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
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
Extend the ARM disassemble context to take a target exception EL instead of a
boolean enable. This change reverses the polarity of the check making a value
of 0 indicate floating point enabled (no exception).
Backports commit 9dbbc748d671c70599101836cd1c2719d92f3017 from qemu
Currently we keep the TB flags PSTATE_SS and SS_ACTIVE in different
bit positions for AArch64 and AArch32. Replace these separate
definitions with a single common flag in the upper part of the
flags word.
Backports commit 3cf6a0fcedd429693d439556543400d5f0e31e1d 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
Avoid shifting potentially negative signed offset values in
disas_ldst_pair() by keeping the offset in a uint64_t rather
than an int64_t.
Backports commit c2ebd862a54b7e12175d65c03ba259926cb2237a from qemu
Shifting a negative integer left is undefined behaviour in C.
Avoid it by assembling and shifting the offset fields as
unsigned values and then sign extending as the final action.
Backports commit 037e1d009e2fcb80784d37f0e12aa999787d46d4 from qemu
The code in logic_imm_decode_wmask attempts to rotate a mask
value within the bottom 'e' bits of the value with
mask = (mask >> r) | (mask << (e - r));
This has two issues:
* if the element size is 64 then a rotate by zero results
in a shift left by 64, which is undefined behaviour
* if the element size is smaller than 64 then this will
leave junk in the value at bit 'e' and above, which is
not valid input to bitfield_replicate(). As it happens,
the bits at bit 'e' to '2e - r' are exactly the ones
which bitfield_replicate is going to copy in there,
so this isn't a "wrong code generated" bug, but it's
confusing and if we ever put an assert in
bitfield_replicate it would fire on valid guest code.
Fix the former by not doing anything if r is zero, and
the latter by masking with bitmask64(e).
Backports commit e167adc9d9f5df4f8109aecd4552c407fdce094a from qemu
Fix attempts to shift into the sign bit of an int, which is undefined
behaviour in C and warned about by the clang sanitizer.
Backports commit 1743d55c8b38bcee632cf6eb2de81131635bb3d2 from qemu
The MMU index to use for unprivileged loads and stores is more
complicated than we currently implement:
* for A64, it should be "if at EL1, access as if EL0; otherwise
access at current EL"
* for A32/T32, it should be "if EL2, UNPREDICTABLE; otherwise
access as if at EL0".
In both cases, if we want to make the access for Secure EL0
this is not the same mmu_idx as for Non-Secure EL0.
Backports commit 579d21cce63f3dd2f6ee49c0b02a14e92cb4a836 from qemu
We currently claim that for ARM the mmu_idx should simply be the current
exception level. However this isn't actually correct -- secure EL0 and EL1
should have separate indexes from non-secure EL0 and EL1 since their
VA->PA mappings may differ. We also will want an index for stage 2
translations when we properly support EL2.
Define and document all seven mmu index values that we require, and
pass the mmu index in the TB flags rather than exception level or
priv/user bit.
This change doesn't update the get_phys_addr() code, so our page
table walking still assumes a simplistic "user or priv?" model for
the moment.
Backports commit c1e3781090b9d36c60e1a254ba297cb34011d3d4 from qemu
While we're at it, emit the opcode adjacent to where we currently
record data for search_pc. This puts gen_io_start et al on the
"correct" side of the marker.
Backports commit 667b8e29c5b1d8c5b4e6ad5f780ca60914eb6e96 from qemu
Usually, eliminate an operation from the translator by combining
a shift with an extract.
In the case of gen_set_NZ64, we don't need a boolean value for cpu_ZF,
merely a non-zero value. Given that we can extract both halves of a
64-bit input in one call, this simplifies the code.
Backports commit 7cb36e18b2f1c1f971ebdc2121de22a8c2e94fd6 from qemu
For !SF, this initial ext32u can't be optimized away by the
current TCG code generator. (It would require backward bit
liveness propagation.)
Backports commit d3a77b42decd0cbfa62a5526e67d1d6d380c83a9 from qemu
This can allow much of a ccmp to be elided when particular
flags are subsequently dead.
Backports commit 7dd03d773e0dafae9271318fc8d6b2b14de74403 from qemu
This is improved type checking for the translators -- it's no longer
possible to accidentally swap arguments to the branch functions.
Note that the code generating backends still manipulate labels as int.
With notable exceptions, the scope of the change is just a few lines
for each target, so it's not worth building extra machinery to do this
change in per-target increments.
Backports commit 42a268c241183877192c376d03bd9b6d527407c7 from qemu
The method by which we count the number of ops emitted
is going to change. Abstract that away into some inlines.
Backports commit fe700adb3db5b028b504423b946d4ee5200a8f2f from qemu.
Thus, use cpu_env as the parameter, not TCG_AREG0 directly.
Update all uses in the translators.
Backports commit e1ccc05444676b92c63708096e36582be27fbee1 from qemu
* arm64eb: arm64 big endian also using little endian instructions.
* arm64: using another example that depends on endians.
example:
1. store a word: 0x12345678
2. load a byte:
* little endian : 0x78
* big endian : 0x12
