When FZ is set, input_denormal exceptions are recognized, but this does
not happen with FZ16. The softfloat code has no way to distinguish
these bits and will raise such exceptions into fp_status_f16.flags,
so ignore them when computing the accumulated flags.
Backports commit 19062c169e5bcdda3d60df9161228e107bf0f96e from qemu
When support for FZ16 was added, we failed to include the bit
within FPCR_MASK, which means that it could never be set.
Continue to zero FZ16 when ARMv8.2-FP16 is not enabled.
Fixes: d81ce0ef2c4
Backports commit 0b62159be33d45d00dfa34a317c6d3da30ffb480 from qemu
Define a "cortex-m0" ARMv6-M CPU model.
Most of the register reset values set by other CPU models are not
relevant for the cut-down ARMv6-M architecture.
Backports commit 191776b96a381b5d2b8d3f90c1c02b3e4779e5f7 from qemu
This allows the default (and maximum) vector length to be set
from the command-line. Which is extraordinarily helpful in
debugging problems depending on vector length without having to
bake knowledge of PR_SET_SVE_VL into every guest binary.
Backports relevant parts of commit
adf92eab90e3f5f34c285da6d14d48952b7a8e72 from qemu
Also fold the FPCR/FPSR state onto the same line as PSTATE,
and mention but do not dump disabled FPU state.
Backports commit 2bf5f3f91bb4e3faa2a19aec042138a938afbf6a from qemu
The scaling should be solely on the memory operation size; the number
of registers being loaded does not come in to the initial computation.
Backports commit 50ef1cbf31caad21019ae6fa8036ed6f29244ba5 from qemu
The immediate should be scaled by the size of the memory reference,
not the size of the elements into which it is loaded.
Backports commit d0e372b0298f897993f831dbff7ad4f1c70f138e from qemu
The expression (int) imm + (uint32_t) len_align turns into uint32_t
and thus with negative imm produces a memory operation at the wrong
offset. None of the numbers involved are particularly large, so
change everything to use int.
Backports commit 19f2acc915a0f8f443a959844540a6f09133cc96 from qemu
The pseudocode for this operation is an increment + compare loop,
so comparing <= the maximum integer produces an all-true predicate.
Rather than bound in both the inline code and the helper, pass the
helper the number of predicate bits to set instead of the number
of predicate elements to set.
Backports commit bbd0968c458d48e34a08b8694fa3309a9fe1c9e7 from qemu
The normal vector element is sign-extended before
comparing with the wide vector element.
Backports commit df4e001093988544d09887122ae824f18ba55c68 from qemu
Tailchaining is an optimization in handling of exception return
for M-profile cores: if we are about to pop the exception stack
for an exception return, but there is a pending exception which
is higher priority than the priority we are returning to, then
instead of unstacking and then immediately taking the exception
and stacking registers again, we can chain to the pending
exception without unstacking and stacking.
For v6M and v7M it is IMPDEF whether tailchaining happens for pending
exceptions; for v8M this is architecturally required. Implement it
in QEMU for all M-profile cores, since in practice v6M and v7M
hardware implementations generally do have it.
(We were already doing tailchaining for derived exceptions which
happened during exception return, like the validity checks and
stack access failures; these have always been required to be
tailchained for all versions of the architecture.)
Backports commit 5f62d3b9e67bfc3deb970e3c7fb7df7e57d46fc3 from qemu
On exception return for M-profile, we must restore the CONTROL.SPSEL
bit from the EXCRET value before we do any kind of tailchaining,
including for the derived exceptions on integrity check failures.
Otherwise we will give the guest an incorrect EXCRET.SPSEL value on
exception entry for the tailchained exception.
Backports commit 89b1fec193b81b6ad0bd2975f2fa179980cc722e from qemu
In do_v7m_exception_exit(), we use the exc_secure variable to track
whether the exception we're returning from is secure or non-secure.
Unfortunately the statement initializing this was accidentally
inside an "if (env->v7m.exception != ARMV7M_EXCP_NMI)" conditional,
which meant that we were using the wrong value for NMI handlers.
Move the initialization out to the right place.
Backports commit b8109608bc6f3337298d44ac4369bf0bc8c3a1e4 from qemu
One of the required effects of setting HCR_EL2.TGE is that when
SCR_EL3.NS is 1 then SCTLR_EL1.M must behave as if it is zero for
all purposes except direct reads. That is, it effectively disables
the MMU for the NS EL0/EL1 translation regime.
Backports commit 3d0e3080d8b7abcddc038d18e8401861c369c4c1 from qemu
The IMO, FMO and AMO bits in HCR_EL2 are defined to "behave as
1 for all purposes other than direct reads" if HCR_EL2.TGE
is set and HCR_EL2.E2H is 0, and to "behave as 0 for all
purposes other than direct reads" if HCR_EL2.TGE is set
and HRC_EL2.E2H is 1.
To avoid having to check E2H and TGE everywhere where we test IMO and
FMO, provide accessors arm_hcr_el2_imo(), arm_hcr_el2_fmo()and
arm_hcr_el2_amo(). We don't implement ARMv8.1-VHE yet, so the E2H
case will never be true, but we include the logic to save effort when
we eventually do get to that.
(Note that in several of these callsites the change doesn't
actually make a difference as either the callsite is handling
TGE specially anyway, or the CPU can't get into that situation
with TGE set; we change everywhere for consistency.)
Backports commit ac656b166b57332ee397e9781810c956f4f5fde5 from qemu
Whene we raise a synchronous exception, if HCR_EL2.TGE is set then
exceptions targeting NS EL1 must be redirected to EL2. Implement
this in raise_exception() -- all synchronous exceptions go through
this function.
(Asynchronous exceptions go via arm_cpu_exec_interrupt(), which
already honours HCR_EL2.TGE when it determines the target EL
in arm_phys_excp_target_el().)
Backports commit 7556edfb4d7bf0583c852c8cfc49ef494c41dd8a from qemu
Some debug registers can be trapped via MDCR_EL2 bits TDRA, TDOSA,
and TDA, which we implement in the functions access_tdra(),
access_tdosa() and access_tda(). If MDCR_EL2.TDE or HCR_EL2.TGE
are 1, the TDRA, TDOSA and TDA bits should behave as if they were 1.
Implement this by having the access functions check MDCR_EL2.TDE
and HCR_EL2.TGE.
Backports commit 30ac6339dca3fe0d05a611f12eedd5af20af585a from qemu
If the "trap general exceptions" bit HCR_EL2.TGE is set, we
must mask all virtual interrupts (as per DDI0487C.a D1.14.3).
Implement this in arm_excp_unmasked().
Backports commit 2ccf0fef632f3d54b2cc9ea08f1e6904ff1f8df4 from qemu
Forbid stack alignment change. (CCR)
Reserve FAULTMASK, BASEPRI registers.
Report any fault as a HardFault. Disable MemManage, BusFault and
UsageFault, so they always escalated to HardFault. (SHCSR)
Backports commit 22ab3460017cfcfb6b50f05838ad142e08becce5 from qemu
MSR_SMI_COUNT started being migrated in QEMU 2.12. Do not migrate it
on older machine types, or the subsection causes a load failure for
guests that use SMM.
Backports part of commit 990e0be2603511560168e1ad61f68294d951c39e from
qemu
Rename DCACHE to DATA_CACHE and ICACHE to INSTRUCTION_CACHE.
This avoids conflict with Linux asm/cachectl.h macros and fixes
build failure on mips hosts.
Backports commit 5f00335aecafc9ad56592d943619d3252f8941f1 from qemu
To correctly handle small (less than TARGET_PAGE_SIZE) MPU regions,
we must correctly handle the case where the address being looked
up hits in an MPU region that is not small but the address is
in the same page as a small region. For instance if MPU region
1 covers an entire page from 0x2000 to 0x2400 and MPU region
2 is small and covers only 0x2200 to 0x2280, then for an access
to 0x2000 we must not return a result covering the full page
even though we hit the page-sized region 1. Otherwise we will
then cache that result in the TLB and accesses that should
hit region 2 will incorrectly find the region 1 information.
Check for the case where we miss an MPU region but it is still
within the same page, and in that case narrow the size we will
pass to tlb_set_page_with_attrs() for whatever the final
outcome is of the MPU lookup.
Backports commit 9d2b5a58f85be2d8e129c4b53d6708ecf8796e54 from qemu
'I' was being double-incremented; correctly within the inner loop
and incorrectly within the outer loop.
Backports commit 628fc75f3a3bb115de3b445c1a18547c44613cfe from qemu
For M-profile exception returns, the mmu index to use for exception
return unstacking is supposed to be that of wherever we are returning to:
* if returning to handler mode, privileged
* if returning to thread mode, privileged or unprivileged depending on
CONTROL.nPRIV for the destination security state
We were passing the wrong thing as the 'priv' argument to
arm_v7m_mmu_idx_for_secstate_and_priv(). The effect was that guests
which programmed the MPU to behave differently for privileged and
unprivileged code could get spurious MemManage Unstack exceptions.
Backports commit 2b83714d4ea659899069a4b94aa2dfadc847a013 from qemu
Use MAKE_64BIT_MASK instead of open-coding. Remove an odd
vector size check that is unlikely to be more profitable
than 3 64-bit integer stores. Correct the iteration for WORD
to avoid writing too much data.
Fixes RISU tests of PTRUE for VL 256.
Backports commit 973558a3f869e591d2406dd8226ec0c4e32a3c3e from qemu
These instructions must perform the sve_access_check, but
since they are implemented as NOPs there is no generated
code to elide when the access check fails.
Backports commit 2f95a3b09aebdcb5c9152a7ac434a5d57441fe82 from qemu
This implements NPT suport for SVM by hooking into
x86_cpu_handle_mmu_fault where it reads the stage-1 page table. Whether
we need to perform this 2nd stage translation, and how, is decided
during vmrun and stored in hflags2, along with nested_cr3 and
nested_pg_mode.
As get_hphys performs a direct cpu_vmexit in case of NPT faults, we need
retaddr in that function. To avoid changing the signature of
cpu_handle_mmu_fault, this passes the value from tlb_fill to get_hphys
via the CPU state.
This was tested successfully via the Jailhouse hypervisor.
Backports commit fe441054bb3f0c75ff23335790342c0408e11c3a from qemu
There is no need to re-set these 3 features already
implied by the call to aarch64_a15_initfn.
Backports commit 0b33968e7f4cf998f678b2d1a5be3d6f3f3513d8 from qemu
There is no need to re-set these 9 features already
implied by the call to aarch64_a57_initfn.
Backports commit 156a7065365578deb3d63c2b5b69a4b5999a8fcc from qemu
Leave ARM_CP_SVE, removing ARM_CP_FPU; the sve_access_check
produced by the flag already includes fp_access_check. If
we also check ARM_CP_FPU the double fp_access_check asserts.
Backports commit 11d7870b1b4d038d7beb827f3afa72e284701351 from qemu
We already check for the same condition within the normal integer
sdiv and sdiv64 helpers. Use a slightly different formation that
does not require deducing the expression type.
Backports commit 7e8fafbfd0537937ba8fb366a90ea6548cc31576 from qemu
Since kernel commit a86bd139f2 (arm64: arch_timer: Enable CNTVCT_EL0
trap..), released in kernel version v4.12, user-space has been able
to read these system registers. As we can't use QEMUTimer's in
linux-user mode we just directly call cpu_get_clock().
Backports commit 26c4a83bd4707797868174332a540f7d61288d15 from qemu
We've already added the helpers with an SVE patch, all that remains
is to wire up the aa64 and aa32 translators. Enable the feature
within -cpu max for CONFIG_USER_ONLY.
Backports commit 26c470a7bb4233454137de1062341ad48947f252 from qemu
Enhance the existing helpers to support SVE, which takes the
index from each 128-bit segment. The change has no effect
for AdvSIMD, since there is only one such segment.
Backports commit 18fc24057815bf3d956cfab892a2bc2344bd1dcb from qemu
For aa64 advsimd, we had been passing the pre-indexed vector.
However, sve applies the index to each 128-bit segment, so we
need to pass in the index separately.
For aa32 advsimd, the fp32 operation always has index 0, but
we failed to interpret the fp16 index correctly.
Backports commit 2cc99919a81a62589a4a6b0f365eabfead1db1a7 from qemu
It calls cpu_loop_exit in system emulation mode (and should never be
called in user emulation mode).
Backports commit 50b3de6e5cd464dcc20e3a48f5a09e0299a184ac from qemu
We need to terminate the translation block after STGI so that pending
interrupts can be injected.
This fixes pending NMI injection for Jailhouse which uses "stgi; clgi"
to open a brief injection window.
Backports commit df2518aa587a0157bbfbc635fe47295629d9914a from qemu
Check for SVM interception prior to injecting an NMI. Tested via the
Jailhouse hypervisor.
Backports commit 02f7fd25a446a220905c2e5cb0fc3655d7f63b29 from qemu
The implementation of these two instructions was swapped.
At the same time, unify the setup of eflags for the insn group.
Backports commit 13672386a93fef64cfd33bd72fbf3d80f2c00e94 from qemu
Offset can be larger than 16 bit from nanoMIPS,
and immediate field can be larger than 16 bits as well.
Backports commit 72e1f16f18fe62504f8f25d7a3f6813b24b221be from qemu
Fix to raise a Reserved Instruction exception when given fs is not
available from CTC1.
Backports commit f48a2cb21824217a61ec7be797860a0702e5325c from qemu
Allow ARMv8M to handle small MPU and SAU region sizes, by making
get_phys_add_pmsav8() set the page size to the 1 if the MPU or
SAU region covers less than a TARGET_PAGE_SIZE.
We choose to use a size of 1 because it makes no difference to
the core code, and avoids having to track both the base and
limit for SAU and MPU and then convert into an artificially
restricted "page size" that the core code will then ignore.
Since the core TCG code can't handle execution from small
MPU regions, we strip the exec permission from them so that
any execution attempts will cause an MPU exception, rather
than allowing it to end up with a cpu_abort() in
get_page_addr_code().
(The previous code's intention was to make any small page be
treated as having no permissions, but unfortunately errors
in the implementation meant that it didn't behave that way.
It's possible that some binaries using small regions were
accidentally working with our old behaviour and won't now.)
We also retain an existing bug, where we ignored the possibility
that the SAU region might not cover the entire page, in the
case of executable regions. This is necessary because some
currently-working guest code images rely on being able to
execute from addresses which are covered by a page-sized
MPU region but a smaller SAU region. We can remove this
workaround if we ever support execution from small regions.
Backports commit 720424359917887c926a33d248131fbff84c9c28 from qemu
We want to handle small MPU region sizes for ARMv7M. To do this,
make get_phys_addr_pmsav7() set the page size to the region
size if it is less that TARGET_PAGE_SIZE, rather than working
only in TARGET_PAGE_SIZE chunks.
Since the core TCG code con't handle execution from small
MPU regions, we strip the exec permission from them so that
any execution attempts will cause an MPU exception, rather
than allowing it to end up with a cpu_abort() in
get_page_addr_code().
(The previous code's intention was to make any small page be
treated as having no permissions, but unfortunately errors
in the implementation meant that it didn't behave that way.
It's possible that some binaries using small regions were
accidentally working with our old behaviour and won't now.)
Backports commit e5e40999b5e03567ef654546e3d448431643f8f3 from qemu
Enable TOPOEXT feature on EPYC CPU. This is required to support
hyperthreading on VM guests. Also extend xlevel to 0x8000001E.
Disable topoext on PC_COMPAT_2_12 and keep xlevel 0x8000000a.
Backports commit e00516475c270dcb6705753da96063f95699abf2 from qemu
This is part of topoext support. To keep the compatibility, it is better
we support all the combination of nr_cores and nr_threads currently
supported. By allowing more nr_cores and nr_threads, we might end up with
more nodes than we can actually support with the real hardware. We need to
fix up the node id to make this work. We can achieve this by shifting the
socket_id bits left to address more nodes.
Backports commit 631be32155dbafa1fe886f2488127956c9120ba6 from qemu
AMD future CPUs expose a mechanism to tell the guest that the
Speculative Store Bypass Disable is not needed and that the
CPU is all good.
This is exposed via the CPUID 8000_0008.EBX[26] bit.
See 124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Backports commit 254790a909a2f153d689bfa7d8e8f0386cda870d from qemu
AMD future CPUs expose _two_ ways to utilize the Intel equivalant
of the Speculative Store Bypass Disable. The first is via
the virtualized VIRT_SPEC CTRL MSR (0xC001_011f) and the second
is via the SPEC_CTRL MSR (0x48). The document titled:
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
gives priority of SPEC CTRL MSR over the VIRT SPEC CTRL MSR.
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Anyhow, this means that on future AMD CPUs there will be _two_ ways to
deal with SSBD.
Backports commit a764f3f7197f4d7ad8fe8424269933de912224cb from qemu
OSPKE is not a static feature flag: it changes dynamically at
runtime depending on CR4, and it was never configurable: KVM
never returned OSPKE on GET_SUPPORTED_CPUID, and on TCG enables
it automatically if CR4_PKE_MASK is set.
Remove OSPKE from the feature name array so users don't try to
configure it manually.
Backports commit 9ccb9784b57804f5c74434ad6ccb66650a015ffc from qemu
OSXAVE is not a static feature flag: it changes dynamically at
runtime depending on CR4, and it was never configurable: KVM
never returned OSXSAVE on GET_SUPPORTED_CPUID, and it is not
included in TCG_EXT_FEATURES.
Remove OSXSAVE from the feature name array so users don't try to
configure it manually.
Backports commit f1a23522b03a569f13aad49294bb4c4b1a9500c7 from qemu
Add support for cpuid leaf CPUID_8000_001E. Build the config that closely
match the underlying hardware. Please refer to the Processor Programming
Reference (PPR) for AMD Family 17h Model for more details.
Backports commit ed78467a214595a63af7800a073a03ffe37cd7db from qemu
Unlike ARMv7-M, ARMv6-M and ARMv8-M Baseline only supports naturally
aligned memory accesses for load/store instructions.
Backports commit 2aeba0d007d33efa12a6339bb140aa634e0d52eb from qemu
This feature is intended to distinguish ARMv8-M variants: Baseline and
Mainline. ARMv7-M compatibility requires the Main Extension. ARMv6-M
compatibility is provided by all ARMv8-M implementations.
Backports commit cc2ae7c9de14efd72c6205825eb7cd980ac09c11 from qemu
The arrays were made static, "if" was simplified because V7M and V8M
define V6 feature.
Backports commit 8297cb13e407db8a96cc7ed6b6a6c318a150759a from qemu
ARMv6-M supports 6 Thumb2 instructions. This patch checks for these
instructions and allows their execution.
Like Thumb2 cores, ARMv6-M always interprets BL instruction as 32-bit.
This patch is required for future Cortex-M0 support.
Backports commit 14120108f87b3f9e1beacdf0a6096e464e62bb65 from qemu
Rearrange the arithmetic so that we are agnostic about the total size
of the vector and the size of the element. This will allow us to index
up to the 32nd byte and with 16-byte elements.
Backports commit 66f2dbd783d0b6172043e3679171421b2d0bac11 from qemu
Add information for cpuid 0x8000001D leaf. Populate cache topology information
for different cache types (Data Cache, Instruction Cache, L2 and L3) supported
by 0x8000001D leaf. Please refer to the Processor Programming Reference (PPR)
for AMD Family 17h Model for more details.
Backports commit 8f4202fb1080f86958782b1fca0bf0279f67d136 from qemu
Always initialize CPUCaches structs with cache information, even
if legacy_cache=true. Use different CPUCaches struct for
CPUID[2], CPUID[4], and the AMD CPUID leaves.
This will simplify a lot the logic inside cpu_x86_cpuid()
Backports commit a9f27ea9adc8c695197bd08f2e938ef7b4183f07 from qemu
Rather than limit total TB size to PAGE-32 bytes, end the TB when
near the end of a page. This should provide proper semantics of
SIGSEGV when executing near the end of a page.
Backports commit 4c7a0f6f34869b3dfe7091d28ff27a8dfbdd8b70 from qemu
Removed ctx->insn_pc in favour of ctx->base.pc_next.
Yes, it is annoying, but didn't want to waste its 4 bytes.
Backports commit a575cbe01caecf22ab322a9baa5930a6d9e39ca6 from qemu
The name gen_lookup_tb is at odds with tcg_gen_lookup_and_goto_tb.
For these cases, we do indeed want to exit back to the main loop.
Similarly, DISAS_UPDATE performs no actual update, whereas DISAS_EXIT
does what it says.
Backports commit 4106f26e95c83b8759c3fe61a4d3a1fa740db0a9 from qemu
These are all indirect or out-of-page direct jumps.
We can indirectly chain to the next TB without going
back to the main loop.
Backports commit 8aaf7da9c3b1f282b5a123de3e87a2e6ca87f3b9 from qemu
We have exited the TB after using goto_tb; there is no
distinction from DISAS_NORETURN.
Backports commit 825340f5659647deb62743c3cb479ec8d78f1862 from qemu
The raise_exception helper does not return. Do not generate
any code following that.
Backports commit cb4add334a5a8db263c20c33c5365be3868f8967 from qemu
Do the cast to uintptr_t within the helper, so that the compiler
can type check the pointer argument. We can also do some more
sanity checking of the index argument.
Backports commit 07ea28b41830f946de3841b0ac61a3413679feb9 from qemu
Depending on the host abi, float16, aka uint16_t, values are
passed and returned either zero-extended in the host register
or with garbage at the top of the host register.
The tcg code generator has so far been assuming garbage, as that
matches the x86 abi, but this is incorrect for other host abis.
Further, target/arm has so far been assuming zero-extended results,
so that it may store the 16-bit value into a 32-bit slot with the
high 16-bits already clear.
Rectify both problems by mapping "f16" in the helper definition
to uint32_t instead of (a typedef for) uint16_t. This forces
the host compiler to assume garbage in the upper 16 bits on input
and to zero-extend the result on output.
Backports commit 6c2be133a7478e443c99757b833d0f265c48e0a6 from qemu
The FRECPX instructions should (like most other floating point operations)
honour the FPCR.FZ bit which specifies whether input denormals should
be flushed to zero (or FZ16 for the half-precision version).
We forgot to implement this, which doesn't affect the results (since
the calculation doesn't actually care about the mantissa bits) but did
mean we were failing to set the FPSR.IDC bit.
Backports commit 2cfbf36ec07f7cac1aabb3b86f1c95c8a55424ba from qemu
AMD Zen expose the Intel equivalant to Speculative Store Bypass Disable
via the 0x80000008_EBX[25] CPUID feature bit.
This needs to be exposed to guest OS to allow them to protect
against CVE-2018-3639.
Backports commit 403503b162ffc33fb64cfefdf7b880acf41772cd from qemu
"Some AMD processors only support a non-architectural means of enabling
speculative store bypass disable (SSBD). To allow a simplified view of
this to a guest, an architectural definition has been created through a new
CPUID bit, 0x80000008_EBX[25], and a new MSR, 0xc001011f. With this, a
hypervisor can virtualize the existence of this definition and provide an
architectural method for using SSBD to a guest.
Add the new CPUID feature, the new MSR and update the existing SSBD
support to use this MSR when present." (from x86/speculation: Add virtualized
speculative store bypass disable support in Linux).
Backports commit cfeea0c021db6234c154dbc723730e81553924ff from qemu
New microcode introduces the "Speculative Store Bypass Disable"
CPUID feature bit. This needs to be exposed to guest OS to allow
them to protect against CVE-2018-3639.
Backports commit d19d1f965904a533998739698020ff4ee8a103da from qemu
Excepting MOVPRFX, which isn't a reduction. Presumably it is
placed within the group because of its encoding.
Backports commit 047cec971d2791b206677b954227ea92ff7ee3db from qemu
These were the instructions that were stubbed out when
introducing the decode skeleton.
Backports commit 39eea56172e668cc4cca611ed9166779df54ac63 from qemu
Including only 4, as-yet unimplemented, instruction patterns
so that the whole thing compiles.
Backports commit 38388f7ee3adc04a7e7246c04352451c4f8d00fb from qemu
This is a preparation for the coming feature of creating dynamically an XML
description for the ARM sysregs.
Add "_S" suffix to the secure version of sysregs that have both S and NS views
Replace (S) and (NS) by _S and _NS for the register that are manually defined,
so all the registers follow the same convention.
Backports commit 9c513e786d85cc58b8ba56a482566f759e0835b6 from qemu
This is a preparation for the coming feature of creating dynamically an XML
description for the ARM sysregs.
A register has ARM_CP_NO_GDB enabled will not be shown in the dynamic XML.
This bit is enabled automatically when creating CP_ANY wildcard aliases.
This bit could be enabled manually for any register we want to remove from the
dynamic XML description.
Backports commit 1f16378718fa87d63f70d0797f4546a88d8e3dd7 from qemu
The ARM ARM specifies FZ16 is suppressed for conversions. Rather than
pushing this logic into the softfloat code we can simply save the FZ
state and temporarily disable it for the softfloat call.
Backports commit 0acb9e7cb341cd767e39ec0875c8706eb2f1c359 from qemu
Instead of passing env and leaving it up to the helper to get the
right fpstatus we pass it explicitly. There was already a get_fpstatus
helper for neon for the 32 bit code. We also add an get_ahp_flag() for
passing the state of the alternative FP16 format flag. This leaves
scope for later tracking the AHP state in translation flags.
Backports commit 486624fcd3eaca6165ab8401d73bbae6c0fb81c1 from qemu
The property legacy-cache will be used to control the cache information.
If user passes "-cpu legacy-cache" then older information will
be displayed even if the hardware supports new information. Otherwise
use the statically loaded cache definitions if available.
Renamed the previous cache structures to legacy_*. If there is any change in
the cache information, then it needs to be initialized in builtin_x86_defs.
Backports commit ab8f992e3e63e91be257e4e343d386dae7be4bcb from qemu
Instead of having a collection of macros that need to be used in
complex expressions to build CPUID data, define a CPUCacheInfo
struct that can hold information about a given cache. Helper
functions will take a CPUCacheInfo struct as input to encode
CPUID leaves for a cache.
This will help us ensure consistency between cache information
CPUID leaves, and make the existing inconsistencies in CPUID info
more visible.
Backports commit 7e3482f824809e1f6ffeb5bb8103ba27a7d1a52a from qemu
The CLDEMOTE instruction hints to hardware that the cache line that
contains the linear address should be moved("demoted") from
the cache(s) closest to the processor core to a level more distant
from the processor core. This may accelerate subsequent accesses
to the line by other cores in the same coherence domain,
especially if the line was written by the core that demotes the line.
Intel Snow Ridge has added new cpu feature, CLDEMOTE.
The new cpu feature needs to be exposed to guest VM.
The bit definition:
CPUID.(EAX=7,ECX=0):ECX[bit 25] CLDEMOTE
The release document ref below link:
https://software.intel.com/sites/default/files/managed/c5/15/\
architecture-instruction-set-extensions-programming-reference.pdf
Backports commit 0da0fb062841d0dcd8ba47e4a989d2e952cdf0ff from qemu
A new cpu model called "KnightsMill" is added to model Knights Mill
processors. Compared to "Skylake-Server" cpu model, the following
features are added:
avx512_4vnniw avx512_4fmaps avx512pf avx512er avx512_vpopcntdq
and the following features are removed:
pcid invpcid clflushopt avx512dq avx512bw clwb smap rtm mpx
xsavec xgetbv1 hle
Backports commit a18495159a35e9c5973d9aa0f612a97318bf684d from qemu
All the hard work is already done by vfp_expand_imm, we just need to
make sure we pick up the correct size.
Backports commit 6ba28ddb9be37bdb67e3e38007a53ccbdcd010df from qemu
In commit d81ce0ef2c4f105 we added an extra float_status field
fp_status_fp16 for Arm, but forgot to initialize it correctly
by setting it to float_tininess_before_rounding. This currently
will only cause problems for the new V8_FP16 feature, since the
float-to-float conversion code doesn't use it yet. The effect
would be that we failed to set the Underflow IEEE exception flag
in all the cases where we should.
Add the missing initialization.
Backports commit bcc531f0364796104df4443d17f99b5fb494eca2 from qemu
Update the variable checked by the loop condition (expDiff).
Backport the update from Previous.
Fixes: 591596b77a ("target/m68k: add fmod/frem")
Backports commit 5a73e7f313da0e4657bcac61b533ced71b0d0224 from qemu
Use write_fp_dreg and clear_vec_high to zero the bits
that need zeroing for these cases.
Backports commit 9a9f1f59521f46e8ff4527d9a2b52f83577e2aa3 from qemu
The instruction "ucvtf v0.4h, v04h, #2", with input 0x8000u,
overflows the intermediate float16 to infinity before we have a
chance to scale the output. Use float64 as the intermediate type
so that no input argument (uint32_t in this case) can overflow
or round before scaling. Given the declared argument, the signed
int32_t function has the same problem.
When converting from float16 to integer, using u/int32_t instead
of u/int16_t means that the bounding is incorrect.
Backports commit 88808a022c06f98d81cd3f2d105a5734c5614839 from qemu
While we have some of the scalar paths for FCVT for fp16,
we failed to decode the fp16 version of these instructions.
Backports commit d0ba8e74acd299b092786ffc30b306638d395a9e from qemu
While we have some of the scalar paths for *CVF for fp16,
we failed to decode the fp16 version of these instructions.
Backports commit a6117fae4576edfe7a5a5b802a742c33112c0993 from qemu
This implements all of the v8.1-Atomics instructions except
for compare-and-swap, which is decoded elsewhere.
Backports commit 74608ea45434c9b07055b21885e093528c5ed98c from qemu
The insns in the ARMv8.1-Atomics are added to the existing
load/store exclusive and load/store reg opcode spaces.
Rearrange the top-level decoders for these to accomodate.
The Atomics insns themselves still generate Unallocated.
Backports commit 68412d2ecedbab5a43b0d346cddb27e00d724aff from qemu
Notes:
- DISAS_TOO_MANY replaces the former "break" in the translation loop.
However, care must be taken not to overwrite a previous condition
in is_jmp; that's why in translate_insn we first check is_jmp and
return if it's != DISAS_NEXT.
- Added an assert in translate_insn, before exiting due to an exception,
to make sure that is_jmp is set to DISAS_NORETURN (the exception
generation function always sets it.)
- Added an assert for the default case in is_jmp's switch.
Backports commit 18f440edfb974feaff8490d4861844b5a2b7a3b5 from qemu
No changes to the logic here; this is just to make the diff
that follows easier to read.
While at it, remove the unnecessary 'struct' in
'struct TranslationBlock'.
Note that checkpatch complains with a false positive:
ERROR: space prohibited after that '&' (ctx:WxW)
\#75: FILE: target/mips/translate.c:20220:
+ ctx->kscrexist = (env->CP0_Config4 >> CP0C4_KScrExist) & 0xff;
^
Backports commit 12be92588cf26a192f1b62846906983fc1e102a7 from qemu
Notes:
- BS_EXCP in generate_exception_err and after hen_helper_wait
becomes DISAS_NORETURN, because we do not return after
raising an exception.
- Some uses of BS_EXCP are misleading in that they're used
only as a "not BS_STOP" exit condition, i.e. they have nothing
to do with an actual exception. For those cases, define
and use DISAS_EXIT, which is clearer. With this and the
above change, BS_EXCP goes away completely.
- fix a comment typo (s/intetrupt/interrupt/).
Backports commit b28425babc2ad4b90cd87d07a1809d3322b9c065 from qemu
The TB after BS_STOP is not fixed (e.g. helper_mtc0_hwrena
changes hflags, which ends up changing the TB flags via
cpu_get_tb_cpu_state). This requires a full lookup (i.e.
with flags) via lookup_and_goto_ptr instead of gen_goto_tb,
since the latter only looks at the PC for in-page goto's. Fix it.
Backports commit cd314a7d0190a03122ca0606ecf71b4b873a22c6 from qemu.
Notes:
- Moved the cross-page check from the end of translate_insn to
init_disas_context.
Backports commit 6e61bc941025345ab01c48d116bef60bb8990406 from qemu
Notes:
- pc and npc are left unmodified, since they can point to out-of-TB
jump targets.
- Got rid of last_pc in gen_intermediate_code(), using base.pc_next
instead. Only update pc_next (1) on a breakpoint (so that tb->size
includes the insn), and (2) after reading the current instruction
from memory. This allows us to use base.pc_next in the BP check,
which is what the translator loop does.
Backports commit af00be490b30d7f576d12ac7b2bc5406ca6fda3f from qemu
While at it, use int for both num_insns and max_insns to make
sure we have same-type comparisons.
Backports commit b542683d77b4f56cef0221b267c341616d87bce9 from qemu
If the PC is in the last page of the address space, next_page_start
overflows to 0. Fix it.
Backports commit 6cd79443d33e6ba6b4c5b787eb713ca1cec56328 from qemu
If the PC is in the last page of the address space, next_page_start
overflows to 0. Fix it.
Backports commit bfe7ad5be77a6a8925a7ab1628452c8942222102 from qemu
The Werror stems from the compiler finding a path through the second
switch via a missing default case in which src1 is uninitialized, and
not being able to prove that the missing default case is unreachable
due to the first switch.
Simplify the second switch to merge default with OS_LONG,
which returns directly. This removes the unreachable path.
Backports commit 5cbc61110738accb16ff8ed1f08a32906d02790f from qemu.
For v8M the instructions VLLDM and VLSTM support lazy saving
and restoring of the secure floating-point registers. Even
if the floating point extension is not implemented, these
instructions must act as NOPs in Secure state, so they can
be used as part of the secure-to-nonsecure call sequence.
Fixes: https://bugs.launchpad.net/qemu/+bug/1768295
Backports commit b1e5336a9899016c53d59eba53ebf6abcc21995c from qemu
The duplication of id_tlbtr_reginfo was unintentionally added within
3281af8114c6b8ead02f08b58e3c36895c1ea047 which should have been
id_mpuir_reginfo.
The effect was that for OMAP and StrongARM CPUs we would
incorrectly UNDEF writes to MPUIR rather than NOPing them.
Backports commit 100061121c1f69a672ce7bb3e9e3781f8018f9f6 from qemu
Path analysis shows that size == 3 && !is_q has been eliminated.
Fixes: Coverity CID1385853
Backports commit a8766e3172c1671cab297c1ef4566a3c5d094822 from qemu
The (size > 3 && !is_q) condition is identical to the preceeding test
of bit 3 in immh; eliminate it. For the benefit of Coverity, assert
that size is within the bounds we expect.
Fixes: Coverity CID1385846
Fixes: Coverity CID1385849
Fixes: Coverity CID1385852
Fixes: Coverity CID1385857
Backports commit 8dae46970532afcf93470b00e83ca9921980efc3 from qemu
floatx80_sin() and floatx80_cos() are derived from one
sincos() function. They have both unused code coming from
their common origin. Remove it.
Backports commit 6361d2984ce88912976a34e1797a5ad5139c649b from qemu
This patch fixes decrement of the pointers for subx mem, mem instructions.
Without the patch pointers are decremented by OS_* constant value instead of
retrieving the corresponding data size and using it as a decrement.
Backports commit 355d4d1c00e708907ff391c24ca708f1c9c06bf0 from qemu
This is a bug fix to ensure 64-bit reads of these registers don't read
adjacent data.
Backports commit e4e91a217c17fff4045dd4b423cdcb471b3d6a0e from qemu
Because the design of the PMU requires that the counter values be
converted between their delta and guest-visible forms for mode
filtering, an additional hook which occurs before the EL is changed is
necessary.
Backports commit b5c53d1b3886387874f8c8582b205aeb3e4c3df6 from qemu
This eliminates the need for fetching it from el_change_hook_opaque, and
allows for supporting multiple el_change_hooks without having to hack
something together to find the registered opaque belonging to GICv3.
Backports commit d5a5e4c93dae0dc3feb402cf7ee78d846da1a7e1 from qemu
In commit 95695effe8caa552b8f2 we changed the v7M/v8M stack
pop code to use a new v7m_stack_read() function that checks
whether the read should fail due to an MPU or bus abort.
We missed one call though, the one which reads the signature
word for the callee-saved register part of the frame.
Correct the omission.
Backports commit 4818bad98c8212fbbb0525d10761b6b65279ab92 from qemu
Remove a stale TODO comment -- we have now made the arm_ldl_ptw()
and arm_ldq_ptw() functions propagate physical memory read errors
out to their callers.
Backports commit 145772707fe80395b87c244ccf5699a756f1946b from qemu
68000 CPUs do not save format in the exception stack frame.
This patch adds feature checking to prevent format saving for 68000.
m68k_ret() already includes this modification, this patch fixes
the exception processing function too.
Backports commit 000761dc0c97d70e7314db3e8f52783880325a22 from qemu
In icount mode, instructions that access io memory spaces in the middle
of the translation block invoke TB recompilation. After recompilation,
such instructions become last in the TB and are allowed to access io
memory spaces.
When the code includes instruction like i386 'xchg eax, 0xffffd080'
which accesses APIC, QEMU goes into an infinite loop of the recompilation.
This instruction includes two memory accesses - one read and one write.
After the first access, APIC calls cpu_report_tpr_access, which restores
the CPU state to get the current eip. But cpu_restore_state_from_tb
resets the cpu->can_do_io flag which makes the second memory access invalid.
Therefore the second memory access causes a recompilation of the block.
Then these operations repeat again and again.
This patch moves resetting cpu->can_do_io flag from
cpu_restore_state_from_tb to cpu_loop_exit* functions.
It also adds a parameter for cpu_restore_state which controls restoring
icount. There is no need to restore icount when we only query CPU state
without breaking the TB. Restoring it in such cases leads to the
incorrect flow of the virtual time.
In most cases new parameter is true (icount should be recalculated).
But there are two cases in i386 and openrisc when the CPU state is only
queried without the need to break the TB. This patch fixes both of
these cases.
Backports commit afd46fcad2dceffda35c0586f5723c127b6e09d8 from qemu
The parameters for tcg_gen_insn_start are target_ulong, which may be split
into two TCGArg parameters for storage in the opcode on 32-bit hosts.
Fixes the ARM target and its direct use of tcg_set_insn_param, which would
set the wrong argument in the 64-on-32 case.
Backports commit 9743cd5736263e90d312b2c33bd739ffe1eae70d from qemu
Currently our PMSAv7 and ARMv7M MPU implementation cannot handle
MPU region sizes smaller than our TARGET_PAGE_SIZE. However we
report that in a slightly confusing way:
DRSR[3]: No support for MPU (sub)region alignment of 9 bits. Minimum is 10
The problem is not the alignment of the region, but its size;
tweak the error message to say so:
DRSR[3]: No support for MPU (sub)region size of 512 bytes. Minimum is 1024.
Backports commit 8aec759b45fa6986c0b159cb27353d6abb0d5d73 from qemu
Make sure we are not treating architecturally Undefined instructions
as a SWP, by verifying the opcodes as per section A8.8.229 of ARMv7-A
specification. Bits [21:20] must be zero for this to be a SWP or SWPB.
We also choose to UNDEF for the architecturally UNPREDICTABLE case of
bits [11:8] not being zero.
Backports commit c4869ca630a57f4269bb932ec7f719cef5bc79b8 from qemu
In commit 7073fbada733c8d10992f00772c9b9299d740e9b, the `andn` instruction
was implemented via `tcg_gen_andc` but passes the operands in the wrong
order:
- X86 defines `andn dest,src1,src2` as: dest = ~src1 & src2
- TCG defines `andc dest,src1,src2` as: dest = src1 & ~src2
The following simple test shows the issue:
int main(void) {
uint32_t ret = 0;
__asm (
"mov $0xFF00, %%ecx\n"
"mov $0x0F0F, %%eax\n"
"andn %%ecx, %%eax, %%ecx\n"
"mov %%ecx, %0\n"
: "=r" (ret));
printf("%08X\n", ret);
return 0;
}
This patch fixes the problem by simply swapping the order of the two last
arguments in `tcg_gen_andc_tl`.
Backports commit 5cd10051c2e02b7a86eae49919d6c65a87dbea46 from qemu
For debug exceptions due to breakpoints or the BKPT instruction which
are taken to AArch32, the Fault Address Register is architecturally
UNKNOWN. We were using that as license to simply not set
env->exception.vaddress, but this isn't correct, because it will
expose to the guest whatever old value was in that field when
arm_cpu_do_interrupt_aarch32() writes it to the guest IFSR. That old
value might be a FAR for a previous guest EL2 or secure exception, in
which case we shouldn't show it to an EL1 or non-secure exception
handler. It might also be a non-deterministic value, which is bad
for record-and-replay.
Clear env->exception.vaddress before taking breakpoint debug
exceptions, to avoid this minor information leak.
Backports commit 548f514cf89dd9ab39c0cb4c063097bccf141fdd from qemu
Now that we have a helper function specifically for the BRK and
BKPT instructions, we can set the exception.fsr there rather
than in arm_cpu_do_interrupt_aarch32(). This allows us to
use our new arm_debug_exception_fsr() helper.
In particular this fixes a bug where we were hardcoding the
short-form IFSR value, which is wrong if the target exception
level has LPAE enabled.
Fixes: https://bugs.launchpad.net/qemu/+bug/1756927
Backports commit 62b94f31d0df75187bb00684fc29e8639eacc0c5 from qemu
When a debug exception is taken to AArch32, it appears as a Prefetch
Abort, and the Instruction Fault Status Register (IFSR) must be set.
The IFSR has two possible formats, depending on whether LPAE is in
use. Factor out the code in arm_debug_excp_handler() which picks
an FSR value into its own utility function, update it to use
arm_fi_to_lfsc() and arm_fi_to_sfsc() rather than hard-coded constants,
and use the correct condition to select long or short format.
In particular this fixes a bug where we could select the short
format because we're at EL0 and the EL1 translation regime is
not using LPAE, but then route the debug exception to EL2 because
of MDCR_EL2.TDE and hand EL2 the wrong format FSR.
Backports commit 81621d9ab8a0f07956e67850b15eebf6d6992eec from qemu
The MDCR_EL2.TDE bit allows the exception level targeted by debug
exceptions to be set to EL2 for code executing at EL0. We handle
this in the arm_debug_target_el() function, but this is only used for
hardware breakpoint and watchpoint exceptions, not for the exception
generated when the guest executes an AArch32 BKPT or AArch64 BRK
instruction. We don't have enough information for a translate-time
equivalent of arm_debug_target_el(), so instead make BKPT and BRK
call a special purpose helper which can do the routing, rather than
the generic exception_with_syndrome helper.
Backports commit c900a2e62dd6dde11c8f5249b638caad05bb15be from qemu
In OE project 4.15 linux kernel boot hang was observed under
single cpu aarch64 qemu. Kernel code was in a loop waiting for
vtimer arrival, spinning in TC generated blocks, while interrupt
was pending unprocessed. This happened because when qemu tried to
handle vtimer interrupt target had interrupts disabled, as
result flag indicating TCG exit, cpu->icount_decr.u16.high,
was cleared but arm_cpu_exec_interrupt function did not call
arm_cpu_do_interrupt to process interrupt. Later when target
reenabled interrupts, it happened without exit into main loop, so
following code that waited for result of interrupt execution
run in infinite loop.
To solve the problem instructions that operate on CPU sys state
(i.e enable/disable interrupt), and marked as DISAS_UPDATE,
should be considered as DISAS_EXIT variant, and should be
forced to exit back to main loop so qemu will have a chance
processing pending CPU state updates, including pending
interrupts.
This change brings consistency with how DISAS_UPDATE is treated
in aarch32 case.
Backports commit a75a52d62418dafe462be4fe30485501d1010bb9 from qemu
Add an Error argument to cpu_exec_init() to let users collect the
error. This is in preparation to change the CPU enumeration logic
in cpu_exec_init(). With the new enumeration logic, cpu_exec_init()
can fail if cpu_index values corresponding to max_cpus have already
been handed out.
Since all current callers of cpu_exec_init() are from instance_init,
use error_abort Error argument to abort in case of an error.
Backports commit 5a790cc4b942e651fec7edc597c19b637fad5a76 from qemu
SRC_EA() and gen_extend() can return either a temporary
TCGv or a memory allocated one. Mark them when they are
allocated, and free them automatically at end of the
instruction translation.
We want to free locally allocated TCGv to avoid
overflow in sequence like:
0xc00ae406: movel %fp@(-132),%fp@(-268)
0xc00ae40c: movel %fp@(-128),%fp@(-264)
0xc00ae412: movel %fp@(-20),%fp@(-212)
0xc00ae418: movel %fp@(-16),%fp@(-208)
0xc00ae41e: movel %fp@(-60),%fp@(-220)
0xc00ae424: movel %fp@(-56),%fp@(-216)
0xc00ae42a: movel %fp@(-124),%fp@(-252)
0xc00ae430: movel %fp@(-120),%fp@(-248)
0xc00ae436: movel %fp@(-12),%fp@(-260)
0xc00ae43c: movel %fp@(-8),%fp@(-256)
0xc00ae442: movel %fp@(-52),%fp@(-276)
0xc00ae448: movel %fp@(-48),%fp@(-272)
...
That can fill a lot of TCGv entries in a sequence,
especially since 15fa08f845 ("tcg: Dynamically allocate TCGOps")
we have no limit to fill the TCGOps cache and we can fill
the entire TCG variables array and overflow it.
Backports commit ecc207d2fc1d45fabb16c38742a6675a7ba56cbc from qemu
Intel processor trace should be disabled when
CPUID.(EAX=14H,ECX=0H).ECX.[bit31] is set.
Generated packets which contain IP payloads will have LIP
values when this bit is set, or IP payloads will have RIP
values.
Currently, The information of CPUID 14H is constant to make
live migration safty and this bit is always 0 in guest even
if host support LIP values.
Guest sees the bit is 0 will expect IP payloads with RIP
values, but the host CPU will generate IP payloads with
LIP values if this bit is set in HW.
To make sure the value of IP payloads correctly, Intel PT
should be disabled when bit[31] is set.
Backports relevant parts of commit c078ca968c6c7cb62781c1843d840cb0f5c72781 from qemu
cpu_init(cpu_model) were replaced by cpu_create(cpu_type) so
no users are left, remove it.
Backports commit 3f71e724e283233753f1b5b3d6a30948d3084636 from qemu
With all targets defining CPU_RESOLVING_TYPE, refactor
cpu_parse_cpu_model(type, cpu_model) to parse_cpu_model(cpu_model)
so that callers won't have to know internal resolving cpu
type. Place it in exec.c so it could be called from both
target independed vl.c and *-user/main.c.
That allows us to stop abusing cpu type from
MachineClass::default_cpu_type
as resolver class in vl.c which were confusing part of
cpu_parse_cpu_model().
Also with new parse_cpu_model(), the last users of cpu_init()
in null-machine.c and bsd/linux-user targets could be switched
to cpu_create() API and cpu_init() API will be removed by
follow up patch.
With no longer users left remove MachineState::cpu_model field,
new code should use MachineState::cpu_type instead and
leave cpu_model parsing to generic code in vl.c.
Backports commit 2278b93941d42c30e2950d4b8dff4943d064e7de from qemu
define default CPU type in generic way in pc_machine_class_init()
and let common machine code to handle cpu_model parsing
Patch also introduces TARGET_DEFAULT_CPU_TYPE define for 2 purposes:
* make foo_machine_class_init() look uniform on every target
* use define in [bsd|linux]-user targets to pick default
cpu type
Backports commit 311ca98d16bbb6a2a38b38ba898baa4a4d4ab9a7 from qemu
Considering that features are converted to global properties and
global properties are automatically applied to every new instance
of created CPU (at object_new() time), there is no point in
parsing cpu_model string every time a CPU created. So move
parsing outside CPU creation loop and do it only once.
Parsing also should be done before any CPU is created so that
features would affect the first CPU a well.
Backports commit 6aff24c6a61c6fec31e555c7748ba6085b7b2c06 from qemu
Considering that features are converted to global properties and
global properties are automatically applied to every new instance
of created CPU (at object_new() time), there is no point in
parsing cpu_model string every time a CPU created. So move
parsing outside CPU creation loop and do it only once.
Parsing also should be done before any CPU is created so that
features would affect the first CPU a well.
Backports commit 6aff24c6a61c6fec31e555c7748ba6085b7b2c06 from qemu
Currently CPUClass->parse_features() is used to parse -cpu
features string and set properties on created CPU instances.
But considering that features specified by -cpu apply to every
created CPU instance, it doesn't make sense to parse the same
features string for every CPU created. It also makes every target
that cares about parsing features string explicitly call
CPUClass->parse_features() parser, which gets in a way if we
consider using generic device_add for CPU hotplug as device_add
has not a clue about CPU specific hooks.
Turns out we can use global properties mechanism to set
properties on every created CPU instance for a given type. That
way it's possible to convert CPU features into a set of global
properties for CPU type specified by -cpu cpu_model and common
Device.device_post_init() will apply them to CPU of given type
automatically regardless whether it's manually created CPU or CPU
created with help of device_add.
Backports commits 62a48a2a5798425997152dea3fc48708f9116c04 and
f313369fdb78f849ecbbd8e5d88f01ddf38786c8 from qemu
it will be used for providing to cpu name resolving class for
parsing cpu model for system and user emulation code.
Along with change add target to null-machine tests, so
that when switch to CPU_RESOLVING_TYPE happens,
it would ensure that null-machine usecase still works.
Backports commit 0dacec874fa3b3fd34b0d0670fa257efdcbbebd0 from qemu
use new M68K_CPU_TYPE_NAME to compose CPU type names
and get rid of intermediate M68kCPUInfo/register_cpu_type()
which is replaced by static TypeInfo array.
Backports commit f61797bd947cff86b12036917b35ebc38628e4df from qemu
