On ARMv8-A, accesses by 32-bit secure EL1 to monitor registers trap to
the upper (64-bit) EL. With Secure EL2 support, we can no longer assume
that that is always EL3, so make room for the value to be computed at
run-time.
Backports 6b340aeb48e4f7f983e1c38790de65ae93079840
The stage_1_mmu_idx() already effectively keeps track of which
translation regimes have two stages. Don't hard-code another test.
Backports 7879460a6149ed5e80c29cac85449191d9c5754a
In the secure stage 2 translation regime, the VSTCR.SW and VTCR.NSW
bits can invert the secure flag for pagetable walks. This patchset
allows S1_ptw_translate() to change the non-secure bit.
Backports 3d4bd397433b12b148d150c8bc5655a696389bd1
The VTTBR write callback so far assumes that the underlying VM lies in
non-secure state. This handles the secure state scenario.
backports c4f060e89effd70ebdb23d3315495d33af377a09
This adds the MMU indices for EL2 stage 1 in secure state.
To keep code contained, which is largelly identical between secure and
non-secure modes, the MMU indices are reassigned. The new assignments
provide a systematic pattern with a non-secure bit.
Backports b6ad6062f1e55bd5b9407ce89e55e3a08b83827c
With the ARMv8.4-SEL2 extension, EL2 is a legal exception level in
secure mode, though it can only be AArch64.
This patch adds the target EL for exceptions from 64-bit S-EL2.
It also fixes the target EL to EL2 when HCR.{A,F,I}MO are set in secure
mode. Those values were never used in practice as the effective value of
HCR was always 0 in secure mode.
Backports 6c85f906261226e87211506bd9f787fd48a09f17
This adds a common helper to compute the effective value of MDCR_EL2.
That is the actual value if EL2 is enabled in the current security
context, or 0 elsewise.
Backports 59dd089cf9e4a9cddee596c8a1378620df51b9bb
Do not assume that EL2 is available in and only in non-secure context.
That equivalence is broken by ARMv8.4-SEL2.
Backports e6ef0169264b00cce552404f689ce137018ff290
In this context, the HCR value is the effective value, and thus is
zero in secure mode. The tests for HCR.{F,I}MO are sufficient.
Backports cc974d5cd84ea60a3dad59752aea712f3d47f8ce
The crypto overhead of emulating pauth can be significant for
some workloads. Add two boolean properties that allows the
feature to be turned off, on with the architected algorithm,
or on with an implementation defined algorithm.
We need two intermediate booleans to control the state while
parsing properties lest we clobber ID_AA64ISAR1 into an invalid
intermediate state.
Backports relevent members from eb94284d0812b4e7c11c5d075b584100ac1c1b9a
Without hardware acceleration, a cryptographically strong
algorithm is too expensive for pauth_computepac.
Even with hardware accel, we are not currently expecting
to link the linux-user binaries to any crypto libraries,
and doing so would generally make the --static build fail.
So choose XXH64 as a reasonably quick and decent hash.
Backports 283fc52ade85eb50141f3b8b85f82b07d016cb17
In commit cd8be50e58f63413c0 we converted the A32 coprocessor
insns to decodetree. This accidentally broke XScale/iWMMXt insns,
because it moved the handling of "cp insns which are handled
by looking up the cp register in the hashtable" from after the
call to the legacy disas_xscale_insn() decode to before it,
with the result that all XScale/iWMMXt insns now UNDEF.
Update valid_cp() so that it knows that on XScale cp 0 and 1
are not standard coprocessor instructions; this will cause
the decodetree trans_ functions to ignore them, so that
execution will correctly get through to the legacy decode again.
Backports e4d51ac6921dc861bfb3d20e4c7dcf345840a9da
When FEAT_MTE is implemented, the AArch64 view of CTR_EL0 adds the
TminLine field in bits [37:32].
Extend the ctr field to be able to hold this context.
Backports a5fd319ae7f6d496ff5448ec1dedcae8e2f59e9f
The AArch64 view of CLIDR_EL1 extends the ICB field to include also bit
32, as well as adding a Ttype<n> field when FEAT_MTE is implemented.
Extend the clidr field to be able to hold this context.
Backports f6450bcb6b2d3e4beae77141edce9e99cb8c277e
Now that we have implemented all the features needed by the v8.1M
architecture, we can add the model of the Cortex-M55. This is the
configuration without MVE support; we'll add MVE later
Backports 590e05d6b48937f6d3c631354fd706f8e005b8f6
Implement the v8.1M FPCXT_NS floating-point system register. This is
a little more complicated than FPCXT_S, because it has specific
handling for "current FP state is inactive", and it only wants to do
PreserveFPState(), not the full set of actions done by
ExecuteFPCheck() which vfp_access_check() implements.
Backports eb20dafdbff92063a88624176fdc396e01961bf3
In commit 64f863baeedc8659 we implemented the v8.1M FPCXT_S register,
but we got the write behaviour wrong. On read, this register reads
bits [27:0] of FPSCR plus the CONTROL.SFPA bit. On write, it doesn't
just write back those bits -- it writes a value to the whole FPSCR,
whose upper 4 bits are zeroes.
We also incorrectly implemented the write-to-FPSCR as a simple store
to vfp.xregs; this skips the "update the softfloat flags" part of
the vfp_set_fpscr helper so the value would read back correctly but
not actually take effect.
Fix both of these things by doing a complete write to the FPSCR
using the helper function.
Backports 7fbf95a037d79c5e923ffb51ac902dbe9599c87f
In 50244cc76abc we updated mte_check_fail to match the ARM
pseudocode, using the correct EL to select the TCF field.
But we failed to update MTE0_ACTIVE the same way, which led
to g_assert_not_reached().
Backports cc97b0019bb590b9b3c2a623e9ebee48831e0ce3
When the 'int N' instruction is executed in protected mode, the
pseudocode in the architecture manual specifies that we need to check:
* vector number within IDT limits
* selected IDT descriptor is a valid type (interrupt, trap or task gate)
* if this was a software interrupt then gate DPL < CPL
The way we had structured the code meant that the privilege check for
software interrupts ended up not in the code path taken for task gate
handling, because all of the task gate handling code was in the 'case 5'
of the switch which was checking "is this descriptor a valid type".
Move the task gate handling code out of that switch (so that it is now
purely doing the "valid type?" check) and below the software interrupt
privilege check.
The effect of this missing check was that in a guest userspace binary
executing 'int 8' would cause a guest kernel panic rather than the
userspace binary being handed a SEGV.
This is essentially the same bug fixed in VirtualBox in 2012:
https://www.halfdog.net/Security/2012/VirtualBoxSoftwareInterrupt0x8GuestCrash/
Note that for QEMU this is not a security issue because it is only
present when using TCG.
Backports 3df1a3d070575419859cbbab1083fafa7ec2669a
I found that there are many spelling errors in the comments of qemu/target/m68k.
I used spellcheck to check the spelling errors and found some errors in the folder.
Backports ce00ff729ee8461dc94a1593d25ceda65d973d3c
Per the SDM, when returning to outer privilege level, for segment
registers (ES, FS, GS, and DS) if the check fails, the segment
selector becomes null, but QEMU clears the base/limit/flags as well
as nullifying the segment selector, which should be a spec violation.
Real hardware seems to be compliant with the spec, at least on one
Coffee Lake board I tested.
Backports c2ba0515f2df58a661fcb5d6485139877d92ab1b
For PDEP and PEXT, the mask is provided in the memory (mod+r/m)
operand, and therefore is loaded in s->T0 by gen_ldst_modrm.
The source is provided in the second source operand (VEX.vvvv)
and therefore is loaded in s->T1. Fix the order in which
they are passed to the helpers.
Backports 75b208c28316095c4685e8596ceb9e3f656592e2
For v8.1M the architecture mandates that CPUs must provide at
least the "minimal RAS implementation" from the Reliability,
Availability and Serviceability extension. This consists of:
* an ESB instruction which is a NOP
-- since it is in the HINT space we need only add a comment
* an RFSR register which will RAZ/WI
* a RAZ/WI AIRCR.IESB bit
-- the code which handles writes to AIRCR does not allow setting
of RES0 bits, so we already treat this as RAZ/WI; add a comment
noting that this is deliberate
* minimal implementation of the RAS register block at 0xe0005000
-- this will be in a subsequent commit
* setting the ID_PFR0.RAS field to 0b0010
-- we will do this when we add the Cortex-M55 CPU model
Backports 46f4976f22a4549322307b34272e053d38653243
v8.1M introduces a new TRD flag in the CCR register, which enables
checking for stack frame integrity signatures on SG instructions.
Add the code in the SG insn implementation for the new behaviour.
Backports 7f484147369080d36c411c4ba969f90d025aed55
v8.1M adds new encodings of VLLDM and VLSTM (where bit 7 is set).
The only difference is that:
* the old T1 encodings UNDEF if the implementation implements 32
Dregs (this is currently architecturally impossible for M-profile)
* the new T2 encodings have the implementation-defined option to
read from memory (discarding the data) or write UNKNOWN values to
memory for the stack slots that would be D16-D31
We choose not to make those accesses, so for us the two
instructions behave identically assuming they don't UNDEF.
Backports fe6fa228a71f0eb8b8ee315452e6a7736c537b1f
In v8.1M a new exception return check is added which may cause a NOCP
UsageFault (see rule R_XLTP): before we clear s0..s15 and the FPSCR
we must check whether access to CP10 from the Security state of the
returning exception is disabled; if it is then we must take a fault.
(Note that for our implementation CPPWR is always RAZ/WI and so can
never cause CP10 accesses to fail.)
The other v8.1M change to this register-clearing code is that if MVE
is implemented VPR must also be cleared, so add a TODO comment to
that effect.
Backports 3423fbf10427db7680d3237d4f62d8370052fca0
In v8.0M, on exception entry the registers R0-R3, R12, APSR and EPSR
are zeroed for an exception taken to Non-secure state; for an
exception taken to Secure state they become UNKNOWN, and we chose to
leave them at their previous values.
In v8.1M the behaviour is specified more tightly and these registers
are always zeroed regardless of the security state that the exception
targets (see rule R_KPZV). Implement this.
Backports a59b1ed618415212c5f0f05abc1192e14ad5fdbb
Implement the new-in-v8.1M FPCXT_S floating point system register.
This is for saving and restoring the secure floating point context,
and it reads and writes bits [27:0] from the FPSCR and the
CONTROL.SFPA bit in bit [31].
Backports 64f863baeedc86590a608e2f1722dd8640aa9431
Factor out the code which handles M-profile lazy FP state preservation
from full_vfp_access_check(); accesses to the FPCXT_NS register are
a special case which need to do just this part (corresponding in the
pseudocode to the PreserveFPState() function), and not the full
set of actions matching the pseudocode ExecuteFPCheck() which
normal FP instructions need to do.
Backports 96dfae686628fc14ba4f993824322b93395e221b
We defined a constant name for the mask of NZCV bits in the FPCR/FPSCR
in the previous commit; use it in a couple of places in existing code,
where we're masking out everything except NZCV for the "load to Rt=15
sets CPSR.NZCV" special case.
Backports 6a017acdf83e3bb6bd5e85289ca90b2ea3282b7e
v8.1M defines a new FP system register FPSCR_nzcvqc; this behaves
like the existing FPSCR, except that it reads and writes only bits
[31:27] of the FPSCR (the N, Z, C, V and QC flag bits). (Unlike the
FPSCR, the special case for Rt=15 of writing the CPSR.NZCV is not
permitted.)
Implement the register. Since we don't yet implement MVE, we handle
the QC bit as RES0, with todo comments for where we will need to add
support later.
Backports 9542c30bcf13c495400d63616dd8dfa825b04685
Implement the new-in-v8.1M VLDR/VSTR variants which directly
read or write FP system registers to memory.
Backports 0bf0dd4dcbd9fab324700ac6e0cd061cd043de0d
The constant-expander functions like negate, plus_2, etc, are
generally useful; move them up in translate.c so we can use them in
the VFP/Neon decoders as well as in the A32/T32/T16 decoders.
Backports f7ed0c9433e7c5c157d2e6235eb5c8b93234a71a
Currently M-profile borrows the A-profile code for VMSR and VMRS
(access to the FP system registers), because all it needs to support
is the FPSCR. In v8.1M things become significantly more complicated
in two ways:
* there are several new FP system registers; some have side effects
on read, and one (FPCXT_NS) needs to avoid the usual
vfp_access_check() and the "only if FPU implemented" check
* all sysregs are now accessible both by VMRS/VMSR (which
reads/writes a general purpose register) and also by VLDR/VSTR
(which reads/writes them directly to memory)
Refactor the structure of how we handle VMSR/VMRS to cope with this:
* keep the M-profile code entirely separate from the A-profile code
* abstract out the "read or write the general purpose register" part
of the code into a loadfn or storefn function pointer, so we can
reuse it for VLDR/VSTR.
Backports 32a290b8c3c2dc85cd88bd8983baf900d575cab
For M-profile before v8.1M, the only valid register for VMSR/VMRS is
the FPSCR. We have a comment that states this, but the actual logic
to forbid accesses for any other register value is missing, so we
would end up with A-profile style behaviour. Add the missing check.
Backports ede97c9d71110821738a48f88ff9f10d6bec017f
