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
More gracefully handle cpregs when EL2 and/or EL3 are missing.
If the reg is entirely inaccessible, do not register it at all.
If the reg is for EL2, and EL3 is present but EL2 is not,
either discard, squash to res0, const, or keep unchanged.
Per rule RJFFP, mark the 4 aarch32 hypervisor access registers
with ARM_CP_EL3_NO_EL2_KEEP, and mark all of the EL2 address
translation and tlb invalidation "regs" ARM_CP_EL3_NO_EL2_UNDEF.
Mark the 2 virtualization processor id regs ARM_CP_EL3_NO_EL2_C_NZ.
This will simplify cpreg registration for conditional arm features.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Give this enum a name and use in ARMCPRegInfo and add_cpreg_to_hashtable.
Add the enumerator ARM_CP_SECSTATE_BOTH to clarify how 0
is handled in define_one_arm_cp_reg_with_opaque.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220501055028.646596-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Give this enum a name and use in ARMCPRegInfo,
add_cpreg_to_hashtable and define_one_arm_cp_reg_with_opaque.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220501055028.646596-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Create a typedef as well, and use it in ARMCPRegInfo.
This won't be perfect for debugging, but it'll nicely
display the most common cases.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220501055028.646596-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Instead of defining ARM_CP_FLAG_MASK to remove flags,
define ARM_CP_SPECIAL_MASK to isolate special cases.
Sort the specials to the low bits. Use an enum.
Split the large comment block so as to document each
value separately.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20220501055028.646596-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove a possible source of error by removing REGINFO_SENTINEL
and using ARRAY_SIZE (convinently hidden inside a macro) to
find the end of the set of regs being registered or modified.
The space saved by not having the extra array element reduces
the executable's .data.rel.ro section by about 9k.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220501055028.646596-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Rearrange the values of the enumerators of CPAccessResult
so that we may directly extract the target el. For the two
special cases in access_check_cp_reg, use CPAccessResult.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220501055028.646596-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move ARMCPRegInfo and all related declarations to a new
internal header, out of the public cpu.h.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220501055028.646596-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
