e6b315594d7d464dacaf3368aff60 from qemu
In the AdvSIMD scalar x indexed element and vector x indexed element
encoding group, the SDOT and UDOT instructions are vector only,
and their opcode is unallocated in the scalar group. Correctly
UNDEF this unallocated encoding.
Backports commit 4977986ca38fb1d5357532e1a8032b984047a369 from qemu
In the encoding groups
* floating-point data-processing (1 source)
* floating-point data-processing (2 source)
* floating-point data-processing (3 source)
* floating-point immediate
* floating-point compare
* floating-ponit conditional compare
* floating-point conditional select
bit 31 is M and bit 29 is S (and bit 30 is 0, already checked at
this point in the decode). None of these groups allocate any
encoding for M=1 or S=1. We checked this in disas_fp_compare(),
disas_fp_ccomp() and disas_fp_csel(), but missed it in disas_fp_1src(),
disas_fp_2src(), disas_fp_3src() and disas_fp_imm().
We also missed that in the fp immediate encoding the imm5 field
must be all zeroes.
Correctly UNDEF the unallocated encodings here.
Backports commit c1e20801f5ee53472dbf2757df605543f3f4ce0b from qemu
In the "add/subtract (extended register)" encoding group, the "opt"
field in bits [23:22] must be zero. Correctly UNDEF the unallocated
encodings where this field is not zero.
Backports commit 4f61106614410945b1d1c93081544ad5b13044fc from qemu
In the AdvSIMD load/store single structure encodings, the
non-post-indexed case should have zeroes in [20:16] (which is the
Rm field for the post-indexed case). Bit 31 must also be zero
(a check we got right in ldst_multiple but not here). Correctly
UNDEF these unallocated encodings.
Backports commit 9c72b68ad746a51f63822cffab4d144b5957823a from qemu
In the AdvSIMD load/store multiple structures encodings,
the non-post-indexed case should have zeroes in [20:16]
(which is the Rm field for the post-indexed case).
Correctly UNDEF the currently unallocated encodings which
have non-zeroes in those bits.
Backports commit e1f220811dbd5d85fb02ff286358f9ee6188938f from qemu
The PRFM prefetch insn in the load/store with imm9 encodings
requires idx field 0b00; we were underdecoding this by
only checking !is_unpriv (which is equivalent to idx != 2).
Correctly UNDEF the unallocated encodings where idx == 0b01
and 0b11 as well as 0b10.
Backports commit a80c4256543987ca88407349ee012a673a10a2ae from qemu
The "system instructions" and "system register move" subcategories
of "branches, exception generating and system instructions" for A64
only apply if bits [23:22] are zero; other values are currently
unallocated. Correctly UNDEF these unallocated encodings.
Backports commit 08d5e3bde6b4ad32996bf69d93aa66ae43d3f3ff from qemu
A bug was introduced during a respin of:
commit 57a4a11b2b281bb548b419ca81bfafb214e4c77a
target/arm: Add array for supported PMU events, generate PMCEID[01]_EL0
This patch introduced two calls to get_pmceid() during CPU
initialization - one each for PMCEID0 and PMCEID1. In addition to
building the register values, get_pmceid() clears an internal array
mapping event numbers to their implementations (supported_event_map)
before rebuilding it. This is an optimization since much of the logic is
shared. However, since it was called twice, the contents of
supported_event_map reflect only the events in PMCEID1 (the second call
to get_pmceid()).
Fix this bug by moving the initialization of PMCEID0 and PMCEID1 back
into a single function call, and name it more appropriately since it is
doing more than simply generating the contents of the PMCEID[01]
registers.
Backports commit bf8d09694ccc07487cd73d7562081fdaec3370c8 from qemu
When tsz == 0, aarch32 selects the address space via exclusion,
and there are no "top_bits" remaining that require validation.
Fixes: ba97be9f4a4
Backports commit 36d820af0eddf4fc6a533579b052d8f0085a9fb8 from qemu
