Enable FEAT_Debugv8p8 for max CPU. This feature is out of scope for QEMU
since it concerns the external debug interface for JTAG, but is
mandatory in Armv8.8 implementations, hence it is reported as supported
in the ID registers.
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240624180915.4528-4-gustavo.romero@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
FEAT_WFxT introduces new instructions WFIT and WFET, which are like
the existing WFI and WFE but allow the guest to pass a timeout value
in a register. The instructions will wait for an interrupt/event as
usual, but will also stop waiting when the value of CNTVCT_EL0 is
greater than or equal to the specified timeout value.
We implement WFIT by setting up a timer to expire at the right
point; when the timer expires it sets the EXITTB interrupt, which
will cause the CPU to leave the halted state. If we come out of
halt for some other reason, we unset the pending timer.
We implement WFET as a nop, which is architecturally permitted and
matches the way we currently make WFE a nop.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240430140035.3889879-3-peter.maydell@linaro.org
FEAT_Spec_FPACC is a feature describing speculative behaviour in the
event of a PAC authontication failure when FEAT_FPACCOMBINE is
implemented. FEAT_Spec_FPACC means that the speculative use of
pointers processed by a PAC Authentication is not materially
different in terms of the impact on cached microarchitectural state
(caches, TLBs, etc) between passing and failing of the PAC
Authentication.
QEMU doesn't do speculative execution, so we can advertise
this feature.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240418152004.2106516-6-peter.maydell@linaro.org
FEAT_ETS2 is a tighter set of guarantees about memory ordering
involving translation table walks than the old FEAT_ETS; FEAT_ETS has
been retired from the Arm ARM and the old ID_AA64MMFR1.ETS == 1
now gives no greater guarantees than ETS == 0.
FEAT_ETS2 requires:
* the virtual address of a load or store that appears in program
order after a DSB cannot be translated until after the DSB
completes (section B2.10.9)
* TLB maintenance operations that only affect translations without
execute permission are guaranteed complete after a DSB
(R_BLDZX)
* if a memory access RW2 is ordered-before memory access RW2,
then RW1 is also ordered-before any translation table walk
generated by RW2 that generates a Translation, Address size
or Access flag fault (R_NNFPF, I_CLGHP)
As with FEAT_ETS, QEMU is already compliant, because we do not
reorder translation table walk memory accesses relative to other
memory accesses, and we always guarantee to have finished TLB
maintenance as soon as the TLB op is done.
Update the documentation to list FEAT_ETS2 instead of the
no-longer-existent FEAT_ETS, and update the 'max' CPU ID registers.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240418152004.2106516-4-peter.maydell@linaro.org
FEAT_CSV2_3 adds a mechanism to identify if hardware cannot disclose
information about whether branch targets and branch history trained
in one hardware described context can control speculative execution
in a different hardware context.
There is no branch prediction in TCG, so we don't need to do anything
to be compliant with this. Upadte the '-cpu max' ID registers to
advertise the feature.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240418152004.2106516-3-peter.maydell@linaro.org
As of version DDI0487K.a of the Arm ARM, some architectural features
which previously didn't have official names have been named. Add
these to the list of features which QEMU's TCG emulation supports.
Mostly these are features which we thought of as part of baseline 8.0
support. For SVE and SVE2, the names have been brought into line
with the FEAT_* naming convention of other extensions, and some
sub-components split into separate FEAT_ items. In a few cases (eg
FEAT_CCIDX, FEAT_DPB2) the omission from our list was just an oversight.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240418152004.2106516-2-peter.maydell@linaro.org
Enable FEAT_NMI on the 'max' CPU.
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20240407081733.3231820-24-ruanjinjie@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Enable all FEAT_ECV features on the 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240301183219.2424889-9-peter.maydell@linaro.org
Enable FEAT_NV2 on the 'max' CPU, and stop filtering it out for
the Neoverse N2 and Neoverse V1 CPUs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
Enable FEAT_NV on the 'max' CPU, and stop filtering it out for the
Neoverse N2 and Neoverse V1 CPUs. We continue to downgrade FEAT_NV2
support to FEAT_NV for the latter two CPU types.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Miguel Luis <miguel.luis@oracle.com>
FEAT_HPMN0 is a small feature which defines that it is valid for
MDCR_EL2.HPMN to be set to 0, meaning "no PMU event counters provided
to an EL1 guest" (previously this setting was reserved). QEMU's
implementation almost gets HPMN == 0 right, but we need to fix
one check in pmevcntr_is_64_bit(). That is enough for us to
advertise the feature in the 'max' CPU.
(We don't need to make the behaviour conditional on feature
presence, because the FEAT_HPMN0 behaviour is within the range
of permitted UNPREDICTABLE behaviour for a non-FEAT_HPMN0
implementation.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230921185445.3339214-1-peter.maydell@linaro.org
Enable FEAT_MOPS on the AArch64 'max' CPU, and add it to
the list of features we implement.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230912140434.1333369-13-peter.maydell@linaro.org
FEAT_HBC (Hinted conditional branches) provides a new instruction
BC.cond, which behaves exactly like the existing B.cond except
that it provides a hint to the branch predictor about the
likely behaviour of the branch.
Since QEMU does not implement branch prediction, we can treat
this identically to B.cond.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230831232441.66020-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Implement the QARMA3 cryptographic algorithm for PAC calculation.
Implement a cpu feature to select the algorithm and document it.
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230829232335.965414-6-richard.henderson@linaro.org
Message-Id: <20230609172324.982888-4-aaron@os.amperecomputing.com>
[rth: Merge cpu feature addition from another patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This is a mandatory feature for Armv8.1 architectures but we don't
state the feature clearly in our emulation list. Also include
FEAT_CRC32 comment in aarch64_max_tcg_initfn for ease of grepping.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20230824075406.1515566-1-alex.bennee@linaro.org
Cc: qemu-stable@nongnu.org
Message-Id: <20230222110104.3996971-1-alex.bennee@linaro.org>
[PMM: pluralize 'instructions' in docs]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This feature allows the operating system to set TCR_ELx.HWU*
to allow the implementation to use the PBHA bits from the
block and page descriptors for for IMPLEMENTATION DEFINED
purposes. Since QEMU has no need to use these bits, we may
simply ignore them.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230811214031.171020-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20230622143046.1578160-1-richard.henderson@linaro.org
[PMM: fixed typo; note experimental status in emulation.rst too]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230530191438.411344-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
FEAT_PAN3 adds an EPAN bit to SCTLR_EL1 and SCTLR_EL2, which allows
the PAN bit to make memory non-privileged-read/write if it is
user-executable as well as if it is user-read/write.
Implement this feature and enable it in the AArch64 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230331145045.2584941-4-peter.maydell@linaro.org
This affects both system and user mode emulation so we should probably
list it up front.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230124180127.1881110-21-alex.bennee@linaro.org>
Update the ID registers for TCG's '-cpu max' to report the
FEAT_EVT Enhanced Virtualization Traps support.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Perform the atomic update for hardware management of the access flag.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221024051851.3074715-13-richard.henderson@linaro.org
[PMM: Fix accidental PROT_WRITE to PAGE_WRITE; add missing
main-loop.h include]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
FEAT_E0PD adds new bits E0PD0 and E0PD1 to TCR_EL1, which allow the
OS to forbid EL0 access to half of the address space. Since this is
an EL0-specific variation on the existing TCR_ELx.{EPD0,EPD1}, we can
implement it entirely in aa64_va_parameters().
This requires moving the existing regime_is_user() to internals.h
so that the code in helper.c can get at it.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20221021160131.3531787-1-peter.maydell@linaro.org
FEAT_GTG is a change tho the ID register ID_AA64MMFR0_EL1 so that it
can report a different set of supported granule (page) sizes for
stage 1 and stage 2 translation tables. As of commit c20281b2a5
we already report the granule sizes that way for '-cpu max', and now
we also correctly make attempts to use unimplemented granule sizes
fail, so we can report the support of the feature in the
documentation.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20221003162315.2833797-4-peter.maydell@linaro.org
Update the ID registers for TCG's '-cpu max' to report a FEAT_PMUv3p5
compliant PMU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822132358.3524971-11-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The architectural feature FEAT_ETS (Enhanced Translation
Synchronization) is a set of tightened guarantees about memory
ordering involving translation table walks:
* if memory access RW1 is ordered-before memory access RW2 then it
is also ordered-before any translation table walk generated by RW2
that generates a translation fault, address size fault or access
fault
* TLB maintenance on non-exec-permission translations is guaranteed
complete after a DSB (ie it does not need the context
synchronization event that you have to have if you don’t have
FEAT_ETS)
For QEMU’s implementation we don’t reorder translation table walk
accesses, and we guarantee to finish the TLB maintenance as soon as
the TLB op is done (the tlb_flush functions will complete at the end
of the TLB, and TLB ops always end the TB because they’re sysreg
writes).
So we’re already compliant and all we need to do is say so in the ID
registers for the 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220819110052.2942289-6-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Note that SME remains effectively disabled for user-only,
because we do not yet set CPACR_EL1.SMEN. This needs to
wait until the kernel ABI is implemented.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-33-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The FEAT_DoubleFault extension adds the following:
* All external aborts on instruction fetches and translation table
walks for instruction fetches must be synchronous. For QEMU this
is already true.
* SCR_EL3 has a new bit NMEA which disables the masking of SError
interrupts by PSTATE.A when the SError interrupt is taken to EL3.
For QEMU we only need to make the bit writable, because we have no
sources of SError interrupts.
* SCR_EL3 has a new bit EASE which causes synchronous external
aborts taken to EL3 to be taken at the same entry point as SError.
(Note that this does not mean that they are SErrors for purposes
of PSTATE.A masking or that the syndrome register reports them as
SErrors: it just means that the vector offset is different.)
* The existing SCTLR_EL3.IESB has an effective value of 1 when
SCR_EL3.NMEA is 1. For QEMU this is a no-op because we don't need
different behaviour based on IESB (we don't need to do anything to
ensure that error exceptions are synchronized).
So for QEMU the things we need to change are:
* Make SCR_EL3.{NMEA,EASE} writable
* When taking a synchronous external abort at EL3, adjust the
vector entry point if SCR_EL3.EASE is set
* Advertise the feature in the ID registers
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220531151431.949322-1-peter.maydell@linaro.org
The architectural feature RASv1p1 introduces the following new
features:
* new registers ERXPFGCDN_EL1, ERXPFGCTL_EL1 and ERXPFGF_EL1
* new bits in the fine-grained trap registers that control traps
for these new registers
* new trap bits HCR_EL2.FIEN and SCR_EL3.FIEN that control traps
for ERXPFGCDN_EL1, ERXPFGCTL_EL1, ERXPFGP_EL1
* a larger number of the ERXMISC<n>_EL1 registers
* the format of ERR<n>STATUS registers changes
The architecture permits that if ERRIDR_EL1.NUM is 0 (as it is for
QEMU) then all these new registers may UNDEF, and the HCR_EL2.FIEN
and SCR_EL3.FIEN bits may be RES0. We don't have any ERR<n>STATUS
registers (again, because ERRIDR_EL1.NUM is 0). QEMU does not yet
implement the fine-grained-trap extension. So there is nothing we
need to implement to be compliant with the feature spec. Make the
'max' CPU report the feature in its ID registers, and document it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220531114258.855804-1-peter.maydell@linaro.org
In commit 5814d587fe we added support for emulating
FEAT_HCX (Support for the HCRX_EL2 register). However we
forgot to add it to the list in emulated.rst. Correct the
omission.
Fixes: 5814d587fe ("target/arm: Enable FEAT_HCX for -cpu max")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220520084320.424166-1-peter.maydell@linaro.org
The Armv8.4 feature FEAT_IDST specifies that exceptions generated by
read accesses to the feature ID space should report a syndrome code
of 0x18 (EC_SYSTEMREGISTERTRAP) rather than 0x00 (EC_UNCATEGORIZED).
The feature ID space is defined to be:
op0 == 3, op1 == {0,1,3}, CRn == 0, CRm == {0-7}, op2 == {0-7}
In our implementation we might return the EC_UNCATEGORIZED syndrome
value for a system register access in four cases:
* no reginfo struct in the hashtable
* cp_access_ok() fails (ie ri->access doesn't permit the access)
* ri->accessfn returns CP_ACCESS_TRAP_UNCATEGORIZED at runtime
* ri->type includes ARM_CP_RAISES_EXC, and the readfn raises
an UNDEF exception at runtime
We have very few regdefs that set ARM_CP_RAISES_EXC, and none of
them are in the feature ID space. (In the unlikely event that any
are added in future they would need to take care of setting the
correct syndrome themselves.) This patch deals with the other
three cases, and enables FEAT_IDST for AArch64 -cpu max.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220509155457.3560724-1-peter.maydell@linaro.org
Enable the FEAT_S2FWB for -cpu max. Since FEAT_S2FWB requires that
CLIDR_EL1.{LoUU,LoUIS} are zero, we explicitly squash these (the
inherited CLIDR_EL1 value from the Cortex-A57 has them as 1).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220505183950.2781801-5-peter.maydell@linaro.org
This extension concerns not merging memory access, which TCG does
not implement. Thus we can trivially enable this feature.
Add a comment to handle_hint for the DGH instruction, but no code.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-23-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns cache speculation, which TCG does
not implement. Thus we can trivially enable this feature.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-22-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
There is no branch prediction in TCG, therefore there is no
need to actually include the context number into the predictor.
Therefore all we need to do is add the state for SCXTNUM_ELx.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns branch speculation, which TCG does
not implement. Thus we can trivially enable this feature.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This feature is AArch64 only, and applies to physical SErrors,
which QEMU does not implement, thus the feature is a nop.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-19-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-18-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns changes to the External Debug interface,
with Secure and Non-secure access to the debug registers, and all
of it is outside the scope of QEMU. Indicating support for this
is mandatory with FEAT_SEL2, which we do implement.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The only portion of FEAT_Debugv8p2 that is relevant to QEMU
is CONTEXTIDR_EL2, which is also conditionally implemented
with FEAT_VHE. The rest of the debug extension concerns the
External debug interface, which is outside the scope of QEMU.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The description in the Arm ARM of the requirements of FEAT_BBM is
admirably clear on the guarantees it provides software, but slightly
more obscure on what that means for implementations. The description
of the equivalent SMMU feature in the SMMU specification (IHI0070D.b
section 3.21.1) is perhaps a bit more detailed and includes some
example valid implementation choices. (The SMMU version of this
feature is slightly tighter than the CPU version: the CPU is permitted
to raise TLB Conflict aborts in some situations that the SMMU may
not. This doesn't matter for QEMU because we don't want to do TLB
Conflict aborts anyway.)
The informal summary of FEAT_BBM is that it is about permitting an OS
to switch a range of memory between "covered by a huge page" and
"covered by a sequence of normal pages" without having to engage in
the 'break-before-make' dance that has traditionally been
necessary. The 'break-before-make' sequence is:
* replace the old translation table entry with an invalid entry
* execute a DSB insn
* execute a broadcast TLB invalidate insn
* execute a DSB insn
* write the new translation table entry
* execute a DSB insn
The point of this is to ensure that no TLB can simultaneously contain
TLB entries for the old and the new entry, which would traditionally
be UNPREDICTABLE (allowing the CPU to generate a TLB Conflict fault
or to use a random mishmash of values from the old and the new
entry). FEAT_BBM level 2 says "for the specific case where the only
thing that changed is the size of the block, the TLB is guaranteed
not to do weird things even if there are multiple entries for an
address", which means that software can now do:
* replace old translation table entry with new entry
* DSB
* broadcast TLB invalidate
* DSB
As the SMMU spec notes, valid ways to do this include:
* if there are multiple entries in the TLB for an address,
choose one of them and use it, ignoring the others
* if there are multiple entries in the TLB for an address,
throw them all out and do a page table walk to get a new one
QEMU's page table walk implementation for Arm CPUs already meets the
requirements for FEAT_BBM level 2. When we cache an entry in our TCG
TLB, we do so only for the specific (non-huge) page that the address
is in, and there is no way for the TLB data structure to ever have
more than one TLB entry for that page. (We handle huge pages only in
that we track what part of the address space is covered by huge pages
so that a TLB invalidate operation for an address in a huge page
results in an invalidation of the whole TLB.) We ignore the Contiguous
bit in page table entries, so we don't have to do anything for the
parts of FEAT_BBM that deal with changis to the Contiguous bit.
FEAT_BBM level 2 also requires that the nT bit in block descriptors
must be ignored; since commit 39a1fd2528 we do this.
It's therefore safe for QEMU to advertise FEAT_BBM level 2 by
setting ID_AA64MMFR2_EL1.BBM to 2.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220426160422.2353158-3-peter.maydell@linaro.org
The Arm FEAT_TTL architectural feature allows the guest to provide an
optional hint in an AArch64 TLB invalidate operation about which
translation table level holds the leaf entry for the address being
invalidated. QEMU's TLB implementation doesn't need that hint, and
we correctly ignore the (previously RES0) bits in TLB invalidate
operation values that are now used for the TTL field. So we can
simply advertise support for it in our 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220426160422.2353158-2-peter.maydell@linaro.org
This feature widens physical addresses (and intermediate physical
addresses for 2-stage translation) from 48 to 52 bits, when using
4k or 16k pages.
This introduces the DS bit to TCR_ELx, which is RES0 unless the
page size is enabled and supports LPA2, resulting in the effective
value of DS for a given table walk. The DS bit changes the format
of the page table descriptor slightly, moving the PS field out to
TCR so that all pages have the same sharability and repurposing
those bits of the page table descriptor for the highest bits of
the output address.
Do not yet enable FEAT_LPA2; we need extra plumbing to avoid
tickling an old kernel bug.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220301215958.157011-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This feature widens physical addresses (and intermediate physical
addresses for 2-stage translation) from 48 to 52 bits, when using
64k pages. The only thing left at this point is to handle the
extra bits in the TTBR and in the table descriptors.
Note that PAR_EL1 and HPFAR_EL2 are nominally extended, but we don't
mask out the high bits when writing to those registers, so no changes
are required there.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220301215958.157011-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Gustavo Romero