Commit graph

441 commits

Author SHA1 Message Date
Emilio G. Cota 170f6e0b3b
tb: consistently use uint32_t for tb->flags
We are inconsistent with the type of tb->flags: usage varies loosely
between int and uint64_t. Settle to uint32_t everywhere, which is
superior to both: at least one target (aarch64) uses the most significant
bit in the u32, and uint64_t is wasteful.

Compile-tested for all targets.

Backports commit 89fee74a0f066dfd73830a7b5fa137e87888c870 from qemu
2018-02-23 21:28:11 -05:00
Peter Maydell fe2000aa32
target-arm: Avoid unnecessary TLB flush on TCR_EL2, TCR_EL3 writes
The TCR_EL2 and TCR_EL3 regdefs were incorrectly using the
vmsa_tcr_el1_write function for writes. Since these registers don't
have the A1 bit that TCR_EL1 does, we don't need to do a tlb_flush()
when they are written. Remove the unnecessary .writefn and also the
harmless but unneeded .raw_writefn and .resetfn definitions.

Backports commit 6459b94c26dd666badb3547fef1456992a08e60b from qemu
2018-02-23 20:09:12 -05:00
Edgar E. Iglesias eb79db28d5
target-arm/translate-a64.c: Unify some of the ldst_reg decoding
The various load/store variants under disas_ldst_reg can all reuse the
same decoding for opc, size, rt and is_vector.

This patch unifies the decoding in preparation for generating
instruction syndromes for data aborts.
This will allow us to reduce the number of places to hook in updates
to the load/store state needed to generate the insn syndromes.

No functional change.

Backports commit cd694521ca061a5d0436d5df4ec8c17c8f4dfcdb from qemu
2018-02-23 20:06:31 -05:00
Edgar E. Iglesias 602e9e34b9
target-arm/translate-a64.c: Use extract32 in disas_ldst_reg_imm9
Use extract32 instead of open coding the bit masking when decoding
is_signed and is_extended. This streamlines the decoding with some
of the other ldst variants.

No functional change.

Backports commit 026a19c3128678d4fe301fc36e8ffacdc9ecccb8 from qemu
2018-02-23 20:04:11 -05:00
Peter Maydell 56e9d7c09e
target-arm: Split data abort syndrome generator
Split the data abort syndrome generator into two versions:
One with a valid Instruction Specific Syndrome (ISS) and another without.

The following new flags are supported by the syndrome generator
with ISS:
* isv - Instruction syndrome valid
* sas - Syndrome access size
* sse - Syndrome sign extend
* srt - Syndrome register transfer
* sf - Sixty-Four bit register width
* ar - Acquire/Release

These flags are not yet used, so this patch has no functional change
except that we will now correctly set the IL bit in data abort
syndromes without ISS information.

Backports commit 094d028a7968236cd2b7f7b96394f7a3b8ad97c8 from qemu
2018-02-23 20:03:04 -05:00
Sergey Sorokin 98a6d44c54
target-arm: Fix descriptor address masking in ARM address translation
There is a bug in ARM address translation regime with a long-descriptor
format. On the descriptor reading its address is formed from an index
which is a part of the input address. And on the first iteration this index
is incorrectly masked with 'grainsize' mask. But it can be wider according
to pseudo-code.
On the other hand on the iterations other than first the descriptor address
is formed from the previous level descriptor by masking with 'descaddrmask'
value. It always clears just 12 lower bits, but it must clear 'grainsize'
lower bits instead according to pseudo-code.
The patch fixes both cases.

Backports commit dddb5223413c5425ae6eaeb3b967627efc9675f7 from qemu
2018-02-23 19:56:56 -05:00
Sergey Sorokin 00e751f18e
target-arm: Stage 2 permission fault was fixed in AArch32 state
As described in AArch32.CheckS2Permission an instruction fetch fails if
XN bit is set or there is no read permission for the address.

Backports commit dfda68377e20943f474505e75238cb96bc6874bf from qemu
2018-02-23 19:55:11 -05:00
Lioncash 88af0b0153
target-arm: Get rid of unused variable warnings 2018-02-23 12:43:09 -05:00
Peter Maydell a632d1b96d
target-arm: Make the 64-bit version of VTCR do the migration
Move the ALIAS tag from VTCR_EL2 to VTCR so that we migrate the
64-bit version, as is usual. (This has no particular effect now
unless the guest wrote to the high RES0 bits of VTCR_EL2.)
Add a comment about why it's OK that we don't have the various
accessor functions that the EL1 TCR regdefs do.

Backports commit bf06c1123a427fefc2cf9cf8019578eafc19eb6f from qemu
2018-02-22 11:53:19 -05:00
Peter Maydell a93e873441
target-arm: Remove incorrect ALIAS tags from ESR_EL2 and ESR_EL3
The regdefs for the ESR_EL2 and ESR_EL3 system registers should not
be marked as ARM_CP_ALIAS, because these are the master copies; the
DFSR regdef in vmsa_pmsa_cp_reginfo[] is marked as an alias.
Remove the ALIAS tags so that these registers are correctly migrated.

Backports commit 094a7d0b9d10812d06be2c5c19288cee4603c693 from qemu
2018-02-22 11:40:20 -05:00
Peter Maydell f1b5b5cea9
target-arm: Correctly reset SCTLR_EL3 for 64-bit CPUs
The regdef for SCTRL_EL3 was incorrectly marked as being an
ARM_CP_ALIAS, with the remark that this was because the 32-bit
definition would take care of reset and migration. However the
intention for banked registers as documented in the comment in
add_cpreg_to_hashtable() is:

* 2) If ARMv8 is enabled then we can count on a 64-bit version
* taking care of the secure bank. This requires that separate
* 32 and 64-bit definitions are provided.

and so it marks the 32-bit secure banked version as an alias.
This results in the sctlr_s/sctlr_el[3] field never being reset
or migrated for a 64-bit CPU with EL3 enabled.

Fix this by removing the ARM_CP_ALIAS annotation from SCTLR_EL3.
Since this means it now needs a real reset value, move the regdef
into the same place that we define the 32-bit SCTLR.

Backports commit e24fdd238a159d830a9a65dd9b08f80fba9b9e06 from qemu
2018-02-22 11:38:16 -05:00
Rutuja Shah d9fdc180d7
Replaced get_tick_per_sec() by NANOSECONDS_PER_SECOND
This patch replaces get_ticks_per_sec() calls with the macro
NANOSECONDS_PER_SECOND. Also, as there are no callers, get_ticks_per_sec()
is then removed. This replacement improves the readability and
understandability of code.

For example,

timer_mod(fdctrl->result_timer,
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (get_ticks_per_sec() / 50));

NANOSECONDS_PER_SECOND makes it obvious that qemu_clock_get_ns
matches the unit of the expression on the right side of the plus.

Backports commit 73bcb24d932912f8e75e1d88da0fc0ac6d4bce78 from qemu
2018-02-21 23:21:36 -05:00
Markus Armbruster 06668850e3
include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef. Since then, we've moved to include qemu/osdep.h
everywhere. Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h. That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h. Include qapi/error.h in .c files that need it and don't
get it now. Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly. Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third. Unfortunately, the number depending on
qapi-types.h shrinks only a little. More work is needed for that one.

Backports commit da34e65cb4025728566d6504a99916f6e7e1dd6a from qemu
2018-02-21 23:08:18 -05:00
Sergey Sorokin da6a9f331b
target-arm: Fix translation level on early translation faults
Qemu reports translation fault on 1st level instead of 0th level in case of
AArch64 address translation if the translation table walk is disabled or
the address is in the gap between the two regions.

Backports commit 1b4093ea6678ff79d3006db3d3abbf6990b4a59b from qemu
2018-02-21 21:53:15 -05:00
Peter Maydell 8309945dcc
target-arm: Implement MRS (banked) and MSR (banked) instructions
Starting with the ARMv7 Virtualization Extensions, the A32 and T32
instruction sets provide instructions "MSR (banked)" and "MRS
(banked)" which can be used to access registers for a mode other
than the current one:
* R<m>_<mode>
* ELR_hyp
* SPSR_<mode>

Implement the missing instructions.

Backports commit 8bfd0550be821cf27d71444e2af350de3c3d2ee3 from qemu
2018-02-21 21:50:42 -05:00
Ralf-Philipp Weinmann 893b9f7f96
target-arm: Only trap SRS from S-EL1 if specified mode is MON
Commit cbc0326b6fb9 caused SRS instructions executed from Secure
EL1 to trap to EL3 even if the specified mode was not monitor mode.

According to the ARMv8 Architecture reference manual [F6.1.203], ALL
of the following conditions need to be met for SRS to trap to EL3:
* It is executed at Secure PL1.
* The specified mode is monitor mode.
* EL3 is using AArch64.

Correct the condition governing the trap to EL3 to check the
specified mode.

Backports commit ba63cf47a93041137a94e86b7d0cd87fc896949b from qemu
2018-02-21 02:49:28 -05:00
Paolo Bonzini 7f23f7004d
target-arm: implement BE32 mode in system emulation
System emulation only has a little-endian target; BE32 mode
is implemented by adjusting the low bits of the address
for every byte and halfword load and store. 64-bit accesses
flip the low and high words.

Backports commit e334bd3190f6c4ca12f1d40d316dc471c70009ab from qemu
2018-02-21 02:47:22 -05:00
Paolo Bonzini aa5be4d6ca
target-arm: implement setend
Since this is not a high-performance path, just use a helper to
flip the E bit and force a lookup in the hash table since the
flags have changed.

Backports commit 9886ecdf31165de2d4b8bccc1a220bd6ac8bc192 from qemu
2018-02-21 02:39:13 -05:00
Peter Crosthwaite 902170741a
target-arm: introduce tbflag for endianness
Introduce a tbflags for endianness, set based upon the CPUs current
endianness. This in turn propagates through to the disas endianness
flag.

Backports commit 91cca2cda9823b1e7a049cb308a05104b5076cba from qemu
2018-02-21 02:35:34 -05:00
Peter Crosthwaite 50a3c7f2ee
target-arm: a64: Add endianness support
Set the dc->mo_endianness flag for AA64 and use it in all ldst ops.

Backports commit aa6489da4e297fb3ffcbc09b50afd700395b6386 from qemu
2018-02-21 02:31:50 -05:00
Paolo Bonzini 9ab3d105fd
target-arm: introduce disas flag for endianness
Introduce a disas flag for setting the CPU data endianness. This allows
control of the endianness from the CPU state rather than hard-coding it
to TARGET_WORDS_BIGENDIAN.

Backports commit dacf0a2ff7d39ab12bd90f2f5496a3889facd54a from qemu
2018-02-21 02:20:50 -05:00
Peter Crosthwaite e5cfcc3221
target-arm: implement SCTLR.EE
Implement SCTLR.EE bit which controls data endianess for exceptions
and page table translations. SCTLR.EE is mirrored to the CPSR.E bit
on exception entry.

Backports commit 73462dddf670c32c45c8ea359658092b0365b2d4 from qemu
2018-02-21 02:14:56 -05:00
Peter Crosthwaite 38f4a833a4
arm: cpu: handle BE32 user-mode as BE
endian with address manipulations on subword accesses (to give the
illusion of BE). But user-mode cannot tell the difference and is
already implemented as straight BE. So handle the difference in the
endianess query, where USER mode is BE and system is not.

Backports commit b2e62d9a7b9a2eb10e451a57813bad168376e122 from qemu
2018-02-21 02:12:39 -05:00
Peter Crosthwaite 1457b73a13
target-arm: cpu: Move cpu_is_big_endian to header
There is a CPU data endianness test that is used to drive the
virtio_big_endian test.

Move this up to the header so it can be more generally used for endian
tests. The KVM specific cpu_syncronize_state call is left behind in the
virtio specific function.

Rename it arm_cpu-data_is_big_endian() to more accurately capture that
this is for data accesses only.

Backports commit ed50ff7875d61a75517c92deb0444d73fbbca878 from qemu
2018-02-21 02:10:48 -05:00
Paolo Bonzini ec15ee10d0
target-arm: implement SCTLR.B, drop bswap_code
bswap_code is a CPU property of sorts ("is the iside endianness the
opposite way round to TARGET_WORDS_BIGENDIAN?") but it is not the
actual CPU state involved here which is SCTLR.B (set for BE32
binaries, clear for BE8).

Replace bswap_code with SCTLR.B, and pass that to arm_ld*_code.
The next patches will make data fetches honor both SCTLR.B and
CPSR.E appropriately.

Backports commit f9fd40ebe4f55e0048e002925b8d65e66d56e7a7 from qemu
2018-02-21 02:08:05 -05:00
Peter Maydell 64a9bec68a
target-arm: Correct handling of writes to CPSR mode bits from gdb in usermode
In helper.c the expression
(env->uncached_cpsr & CPSR_M) != CPSR_USER
is always true; the right hand side was supposed to be ARM_CPU_MODE_USR
(an error in commit cb01d391).

Since the incorrect expression was always true, this just meant that
commit cb01d391 had no effect.

However simply changing the RHS here would reveal a logic error: if
the mode is USR we wish to completely ignore the attempt to set the
mode bits, which means that we must clear the CPSR_M bits from mask
to avoid the uncached_cpsr bits being updated at the end of the
function.

Move the condition into the correct place in the code, fix its RHS
constant, and add a comment about the fact that we must be doing a
gdbstub write if we're in user mode.

Backports commit 8c4f0eb94cc65ee32a12feba88d0b32e3665d5ea from qemu
2018-02-21 01:57:34 -05:00
Peter Maydell 20712bcb9a
target-arm: Make reserved ranges in ID_AA64* spaces RAZ, not UNDEF
The v8 ARM ARM defines that unused spaces in the ID_AA64* system
register ranges are Reserved and must RAZ, rather than being UNDEF.
Implement this.

In particular, ARM v8.2 adds a new feature register ID_AA64MMFR2,
and newer versions of the Linux kernel will attempt to read this,
which causes them not to boot up on versions of QEMU missing this fix.

Since the encoding .opc0 = 3, .opc1 = 0, .crn = 0, .crm = 2, .opc2 = 6
is actually defined in ARMv8 (as ID_MMFR4), we give it an entry in
the ARMCPU struct so CPUs can override it, though since none do
this too will just RAZ.

Backports commit e20d84c1407d43d5a2e2ac95dbb46db3b0af8f9f from qemu
2018-02-20 22:49:43 -05:00
Edgar E. Iglesias 66c4bd02eb
target-arm: Mark CNTHP_TVAL_EL2 as ARM_CP_NO_RAW
Mark CNTHP_TVAL_EL2 as ARM_CP_NO_RAW due to the register not
having any underlying state. This fixes an issue with booting
KVM enabled kernels when EL2 is on.

Backports commit d44ec156300a149b386a14d3ab349d3b83b66b8c from qemu
2018-02-20 22:30:44 -05:00
Peter Maydell eb02f0e818
target-arm: Implement MDCR_EL3.TPM and MDCR_EL2.TPM traps
Implement the performance monitor register traps controlled
by MDCR_EL3.TPM and MDCR_EL2.TPM. Most of the performance
registers already have an access function to deal with the
user-enable bit, and the TPM checks can be added there. We
also need a new access function which only implements the
TPM checks for use by the few not-EL0-accessible registers
and by PMUSERENR_EL0 (which is always EL0-readable).

Backports commit 1fce1ba985d9c5c96e5b9709e1356d1814b8fa9e from qemu
2018-02-20 22:29:26 -05:00
Peter Maydell ece364e7cc
target-arm: Fix handling of SDCR for 32-bit code
Fix two issues with our implementation of the SDCR:
* it is only present from ARMv8 onwards
* it does not contain several of the trap bits present in its 64-bit
counterpart the MDCR_EL3

Put the register description in the right place so that it does not
get enabled for ARMv7 and earlier, and give it a write function so that
we can mask out the bits which should not be allowed to have an effect
if EL3 is 32-bit.

Backports commit a8d64e735182cbbb5dcc98f41656b118c45e57cc from qemu
2018-02-20 22:26:58 -05:00
Peter Maydell 8477ed6389
target-arm: Make Monitor->NS PL1 mode changes illegal if HCR.TGE is 1
If HCR.TGE is 1 then mode changes via CPS and MSR from Monitor to
NonSecure PL1 modes are illegal mode changes. Implement this check
in bad_mode_switch().

(We don't currently implement HCR.TGE, but this is the only missing
check from the v8 ARM ARM G1.9.3 and so it's worth adding now; the
rest of the HCR.TGE checks can be added later as necessary.)

Backports commit 10eacda787ac9990dc22d4437b289200c819712c from qemu
2018-02-20 22:24:19 -05:00
Peter Maydell 8bfdc63424
target-arm: Make mode switches from Hyp via CPS and MRS illegal
Mode switches from Hyp to any other mode via the CPS and MRS
instructions are illegal mode switches (though obviously switching
via exception return is valid). Add this check to bad_mode_switch().

Backports commit af393ffc6da116b9dd4c70901bad1f4cafb1773d from qemu
2018-02-20 22:23:23 -05:00
Peter Maydell 00d06bf20e
target-arm: In v8, make illegal AArch32 mode changes set PSTATE.IL
In v8, the illegal mode changes which are UNPREDICTABLE in v7 are
given architected behaviour:
* the mode field is unchanged
* PSTATE.IL is set (so any subsequent instructions will UNDEF)
* any other CPSR fields are written to as normal

This is pretty much the same behaviour we picked for our
UNPREDICTABLE handling, with the exception that for v8 we
need to set the IL bit.

Backports commit 81907a582901671c15be36a63b5063f88f3487e2 from qemu
2018-02-20 22:22:01 -05:00
Peter Maydell 2296fb5915
target-arm: Forbid mode switch to Mon from Secure EL1
In v8 trying to switch mode to Mon from Secure EL1 is an
illegal mode switch. (In v7 this is impossible as all secure
modes except User are at EL3.) We can handle this case by
making a switch to Mon valid only if the current EL is 3,
which then gives the correct answer whether EL3 is AArch32
or AArch64.

Backports commit 58ae2d1f037fae1d90eed4522053a85d79edfbec from qemu
2018-02-20 22:21:10 -05:00
Peter Maydell 4919c7287c
target-arm: Add Hyp mode checks to bad_mode_switch()
We don't actually support Hyp mode yet, but add the correct
checks for it to the bad_mode_switch() function for completeness.

Backports commit e6c8fc07b4fce0729bb747770756835f4b0ca7f4 from qemu
2018-02-20 22:20:19 -05:00
Peter Maydell 339e3e340e
target-arm: Add comment about not implementing NSACR.RFR
QEMU doesn't implement the NSACR.RFR bit, which is a permitted
IMPDEF in choice in ARMv7 and the only permitted choice in ARMv8.
Add a comment to bad_mode_switch() to note that this is why
FIQ is always a valid mode regardless of the CPU's Secure state.

Backports commit 52ff951b4f63a29593650a15efdf82f63d6d962d from qemu
2018-02-20 22:19:38 -05:00
Peter Maydell a468baff61
target-arm: In cpsr_write() ignore mode switches from User mode
The only case where we can attempt a cpsr_write() mode switch from
User is from the gdbstub; all other cases are handled in the
calling code (notably translate.c). Architecturally attempts to
alter the mode bits from user mode are simply ignored (and not
treated as a bad mode switch, which in v8 sets CPSR.IL). Make
mode switches from User ignored in cpsr_write() as well, for
consistency.

Backports commit cb01d3912c8b000ed26d5fe95f6c194b3e3ba7a6 from qemu
2018-02-20 22:18:48 -05:00
Peter Maydell 553e230088
target-arm: Raw CPSR writes should skip checks and bank switching
Raw CPSR writes should skip the architectural checks for whether
we're allowed to set the A or F bits and should also not do
the switching of register banks if the mode changes. Handle
this inside cpsr_write(), which allows us to drop the "manually
set the mode bits to avoid the bank switch" code from all the
callsites which are using CPSRWriteRaw.

This fixes a bug in 32-bit KVM handling where we had forgotten
the "manually set the mode bits" part and could thus potentially
trash the register state if the mode from the last exit to userspace
differed from the mode on this exit.

Backports commit f8c88bbcda76d5674e4bb125471371b41d330df8 from qemu
2018-02-20 22:17:48 -05:00
Peter Maydell 611d4dad4b
target-arm: Add write_type argument to cpsr_write()
Add an argument to cpsr_write() to indicate what kind of CPSR
write is being requested, since the exact behaviour should
differ for the different cases.

Backports commit 50866ba5a2cfe922aaf3edb79f6eac5b0653477a from qemu
2018-02-20 22:15:53 -05:00
Peter Maydell 6ae2357be6
target-arm: Give CPSR setting on 32-bit exception return its own helper
The rules for setting the CPSR on a 32-bit exception return are
subtly different from those for setting the CPSR via an instruction
like MSR or CPS. (In particular, in Hyp mode changing the mode bits
is not valid via MSR or CPS.) Split the exception-return case into
its own helper for setting CPSR, so we can eventually handle them
differently in the helper function.

Backports commit 235ea1f5c89abf30e452539b973b0dbe43d3fe2b from qemu
2018-02-20 22:08:35 -05:00
Alistair Francis a8807cd3b9
target-arm: Add PMUSERENR_EL0 register
The Linux kernel accesses this register early in its setup.

Backports commit 8a83ffc2dafad3499b87a736b17ab1b203fdb00b from qemu
2018-02-20 15:36:31 -05:00
Lioncash b29e024f56
target-arm: Correct bad VBAR patch merge 2018-02-20 15:34:32 -05:00
Alistair Francis 2945893f40
target-arm: Add the pmovsclr_el0 and pmintenclr_el1 registers
Backports commit 978364f12adebb4b8d90fdeb71242cb3c1405740 from qemu
2018-02-20 15:27:50 -05:00
Alistair Francis c31856e34e
target-arm: Add the pmceid0 and pmceid1 registers
Backports commit 4054bfa9e7986c9b7d2bf70f9e10af9647e376fc from qemu
2018-02-20 15:22:41 -05:00
Peter Maydell 57a9474cc7
target-arm: UNDEF in the UNPREDICTABLE SRS-from-System case
Make get_r13_banked() raise an exception at runtime for the
corner case of SRS from System mode, so that we can UNDEF it;
this brings us in to line with the ARM ARM's set of permitted
CONSTRAINED UNPREDICTABLE choices.

Backports commit f01377f591fe15c652f947646c4a69a7d4a71ad9 from qemu
2018-02-20 15:12:25 -05:00
Peter Maydell 88d21504e4
target-arm: Combine user-only and softmmu get/set_r13_banked()
The user-mode versions of get/set_r13_banked() exist just to assert
if they're ever called -- the translate time code should never
emit calls to them because SRS from user mode always UNDEF.
There's no code in the softmmu versions that can't compile in
CONFIG_USER_ONLY, and the assertion is not particularly useful,
so combine the two functions rather than having completely split
versions under ifdefs.

Backports commit d86d57d4fe683c99823f625f941eff26c07c72c3 from qemu
2018-02-20 15:09:58 -05:00
Peter Maydell 3d4f8b2d8f
target-arm: Move get/set_r13_banked() to op_helper.c
Move get/set_r13_banked() from helper.c to op_helper.c. This will
let us add exception-raising code to them, and also puts them
in the same file as get/set_user_reg(), which makes some conceptual
sense.

(The original reason for the helper.c/op_helper.c split was that
only op_helper.c had access to the CPU env pointer; this distinction
has not been true for a long time, though, and so the split is
now rather arbitrary.)

Backports commit 72309cee482868d6c4711931c3f7e02ab9dec229 from qemu

target-arm: Move bank_number() into internals.h

Move bank_number()'s implementation into internals.h, so
it's available in the user-mode-only compile as well.

Backports commit c766568d3604082c6fd45cbabe42c48e4861a13f from qemu
2018-02-20 15:09:07 -05:00
Peter Maydell a6aac0dbb4
target-arm: Clean up trap/undef handling of SRS
The SRS instruction is:
* UNDEFINED in Hyp mode
* UNPREDICTABLE in User or System mode
* UNPREDICTABLE if the specified mode isn't accessible
* trapped to EL3 if EL3 is AArch64 and we are at Secure EL1

Clean up the code to handle all these cases cleanly, including
picking UNDEF as our choice of UNPREDICTABLE behaviour rather
blindly trusting the mode field passed in the instruction.
As part of this, move the check for IS_USER into gen_srs()
itself rather than having it done by the caller.

The exception is that we don't UNDEF for calls from System
mode, which need a runtime check. This will be dealt with in
the following commits.

Backports commit cbc0326b6fb905f80b7cef85b24571f7ebb62077 from qemu
2018-02-20 15:02:45 -05:00
Peter Maydell 56a88557db
target-arm: Report correct syndrome for FPEXC32_EL2 traps
If access to FPEXC32_EL2 is trapped by CPTR_EL2.TFP or CPTR_EL3.TFP,
this should be reported with a syndrome register indicating an
FP access trap, not one indicating a system register access trap.

Backports commit f2cae6092767aaf418778eada15be444c23883be from qemu
2018-02-20 15:00:32 -05:00
Peter Maydell 425db8c149
target-arm: Implement MDCR_EL3.TDA and MDCR_EL2.TDA traps
Implement the debug register traps controlled by MDCR_EL2.TDA
and MDCR_EL3.TDA.

Backports commit d6c8cf815171e35e0b1ef4e0cff602ab3d575747 from qemu
2018-02-20 14:58:52 -05:00