In commit 9b6a3ea7a699594 store_reg() was changed to mask
both bits 0 and 1 of the new PC value when in ARM mode.
Unfortunately this broke the exception return code paths
when doing a return from ARM mode to Thumb mode: in some
of these we write a new CPSR including new Thumb mode
bit via gen_helper_cpsr_write_eret(), and then use store_reg()
to write the new PC. In this case if the new CPSR specified
Thumb mode then masking bit 1 of the PC is incorrect
(these code paths correspond to the v8 ARM ARM pseudocode
function AArch32.ExceptionReturn(), which always aligns the
new PC appropriately for the new instruction set state).
Instead of using store_reg() in exception-return code paths,
call a new store_pc_exc_ret() which stores the raw new PC
value to env->regs[15], and then mask it appropriately in
the subsequent helper_cpsr_write_eret() where the new
env->thumb state is available.
This fixes a bug introduced by 9b6a3ea7a699594 which caused
crashes/hangs or otherwise bad behaviour for Linux when
userspace was using Thumb.
Backports commit fb0e8e79a9d77ee240dbca036fa8698ce654e5d1 from qemu
If an alignment fault occurred and target EL is using AArch32,
then DFSR/IFSR bit LPAE[9] must be set correctly.
Backports commit e0fe723c24562c8f909bb40f131bfdbe75650677 from qemu
There are functions tlb_fill(), cpu_unaligned_access() and
do_unaligned_access() that are called with access type and mmu index
arguments. But these arguments are named 'is_write' and 'is_user' in their
declarations. The patches fix the arguments to avoid a confusion.
Backports commit b35399bb4e9968296a12303b00f9f2066470e987 from qemu
The GICv3 CPU interface needs to know when the CPU it is attached
to makes an exception level or mode transition that changes the
security state, because whether it is asserting IRQ or FIQ can change
depending on these things. Provide a mechanism for letting the GICv3
device register a hook to be called on such changes.
Backports commit bd7d00fc50c9960876dd194ebf0c88889b53e765 from qemu
Add support for generating the ISS (Instruction Specific Syndrome) for
Data Abort exceptions taken from AArch64.
These syndromes are used by hypervisors for example to trap and emulate
memory accesses.
We save the decoded data out-of-band with the TBs at translation time.
When exceptions hit, the extra data attached to the TB is used to
recreate the state needed to encode instruction syndromes.
This avoids the need to emit moves with every load/store.
Based on a suggestion from Peter Maydell.
Backports commit aaa1f954d4cab243e3d5337a72bc6d104e1c4808 from qemu
exec-all.h contains TCG-specific definitions. It is not needed outside
TCG-specific files such as translate.c, exec.c or *helper.c.
One generic function had snuck into include/exec/exec-all.h; move it to
include/qom/cpu.h.
Backports commit 63c915526d6a54a95919ebece83fa9ca631b2508 from qemu
Split the data abort syndrome generator into two versions:
One with a valid Instruction Specific Syndrome (ISS) and another without.
The following new flags are supported by the syndrome generator
with ISS:
* isv - Instruction syndrome valid
* sas - Syndrome access size
* sse - Syndrome sign extend
* srt - Syndrome register transfer
* sf - Sixty-Four bit register width
* ar - Acquire/Release
These flags are not yet used, so this patch has no functional change
except that we will now correctly set the IL bit in data abort
syndromes without ISS information.
Backports commit 094d028a7968236cd2b7f7b96394f7a3b8ad97c8 from qemu
Starting with the ARMv7 Virtualization Extensions, the A32 and T32
instruction sets provide instructions "MSR (banked)" and "MRS
(banked)" which can be used to access registers for a mode other
than the current one:
* R<m>_<mode>
* ELR_hyp
* SPSR_<mode>
Implement the missing instructions.
Backports commit 8bfd0550be821cf27d71444e2af350de3c3d2ee3 from qemu
Since this is not a high-performance path, just use a helper to
flip the E bit and force a lookup in the hash table since the
flags have changed.
Backports commit 9886ecdf31165de2d4b8bccc1a220bd6ac8bc192 from qemu
Raw CPSR writes should skip the architectural checks for whether
we're allowed to set the A or F bits and should also not do
the switching of register banks if the mode changes. Handle
this inside cpsr_write(), which allows us to drop the "manually
set the mode bits to avoid the bank switch" code from all the
callsites which are using CPSRWriteRaw.
This fixes a bug in 32-bit KVM handling where we had forgotten
the "manually set the mode bits" part and could thus potentially
trash the register state if the mode from the last exit to userspace
differed from the mode on this exit.
Backports commit f8c88bbcda76d5674e4bb125471371b41d330df8 from qemu
Add an argument to cpsr_write() to indicate what kind of CPSR
write is being requested, since the exact behaviour should
differ for the different cases.
Backports commit 50866ba5a2cfe922aaf3edb79f6eac5b0653477a from qemu
The rules for setting the CPSR on a 32-bit exception return are
subtly different from those for setting the CPSR via an instruction
like MSR or CPS. (In particular, in Hyp mode changing the mode bits
is not valid via MSR or CPS.) Split the exception-return case into
its own helper for setting CPSR, so we can eventually handle them
differently in the helper function.
Backports commit 235ea1f5c89abf30e452539b973b0dbe43d3fe2b from qemu
Make get_r13_banked() raise an exception at runtime for the
corner case of SRS from System mode, so that we can UNDEF it;
this brings us in to line with the ARM ARM's set of permitted
CONSTRAINED UNPREDICTABLE choices.
Backports commit f01377f591fe15c652f947646c4a69a7d4a71ad9 from qemu
The user-mode versions of get/set_r13_banked() exist just to assert
if they're ever called -- the translate time code should never
emit calls to them because SRS from user mode always UNDEF.
There's no code in the softmmu versions that can't compile in
CONFIG_USER_ONLY, and the assertion is not particularly useful,
so combine the two functions rather than having completely split
versions under ifdefs.
Backports commit d86d57d4fe683c99823f625f941eff26c07c72c3 from qemu
Move get/set_r13_banked() from helper.c to op_helper.c. This will
let us add exception-raising code to them, and also puts them
in the same file as get/set_user_reg(), which makes some conceptual
sense.
(The original reason for the helper.c/op_helper.c split was that
only op_helper.c had access to the CPU env pointer; this distinction
has not been true for a long time, though, and so the split is
now rather arbitrary.)
Backports commit 72309cee482868d6c4711931c3f7e02ab9dec229 from qemu
target-arm: Move bank_number() into internals.h
Move bank_number()'s implementation into internals.h, so
it's available in the user-mode-only compile as well.
Backports commit c766568d3604082c6fd45cbabe42c48e4861a13f from qemu
If access to FPEXC32_EL2 is trapped by CPTR_EL2.TFP or CPTR_EL3.TFP,
this should be reported with a syndrome register indicating an
FP access trap, not one indicating a system register access trap.
Backports commit f2cae6092767aaf418778eada15be444c23883be from qemu
We weren't quite implementing the handling of SCR.SMD correctly.
The condition governing whether the SMD bit should apply only
for NS state is "is EL3 is AArch32", not "is the current EL AArch32".
Fix the condition, and clarify the comment both to reflect this and
to expand slightly on what's going on for the v7-no-Virtualization case.
Backports commit f096e92b6385fd87e8ea948ad3af70faf752c13a from qemu
ARM stops before access to a location covered by watchpoint. Also, QEMU
watchpoint fire is not necessarily an architectural watchpoint match.
Unfortunately, that is hardly possible to ignore a fired watchpoint in
debug exception handler. So move watchpoint check from debug exception
handler to the dedicated watchpoint checking callback.
Backports commit 3826121d9298cde1d29ead05910e1f40125ee9b0 from qemu
System registers might have access requirements which need to
be described via a CPAccessFn and which differ for reads and
writes. For this to be possible we need to pass the access
function a parameter to tell it whether the access being checked
is a read or a write.
Backports commit 3f208fd76bcc91a8506681bb8472f2398fe6f487 from qemu
The architecture requires that for an exception return to AArch32 the
low bits of ELR_ELx are ignored when the PC is set from them:
* if returning to Thumb mode, ignore ELR_ELx[0]
* if returning to ARM mode, ignore ELR_ELx[1:0]
We were only squashing bit 0; also squash bit 1 if the SPSR T bit
indicates this is a return to ARM code.
Backports commit c1e0371442bf3a7e42ad53c2a3d816ed7099f81d from qemu
We already implement almost all the checks for the illegal
return events from AArch64 state described in the ARM ARM section
D1.11.2. Add the two missing ones:
* return to EL2 when EL3 is implemented and SCR_EL3.NS is 0
* return to Non-secure EL1 when EL2 is implemented and HCR_EL2.TGE is 1
(We don't implement external debug, so the case of "debug state exit
from EL0 using AArch64 state to EL0 using AArch32 state" doesn't apply
for QEMU.)
Backports commit e393f339af87da7210f6c86902b321df6a2e8bf5 from qemu
Remove the assumptions that the AArch64 exception return code was
making about a return to AArch32 always being a return to EL0.
This includes pulling out the illegal-SPSR checks so we can apply
them for return to 32 bit as well as return to 64-bit.
Backports commit 3809951bf61605974b91578c582de4da28f8ed07 from qemu
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Backports commit 74c21bd07491739c6e56bcb1f962e4df730e77f3 from qemu
arm_regime_using_lpae_format checks whether the LPAE extension is used
for stage 1 translation regimes. MMU indexes not exclusively of a stage 1
regime won't work with this method.
In case of ARMMMUIdx_S12NSE0 or ARMMMUIdx_S12NSE1, offset these values
by ARMMMUIdx_S1NSE0 to get the right index indicating a stage 1
translation regime.
Rename also the function to arm_s1_regime_using_lpae_format and update
the comments to reflect the change.
Backports commit deb2db996cbb9470b39ae1e383791ef34c4eb3c2 from qemu
Qemu does not generally perform alignment checks. However, the ARM ARM
requires implementation of alignment exceptions for a number of cases
including LDREX, and Windows-on-ARM relies on this.
This change adds plumbing to enable alignment checks on loads using
MO_ALIGN, a do_unaligned_access hook to raise the exception (data
abort), and uses the new aligned loads in LDREX (for all but
single-byte loads).
Backports commit 30901475b91ef1f46304404ab4bfe89097f61b96 from qemu
Do not raise a CPU exception if no CPU breakpoint has fired, since
singlestep is also done by generating a debug internal exception. This
fixes a bug with singlestepping in gdbstub.
Backports commit 5c629f4ff4dc9ae79cc732f59a8df15ede796ff7 from qemu
Introduce ARMMMUFaultInfo to propagate MMU Fault information
across the MMU translation code path. This is in preparation for
adding Stage-2 translation.
No functional changes.
Backports commit e14b5a23d8c83304559f31397f95d22ada60a19a from qemu
A QEMU breakpoint match is not definitely an architectural breakpoint
match. If an exception is generated unconditionally during translation,
it is hardly possible to ignore it in the debug exception handler.
Generate a call to a helper to check CPU breakpoints and raise an
exception only if any breakpoint matches architecturally.
Backports commit 5d98bf8f38c17a348ab6e8af196088cd4953acd0 from qemu
GDB breakpoints have higher priority so they have to be checked first.
Should GDB breakpoint match, just return from the debug exception
handler.
Backports commit e63a2d4d9ed73e33a0b7483085808048be8bbcb1 from qemu
Some coprocessor register access functions need to be able
to report "trap to EL3 with an 'uncategorized' syndrome";
add the necessary CPAccessResult enum and handling for it.
I don't currently know of any registers that need to trap
to EL2 with the 'uncategorized' syndrome, but adding the
_EL2 enum as well is trivial and fills in what would
otherwise be an odd gap in the handling.
Backports commit e76157264da20b85698b09fa5eb8e02e515e232c from qemu
Currently we use DISAS_WFE for both WFE and YIELD instructions.
This is functionally correct because at the moment both of them
are implemented as "yield this CPU back to the top level loop so
another CPU has a chance to run". However it's rather confusing
that YIELD ends up calling HELPER(wfe), and if we ever want to
implement real behaviour for WFE and SEV it's likely to trip us up.
Split out the yield codepath to use DISAS_YIELD and a new
HELPER(yield) function, and have HELPER(wfe) call HELPER(yield).
Backports commit 049e24a191c212d9468db84169197887f2c91586 from qemu
Currently, the return code for get_phys_addr is overloaded for both
success/fail and FSR value return. This doesn't handle the case where
there is an error with a 0 FSR. This case exists in PMSAv7.
So rework get_phys_addr and friends to return a success/failure boolean
return code and populate the FSR via a caller provided uint32_t
pointer.
Backports commit b7cc4e82f04a1c5b218a657f677a2fdd1e1c2889 from qemu
Add support for trapping WFI and WFE instructions to the proper EL when
SCTLR/SCR/HCR settings apply.
Backports commit b1eced713d9913a5c58ba9daa795f10e4c856c49 from qemu
Just NOP the WFI instruction if we have work to do.
This doesn't make much difference currently (though it does avoid
jumping out to the top level loop and immediately restarting),
but the distinction between "halt" and "don't halt" will become
more important when the decision to halt requires us to trap
to a higher exception level instead.
Backport commit 84549b6dcf9147559ec08b066de673587be6b763 from qemu
Some coprocessor access functions will need to indicate that the
instruction should trap to EL2 or EL3 rather than the default
target exception level; add corresponding CPAccessResult enum
entries and handling code.
Backports commit 38836a2cd47c20daaaa84873e3d6020f19e4bfca from qemu
Rather than making every caller of raise_exception set the
syndrome and target EL by hand, make these arguments to
raise_exception() and have that do the job.
Backports commit c63285991b371c031147ad620dd7671662a90303 from qemu
Move the code which sets exception information out of
arm_cpu_handle_mmu_fault and into tlb_fill. tlb_fill
is the only caller which wants to raise_exception()
so it makes more sense for it to handle the whole of
the exception setup.
As part of this cleanup, move the user-mode-only
implementation function for the handle_mmu_fault CPU
method into cpu.c so we don't need to make it globally
visible, and rename the softmmu-only utility function
arm_cpu_handle_mmu_fault to arm_tlb_fill so it's clear
that it's not the same thing.
Backports commit 8c6084bf10fe721929ca94cf16acd6687e61d3ec from qemu
If the SCTLR.UMA trap bit is set then attempts by EL0 to update
the PSTATE DAIF bits via "MSR DAIFSet, imm" and "MSR DAIFClr, imm"
instructions will raise an exception. We were failing to set
the syndrome information for this exception, which meant that
it would be reported as a repeat of whatever the previous
exception was. Set the correct syndrome information.
Backports commit f2932df777dace044719dc2f394f5a5a8aa1b1cd from qemu
Updated the various helper routines to set the target EL as needed using a
dedicated function.
Backports commit e3b1d480995f6e2e86ef062038e618c1234dbcf1 from qemu
Add a CPU state exception target EL field that will be used for communicating
the EL to which an exception should be routed.
Add a disassembly context field for tracking the EL3 architecture needed for
determining the target exception EL.
Add a target EL argument to the generic exception helper for callers to specify
the EL to which the exception should be routed. Extended the helper to set
the newly added CPU state exception target el.
Added a function for setting the target exception EL and updated calls to helpers
to call it.
Backports commit 737103619869600668cc7e8700e4f6eab3943896 from qemu
Add AArch32 to AArch64 register sychronization functions.
Replace manual register synchronization with new functions in
aarch64_cpu_do_interrupt() and HELPER(exception_return)().
Backports commit ce02049dbf1828b4bc77d921b108a9d84246e5aa from qemu
When EL3 is running in AArch32 (or ARMv7 with Security Extensions)
FCSEIDR, CONTEXTIDR, TPIDRURW, TPIDRURO and TPIDRPRW have a secure
and a non-secure instance.
Backports commit 54bf36ed351c526cde0c853079f9ff1ab7e2ff89 from qemu
