A lot of the code called from helper_exception_bkpt_insn() is written
assuming A-profile, but we will also call this helper on M-profile
CPUs when they execute a BKPT insn. This used to work by accident,
but recent changes mean that we will hit an assert when some of this
code calls down into lower level functions that end up calling
arm_security_space_below_el3(), arm_el_is_aa64(), and other functions
that now explicitly assert that the guest CPU is not M-profile.
Handle M-profile directly to avoid the assertions:
* in arm_debug_target_el(), M-profile debug exceptions always
go to EL1
* in arm_debug_exception_fsr(), M-profile always uses the short
format FSR (compare commit d7fe699be5, though in this case
the code in arm_v7m_cpu_do_interrupt() does not need to
look at the FSR value at all)
Cc: qemu-stable@nongnu.org
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1775
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230721143239.1753066-1-peter.maydell@linaro.org
Accessing EL0-accessible Debug Communication Channel (DCC) registers in
user mode emulation is currently enabled. However, it does not match
Linux behavior as Linux sets MDSCR_EL1.TDCC on startup to disable EL0
access to DCC (see __cpu_setup() in arch/arm64/mm/proc.S).
This patch fixes access_tdcc() to check MDSCR_EL1.TDCC for EL0 and sets
MDSCR_EL1.TDCC for user mode emulation to match Linux.
Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: DS7PR12MB630905198DD8E69F6817544CAC4EA@DS7PR12MB6309.namprd12.prod.outlook.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The commit b3aa2f2128 (target/arm: provide stubs for more external
debug registers) was added to handle HyperV's unconditional usage of
Debug Communications Channel. It turns out that Linux will similarly
break if you enable CONFIG_HVC_DCC "ARM JTAG DCC console".
Extend the registers we RAZ/WI set to avoid this.
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Evgeny Iakovlev <eiakovlev@linux.microsoft.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230516104420.407912-1-alex.bennee@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The next few patches will move helpers under CONFIG_TCG. We'd prefer
to keep the debug helpers and debug registers close together, so
rearrange the file a bit to be able to wrap the helpers with a TCG
ifdef.
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This is in preparation for restricting compilation of some parts of
debug_helper.c to TCG only.
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
FEAT_FGT also implements an extra trap bit in the MDCR_EL2 and
MDCR_EL3 registers: bit TDCC enables trapping of use of the Debug
Comms Channel registers OSDTRRX_EL1, OSDTRTX_EL1, MDCCSR_EL0,
MDCCINT_EL0, DBGDTR_EL0, DBGDTRRX_EL0 and DBGDTRTX_EL0 (and their
AArch32 equivalents). This trapping is independent of whether
fine-grained traps are enabled or not.
Implement these extra traps. (We don't implement DBGDTR_EL0,
DBGDTRRX_EL0 and DBGDTRTX_EL0.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-23-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-23-peter.maydell@linaro.org
Mark up the sysreg definitons for the registers trapped
by HDFGRTR/HDFGWTR bits 0..11. These cover various debug
related registers.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Fuad Tabba <tabba@google.com>
Message-id: 20230130182459.3309057-15-peter.maydell@linaro.org
Message-id: 20230127175507.2895013-15-peter.maydell@linaro.org
Qemu doesn't implement Debug Communication Channel, as well as the rest
of external debug interface. However, Microsoft Hyper-V in tries to
access some of those registers during an EL2 context switch.
Since there is no architectural way to not advertise support for external
debug, provide RAZ/WI stubs for OSDTRRX_EL1, OSDTRTX_EL1 and OSECCR_EL1
registers in the same way the rest of DCM is currently done. Do account
for access traps though with access_tda.
Signed-off-by: Evgeny Iakovlev <eiakovlev@linux.microsoft.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230120155929.32384-3-eiakovlev@linux.microsoft.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The architecture does not define any functionality for the CLAIM tag bits.
So we will just keep the raw bits, as per spec.
Signed-off-by: Evgeny Iakovlev <eiakovlev@linux.microsoft.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230120155929.32384-2-eiakovlev@linux.microsoft.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
ARMv8-R AArch32 CPUs behave as if TTBCR.EAE is always 1 even
tough they don't have the TTBCR register.
See ARM Architecture Reference Manual Supplement - ARMv8, for the ARMv8-R
AArch32 architecture profile Version:A.c section C1.2.
Signed-off-by: Tobias Röhmel <tobias.roehmel@rwth-aachen.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20221206102504.165775-5-tobias.roehmel@rwth-aachen.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Change the representation of the TCR_EL* registers in the CPU state
struct from struct TCR to uint64_t. This allows us to drop the
custom vmsa_ttbcr_raw_write() function, moving the "enforce RES0"
checks to their more usual location in the writefn
vmsa_ttbcr_write(). We also don't need the resetfn any more.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220714132303.1287193-7-peter.maydell@linaro.org
The architecture defines the OS DoubleLock as a register which
(similarly to the OS Lock) suppresses debug events for use in CPU
powerdown sequences. This functionality is required in Arm v7 and
v8.0; from v8.2 it becomes optional and in v9 it must not be
implemented.
Currently in QEMU we implement the OSDLR_EL1 register as a NOP. This
is wrong both for the "feature implemented" and the "feature not
implemented" cases: if the feature is implemented then the DLK bit
should read as written and cause suppression of debug exceptions, and
if it is not implemented then the bit must be RAZ/WI.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Starting with v7 of the debug architecture, there are three extra
ID registers that add information on top of that provided in
DBGDIDR. These are DBGDEVID, DBGDEVID1 and DBGDEVID2. In the
v7 debug architecture, DBGDEVID is optional, present only of
DBGDIDR.DEVID_imp is set. In v7.1 all three must be present.
Implement the missing registers. Note that we only need to set the
values in the ARMISARegisters struct for the CPUs Cortex-A7, A15,
A53, A57 and A72 (plus the 32-bit 'max' which uses the Cortex-A53
values): earlier CPUs didn't implement v7 of the architecture, and
our other 64-bit CPUs (Cortex-A76, Neoverse-N1 and A64fx) don't have
AArch32 support at EL1.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220630194116.3438513-5-peter.maydell@linaro.org
The "OS Lock" in the Arm debug architecture is a way for software
to suppress debug exceptions while it is trying to power down
a CPU and save the state of the breakpoint and watchpoint
registers. In QEMU we implemented the support for writing
the OS Lock bit via OSLAR_EL1 and reading it via OSLSR_EL1,
but didn't implement the actual behaviour.
The required behaviour with the OS Lock set is:
* debug exceptions (apart from BKPT insns) are suppressed
* some MDSCR_EL1 bits allow write access to the corresponding
EDSCR external debug status register that they shadow
(we can ignore this because we don't implement external debug)
* similarly with the OSECCR_EL1 which shadows the EDECCR
(but we don't implement OSECCR_EL1 anyway)
Implement the missing behaviour of suppressing debug
exceptions.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220630194116.3438513-4-peter.maydell@linaro.org
The target/arm/helper.c file is very long and is a grabbag of all
kinds of functionality. We have already a debug_helper.c which has
code for implementing architectural debug. Move the code which
defines the debug-related system registers out to this file also.
This affects the define_debug_regs() function and the various
functions and arrays which are used only by it.
The functions raw_write() and arm_mdcr_el2_eff() and
define_debug_regs() now need to be global rather than local to
helper.c; everything else is pure code movement.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220630194116.3438513-3-peter.maydell@linaro.org
This function is no longer used outside debug_helper.c.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-23-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Handle the debug vs current el exception test in one place.
Leave EXCP_BKPT alone, since that treats debug < current differently.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-22-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move the computation from gen_swstep_exception into a helper.
This fixes a bug when:
- MDSCR_EL1.KDE == 1 to enable debug exceptions within EL_D itself
- we singlestep an ERET from EL_D to some lower EL
Previously we were computing 'same el' based on the EL which
executed the ERET instruction, whereas it ought to be computed
based on the EL to which ERET returned. This happens naturally
with the new helper, which runs after EL has been changed.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This function now now only used in debug_helper.c, so there is
no reason to have a declaration in a header.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-8-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Use the accessor rather than the raw structure member.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move arm_generate_debug_exceptions and its two subroutines,
{aa32,aa64}_generate_debug_exceptions into debug_helper.c,
and the one interface declaration to internals.h.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-6-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Move the function to debug_helper.c, and the
declaration to internals.h.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220609202901.1177572-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
While defining these names, use the correct field width of 5 not 4 for
DBGWCR.MASK. This typo prevented setting a watchpoint larger than 32k.
Reported-by: Chris Howard <cvz185@web.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20220427051926.295223-1-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Both single-step and pc alignment faults have priority over
breakpoint exceptions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The hook is now unused, with breakpoints checked outside translation.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reuse the code at the bottom of helper_check_breakpoints,
which is what we currently call from *_tr_breakpoint_check.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The AArch32 DBGDIDR defines properties like the number of
breakpoints, watchpoints and context-matching comparators. On an
AArch64 CPU, the register may not even exist if AArch32 is not
supported at EL1.
Currently we hard-code use of DBGDIDR to identify the number of
breakpoints etc; this works for all our TCG CPUs, but will break if
we ever add an AArch64-only CPU. We also have an assert() that the
AArch32 and AArch64 registers match, which currently works only by
luck for KVM because we don't populate either of these ID registers
from the KVM vCPU and so they are both zero.
Clean this up so we have functions for finding the number
of breakpoints, watchpoints and context comparators which look
in the appropriate ID register.
This allows us to drop the "check that AArch64 and AArch32 agree
on the number of breakpoints etc" asserts:
* we no longer look at the AArch32 versions unless that's the
right place to be looking
* it's valid to have a CPU (eg AArch64-only) where they don't match
* we shouldn't have been asserting the validity of ID registers
in a codepath used with KVM anyway
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200214175116.9164-11-peter.maydell@linaro.org
Not all of the breakpoint types are supported, but those that
only examine contextidr are extended to support the new register.
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200206105448.4726-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
These routines are TCG specific.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190701194942.10092-2-philmd@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
