In U-boot, we switch from S-SVC -> Mon -> Hyp mode when we want to
enter Hyp mode. The change into Hyp mode is done by doing an
exception return from Mon. This doesn't work with current QEMU.
The problem is that in bad_mode_switch() we refuse to allow
the change of mode.
Note that bad_mode_switch() is used to do validation for two situations:
(1) changes to mode by instructions writing to CPSR.M
(ie not exception take/return) -- this corresponds to the
Armv8 Arm ARM pseudocode Arch32.WriteModeByInstr
(2) changes to mode by exception return
Attempting to enter or leave Hyp mode via case (1) is forbidden in
v8 and UNPREDICTABLE in v7, and QEMU is correct to disallow it
there. However, we're already doing that check at the top of the
bad_mode_switch() function, so if that passes then we should allow
the case (2) exception return mode changes to switch into Hyp mode.
We want to test whether we're trying to return to the nonexistent
"secure Hyp" mode, so we need to look at arm_is_secure_below_el3()
rather than arm_is_secure(), since the latter is always true if
we're in Mon (EL3).
Backports commit 2d2a4549cc29850aab891495685a7b31f5254b12 from qemu
Use "register" TBFLAG_ANY to indicate shared state between
A32 and A64, and "registers" TBFLAG_A32 & TBFLAG_A64 for
fields that are specific to the given cpu state.
Move ARM_TBFLAG_BE_DATA to shared state, instead of its current
placement within "Bit usage when in AArch32 state".
Backports commit aad821ac4faad369fad8941d25e59edf2514246b 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 arm_hcr_el2_eff includes a check against
arm_is_secure_below_el3, we can often remove a
nearby check against secure state.
In some cases, sort the call to arm_hcr_el2_eff
to the end of a short-circuit logical sequence.
Backports commit 7c208e0f4171c9e2cc35efc12e1bf264a45c229f from qemu
Replace arm_hcr_el2_{fmo,imo,amo} with a more general routine
that also takes SCR_EL3.NS (aka arm_is_secure_below_el3) into
account, as documented for the plethora of bits in HCR_EL2.
Backports commit f77784446045231f7dfa46c9b872091241fa1557 from qemu
The bulk of the work here, beyond base HPD, is defining the
TTBCR2 register. In addition we must check TTBCR.T2E, which
is not present (RES0) for AArch64.
Backports commit ab638a328fd099ba0b23c8c818eb39f2c35414f3 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
Because EL3 has a fixed execution mode, we can properly decide
which of the bits are RES{0,1}.
Backports commit ea22747c63c9a894777aa41a7af85c3d08e39f81 from qemu
The enable for TGE has already occurred within arm_hcr_el2_amo
and friends. Moreover, when E2H is also set, the sense is
supposed to be reversed, which has also already occurred within
the helpers.
Backports commit 619959c3583dad325c36f09ce670e7d091382cae from qemu
At the same time, define the fields for these registers,
and use those defines in arm_pamax().
Backports commit 3dc91ddbc68391f934bf6945853e99cf6810fc00 from qemu
Hyp mode is an exception to the general rule that each AArch32
mode has its own r13, r14 and SPSR -- it has a banked r13 and
SPSR but shares its r14 with User and System mode. We were
incorrectly implementing it as banked, which meant that on
entry to Hyp mode r14 was 0 rather than the USR/SYS r14.
We provide a new function r14_bank_number() which is like
the existing bank_number() but provides the index into
env->banked_r14[]; bank_number() provides the index to use
for env->banked_r13[] and env->banked_cpsr[].
All the points in the code that were using bank_number()
to index into env->banked_r14[] are updated for consintency:
* switch_mode() -- this is the only place where we fix
an actual bug
* aarch64_sync_32_to_64() and aarch64_sync_64_to_32():
no behavioural change as we already special-cased Hyp R14
* kvm32.c: no behavioural change since the guest can't ever
be in Hyp mode, but conceptually the right thing to do
* msr_banked()/mrs_banked(): we can never get to the case
that accesses banked_r14[] with tgtmode == ARM_CPU_MODE_HYP,
so no behavioural change
Backports commit 593cfa2b637b92d37eef949653840dc065cdb960 from qemu
In commit 8a0fc3a29fc2315325400 we tried to implement HCR_EL2.{VI,VF},
but we got it wrong and had to revert it.
In that commit we implemented them as simply tracking whether there
is a pending virtual IRQ or virtual FIQ. This is not correct -- these
bits cause a software-generated VIRQ/VFIQ, which is distinct from
whether there is a hardware-generated VIRQ/VFIQ caused by the
external interrupt controller. So we need to track separately
the HCR_EL2 bit state and the external virq/vfiq line state, and
OR the two together to get the actual pending VIRQ/VFIQ state.
Fixes: 8a0fc3a29fc2315325400c738f807d0d4ae0ab7f
Backports commit 89430fc6f80a5aef1d4cbd6fc26b40c30793786c from qemu
This reverts commit 8a0fc3a29fc2315325400c738f807d0d4ae0ab7f.
The implementation of HCR.VI and VF in that commit is not
correct -- they do not track the overall "is there a pending
VIRQ or VFIQ" status, but whether there is a pending interrupt
due to "this mechanism", ie the hypervisor having set the VI/VF
bits. The overall pending state for VIRQ and VFIQ is effectively
the logical OR of the inbound lines from the GIC with the
VI and VF bits. Commit 8a0fc3a29fc231 would result in pending
VIRQ/VFIQ possibly being lost when the hypervisor wrote to HCR.
As a preliminary to implementing the HCR.VI/VF feature properly,
revert the broken one entirely.
Backports commit c624ea0fa7ffc9e2cc3e2b36c92b5c960954489f from qemu
Before we supported direct execution from MMIO regions, we
implemented workarounds in commit 720424359917887c926a33d2
which let us avoid doing so, even if the SAU or MPU region
was less than page-sized.
Once we implemented execute-from-MMIO, we removed part
of those workarounds in commit d4b6275df320cee76; but
we forgot the one in get_phys_addr_pmsav8() which
suppressed use of small SAU regions in executable regions.
Remove that workaround now.
Backports commit 521ed6b4015ba39a2e39c65a94643f3e6412edc4 from qemu
Now that we have full support for small regions, including execution,
we can remove the workarounds where we marked all small regions as
non-executable for the M-profile MPU and SAU.
Backports commit d4b6275df320cee764d56b194b1898547f545857 from qemu
Remove a TODO comment about implementing the vectored interrupt
controller. We have had an implementation of that for a decade;
it's in hw/intc/pl190.c.
Backports commit e24ad484909e7a00ca4f6332f3698facf0ba3394 from qemu
ATS1HR and ATS1HW (which allow AArch32 EL2 to do address translations
on the EL2 translation regime) were implemented in commit 14db7fe09a2c8.
However, we got them wrong: these should do stage 1 address translations
as defined for NS-EL2, which is ARMMMUIdx_S1E2. We were incorrectly
making them perform stage 2 translations.
A few years later in commit 1313e2d7e2cd we forgot entirely that
we'd implemented ATS1Hx, and added a comment that ATS1Hx were
"not supported yet". Remove the comment; there is no extra code
needed to handle these operations in do_ats_write(), because
arm_s1_regime_using_lpae_format() returns true for ARMMMUIdx_S1E2,
which forces 64-bit PAR format.
Backports commit 23463e0e4aeb2f0a9c60549a2c163f4adc0b8512 from qemu
In do_ats_write() we construct a PAR value based on the result
of the translation. A comment says "S2WLK and FSTAGE are always
zero, because we don't implement virtualization".
Since we do in fact now implement virtualization, add the missing
code that sets these bits based on the reported ARMMMUFaultInfo.
(These bits are named PTW and S in ARMv8, so we follow that
convention in the new comments in this patch.)
Backports commit 0f7b791b35f24cb1333f779705a3f6472e6935de from qemu
Since QEMU does not implement ASIDs, changes to the ASID must flush the
tlb. However, if the ASID does not change there is no reason to flush.
In testing a boot of the Ubuntu installer to the first menu, this reduces
the number of flushes by 30%, or nearly 600k instances.
Backports commit 93f379b0c43617b1361f742f261479eaed4959cb from qemu
The EL3 version of this register does not include an ASID,
and so the tlb_flush performed by vmsa_ttbr_write is not needed.
Backports commit f478847f1ee0df9397f561025ab2f687fd923571 from qemu
For traps of FP/SIMD instructions to AArch32 Hyp mode, the syndrome
provided in HSR has more information than is reported to AArch64.
Specifically, there are extra fields TA and coproc which indicate
whether the trapped instruction was FP or SIMD. Add this extra
information to the syndromes we construct, and mask it out when
taking the exception to AArch64.
Backports commit 4be42f4013fa1a9df47b48aae5148767bed8e80c from qemu
For the v7 version of the Arm architecture, the IL bit in
syndrome register values where the field is not valid was
defined to be UNK/SBZP. In v8 this is RES1, which is what
QEMU currently implements. Handle the desired v7 behaviour
by squashing the IL bit for the affected cases:
* EC == EC_UNCATEGORIZED
* prefetch aborts
* data aborts where ISV is 0
(The fourth case listed in the v8 Arm ARM DDI 0487C.a in
section G7.2.70, "illegal state exception", can't happen
on a v7 CPU.)
This deals with a corner case noted in a comment.
Backports commit 2ed08180db096ea5e44573529b85e09b1ed10b08 from qemu
Create and use a utility function to extract the EC field
from a syndrome, rather than open-coding the shift.
Backports commit 64b91e3f890a8c221b65c6820a5ee39107ee40f5 from qemu
If the HCR_EL2 PTW virtualizaiton configuration register bit
is set, then this means that a stage 2 Permission fault must
be generated if a stage 1 translation table access is made
to an address that is mapped as Device memory in stage 2.
Implement this.
Backports commit eadb2febf05452bd8062c4c7823d7d789142500c from qemu
The HCR_EL2 VI and VF bits are supposed to track whether there is
a pending virtual IRQ or virtual FIQ. For QEMU we store the
pending VIRQ/VFIQ status in cs->interrupt_request, so this means:
* if the register is read we must get these bit values from
cs->interrupt_request
* if the register is written then we must write the bit
values back into cs->interrupt_request
Backports commit 8a0fc3a29fc2315325400c738f807d0d4ae0ab7f from qemu
The A/I/F bits in ISR_EL1 should track the virtual interrupt
status, not the physical interrupt status, if the associated
HCR_EL2.AMO/IMO/FMO bit is set. Implement this, rather than
always showing the physical interrupt status.
We don't currently implement anything to do with external
aborts, so this applies only to the I and F bits (though it
ought to be possible for the outer guest to present a virtual
external abort to the inner guest, even if QEMU doesn't
emulate physical external aborts, so there is missing
functionality in this area).
Backports commit 636540e9c40bd0931ef3022cb953bb7dbecd74ed from qemu
The HCR.DC virtualization configuration register bit has the
following effects:
* SCTLR.M behaves as if it is 0 for all purposes except
direct reads of the bit
* HCR.VM behaves as if it is 1 for all purposes except
direct reads of the bit
* the memory type produced by the first stage of the EL1&EL0
translation regime is Normal Non-Shareable,
Inner Write-Back Read-Allocate Write-Allocate,
Outer Write-Back Read-Allocate Write-Allocate.
Implement this behaviour.
Backports commit 9d1bab337caf2324a233e5937f415fad4ce1641b from qemu
The HCR.FB virtualization configuration register bit requests that
TLB maintenance, branch predictor invalidate-all and icache
invalidate-all operations performed in NS EL1 should be upgraded
from "local CPU only to "broadcast within Inner Shareable domain".
For QEMU we NOP the branch predictor and icache operations, so
we only need to upgrade the TLB invalidates:
AArch32 TLBIALL, TLBIMVA, TLBIASID, DTLBIALL, DTLBIMVA, DTLBIASID,
ITLBIALL, ITLBIMVA, ITLBIASID, TLBIMVAA, TLBIMVAL, TLBIMVAAL
AArch64 TLBI VMALLE1, TLBI VAE1, TLBI ASIDE1, TLBI VAAE1,
TLBI VALE1, TLBI VAALE1
Backports commit b4ab8ce98b8c482c8986785800f238d32a1578a9 from qemu
For AArch32, exception return happens through certain kinds
of CPSR write. We don't currently have any CPU_LOG_INT logging
of these events (unlike AArch64, where we log in the ERET
instruction). Add some suitable logging.
This will log exception returns like this:
Exception return from AArch32 hyp to usr PC 0x80100374
paralleling the existing logging in the exception_return
helper for AArch64 exception returns:
Exception return from AArch64 EL2 to AArch64 EL0 PC 0x8003045c
Exception return from AArch64 EL2 to AArch32 EL0 PC 0x8003045c
(Note that an AArch32 exception return can only be
AArch32->AArch32, never to AArch64.)
Backports commit 81e3728407bf4a12f83e14fd410d5f0a7d29b5b4 from qemu
Instantiating mps2-an505 (cortex-m33) will fail make check when
V7VE asserts that ID_ISAR0.Divide includes ARM division. It is
also wrong to include ARM_FEATURE_LPAE.
Backports commit 5256df880d1312a58472af3fb0a3c51e708f2161 from qemu
The get_phys_addr() functions take a pointer to an ARMMMUFaultInfo
struct, which they fill in only if a fault occurs. This means that
the caller must always zero-initialize the struct before passing
it in. We forgot to do this in v7m_stack_read() and v7m_stack_write().
Correct the error.
Backports commit ab44c7b71fa683b9402bea0d367b87c881704188 from qemu
This is an amendment to my earlier patch:
commit 7ece99b17e832065236c07a158dfac62619ef99b
Backports commit 599b71e277ac7e92807191b20b7163a28c5450ad from qemu
At present we assert:
arm_el_is_aa64: Assertion `el >= 1 && el <= 3' failed.
The comment in arm_el_is_aa64 explains why asking about EL0 without
extra information is impossible. Add an extra argument to provide
it from the surrounding context.
Fixes: 0ab5953b00b3
Backports commit 9a05f7b67436abdc52bce899f56acfde2e831454 from qemu
Updating the NS stack pointer via MSR to SP_NS should include
a check whether the new SP value is below the stack limit.
No other kinds of update to the various stack pointer and
limit registers via MSR should perform a check.
Backports commit 167765f0739e4a108e8c2e2ff2f37917df5658f9 from qemu
Add checks for breaches of the v8M stack limit when the
stack pointer is decremented to push the exception frame
for exception entry.
Note that the exception-entry case is unique in that the
stack pointer is updated to be the limit value if the limit
is hit (per rule R_ZLZG).
Backports commit c32da7aa6205a5ff62ae8d5062f7cad0eae4c1fd from qemu
We're going to want v7m_using_psp() in op_helper.c in the
next patch, so move it from helper.c to internals.h.
Backports commit 5529bf188d996391ff52a0e1801daf9c6a6bfcb0 from qemu
Define EXCP_STKOF, and arrange for it to cause us to take
a UsageFault with CFSR.STKOF set.
Backports commit 86f026de22d8854eecc004af44895de74225794f from qemu
The Arm v8M architecture includes hardware stack limit checking.
When certain instructions update the stack pointer, if the new
value of SP is below the limit set in the associated limit register
then an exception is taken. Add a TB flag that tracks whether
the limit-checking code needs to be emitted.
Backports commit 4730fb85035e99c909db7d14ef76cd17f28f4423 from qemu
Use the existing helpers to determine if (1) the fpu is enabled,
(2) sve state is enabled, and (3) the current sve vector length.
Backports commit ced3155141755ba244c988c72c4bde32cc819670 from qemu
SVE vector length can change when changing EL, or when writing
to one of the ZCR_ELn registers.
For correctness, our implementation requires that predicate bits
that are inaccessible are never set. Which means noticing length
changes and zeroing the appropriate register bits.
Backports commit 0ab5953b00b3165877d00cf75de628c51670b550 from qemu
We are going to want to determine whether sve is enabled
for EL other than current.
Backports commit 2de7ace292cf7846b0cda0e940272d2cb0e06859 from qemu
Check for EL3 before testing CPTR_EL3.EZ. Return 0 when the exception
should be routed via AdvSIMDFPAccessTrap. Mirror the structure of
CheckSVEEnabled more closely.
Fixes: 5be5e8eda78
Backports commit 60eed0869d68b91eff71cc0a0facb01983726a5d from qemu
Given that the only field defined for this new register may only
be 0, we don't actually need to change anything except the name.
Backports commit 9516d7725ec1deaa6ef5ccc5a26d005650d6c524 from qemu
A cut-and-paste error meant we were reading r4 from the v8M
callee-saves exception stack frame twice. This is harmless
since it just meant we did two memory accesses to the same
location, but it's unnecessary. Delete it.
Backports commit e5ae4d0c063fbcca4cbbd26bcefbf1760cfac2aa from qemu
