Improve the segment definitions used by get_physical_address() to yield
target_ulong types, e.g. 0xffffffff80000000 instead of 0x80000000. This
is in preparation for enabling emulation of MIPS KVM T&E segments in TCG
MIPS targets, which unlike KVM could potentially have 64-bit
target_ulong. In such a case the offset guest KSEG0 address ends up at
e.g. 0x000000008xxxxxxx instead of 0xffffffff8xxxxxxx.
This also allows the casts to int32_t that force sign extension to be
removed, which removes any confusion due to relational comparison of
unsigned (target_ulong) and signed (int32_t) types.
Backports commit 6743334568933199927af4992a04bfb3c30610f5 from qemu
Writing to the MIPS DESAVE register (and now the KScratch registers)
will stop translation, supposedly due to risk of execution mode
switches. However these registers are basically RW scratch registers
with no side effects so there is no risk of them triggering execution
mode changes.
Drop the bstate = BS_STOP for these registers for both mtc0 and dmtc0.
Backports commit cb539fd241900f51de7d21244f7a55422ad0d40a from qemu
When the PMSAv7 implementation was originally added it was for R profile
CPUs only, and reset was handled using the cpreg .resetfn hooks.
Unfortunately for M profile cores this doesn't work, because they do
not register any cpregs. Move the reset handling into arm_cpu_reset(),
where it will work for both R profile and M profile cores.
Backports commit 69ceea64bf565559a2b865ffb2a097d2caab805b from qemu
Almost all of the PMSAv7 state is in the pmsav7 substruct of
the ARM CPU state structure. The exception is the region
number register, which is in cp15.c6_rgnr. This exception
is a bit odd for M profile, which otherwise generally does
not store state in the cp15 substruct.
Rename cp15.c6_rgnr to pmsav7.rnr accordingly.
Backports commit 8531eb4f614a60e6582d4832b15eee09f7d27874 from qemu
For an M profile v7PMSA, the system space (0xe0000000 - 0xffffffff) can
never be executable, even if the guest tries to set the MPU registers
up that way. Enforce this restriction.
Backports commit bf446a11dfb17ae7d8ed2b61a2444804eb458075 from qemu
The M profile PMSAv7 specification says that if the address being looked
up is in the PPB region (0xe0000000 - 0xe00fffff) then we do not use
the MPU regions but always use the default memory map. Implement this
(we were previously behaving like an R profile PMSAv7, which does not
special case this).
Backports commit 38aaa60ca464b48e6feef346709e97335d01b289 from qemu
Correct off-by-one bug in the PSMAv7 MPU tracing where it would print
a write access as "reading", an insn fetch as "writing", and a read
access as "execute".
Since we have an MMUAccessType enum now, we can make the code clearer
in the process by using that rather than the raw 0/1/2 values.
Backports commit 709e4407add7acacc593cb6cdac026558c9a8fb6 from qemu
Enable the CP0_EBase.WG (write gate) on the I6400 and MIPS64R2-generic
CPUs. This allows 64-bit guests to run KVM itself, which uses
CP0_EBase.WG to point CP0_EBase at XKPhys.
Backports commit bad63a8008a0aaefcd00542c89bee01623d7c9de from qemu
Add the Enhanced Virtual Addressing (EVA) feature to the P5600 core
configuration, along with the related Segmentation Control (SC) feature
and writable CP0_EBase.WG bit.
This allows it to run Malta EVA kernels.
Backports commit 574da58e4678b3c09048f268821295422d8cde6d from qemu
Implement the optional segmentation control feature in the virtual to
physical address translation code.
The fixed legacy segment and xkphys handling is replaced with a dynamic
layout based on the segmentation control registers (which should be set
up even when the feature is not exposed to the guest).
Backports commit 480e79aedd322fcfac17052caff21626ea7c78e2 from qemu
The optional segmentation control registers CP0_SegCtl0, CP0_SegCtl1 &
CP0_SegCtl2 control the behaviour and required privilege of the legacy
virtual memory segments.
Add them to the CP0 interface so they can be read and written when
CP0_Config3.SC=1, and initialise them to describe the standard legacy
layout so they can be used in future patches regardless of whether they
are exposed to the guest.
Backports commit cec56a733dd2c3fa81dbedbecf03922258747f7d from qemu
The segmentation control feature allows a legacy memory segment to
become unmapped uncached at error level (according to CP0_Status.ERL),
and in fact the user segment is already treated in this way by QEMU.
Add a new MMU mode for this state so that QEMU's mappings don't persist
between ERL=0 and ERL=1.
Backports commit 42c86612d507c2a8789f2b8d920a244693c4ef7b from qemu
The MIPS mmu_idx is sometimes calculated from hflags without an env
pointer available as cpu_mmu_index() requires.
Create a common hflags_mmu_index() for the purpose of this calculation
which can operate on any hflags, not just with an env pointer, and
update cpu_mmu_index() itself and gen_intermediate_code() to use it.
Also update debug_post_eret() and helper_mtc0_status() to log the MMU
mode with the status change (SM, UM, or nothing for kernel mode) based
on cpu_mmu_index() rather than directly testing hflags.
This will also allow the logic to be more easily updated when a new MMU
mode is added.
Backports commit b0fc6003224543d2bdb172eca752656a6223e4a1 from qemu
When performing virtual to physical address translation, check the
required privilege level based on the mem_idx rather than the mode in
the hflags. This will allow EVA loads & stores to operate safely only on
user memory from kernel mode.
For the cases where the mmu_idx doesn't need to be overridden
(mips_cpu_get_phys_page_debug() and cpu_mips_translate_address()), we
calculate the required mmu_idx using cpu_mmu_index(). Note that this
only tests the MIPS_HFLAG_KSU bits rather than MIPS_HFLAG_MODE, so we
don't test the debug mode hflag MIPS_HFLAG_DM any longer. This should be
fine as get_physical_address() only compares against MIPS_HFLAG_UM and
MIPS_HFLAG_SM, neither of which should get set by compute_hflags() when
MIPS_HFLAG_DM is set.
Backports commit 9fbf4a58c90183b30bb2c8ad971ccce7e6716a16 from qemu
Implement decoding of microMIPS EVA load and store instruction groups in
the POOL31C pool. These use the same gen_ld(), gen_st(), gen_st_cond()
helpers as the MIPS32 decoding, passing the equivalent MIPS32 opcodes as
opc.
Backports commit 8fffc64696783b1ff1d17262d098976479895660 from qemu
Add CP0.ErrCtl register with WST, SPR and ITC bits. In 34K and interAptiv
processors these bits are used to enable CACHE instruction access to
different arrays. When WST=0, SPR=0 and ITC=1 the CACHE instruction will
access ITC tag values.
Generally we do not model caches and we have been treating the CACHE
instruction as NOP. But since CACHE can operate on ITC Tags new
MIPS_HFLAG_ITC_CACHE hflag is introduced to generate the helper only when
CACHE is in the ITC Access mode.
Backports commit 0d74a222c27e26fc40f4f6120c61c3f9ceaa3776 from qemu
Implement decoding of MIPS32 EVA loads and stores. These access the user
address space from kernel mode when implemented, so for each instruction
we need to check that EVA is available from Config5.EVA & check for
sufficient COP0 privilege (with the new check_eva()), and then override
the mem_idx used for the operation.
Unfortunately some Loongson 2E instructions use overlapping encodings,
so we must be careful not to prevent those from being decoded when EVA
is absent.
Backports commit 7696414729b2d0f870c80ad1dd637d854bc78847 from qemu
EVA load and store instructions access the user mode address map, so
they need to use mem_idx of MIPS_HFLAG_UM. Update the various utility
functions to allow mem_idx to be more easily overridden from the
decoding logic.
Specifically we add a mem_idx argument to the op_ld/st_* helpers used
for atomics, and a mem_idx local variable to gen_ld(), gen_st(), and
gen_st_cond().
Backports commit dd4096cd2ccc19384770f336c930259da7a54980 from qemu
Add support for the CP0_EBase.WG bit, which allows upper bits to be
written (bits 31:30 on MIPS32, or bits 63:30 on MIPS64), along with the
CP0_Config5.CV bit to control whether the exception vector for Cache
Error exceptions is forced into KSeg1.
This is necessary on MIPS32 to support Segmentation Control and Enhanced
Virtual Addressing (EVA) extensions (where KSeg1 addresses may not
represent an unmapped uncached segment).
It is also useful on MIPS64 to allow the exception base to reside in
XKPhys, and possibly out of range of KSEG0 and KSEG1.
Backports commit 74dbf824a1313b6064bbebb981a7440951d70896 from qemu
There is no need to invalidate any shadow TLB entries when the ASID
changes or when access to one of the 64-bit segments has been disabled,
since doing so doesn't reveal to software whether any TLB entries have
been evicted into the shadow half of the TLB.
Therefore weaken the tlb flushes in these cases to only flush the QEMU
TLB.
Backports commit 9658e4c342e6ae0d775101f8f6bb6efb16789af1 from qemu
Writing specific TLB entries with TLBWI flushes shadow TLB entries
unless an existing entry is having its access permissions upgraded. This
is necessary as software would from then on expect the previous mapping
in that entry to no longer be in effect (even if QEMU has quietly
evicted it to the shadow TLB on a TLBWR).
However it won't do this if only EHINV, XI, or RI bits have been set,
even if that results in a reduction of permissions, so add the necessary
checks to invoke the flush when these bits are set.
Backports commit eff6ff9431aa9776062a5f4a08d1f6503ca9995a from qemu
Using MFC0 to read CP0_UserLocal uses tcg_gen_ld32s_tl, however
CP0_UserLocal is a target_ulong. On a big endian host with a MIPS64
target this reads and sign extends the more significant half of the
64-bit register.
Fix this by using ld_tl to load the whole target_ulong and ext32s_tl to
sign extend it, as done for various other target_ulong COP0 registers.
Backports commit e40df9a80bb7cdb0a4ca650985fa9fe572097fa7 from qemu
Introduce Skylake-Server cpu mode which inherits the features from
Skylake-Client and supports some additional features that are: AVX512,
CLWB and PGPE1GB.
Backports commit 53f9a6f45fb214540cb40af45efc11ac40ac454c from qemu
Currently when running KVM, we expose "KVMKVMKVM\0\0\0" in
the 0x40000000 CPUID leaf. Other hypervisors (VMWare,
HyperV, Xen, BHyve) all do the same thing, which leaves
TCG as the odd one out.
The CPUID signature is used by software to detect which
virtual environment they are running in and (potentially)
change behaviour in certain ways. For example, systemd
supports a ConditionVirtualization= setting in unit files.
The virt-what command can also report the virt type it is
running on
Currently both these apps have to resort to custom hacks
like looking for 'fw-cfg' entry in the /proc/device-tree
file to identify TCG.
This change thus proposes a signature "TCGTCGTCGTCG" to be
reported when running under TCG.
To hide this, the -cpu option tcg-cpuid=off can be used.
Backports commits 4ed3d478c63dc65a02eba774c35116618ea5ff10 and 1ce36bfe6424243082d3d7c2330e1a0a4ff72a43 from qemu
This patch fixes setting DExcCode field of CP0 Debug register
when SDBBP instruction is executed. According to EJTAG specification,
this field must be set to the value 9 (Bp).
Backports commit c6c2c0fc32362ba234ae3bdad1a55c2d6aefaa12 from qemu
Previously DISAS_JUMP did ensure this but with the optimisation of
8a6b28c7 (optimize indirect branches) we might not leave the loop.
This means if any pending interrupts are cleared by changing IRQ flags
we might never get around to servicing them. You usually notice this
by seeing the lookup_tb_ptr() helper gainfully chaining TBs together
while cpu->interrupt_request remains high and the exit_request has not
been set.
This breaks amongst other things the OPTEE test suite which executes
an eret from the secure world after a non-secure world IRQ has gone
pending which then never gets serviced.
Instead of using the previously implied semantics of DISAS_JUMP we use
DISAS_EXIT which will always exit the run-loop.
Backports commit b29fd33db578decacd14f34933b29aece3e7c25e from qemu
While an ISB will ensure any raised IRQs happen on the next
instruction it doesn't cause any to get raised by itself. We can
therefore use a simple tb exit for ISB instructions and rely on the
exit_request check at the top of each TB to deal with exiting if
needed.
Backports commit 0b609cc128ba5ef16cc841bcade898d1898f1dc3 from qemu
As the gen_goto_tb function can do both static and dynamic jumps it
should also set the is_jmp field. This matches the behaviour of the
a64 code.
Backports commit 4cae8f56fbab2798586576a56cc669f0127d04fb from qemu
We already have an exit condition, DISAS_UPDATE which will exit the
run-loop. Expand on the difference with DISAS_EXIT in the comments
Backports commit abd1fb0ee2c58b99f4b2d15718f1825fe4984e12 from qemu
DISAS_UPDATE should be used when the wider CPU state other than just
the PC has been updated and we should therefore exit the TCG runtime
and return to the main execution loop rather assuming DISAS_JUMP would
do that.
Backports commit e8d5230221851e8933811f1579fd13371f576955 from qemu
The Cortex-M3 and M4 CPUs always have 8 PMSA MPU regions (this isn't
a configurable option for the hardware). Make the default value of
the pmsav7-dregion property be set per-cpu, so we don't need to have
every user of these CPUs set it manually. (The existing default of
16 is correct for the other PMSAv7 core, the Cortex-R5.)
This fixes a bug where we were creating the M3 and M4 with
too many regions; most guest software would not notice or
care, though, since it would just not use the registers
associated with the unexpected extra regions.
Backports commit 8d92e26b452f8961ec90df3f93cf5f3b7a9d158f from qemu
This patch fixes the msa copy_[s|u]_df instruction emulation when
the destination register rd is zero. Without this patch the zero
register would get clobbered, which should never happen because it
is supposed to be hardwired to 0.
Fix this corner case by explicitly checking rd = 0 and effectively
making these instructions emulation no-op in that case.
Backports commit cab4888136a92250fdd401402622824994f7ce0b from qemu
Move cpu_get_fp80()/cpu_set_fp80() from fpu_helper.c to
machine.c because fpu_helper.c will be disabled if tcg is
disabled in the build.
Backports commit db573d2cf7ae6b5a4fc324be6f55e078fc218464 from qemu.
In unicorn's case, they can be moved into unicorn.c
Move cpu_sync_bndcs_hflags() function from mpx_helper.c
to helper.c because mpx_helper.c need be disabled when
tcg is disabled.
Backports commit ab0a19d4f08d924e052eb369420d264240872f8a from qemu
Move the handling of conforming code segments before the handling
of stack switch.
Because dpl == cpl after the new "if", it's now unnecessary to check
the C bit when testing dpl < cpl. Furthermore, dpl > cpl is checked
slightly above the modified code, so the final "else" is unreachable
and we can remove it.
Backports commit 1110bfe6f5600017258fa6578f9c17ec25b32277 from qemu
In do_interrupt64(), when interrupt stack table(ist) is enabled
and the the target code segment is conforming(e2 & DESC_C_MASK), the
old implementation always set new CPL to 0, and SS.RPL to 0.
This is incorrect for when CPL3 code access a CPL0 conforming code
segment, the CPL should remain unchanged. Otherwise higher privileged
code can be compromised.
The patch fix this for always set dpl = cpl when the target code segment
is conforming, and modify the last parameter `flags`, which contains
correct new CPL, in cpu_x86_load_seg_cache().
Backports commit e95e9b88ba5f4a6c17f4d0c3a3a6bf3f648bb328 from qemu
Add fsabs, fdabs, fsneg, fdneg, fsmove and fdmove.
The value is converted using the new floatx80_round() function.
Backports commit 77bdb2292492fafc4bc0fbb4d8c44fdd0ef1fa8e from qemu
fmovecr moves a floating point constant from the
FPU ROM to a floating point register.
Backports commit 9d403660d91229922c2786e81c23cc9dd8e644f1 from qemu
Coldfire uses float64, but 680x0 use floatx80.
This patch introduces the use of floatx80 internally
and enables 680x0 80bits FPU.
Backports commit f83311e4764f1f25a8abdec2b32c64483be1759b from qemu
V flag for subtraction is:
v = (res ^ src1) & (src1 ^ src2)
(see COMPUTE_CCR() in target/m68k/helper.c)
But gen_flush_flags() uses:
v = (res ^ src2) & (src1 ^ src2)
The problem has been found with the following program:
.global _start
_start:
move.l #-2147483648,%d0
subq.l #1,%d0
jvc 1f
move.l #1,%d1
move.l #1,%d0
trap #0
1:
move.l #0,%d1
move.l #1,%d0
trap #0
It works fine (exit(1)) on real hardware, and with "-singlestep".
"-singlestep" uses gen_helper_flush_flags(), whereas
without "-singlestep", V flag is computed directly in
gen_flush_flags().
This patch updates gen_flush_flags() to have the same result
as with gen_helper_flush_flags().
Backports commit 043b936ef6fe53396b3c6b8f5562ea3e238a071d from qemu
Running Windows with icount causes a crash in instruction of write cr.
This patch fixes it.
Reading and writing cr cause an icount read because there are called
cpu_get_apic_tpr and cpu_set_apic_tpr functions. So, there is need
gen_io_start()/gen_io_end() calls.
Backports commit 5b003a40bb1ab14d0398e91f03393d3c6b9577cd from qemu
This speeds up SMM switches. Later on it may remove the need to take
the BQL, and it may also allow to reuse code between TCG and KVM.
Backports commit f8c45c6550b9ff1e1f0b92709ff3213a79870879 from qemu
Instead of unconditionally exiting to the exec loop, use the
gen_jr helper to jump to the target if it is valid.
Perf impact: see next commit's log.
Backports commit fe62089563ffc6a42f16ff28a6b6be34d2697766 from qemu
Instead of unconditionally exiting to the exec loop, use the
lookup_and_goto_ptr helper to jump to the target if it is valid.
Perf impact: see next commit's log.
Backports commit 7ad55b4ffd982c80f26f7f3658138d94cdc678e8 from qemu
The cp15, CRn=15, opc1=0, CRm=5, opc2=0 instruction invalidates all the
data cache on the cortex-r5. Implementing it as a NOP.
Backports commit 95e9a242e2a393c7d4e5cc04340e39c3a9420f03 from qemu
M profile doesn't implement ARM, and the architecturally required
behaviour for attempts to execute with the Thumb bit clear is to
generate a UsageFault with the CFSR INVSTATE bit set. We were
incorrectly implementing this as generating an UNDEFINSTR UsageFault;
fix this.
Backports commit e13886e3a790b52f0b2e93cb5e84fdc2ada5471a from qemu
Implement the exception return consistency checks
described in the v7M pseudocode ExceptionReturn().
Inspired by a patch from Michael Davidsaver's series, but
this is a reimplementation from scratch based on the
ARM ARM pseudocode.
Backports commit aa488fe3bb5460c6675800ccd80f6dccbbd70159 from qemu
Extract the code from the tail end of arm_v7m_do_interrupt() which
enters the exception handler into a pair of utility functions
v7m_exception_taken() and v7m_push_stack(), which correspond roughly
to the pseudocode PushStack() and ExceptionTaken().
This also requires us to move the arm_v7m_load_vector() utility
routine up so we can call it.
Handling illegal exception returns has some cases where we want to
take a UsageFault either on an existing stack frame or with a new
stack frame but with a specific LR value, so we want to be able to
call these without having to go via arm_v7m_cpu_do_interrupt().
Backports commit 39ae2474e337247e5930e8be783b689adc9f6215 from qemu
All the places in armv7m_cpu_do_interrupt() which pend an
exception in the NVIC are doing so for synchronous
exceptions. We know that we will always take some
exception in this case, so we can just acknowledge it
immediately, rather than returning and then immediately
being called again because the NVIC has raised its outbound
IRQ line.
Backports commit a25dc805e2e63a55029e787a52335e12dabf07dc from qemu
The M profile condition for when we can take a pending exception or
interrupt is not the same as that for A/R profile. The code
originally copied from the A/R profile version of the
cpu_exec_interrupt function only worked by chance for the
very simple case of exceptions being masked by PRIMASK.
Replace it with a call to a function in the NVIC code that
correctly compares the priority of the pending exception
against the current execution priority of the CPU.
Backports commit 7ecdaa4a9635f1ded0dfa9218c25273b6d4dcd44 from qemu
Having armv7m_nvic_acknowledge_irq() return the new value of
env->v7m.exception and its one caller assign the return value
back to env->v7m.exception is pointless. Just make the return
type void instead.
Backports commit a5d8235545e98c1ce02560d5f4f57552d937efe9 from qemu
Implement HFNMIENA support for the M profile MPU. This bit controls
whether the MPU is treated as enabled when executing at execution
priorities of less than zero (in NMI, HardFault or with the FAULTMASK
bit set).
Doing this requires us to use a different MMU index for "running
at execution priority < 0", because we will have different
access permissions for that case versus the normal case.
Backports commit 3bef7012560a7f0ea27b265105de5090ba117514 from qemu
The M series MPU is almost the same as the already implemented R
profile MPU (v7 PMSA). So all we need to implement here is the MPU
register interface in the system register space.
This implementation has the same restriction as the R profile MPU
that it doesn't permit regions to be sized down smaller than 1K.
We also do not yet implement support for MPU_CTRL.HFNMIENA; this
bit should if zero disable use of the MPU when running HardFault,
NMI or with FAULTMASK set to 1 (ie at an execution priority of
less than zero) -- if the MPU is enabled we don't treat these
cases any differently.
Backports commit 29c483a506070e8f554c77d22686f405e30b9114 from qemu
General logic is that operations stopped by the MPU are MemManage,
and those which go through the MPU and are caught by the unassigned
handle are BusFault. Distinguish these by looking at the
exception.fsr values, and set the CFSR bits and (if appropriate)
fill in the BFAR or MMFAR with the exception address.
Backports commit 5dd0641d234e355597be62e5279d8a519c831625 from qemu
All M profile CPUs are PMSA, so set the feature bit.
(We haven't actually implemented the M profile MPU register
interface yet, but setting this feature bit gives us closer
to correct behaviour for the MPU-disabled case.)
Backports commit 790a11503cfb5e1dcd031ea2212bbebae4ca3cec from qemu
Add support for the M profile default memory map which is used
if the MPU is not present or disabled.
The main differences in behaviour from implementing this
correctly are that we set the PAGE_EXEC attribute on
the right regions of memory, such that device regions
are not executable.
Backports commit 3a00d560bcfca7ad04327062c1986a016c104b1f from qemu
Improve the "-d mmu" tracing for the PMSAv7 MPU translation
process as an aid in debugging guest MPU configurations:
* fix a missing newline for a guest-error log
* report the region number with guest-error or unimp
logs of bad region register values
* add a log message for the overall result of the lookup
* print "0x" prefix for hex values
Backports commit c9f9f1246d630960bce45881e9c0d27b55be71e2 from qemu
Now that we enforce both:
* pmsav7_dregion == 0 implies has_mpu == false
* PMSA with has_mpu == false means SCTLR.M cannot be set
we can remove a check on pmsav7_dregion from get_phys_addr_pmsav7(),
because we can only reach this code path if the MPU is enabled
(and so region_translation_disabled() returned false).
Backports commit e9235c6983b261e04e897e8ff900b2b7a391e644 from qemu
If the CPU is a PMSA config with no MPU implemented, then the
SCTLR.M bit should be RAZ/WI, so that the guest can never
turn on the non-existent MPU.
Backports commit 06312febfb2d35367006ef23608ddd6a131214d4 from qemu
Fix the handling of QOM properties for PMSA CPUs with no MPU:
Allow no-MPU to be specified by either:
* has-mpu = false
* pmsav7_dregion = 0
and make setting one imply the other. Don't clear the PMSA
feature bit in this situation.
Backports commit f50cd31413d8bc9d1eef8edd1f878324543bf65d from qemu
ARM CPUs come in two flavours:
* proper MMU ("VMSA")
* only an MPU ("PMSA")
For PMSA, the MPU may be implemented, or not (in which case there
is default "always acts the same" behaviour, but it isn't guest
programmable).
QEMU is a bit confused about how we indicate this: we have an
ARM_FEATURE_MPU, but it's not clear whether this indicates
"PMSA, not VMSA" or "PMSA and MPU present" , and sometimes we
use it for one purpose and sometimes the other.
Currently trying to implement a PMSA-without-MPU core won't
work correctly because we turn off the ARM_FEATURE_MPU bit
and then a lot of things which should still exist get
turned off too.
As the first step in cleaning this up, rename the feature
bit to ARM_FEATURE_PMSA, which indicates a PMSA CPU (with
or without MPU).
Backports commit 452a095526a0537f16c271516a2200877a272ea8 from qemu
Make M profile use completely separate ARMMMUIdx values from
those that A profile CPUs use. This is a prelude to adding
support for the MPU and for v8M, which together will require
6 MMU indexes which don't map cleanly onto the A profile
uses:
non secure User
non secure Privileged
non secure Privileged, execution priority < 0
secure User
secure Privileged
secure Privileged, execution priority < 0
Backports commit e7b921c2d9efc249f99b9feb0e7dca82c96aa5c4 from qemu
The v7M exception architecture requires that if a synchronous
exception cannot be taken immediately (because it is disabled
or at too low a priority) then it should be escalated to
HardFault (and the HardFault exception is then taken).
Implement this escalation logic.
Backports commit a73c98e159d18155445d29b6044be6ad49fd802f from qemu
The M profile CPU's MPU has an awkward corner case which we
would like to implement with a different MMU index.
We can avoid having to bump the number of MMU modes ARM
uses, because some of our existing MMU indexes are only
used by non-M-profile CPUs, so we can borrow one.
To avoid that getting too confusing, clean up the code
to try to keep the two meanings of the index separate.
Instead of ARMMMUIdx enum values being identical to core QEMU
MMU index values, they are now the core index values with some
high bits set. Any particular CPU always uses the same high
bits (so eventually A profile cores and M profile cores will
use different bits). New functions arm_to_core_mmu_idx()
and core_to_arm_mmu_idx() convert between the two.
In general core index values are stored in 'int' types, and
ARM values are stored in ARMMMUIdx types.
Backports commit 8bd5c82030b2cb09d3eef6b444f1620911cc9fc5 from qemu
The PMUv3 driver of linux kernel (in arch/arm64/kernel/perf_event.c)
relies on the PMUVER field of id_aa64dfr0_el1 to decide if PMU support
is present or not. This patch clears the PMUVER field under TCG mode
when vPMU=off. Without it, PMUv3 will init insider guest VMs even
with vPMU=off. This patch also removes a redundant line inside the
if-statement.
Backports commit 2b3ffa929249b15a75d8bde3e8e57a744f52aff0 from qemu
When identifying the DFSR format for an alignment fault, use
the mmu index that we are passed, rather than calling cpu_mmu_index()
to get the mmu index for the current CPU state. This doesn't actually
make any difference since the only cases where the current MMU index
differs from the index used for the load are the "unprivileged
load/store" instructions, and in that case the mmu index may
differ but the translation regime is the same (apart from the
"use from Hyp mode" case which is UNPREDICTABLE).
However it's the more logical thing to do.
Backports commit e517d95b63427fae9f03958dbc005c36b4ebf2cf from qemu
Now that we've rewritten M-profile exception return so that the magic
PC values are not visible to other parts of QEMU, we can delete the
special casing of them elsewhere.
Backports commit f4e8e4edda875cab9df91dc4ae9767f7cb1f50aa from qemu
On M profile, return from exceptions happen when code in Handler mode
executes one of the following function call return instructions:
* POP or LDM which loads the PC
* LDR to PC
* BX register
and the new PC value is 0xFFxxxxxx.
QEMU tries to implement this by not treating the instruction
specially but then catching the attempt to execute from the magic
address value. This is not ideal, because:
* there are guest visible differences from the architecturally
specified behaviour (for instance jumping to 0xFFxxxxxx via a
different instruction should not cause an exception return but it
will in the QEMU implementation)
* we have to account for it in various places (like refusing to take
an interrupt if the PC is at a magic value, and making sure that
the MPU doesn't deny execution at the magic value addresses)
Drop these hacks, and instead implement exception return the way the
architecture specifies -- by having the relevant instructions check
for the magic value and raise the 'do an exception return' QEMU
internal exception immediately.
The effect on the generated code is minor:
bx lr, old code (and new code for Thread mode):
TCG:
mov_i32 tmp5,r14
movi_i32 tmp6,$0xfffffffffffffffe
and_i32 pc,tmp5,tmp6
movi_i32 tmp6,$0x1
and_i32 tmp5,tmp5,tmp6
st_i32 tmp5,env,$0x218
exit_tb $0x0
set_label $L0
exit_tb $0x7f2aabd61993
x86_64 generated code:
0x7f2aabe87019: mov %ebx,%ebp
0x7f2aabe8701b: and $0xfffffffffffffffe,%ebp
0x7f2aabe8701e: mov %ebp,0x3c(%r14)
0x7f2aabe87022: and $0x1,%ebx
0x7f2aabe87025: mov %ebx,0x218(%r14)
0x7f2aabe8702c: xor %eax,%eax
0x7f2aabe8702e: jmpq 0x7f2aabe7c016
bx lr, new code when in Handler mode:
TCG:
mov_i32 tmp5,r14
movi_i32 tmp6,$0xfffffffffffffffe
and_i32 pc,tmp5,tmp6
movi_i32 tmp6,$0x1
and_i32 tmp5,tmp5,tmp6
st_i32 tmp5,env,$0x218
movi_i32 tmp5,$0xffffffffff000000
brcond_i32 pc,tmp5,geu,$L1
exit_tb $0x0
set_label $L1
movi_i32 tmp5,$0x8
call exception_internal,$0x0,$0,env,tmp5
x86_64 generated code:
0x7fe8fa1264e3: mov %ebp,%ebx
0x7fe8fa1264e5: and $0xfffffffffffffffe,%ebx
0x7fe8fa1264e8: mov %ebx,0x3c(%r14)
0x7fe8fa1264ec: and $0x1,%ebp
0x7fe8fa1264ef: mov %ebp,0x218(%r14)
0x7fe8fa1264f6: cmp $0xff000000,%ebx
0x7fe8fa1264fc: jae 0x7fe8fa126509
0x7fe8fa126502: xor %eax,%eax
0x7fe8fa126504: jmpq 0x7fe8fa122016
0x7fe8fa126509: mov %r14,%rdi
0x7fe8fa12650c: mov $0x8,%esi
0x7fe8fa126511: mov $0x56095dbeccf5,%r10
0x7fe8fa12651b: callq *%r10
which is a difference of one cmp/branch-not-taken. This will
be lost in the noise of having to exit generated code and
look up the next TB anyway.
Backports commit 3bb8a96f5348913ee130169504f3642f501b113e from qemu
For M profile exception-return handling we'd like to generate different
code for some instructions depending on whether we are in Handler
mode or Thread mode. This isn't the same as "are we privileged
or user", so we need an extra bit in the TB flags to distinguish.
Backports commit 064c379c99b835bdcc478d21a3849507ea07d53a from qemu
Move the code to generate the "condition failed" instruction
codepath out of the if (singlestepping) {} else {}. This
will allow adding support for handling a new is_jmp type
which can't be neatly split into "singlestepping case"
versus "not singlestepping case".
Backports commit f021b2c4627890d82fbcc300db3bd782b37b7f8a from qemu
arm: Abstract out "are we singlestepping" test to utility function
We now test for "are we singlestepping" in several places and
it's not a trivial check because we need to care about both
architectural singlestep and QEMU gdbstub singlestep. We're
also about to add another place that needs to make this check,
so pull the condition out into a function.
Backports commit b636649f5a2e108413dd171edaf320f781f57942 from qemu
