Prepare for, but do not yet implement, the EL2&0 regime.
This involves adding the new MMUIdx enumerators and adjusting
some of the MMUIdx related predicates to match.
Backports commit b9f6033c1a5fb7da55ed353794db8ec064f78bb2 from qemu.
Replace the magic numbers with the relevant ARM_MMU_IDX_M_* constants.
Keep the definitions short by referencing previous symbols.
Backports commit 25568316b2a7e73d68701042ba6ebdb217205e20 from qemu
Define via macro expansion, so that renumbering of the base ARMMMUIdx
symbols is automatically reflected in the bit definitions.
Backports commit 5f09a6dfbfbff4662f52cc3130a2e07044816497 from qemu
We are about to expand the number of mmuidx to 10, and so need 4 bits.
For the benefit of reading the number out of -d exec, align it to the
penultimate nibble.
Backports commit 506f149815c2168f16ade17893e117419d93f248 from qemu
We had completely run out of TBFLAG bits.
Split A- and M-profile bits into two overlapping buckets.
This results in 4 free bits.
We used to initialize all of the a32 and m32 fields in DisasContext
by assignment, in arm_tr_init_disas_context. Now we only initialize
either the a32 or m32 by assignment, because the bits overlap in
tbflags. So zero the entire structure in gen_intermediate_code.
Backports commit 79cabf1f473ca6e9fa0727f64ed9c2a84a36f0aa from qemu
This is part of a reorganization to the set of mmu_idx.
The non-secure EL2 regime only has a single stage translation;
there is no point in pointing out that the idx is for stage1.
Backports commit e013b7411339342aac8d986c5d5e329e1baee8e1 from qemu
This is part of a reorganization to the set of mmu_idx.
The EL3 regime only has a single stage translation, and
is always secure.
Backports commit 127b2b086303296289099a6fb10bbc51077f1d53 from qemu
This is part of a reorganization to the set of mmu_idx.
This emphasizes that they apply to the Secure EL1&0 regime.
Backports commit fba37aedecb82506c62a1f9e81d066b4fd04e443 from qemu
This is part of a reorganization to the set of mmu_idx.
The EL1&0 regime is the only one that uses 2-stage translation.
Spelling out Stage avoids confusion with Secure.
Backports commit 2859d7b590760283a7b5aef40b723e9dfd7c98ba from qemu
This is part of a reorganization to the set of mmu_idx.
This emphasizes that they apply to the EL1&0 regime.
The ultimate goal is
-- Non-secure regimes:
ARMMMUIdx_E10_0,
ARMMMUIdx_E20_0,
ARMMMUIdx_E10_1,
ARMMMUIdx_E2,
ARMMMUIdx_E20_2,
-- Secure regimes:
ARMMMUIdx_SE10_0,
ARMMMUIdx_SE10_1,
ARMMMUIdx_SE3,
-- Helper mmu_idx for non-secure EL1&0 stage1 and stage2
ARMMMUIdx_Stage2,
ARMMMUIdx_Stage1_E0,
ARMMMUIdx_Stage1_E1,
The 'S' prefix is reserved for "Secure". Unless otherwise specified,
each mmu_idx represents all stages of translation.
Backports commit 01b98b686460b3a0fb47125882e4f8d4268ac1b6 from qemu
At the same time, add writefn to TTBR0_EL2 and TCR_EL2.
A later patch will update any ASID therein.
Backports commit ed30da8eee6906032b38a84e4807e2142b09d8ec from qemu
Not all of the breakpoint types are supported, but those that
only examine contextidr are extended to support the new register.
Backports commit e2a1a4616c86159eb4c07659a02fff8bb25d3729 from qemu
When support for the AHP flag was added we inexplicably only freed the
new temps in one of the two legs. Move those tcg_temp_free to the same
level as the allocation to fix that leak.
Backports commit aeab8e5eb220cc5ff84b0b68b9afccc611bf0fcd from qemu
In the PAC computation, sbox was applied over wrong bits.
As this is a 4-bit sbox, bit index should be incremented by 4 instead of 16.
Test vector from QARMA paper (https://eprint.iacr.org/2016/444.pdf) was
used to verify one computation of the pauth_computepac() function which
uses sbox2.
Launchpad: https://bugs.launchpad.net/bugs/1859713
Backports commit de0b1bae6461f67243282555475f88b2384a1eb9 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
During the conversion to decodetree, the setting of
ISSIs16Bit got lost. This causes the guest os to
incorrectly adjust trapping memory operations.
Backports commit 1a1fbc6cbb34c26d43d8360c66c1d21681af14a9 from qemu
The IL bit is set for 32-bit instructions, thus passing false
with the is_16bit parameter to syn_data_abort_with_iss() makes
a syn mask that always has the IL bit set.
Pass is_16bit as true to make the initial syn mask have IL=0,
so that the final IL value comes from or'ing template_syn.
Cc: qemu-stable@nongnu.org
Fixes: aaa1f954d4ca ("target-arm: A64: Create Instruction Syndromes for Data Aborts")
Backports commit 30d544839e278dc76017b9a42990c41e84a34377 from qemu
The wfi instruction can be configured to be trapped by a higher exception
level, such as the EL2 hypervisor. When the instruction is trapped, the
program counter should contain the address of the wfi instruction that
caused the exception. The program counter is adjusted for this in the wfi op
helper function.
However, this correction is done to env->pc, which only applies to AArch64
mode. For AArch32, the program counter is stored in env->regs[15]. This
adds an if-else statement to modify the correct program counter location
based on the the current CPU mode.
Backports commit 855532912b0e1bf803ae393e5b0c7e80948cd6a4 from qemu
The SPSR register is named within the Unicorn headers, but the code
to access it is absent. This means that it will always read as 0 and
ignore writes. This makes it harder to work with changes in processor
mode, as the usual way to return from a CPU exception is a
`MOVS pc, lr` for undefined instructions or `SUBS pc, lr, #4`
for most other aborts - which implicitly restores the CPSR from SPSR.
This change adds the access to the SPSR so that it can be read and
written as the caller might expect.
Backports commit 99097cab4c39fb3fc50eea8f0006954f62a149b2 from unicorn.
Fixes:
target/arm/translate-a64.c: In function 'disas_crypto_three_reg_sha512':
target/arm/translate-a64.c:13625:9: error: 'genfn' may be used uninitialized in this function [-Werror=maybe-uninitialized]
genfn(tcg_rd_ptr, tcg_rn_ptr, tcg_rm_ptr);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
qemu/target/arm/translate-a64.c:13609:8: error: 'feature' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (!feature) {
Backports commit c7a5e7910517e2711215a9e869a733ffde696091 from qemu
Before we introduce blocking semihosting calls we need to ensure we
can restart the system on semi hosting exception. To be able to do
this the EXCP_SEMIHOST operation should be idempotent until it finally
completes. Practically this means ensureing we only update the pc
after the semihosting call has completed.
Backports commit 4ff5ef9e911c670ca10cdd36dd27c5395ec2c753 from qemu
All semihosting exceptions are dealt with earlier in the common code
so we should never get here.
Backports commit b906acbb3aceed5b1eca30d9d365d5bd7431400b from qemu
A write to the SCR can change the effective EL by droppping the system
from secure to non-secure mode. However if we use a cached current_el
from before the change we'll rebuild the flags incorrectly. To fix
this we introduce the ARM_CP_NEWEL CP flag to indicate the new EL
should be used when recomputing the flags.
Backports partof commit f80741d107673f162e3b097fc76a1590036cc9d1 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
This change ensures that the FPU can be accessed in Non-Secure mode
when the CPU core is reset using the arm_set_cpu_on() function call.
The NSACR.{CP11,CP10} bits define the exception level required to
access the FPU in Non-Secure mode. Without these bits set, the CPU
will give an undefined exception trap on the first FPU access for the
secondary cores under Linux.
This is necessary because in this power-control codepath QEMU
is effectively emulating a bit of EL3 firmware, and has to set
the CPU up as the EL3 firmware would.
Fixes: fc1120a7f5
Backports commit 0c7f8c43daf6556078e51de98aa13f069e505985 from qemu
QEMU lacks the minimum Jazelle implementation that is required
by the architecture (everything is RAZ or RAZ/WI). Add it
together with the HCR_EL2.TID0 trapping that goes with it.
Backports commit f96f3d5f09973ef40f164cf2d5fd98ce5498b82a from qemu
HSTR_EL2 offers a way to trap ranges of CP15 system register
accesses to EL2, and it looks like this register is completely
ignored by QEMU.
To avoid adding extra .accessfn filters all over the place (which
would have a direct performance impact), let's add a new TB flag
that gets set whenever HSTR_EL2 is non-zero and that QEMU translates
a context where this trap has a chance to apply, and only generate
the extra access check if the hypervisor is actively using this feature.
Tested with a hand-crafted KVM guest accessing CBAR.
Backports commit 5bb0a20b74ad17dee5dae38e3b8b70b383ee7c2d from qemu
HCR_EL2.TID3 requires that AArch32 reads of MVFR[012] are trapped to
EL2, and HCR_EL2.TID0 does the same for reads of FPSID.
In order to handle this, introduce a new TCG helper function that
checks for these control bits before executing the VMRC instruction.
Tested with a hacked-up version of KVM/arm64 that sets the control
bits for 32bit guests.
Backports commit 9ca1d776cb49c09b09579d9edd0447542970c834 from qemu
HCR_EL2.TID1 mandates that access from EL1 to REVIDR_EL1, AIDR_EL1
(and their 32bit equivalents) as well as TCMTR, TLBTR are trapped
to EL2. QEMU ignores it, making it harder for a hypervisor to
virtualize the HW (though to be fair, no known hypervisor actually
cares).
Do the right thing by trapping to EL2 if HCR_EL2.TID1 is set.
Backports commit 93fbc983b29a2eb84e2f6065929caf14f99c3681 from qemu
HCR_EL2.TID2 mandates that access from EL1 to CTR_EL0, CCSIDR_EL1,
CCSIDR2_EL1, CLIDR_EL1, CSSELR_EL1 are trapped to EL2, and QEMU
completely ignores it, making it impossible for hypervisors to
virtualize the cache hierarchy.
Do the right thing by trapping to EL2 if HCR_EL2.TID2 is set.
Backports commit 630fcd4d2ba37050329e0adafdc552d656ebe2f3 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
HCR_EL2.TID3 mandates that access from EL1 to a long list of id
registers traps to EL2, and QEMU has so far ignored this requirement.
This breaks (among other things) KVM guests that have PtrAuth enabled,
while the hypervisor doesn't want to expose the feature to its guest.
To achieve this, KVM traps the ID registers (ID_AA64ISAR1_EL1 in this
case), and masks out the unsupported feature.
QEMU not honoring the trap request means that the guest observes
that the feature is present in the HW, starts using it, and dies
a horrible death when KVM injects an UNDEF, because the feature
*really* isn't supported.
Do the right thing by trapping to EL2 if HCR_EL2.TID3 is set.
Note that this change does not include trapping of the MVFR
registers from AArch32 (they are accessed via the VMRS
instruction and need to be handled in a different way).
Backports commit 6a4ef4e5d1084ce41fafa7d470a644b0fd3d9317 from qemu
The ARMv8 ARM states when executing at EL2, EL3 or Secure EL1,
ISR_EL1 shows the pending status of the physical IRQ, FIQ, or
SError interrupts.
Unfortunately, QEMU's implementation only considers the HCR_EL2
bits, and ignores the current exception level. This means a hypervisor
trying to look at its own interrupt state actually sees the guest
state, which is unexpected and breaks KVM as of Linux 5.3.
Instead, check for the running EL and return the physical bits
if not running in a virtualized context.
Backports commit 7cf95aed53c8770a338617ef40d5f37d2c197853 from qemu
According to the PushStack() pseudocode in the armv7m RM,
bit 4 of the LR should be set to NOT(CONTROL.PFCA) when
an FPU is present. Current implementation is doing it for
armv8, but not for armv7. This patch makes the existing
logic applicable to both code paths.
Backports commit f900b1e5b087a02199fbb6de7038828008e9e419 from qemu
Simply moving the non-stub helper_v7m_mrs/msr outside of
!CONFIG_USER_ONLY is not an option, because of all of the
other system-mode helpers that are called.
But we can split out a few subroutines to handle the few
EL0 accessible registers without duplicating code.
Backports commit 04c9c81b8fa2ee33f59a26265700fae6fc646062 from qemu
There was too much cut and paste between ldrexd and strexd,
as ldrexd does prohibit two output registers the same.
Fixes: af288228995
Backports commit 655b02646dc175dc10666459b0a1e4346fc8d46a from qemu
Preparation for collapsing the two byte swaps, adjust_endianness and
handle_bswap, along the I/O path.
Target dependant attributes are conditionalized upon NEED_CPU_H.
Backports commit 14776ab5a12972ea439c7fb2203a4c15a09094b4 from qemu
There are only two remaining uses of gen_bx_im. In each case, we
know the destination mode -- not changing in the case of gen_jmp
or changing in the case of trans_BLX_i. Use this to simplify the
surrounding code.
For trans_BLX_i, use gen_jmp for the actual branch. For gen_jmp,
use gen_set_pc_im to set up the single-step.
Backports commit eac2f39602e0423adf56be410c9a22c31fec9a81 from qemu
Now that all callers pass a constant value, split the switch
statement into the individual trans_* functions.
Backports commit 279de61a21a1622cb875ead82d6e78c989ba2966 from qemu
Add a check for ARMv6 in trans_CPS. We had this correct in
the T16 path, but had previously forgotten the check on the
A32 and T32 paths.
Backports commit 20556e7bd6111266fbf1d81e4ff7a89bfa5795a7 from qemu
Fold away all of the cases that now just goto illegal_op,
because all of their internal bits are now in decodetree.
Backports commit 590057d969a54de5d97261701c5702b3bebc9c07 from qemu
Fold away all of the cases that now just goto illegal_op,
because all of their internal bits are now in decodetree.
Backports commit f843e77144c9334e244a422848177f2fbef5eb05 from qemu
We have been using store_reg and not store_reg_for_load when writing
back a loaded value into the base register. At first glance this is
incorrect when base == pc, however that case is UNPREDICTABLE.
Backports commit b0e382b8cf365fed8b8c43482029ac7655961a85 from qemu
This has been a TODO item for quite a while. The minimum bit
count for A32 and T16 is 1, and for T32 is 2.
Backports commit 4b222545dbf30b60c033e1cd6eddda612575fd8c from qemu
Prior to v7, for the A32 encoding, this operation wrote an UNKNOWN
value back to the base register. Starting in v7 this is UNPREDICTABLE.
Backports commit 3949f4675d13c587078f8f423845a3a537a22595 from qemu
This includes a minor bug fix to LDM (user), which requires
bit 21 to be 0, which means no writeback.
Backports commit c5c426d4c680f908a1e262091a17b088b5709200 from qemu
In op_bfx, note that tcg_gen_{,s}extract_i32 already checks
for width == 32, so we don't need to special case that here.
Backports commit 86d21e4b509a2835ed79f234f476a4c5191d435b from qemu
Pass the T5 encoding of SUBS PC, LR, #IMM through the normal SUBS path
to make it clear exactly what's happening -- we hit ALUExceptionReturn
along that path.
Backports commit ef11bc3c461e2c650e8bef552146a4b08f81884e from qemu
Document our choice about the T32 CONSTRAINED UNPREDICTABLE behaviour.
This matches the undocumented choice made by the legacy decoder.
Backports commit 4c97f5b2f0fa9b37f9ff497f15411d809e6fd098 from qemu
The m-profile and a-profile decodings overlap. Only return false
for the case of wrong profile; handle UNDEFINED for permission failure
directly. This ensures that we don't accidentally pass an insn that
applies to the wrong profile.
Backports commit d0b26644502103ca97093ef67749812dc1df7eea from qemu
By shifting the 16-bit input left by 16, we can align the desired
portion of the 48-bit product and use tcg_gen_muls2_i32.
Backports commit 485b607d4f393e0de92c922806a68aef22340c98 from qemu
Since all of the inputs and outputs are i32, dispense with
the intermediate promotion to i64 and use tcg_gen_add2_i32.
Backports commit ea96b374641bc429269096d88d4e91ee544273e9 from qemu
Since all of the inputs and outputs are i32, dispense with
the intermediate promotion to i64 and use tcg_gen_mulu2_i32
and tcg_gen_add2_i32.
Backports commit 2409d56454f0d028619fb1002eda86bf240906dd from qemu
Convert the modified immediate form of the data processing insns.
For A32, we can finally remove any code that was intertwined with
the register and register-shifted-register forms.
Backports commit 581c6ebd17c8f56ad52772216e6c6d8cc8997e8b from qemu
Convert the register shifted by register form of the data
processing insns. For A32, we cannot yet remove any code
because the legacy decoder intertwines the immediate form.
Backports commit 5be2c12337f4cbdbda4efe6ab485350f730faaad from qemu
Convert the register shifted by immediate form of the data
processing insns. For A32, we cannot yet remove any code
because the legacy decoder intertwines the reg-shifted-reg
and immediate forms.
Backports commit 25ae32c558182c07fc6ad01b936e9151cbf00c44 from qemu
Add the infrastructure that will become the new decoder.
No instructions adjusted so far.
Backports commit 51409b9e8cfe997b1ac3365df7400e0c6e844437 from qemu
This function already includes the test for an interworking write
to PC from a load. Change the T32 LDM implementation to match the
A32 LDM implementation.
For LDM, the reordering of the tests does not change valid
behaviour because the only case that differs is has rn == 15,
which is UNPREDICTABLE.
Backports commit 69be3e13764111737e1a7a13bb0c231e4d5be756 from qemu
The previous simplification got the order of operands to the
subtraction wrong. Since the 64-bit product is the subtrahend,
we must use a 64-bit subtract to properly compute the borrow
from the low-part of the product.
Fixes: 5f8cd06ebcf5 ("target/arm: Simplify SMMLA, SMMLAR, SMMLS, SMMLSR")
Backports commit e0a0c8322b8ebcdad674f443a3e86db8708d6738 from qemu
The translation table walk for an ATS instruction can result in
various faults. In general these are just reported back via the
PAR_EL1 fault status fields, but in some cases the architecture
requires that the fault is turned into an exception:
* synchronous stage 2 faults of any kind during AT S1E0* and
AT S1E1* instructions executed from NS EL1 fault to EL2 or EL3
* synchronous external aborts are taken as Data Abort exceptions
(This is documented in the v8A Arm ARM DDI0487A.e D5.2.11 and
G5.13.4.)
Backports commit 0710b2fa84a4aeb925422e1e88edac49ed407c79 from qemu
Currently the only part of an ARMCPRegInfo which is allowed to cause
a CPU exception is the access function, which returns a value indicating
that some flavour of UNDEF should be generated.
For the ATS system instructions, we would like to conditionally
generate exceptions as part of the writefn, because some faults
during the page table walk (like external aborts) should cause
an exception to be raised rather than returning a value.
There are several ways we could do this:
* plumb the GETPC() value from the top level set_cp_reg/get_cp_reg
helper functions through into the readfn and writefn hooks
* add extra readfn_with_ra/writefn_with_ra hooks that take the GETPC()
value
* require the ATS instructions to provide a dummy accessfn,
which serves no purpose except to cause the code generation
to emit TCG ops to sync the CPU state
* add an ARM_CP_ flag to mark the ARMCPRegInfo as possibly
throwing an exception in its read/write hooks, and make the
codegen sync the CPU state before calling the hooks if the
flag is set
This patch opts for the last of these, as it is fairly simple
to implement and doesn't require invasive changes like updating
the readfn/writefn hook function prototype signature.
Backports commit 37ff584c15bc3e1dd2c26b1998f00ff87189538c from qemu
Make this a static function private to translate.c.
Thus we can use the same idiom between aarch64 and aarch32
without actually sharing function implementations.
Backports commit 1ce21ba1eaf08b22da5925f3e37fc0b4322da858 from qemu
Despite the fact that the text for the call to gen_exception_insn
is identical for aarch64 and aarch32, the implementation inside
gen_exception_insn is totally different.
This fixes exceptions raised from aarch64.
This reverts commit fb2d3c9a9a.
Separate shift + extract low will result in one extra insn
for hosts like RISC-V, MIPS, and Sparc.
Backports commit 664b7e3b97d6376f3329986c465b3782458b0f8b from qemu
All of the inputs to these instructions are 32-bits. Rather than
extend each input to 64-bits and then extract the high 32-bits of
the output, use tcg_gen_muls2_i32 and other 32-bit generator functions.
Backports commit 5f8cd06ebcf57420be8fea4574de2e074de46709 from qemu
Rotate is the more compact and obvious way to swap 16-bit
elements of a 32-bit word.
Backports commit adefba76e8bf10dfb342094d2f5debfeedb1a74d from qemu
The helper function is more documentary, and also already
handles the case of rotate by zero.
Backports commit dd861b3f29be97a9e3cdb9769dcbc0c7d7825185 from qemu
The immediate shift generator functions already test for,
and eliminate, the case of a shift by zero.
Backports commit 464eaa9571fae5867d9aea7d7209c091c8a50223 from qemu
Unless we're guaranteed to always increase ARM_MAX_VQ by a multiple of
four, then we should use DIV_ROUND_UP to ensure we get an appropriate
array size.
Backports commit 46417784d21c89446763f2047228977bdc267895 from qemu
The current implementation of ZCR_ELx matches the architecture, only
implementing the lower four bits, with the rest RAZ/WI. This puts
a strict limit on ARM_MAX_VQ of 16. Make sure we don't let ARM_MAX_VQ
grow without a corresponding update here.
Backports commit 7b351d98709d3f77d6bb18562e1bf228862b0d57 from qemu
Replace x = double_saturate(y) with x = add_saturate(y, y).
There is no need for a separate more specialized helper.
Backports commit 640581a06d14e2d0d3c3ba79b916de6bc43578b0 from qemu
Promote this function from aarch64 to fully general use.
Use it to unify the code sequences for generating illegal
opcode exceptions.
Backports commit 3cb36637157088892e9e33ddb1034bffd1251d3b from qemu
Unlike the other more generic gen_exception{,_internal}_insn
interfaces, breakpoints always refer to the current instruction.
Backports commit 06bcbda3f64d464b6ecac789bce4bd69f199cd68 from qemu
The offset is variable depending on the instruction set.
Passing in the actual value is clearer in intent.
Backpors commit aee828e7541a5895669ade3a4b6978382b6b094a from qemu
We must update s->base.pc_next when we return from the translate_insn
hook to the main translator loop. By incrementing s->base.pc_next
immediately after reading the insn word, "pc_next" contains the address
of the next instruction throughout translation.
All remaining uses of s->pc are referencing the address of the next insn,
so this is now a simple global replacement. Remove the "s->pc" field.
Backports commit a04159166b880b505ccadc16f2fe84169806883d from qemu
Provide a common routine for the places that require ALIGN(PC, 4)
as the base address as opposed to plain PC. The two are always
the same for A32, but the difference is meaningful for thumb mode.
Backports commit 16e0d8234ef9291747332d2c431e46808a060472 from qemu
We currently have 3 different ways of computing the architectural
value of "PC" as seen in the ARM ARM.
The value of s->pc has been incremented past the current insn,
but that is all. Thus for a32, PC = s->pc + 4; for t32, PC = s->pc;
for t16, PC = s->pc + 2. These differing computations make it
impossible at present to unify the various code paths.
With the newly introduced s->pc_curr, we can compute the correct
value for all cases, using the formula given in the ARM ARM.
This changes the behaviour for load_reg() and load_reg_var()
when called with reg==15 from a 32-bit Thumb instruction:
previously they would have returned the incorrect value
of pc_curr + 6, and now they will return the architecturally
correct value of PC, which is pc_curr + 4. This will not
affect well-behaved guest software, because all of the places
we call these functions from T32 code are instructions where
using r15 is UNPREDICTABLE. Using the architectural PC value
here is more consistent with the T16 and A32 behaviour.
Backports commit fdbcf6329d0c2984c55d7019419a72bf8e583c36 from qemu
Add a new field to retain the address of the instruction currently
being translated. The 32-bit uses are all within subroutines used
by a32 and t32. This will become less obvious when t16 support is
merged with a32+t32, and having a clear definition will help.
Convert aarch64 as well for consistency. Note that there is one
instance of a pre-assert fprintf that used the wrong value for the
address of the current instruction.
Backports commit 43722a6d4f0c92f7e7e1e291580039b0f9789df1 from qemu
This function is used in two different contexts, and it will be
clearer if the function is given the address to which it applies.
Backports commit 331b1ca616cb708db30dab68e3262d286e687f24 from qemu
When generating an architectural single-step exception we were
routing it to the "default exception level", which is to say
the same exception level we execute at except that EL0 exceptions
go to EL1. This is incorrect because the debug exception level
can be configured by the guest for situations such as single
stepping of EL0 and EL1 code by EL2.
We have to track the target debug exception level in the TB
flags, because it is dependent on CPU state like HCR_EL2.TGE
and MDCR_EL2.TDE. (That we were previously calling the
arm_debug_target_el() function to determine dc->ss_same_el
is itself a bug, though one that would only have manifested
as incorrect syndrome information.) Since we are out of TB
flag bits unless we want to expand into the cs_base field,
we share some bits with the M-profile only HANDLER and
STACKCHECK bits, since only A-profile has this singlestep.
Fixes: https://bugs.launchpad.net/qemu/+bug/1838913
Backports commit 8bd587c1066f4456ddfe611b571d9439a947d74c from qemu
Factor out code to 'generate a singlestep exception', which is
currently repeated in four places.
To do this we need to also pull the identical copies of the
gen-exception() function out of translate-a64.c and translate.c
into translate.h.
(There is a bug in the code: we're taking the exception to the wrong
target EL. This will be simpler to fix if there's only one place to
do it.)
Backports commit c1d5f50f094ab204accfacc2ee6aafc9601dd5c4 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
rt==15 is a special case when reading the flags: it means the
destination is APSR. This patch avoids rejecting vmrs apsr_nzcv, fpscr
as illegal instruction.
Backports commit cdc6896659b85f7ed8f7552850312e55170de0c5 from qemu
An attempt to do an exception-return (branch to one of the magic
addresses) in linux-user mode for M-profile should behave like
a normal branch, because linux-user mode is always going to be
in 'handler' mode. This used to work, but we broke it when we added
support for the M-profile security extension in commit d02a8698d7ae2bfed.
In that commit we allowed even handler-mode calls to magic return
values to be checked for and dealt with by causing an
EXCP_EXCEPTION_EXIT exception to be taken, because this is
needed for the FNC_RETURN return-from-non-secure-function-call
handling. For system mode we added a check in do_v7m_exception_exit()
to make any spurious calls from Handler mode behave correctly, but
forgot that linux-user mode would also be affected.
How an attempted return-from-non-secure-function-call in linux-user
mode should be handled is not clear -- on real hardware it would
result in return to secure code (not to the Linux kernel) which
could then handle the error in any way it chose. For QEMU we take
the simple approach of treating this erroneous return the same way
it would be handled on a CPU without the security extensions --
treat it as a normal branch.
The upshot of all this is that for linux-user mode we should never
do any of the bx_excret magic, so the code change is simple.
This ought to be a weird corner case that only affects broken guest
code (because Linux user processes should never be attempting to do
exception returns or NS function returns), except that the code that
assigns addresses in RAM for the process and stack in our linux-user
code does not attempt to avoid this magic address range, so
legitimate code attempting to return to a trampoline routine on the
stack can fall into this case. This change fixes those programs,
but we should also look at restricting the range of memory we
use for M-profile linux-user guests to the area that would be
real RAM in hardware.
Backports commit 9027d3fba605d8f6093342ebe4a1da450d374630 from qemu
The function neon_store_reg32() doesn't free the TCG temp that it
is passed, so the caller must do that. We got this right in most
places but forgot to free the TCG temps in trans_VMOV_64_sp().
Backports commit 38fb634853ac6547326d9f88b9a068d9fc6b4ad4 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
Most Arm architectural debug exceptions (eg watchpoints) are ignored
if the configured "debug exception level" is below the current
exception level (so for example EL1 can't arrange to get debug exceptions
for EL2 execution). Exceptions generated by the BRK or BPKT instructions
are a special case -- they must always cause an exception, so if
we're executing above the debug exception level then we
must take them to the current exception level.
This fixes a bug where executing BRK at EL2 could result in an
exception being taken at EL1 (which is strictly forbidden by the
architecture).
Fixes: https://bugs.launchpad.net/qemu/+bug/1838277
Backports commit 987a23224218fa3bb3aa0024ad236dcf29ebde9e 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
