The ARMv8 address translation system defines that a page table walk
starts at a level which depends on the translation granule size
and the number of bits of virtual address that need to be resolved.
Where the translation granule is 64KB and the guest sets the
TCR.TxSZ field to between 35 and 39, it's actually possible to
start at level 3 (the final level). QEMU's implementation failed
to handle this case, and so we would set level to 2 and behave
incorrectly (including invoking the C undefined behaviour of
shifting left by a negative number). Correct the code that
determines the starting level to deal with the start-at-3 case,
by replacing the if-else ladder with an expression derived from
the ARM ARM pseudocode version.
This error was detected by the Coverity scan, which spotted
the potential shift by a negative number.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1415890569-7454-1-git-send-email-peter.maydell@linaro.org
The M profile cpu_exec_interrupt handling is fairly simple
but does include an M profile specific oddity (disabling
interrupts for certain PC values). A/R profile handling
on the other hand is getting rapidly more complicated
with the support for EL2 and EL3. Split the M profile
code out into its own implementation of cpu_exec_interrupt
to keep these two things out of each others' way.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1414684132-23971-2-git-send-email-peter.maydell@linaro.org
Passing the CPUARMState around in the decoder is a recipe for
bugs where we accidentally generate code that depends on CPU
state which isn't reflected in the TB flags. Stop doing this
and instead use DisasContext as a way to pass around those
bits of CPU state which are known to be safe to use.
This commit simply removes initial "CPUARMState *env" parameters
from various function definitions, and removes the initial "env"
argument from the places where those functions are called.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1414524244-20316-5-git-send-email-peter.maydell@linaro.org
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
The DZP bit in the DCZID system register should be set if
the control bits which prohibit use of the DC ZVA instruction
have been set (it stands for Data Zero Prohibited). However
we had the sense of the test inverted; fix this so that the
bit reads correctly.
To avoid this regressing the behaviour of the user-mode
emulator, we must set the DZE bit in the SCTLR for that
config so that userspace continues to see DZP as zero (it
was getting the correct result by accident previously).
Reported-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Message-id: 1412959792-20708-1-git-send-email-peter.maydell@linaro.org
Add support for handling PSCI calls in system emulation. Both version
0.1 and 0.2 of the PSCI spec are supported. Platforms can enable support
by setting the "psci-conduit" QOM property on the cpus to SMC or HVC
emulation and having a PSCI binding in their dtb.
Signed-off-by: Rob Herring <rob.herring@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1412865028-17725-7-git-send-email-peter.maydell@linaro.org
[PMM: made system reset/off PSCI functions power down the CPU so
we obey the PSCI API requirement never to return from them;
rearranged how the code is plumbed into the exception system,
so that we split "is this a valid call?" from "do the call"]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add support for HVC and SMC instructions to the A32 and
T32 decoder. Using these for real exceptions to EL2 or EL3
is currently not supported (the do_interrupt routine does
not handle them) but we require the instruction support to
implement PSCI.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1412865028-17725-6-git-send-email-peter.maydell@linaro.org
SMC must UNDEF if EL3 is not implemented; similarly HVC UNDEFs
if EL2 is not implemented. Move the handling of this from
translate-a64.c into the pre_smc and pre_hvc helper functions.
This is necessary because use of these instructions for PSCI
takes precedence over this UNDEF case, and we can't tell if
this is a PSCI call until runtime.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1412865028-17725-5-git-send-email-peter.maydell@linaro.org
GDB assumes that watchpoint set via the gdbstub remote protocol will
behave in the same way as hardware watchpoints for the target. In
particular, whether the CPU stops with the PC before or after the insn
which triggers the watchpoint is target dependent. Allow guest CPU
code to specify which behaviour to use. This fixes a bug where with
guest CPUs which stop before the accessing insn GDB would manually
step forward over what it thought was the insn and end up one insn
further forward than it should be.
We set this flag for the CPU architectures which set
gdbarch_have_nonsteppable_watchpoint in gdb 7.7:
ARM, CRIS, LM32, MIPS and Xtensa.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Michael Walle <michael@walle.cc> (for lm32)
Message-id: 1410545057-14014-1-git-send-email-peter.maydell@linaro.org
At the moment we try to handle c15_cpar with the strategy of:
* emit generated code which makes assumptions about its value
* when the register value changes call tb_flush() to throw
away the now-invalid generated code
This works because XScale CPUs are always uniprocessor, but
it's confusing because it suggests that the same approach can
be taken for other registers. It also means we do a tb_flush()
on CPU reset, which makes multithreaded linux-user binaries
even more likely to fail than would otherwise be the case.
Replace it with a combination of TB flags for the access
checks done on cp0/cp1 for the XScale and iwMMXt instructions,
plus a runtime check for cp2..cp13 coprocessor accesses.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1411056959-23070-1-git-send-email-peter.maydell@linaro.org
Implement handling of breakpoint event firing to correctly
inject the debug exception into the guest.
Since the breakpoint and watchpoint control register format is
very similar we adjust wp_matches() to also handle breakpoints
as well rather than using a separate function.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1410523465-13400-3-git-send-email-peter.maydell@linaro.org
This patch adds support for setting guest breakpoints
based on values the guest writes to the DBGBVR and DBGBCR
registers. (It doesn't include the code to handle when
these breakpoints fire, so has no guest-visible effect.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1410523465-13400-2-git-send-email-peter.maydell@linaro.org
The ARM architecture defines that the "IS" variants of TLB
maintenance operations must affect all TLBs in the Inner Shareable
domain, which for us means all CPUs. We were incorrectly implementing
these to only affect the current CPU, which meant that SMP TCG
operation was unstable.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1410274883-9578-3-git-send-email-peter.maydell@linaro.org
Cc: qemu-stable@nongnu.org
When we implemented ARMv8 in QEMU we retained our legacy loose
wildcarded decoding of the TLB maintenance operations for v7
and earlier CPUs and provided the correct stricter decode for
v8. However the loose decode is in fact wrong for v7MP, because
it doesn't correctly implement the operations which must apply
to every CPU in the Inner Shareable domain.
Move the legacy wildcarding from the not_v8 reginfo array
into the not_v7 array, and move the strictly decoded operations
from the v8 reginfo to v7 or v7mp arrays as appropriate.
Cache and TLB lockdown legacy wildcarding remains in the
not_v8 array for the moment.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1410274883-9578-2-git-send-email-peter.maydell@linaro.org
Cc: qemu-stable@nongnu.org
Implement debug registers DBGVCR, OSDLR_EL1 and MDCCSR_EL0
(as dummy or limited-functionality). 32 bit Linux kernels will
access these at startup so they are required for breakpoints
and watchpoints to be supported.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
MDSCR_EL1 has actual functionality now; remove the out of date
comment that claims it is a dummy implementation.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
For debug exceptions taken to AArch32 we have to set the
DBGDSCR.MOE (Method Of Entry) bits; we can identify the
kind of debug exception from the information in
exception.syndrome.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move the utility function extended_addresses_enabled() into
internals.h; we're going to need to call it from op_helper.c.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Implement support for setting QEMU watchpoints based on the
values the guest writes to the ARM architected watchpoint
registers. (We do not yet report the firing of the watchpoints
to the guest, so they will just be ignored.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
