Since FlatViews are shared now and ASes not, this gets rid of
address_space_init_shareable().
This should cause no behavioural change.
Backports commit b516572f31c0ea0937cd9d11d9bd72dd83809886 from qemu
This allows sharing flat views between address spaces (AS) when
the same root memory region is used when creating a new address space.
This is done by walking through all ASes and caching one FlatView per
a physical root MR (i.e. not aliased).
This removes search for duplicates from address_space_init_shareable() as
FlatViews are shared elsewhere and keeping as::ref_count correct seems
an unnecessary and useless complication.
This should cause no change and memory use or boot time yet.
Backports commit 967dc9b1194a9281124b2e1ce67b6c3359a2138f from qemu
This renames some helpers to reflect better what they do.
This should cause no behavioural change.
Backports commit 8629d3fcb77e9775e44d9051bad0fb5187925eae from qemu
FlatView's will be shared between AddressSpace's and subpage_t
and MemoryRegionSection cannot store AS anymore, hence this change.
In particular, for:
typedef struct subpage_t {
MemoryRegion iomem;
- AddressSpace *as;
+ FlatView *fv;
hwaddr base;
uint16_t sub_section[];
} subpage_t;
struct MemoryRegionSection {
MemoryRegion *mr;
- AddressSpace *address_space;
+ FlatView *fv;
hwaddr offset_within_region;
Int128 size;
hwaddr offset_within_address_space;
bool readonly;
};
This should cause no behavioural change.
Backports commit 166206845f7fd75e720e6feea0bb01957c8da07f from qemu
As we are going to share FlatView's between AddressSpace's,
and AddressSpaceDispatch is a structure to perform quick lookup
in FlatView, this moves ASD to FlatView.
After previosly open coded ASD rendering, we can also remove
as->next_dispatch as the new FlatView pointer is stored
on a stack and set to an AS atomically.
flatview_destroy() is executed under RCU instead of
address_space_dispatch_free() now.
This makes mem_begin/mem_commit to work with ASD and mem_add with FV
as later on mem_add will be taking FV as an argument anyway.
This should cause no behavioural change.
Backports commit 66a6df1dc6d5b28cc3e65db0d71683fbdddc6b62 from qemu
machine_class_base_init() member name is allocated by
machine_class_base_init(), but not freed by
machine_class_finalize(). Simply freeing there doesn't work,
because DEFINE_PC_MACHINE() overwrites it with a literal string.
Fix DEFINE_PC_MACHINE() not to overwrite it, and add the missing
free to machine_class_finalize().
Backports commit 8ea753718b2d1a42e9ce7b8db9f5e4e1f330e827 from qemu
The script used for converting from QEMUMachine had used one
DEFINE_MACHINE() per machine registered. In cases where multiple
machines are registered from one source file, avoid the excessive
generation of module init functions by reverting this unrolling.
Backports commit 8a661aea0e7f6e776c6ebc9abe339a85b34fea1d from qemu
Convert all machines to use DEFINE_MACHINE() instead of QEMUMachine
automatically using a script.
Backports commit e264d29de28c5b0be3d063307ce9fb613b427cc3 from qemu
The macro will allow easy registration of a TYPE_MACHINE subclass, using
only the machine name and a MachineClass initialization function as
parameter.
Backports commit ed0b6de343448d1014b53bcf541041373322fa1c from qemu
Now all TYPE_MACHINE subclasses use MACHINE_TYPE_NAME to generate the
class name. So instead of requiring each subclass to set
MachineClass::name manually, we can now set it automatically at the
TYPE_MACHINE class_base_init() function.
Backports commit 98cec76a7076c4a38e16f1a9de170a7942b3be54 from qemu
Now that all non-abstract TYPE_MACHINE subclasses have the -machine
suffix, add an assert to ensure this will be always true.
Backports commit dcb3d601115eed77aef543fe3a920adc17544e06 from qemu
The macro will be useful to ensure the machine class names follow the
right format to make machine class lookup by class name work correctly.
Backports commit c84a8f01b2a5d8bf98c447796d4a747333a5b1fd from qemu
This removes the following fields from QEMUMachine: family, alias,
reset, hot_add_cpu, units_per_default_bus, no_serial, no_parallel,
use_virtcon, use_sclp, no_floppy, no_cdrom, default_display,
compat_props, and hw_version.
The only users of those fields were already converted to use QOM and
MachineClass directly, so they are not needed anymore.
Backports commit d48f4fa69eb3efb03a2efe2e4606a97a17cf222f from qemu
Now that we have a DEFINE_PC_MACHINE helper macro that just requires an
initialization function, it is trivial to convert them to register a QOM
machine class directly, instead of using QEMUMachine.
Backports commit 865906f7fdadd2732441ab158787f81f6a212bfe from qemu
This removes the following fields from QEMUMachine: family, alias,
reset, hot_add_cpu, units_per_default_bus, no_serial, no_parallel,
use_virtcon, use_sclp, no_floppy, no_cdrom, default_display,
compat_props, and hw_version.
The only users of those fields were already converted to use QOM and
MachineClass directly, so they are not needed anymore.
Backports commit d48f4fa69eb3efb03a2efe2e4606a97a17cf222f from qemu
Simplify a bit the code by using g_strdup_printf() and store it in a
non-const value so casting is no longer needed, and ownership is
clearer.
Backports commit f73480c36f49562556b80bb5bf8acc45e20dcca1 from qemu
Now that CPUs show up in the help text of "-device ?",
we should group them into an appropriate category.
Backports commit ba31cc7226ebcee639f18faa90c1542bd364fba3 from qemu
Solaris 9 was released in 2002, its successor Solaris 10 was
released in 2005, and Solaris 9 was end-of-lifed in 2014.
Nobody has stepped forward to express interest in supporting
Solaris of any flavour, so removing support for the ancient
versions seems uncontroversial.
In particular, this allows us to remove a use of 'uname'
in configure that won't work if you're cross-compiling.
Backports commit 91939262ffcd3c85ea6a4793d3029326eea1d649 from qemu
Clang 3.9 passes the CONFIG_AVX2_OPT configure test. However, the
supplied <cpuid.h> does not contain the bit_AVX2 define that we use
when detecting whether the routine can be enabled.
Introduce a qemu-specific header that uses the compiler's definition
of __cpuid et al, but supplies any missing bit_* definitions needed.
This avoids introducing any extra ifdefs to util/bufferiszero.c, and
allows quite a few to be removed from tcg/i386/tcg-target.inc.c.
Backports commit 5dd8990841a9e331d9d4838a116291698208cbb6 from qemu
We dropped support for ia64 host CPUs in the 2.11 release (removing
the TCG backend for it, and advertising the support as being
completely removed in the changelog). However there are a few bits
and pieces of code still floating about. Remove those, too.
We can drop the check in configure for "ia64 or hppa host?"
entirely, because we don't support hppa hosts either any more.
Backports commit b1cef6d02f84bd842fb94a6109ad4e2ad873e8e5 from qemu
Move qapi-schema.json to qapi/, so it's next to its modules, and all
files get generated to qapi/, not just the ones generated for modules.
Consistently name the generated files qapi-MODULE.EXT:
qmp-commands.[ch] become qapi-commands.[ch], qapi-event.[ch] become
qapi-events.[ch], and qmp-introspect.[ch] become qapi-introspect.[ch].
This gets rid of the temporary hacks in scripts/qapi/commands.py,
scripts/qapi/events.py, and scripts/qapi/common.py.
Backports commit eb815e248f50cde9ab86eddd57eca5019b71ca78 from qemu
In my "build everything" tree, a change to the types in
qapi-schema.json triggers a recompile of about 4800 out of 5100
objects.
The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h,
qapi-types.h. Each of these headers still includes all its shards.
Reduce compile time by including just the shards we actually need.
To illustrate the benefits: adding a type to qapi/migration.json now
recompiles some 2300 instead of 4800 objects. The next commit will
improve it further.
Backports commit 9af2398977a78d37bf184d6ff6bd04c72bfbf006 from qemu
Since f3218a8 ("softfloat: add floatx80 constants")
floatx80_infinity is defined but never used.
This patch updates floatx80 functions to use
this definition.
This allows to define a different default Infinity
value on m68k: the m68k FPU defines infinity with
all bits set to zero in the mantissa.
Backports commit 0f605c889ca3fe9744166ad4149d0dff6dacb696 from qemu
Move fpu/softfloat-macros.h to include/fpu/
Export floatx80 functions to be used by target floatx80
specific implementations.
Exports:
propagateFloatx80NaN(), extractFloatx80Frac(),
extractFloatx80Exp(), extractFloatx80Sign(),
normalizeFloatx80Subnormal(), packFloatx80(),
roundAndPackFloatx80(), normalizeRoundAndPackFloatx80()
Also exports packFloat32() that will be used to implement
m68k fsinh, fcos, fsin, ftan operations.
Backports commit 88857aca93f6ec8f372fb9c8201394b0e5582034 from qemu
As some of the constants here will also be needed
elsewhere (specifically for the upcoming SVE support) we move them out
to softfloat.h.
Backports commit 026e2d6ef74000afb9049f46add4b94f594c8fb3 from qemu
Backports commit 2deb992b767d28035fac3b374c7730494ff0b43d from qemu
Also backports the fp16 changes introduced in commit f566c0474a9b9bbd9ed248607e4007e24d3358c0
This allows us to explicitly pass float16 to helpers rather than
assuming uint32_t and dealing with the result. Of course they will be
passed in i32 sized registers by default.
Backports commit 35737497008aeabce5dc381a41d3827bec486192 from qemu
This is a little bit of a departure from softfloat's original approach
as we skip the estimate step in favour of a straight iteration. There
is a minor optimisation to avoid calculating more bits of precision
than we need however this still brings a performance drop, especially
for float64 operations.
Backports commit c13bb2da9eedfbc5886c8048df1bc1114b285fb0 from qemu
The compare function was already expanded from a macro. I keep the
macro expansion but move most of the logic into a compare_decomposed.
Backports commit 0c4c90929143a530730e2879204a55a30bf63758 from qemu
Let's do the same re-factor treatment for minmax functions. I still
use the MACRO trick to expand but now all the checking code is common.
Backports commit 89360067071b1844bf745682e18db7dde74cdb8d from qemu
This is one of the simpler manipulations you could make to a floating
point number.
Backports commit 0bfc9f195209593e91a98cf2233753f56a2e5c02 from qemu
These are considerably simpler as the lower order integers can just
use the higher order conversion function. As the decomposed fractional
part is a full 64 bit rounding and inexact handling comes from the
pack functions.
Backports commit c02e1fb80b553d47420f7492de4bc590c2461a86 from qemu
We share the common int64/uint64_pack_decomposed function across all
the helpers and simply limit the final result depending on the final
size.
Backports commit ab52f973a504f8de0c5df64631ba4caea70a7d9e from qemu
We can now add float16_round_to_int and use the common round_decomposed and
canonicalize functions to have a single implementation for
float16/32/64 round_to_int functions.
Backports commit dbe4d53a590f5689772b683984588b3cf6df163e from qemu
We can now add float16_muladd and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 muladd functions.
Backports commit d446830a3aac33e7221e361dad3ab1e1892646cb from qemu
We can now add float16_div and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.
Backports commit cf07323d494f4bc225e405688c2e455c3423cc40 from qemu
We can now add float16_mul and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.
Backports commit 74d707e2cc1e406068acad8e5559cd2584b1073a from qemu
We can now add float16_add/sub and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 add and sub functions.
Backports commit 6fff216769cf7eaa3961c85dee7a72838696d365 from qemu
We can now add float16_add/sub and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 add and sub functions.
Backports commit 6fff216769cf7eaa3961c85dee7a72838696d365 from qemu
This defines the same set of common constants for float 16 as defined
for 32 and 64 bit floats. These are often used by target helper
functions. I've also removed constants that are not used by anybody.
Backports commit efd4829edfa036c5506a16d05c91268faa1f6332 from qemu
This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.
Backports commit 28136775cd99c628f7d7c642b04eb87f062efef8 from qemu
As cpu.h is another typically widely included file which doesn't need
full access to the softfloat API we can remove the includes from here
as well. Where they do need types it's typically for float_status and
the rounding modes so we move that to softfloat-types.h as well.
As a result of not having softfloat in every cpu.h call we now need to
add it to various helpers that do need the full softfloat.h
definitions.
Backports commit 24f91e81b65fcdd0552d1f0fcb0ea7cfe3829c19 from qemu
The main culprit here is bswap.h which pulled in softfloat.h so it
could use the types in its CPU_Float* and ldfl/stfql functions. As
bswap.h is very widely included this added a compile dependency every
time we touch softfloat.h. Move the typedefs for each float type into
their own file so we don't re-build the world every time we tweak the
main softfloat.h header.
Backports commit cfd88fc6f2722def193f5ef271381d8f6e2a2526 from qemu
It's not actively built and when enabled things fail to compile. I'm
not sure the type-checking is really helping here. Seeing as we "own"
our softfloat now lets remove the cruft.
Backports commit a9579fff616563ca34977af68c9646c8f7be1120 from qemu
This will be required when expanding the MINMAX() macro for 16
bit/half-precision operations.
Backports commit 210cbd4910ae9e41e0a1785b96890ea2c291b381 from qemu
This cleanup makes the number of objects depending on qapi/qmp/qlist.h
drop from 4551 (out of 4743) to 16 in my "build everything" tree.
While there, separate #include from file comment with a blank line.
Backports commit 47e6b297e76007c04a1e9c492006fe093d932cd9 from qemu
This generic function (along with its implementations for different
types) determines whether two QObjects are equal.
Backports commit b38dd678a21582e03ecd2dec76ccf8290455628a from qemu
The macro expansions of qdict_put_TYPE() and qlist_append_TYPE() need
qbool.h, qnull.h, qnum.h and qstring.h to compile. We include qnull.h
and qnum.h in the headers, but not qbool.h and qstring.h. Works,
because we include those wherever the macros get used.
Open-coding these helpers is of dubious value. Turn them into
functions and drop the includes from the headers.
This cleanup makes the number of objects depending on qapi/qmp/qnum.h
from 4551 (out of 4743) to 46 in my "build everything" tree. For
qapi/qmp/qnull.h, the number drops from 4552 to 21.
Backports commit 15280c360e54a65e2c7be1a47bfbe41dce1ef986 from qemu
compare_litqobj_to_qobj() lacks a qlit_ prefix. Moreover, "compare"
suggests -1, 0, +1 for less than, equal and greater than. The
function actually returns non-zero for equal, zero for unequal.
Rename to qlit_equal_qobject().
Its return type will be cleaned up in the next patch.
Backports commit 60cc2eb7afd40b9cbaa35a5e0b54f365ac6e49f1 from qemu
The QLIT_QFOO() macros expand into compound literals. Sadly, gcc
doesn't recognizes these as constant expressions (clang does), which
makes the macros useless for initializing objects with static storage
duration.
There is a gcc bug about it:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71713
Change the macros to expand into initializers.
Backports commit d5cd8fbf130312bea91823c41de87d55818d599b from qemu
Make visit_type_null() take an @obj argument like its buddies. This
helps keep the next commit simple.
Backports commit d2f95f4d482374485234790a6fc3cca29ebb7355 from qemu
qapi/qmp/types.h is a convenience header to include a number of
qapi/qmp/ headers. Since we rarely need all of the headers
qapi/qmp/types.h includes, we bypass it most of the time. Most of the
places that use it don't need all the headers, either.
Include the necessary headers directly, and drop qapi/qmp/types.h.
Backports commit 6b67395762a4c8b6ca94364e0a0f616a6470c46a from qemu
This renders many inclusions of qapi/qmp/q*.h superfluous. They'll be
dropped in the next few commits.
Backports commit 9f5c734d591e26186a71f9e36d752f4798df3672 from qemu
The MC68040 MMU provides the size of the access that
triggers the page fault.
This size is set in the Special Status Word which
is written in the stack frame of the access fault
exception.
So we need the size in m68k_cpu_unassigned_access() and
m68k_cpu_handle_mmu_fault().
To be able to do that, this patch modifies the prototype of
handle_mmu_fault handler, tlb_fill() and probe_write().
do_unassigned_access() already includes a size parameter.
This patch also updates handle_mmu_fault handlers and
tlb_fill() of all targets (only parameter, no code change).
Backports commit 98670d47cd8d63a529ff230fd39ddaa186156f8c from qemu
With no fixed array allocation, we can't overflow a buffer.
This will be important as optimizations related to host vectors
may expand the number of ops used.
Use QTAILQ to link the ops together.
Backports commit 15fa08f8451babc88d733bd411d4c94976f9d0f8 from qemu
Normally we create an address space for that CPU and pass that address
space into the function. Let's just do it inside to unify address space
creations. It'll simplify my next patch to rename those address spaces.
Backports commit 80ceb07a83375e3a0091591f96bd47bce2f640ce from qemu
This was never used since its introduction in commit
196ea13104f8 ("memory: Add global-locking property to memory
regions").
Backports commit e2fbe20851ceec5ccd7b539a89db0420393fb85d from qemu
In our various supported host OSes, the time_t type may be either 32
or 64 bit, and could in theory also be either signed or unsigned.
Notably, in OpenBSD time_t is a 64 bit type even if 'long' is 32
bits, so using LONG_MAX for TIME_MAX is incorrect.
Use an approach suggested by Paolo Bonzini which calculates
the maximum value of the type rather than hardcoding it;
to do this we use the TYPE_MAXIMUM macro from Gnulib.
Backports commit e7b47c22e2df14d55e3e4426688c929bf8e3f7fb from qemu
The GET and MAKE functions weren't really specific enough.
We now have a full complement of functions that convert exactly
between temporaries, arguments, tcgv pointers, and indices.
The target/sparc change is also a bug fix, which would have affected
a host that defines TCG_TARGET_HAS_extr[lh]_i64_i32, i.e. MIPS64.
Backports commit dc41aa7d34989b552efe712ffe184236216f960b from qemu
Transform TCGv_* to an "argument" or a temporary.
For now, an argument is simply the temporary index.
Backports commit ae8b75dc6ec808378487064922f25f1e7ea7a9be from qemu
DEFINE_TYPES() will help to simplify following routine patterns:
static void foo_register_types(void)
{
type_register_static(&foo1_type_info);
type_register_static(&foo2_type_info);
...
}
type_init(foo_register_types)
or
static void foo_register_types(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(type_infos); i++) {
type_register_static(&type_infos[i]);
}
}
type_init(foo_register_types)
with a single line
DEFINE_TYPES(type_infos)
where types have static definition which could be consolidated in
a single array of TypeInfo structures.
It saves us ~6-10LOC per use case and would help to replace
imperative foo_register_types() there with declarative style of
type registration.
Backports commit 38b5d79b2e8cf6085324066d84e8bb3b3bbe8548 from qemu
it will help to remove code duplication of registration
static types in places that have open coded loop to
perform batch type registering.
Backports commit aa04c9d20704fa5b9ab239d5111adbcce5f49808 from qemu
In preparation for adding tc.size to be able to keep track of
TB's using the binary search tree implementation from glib.
Backports commit e7e168f41364c6e83d0f75fc1b3ce7f9c41ccf76 from qemu
And fix the following warning when DEBUG_TB_INVALIDATE is enabled
in translate-all.c:
CC mipsn32-linux-user/accel/tcg/translate-all.o
/data/src/qemu/accel/tcg/translate-all.c: In function ‘tb_alloc_page’:
/data/src/qemu/accel/tcg/translate-all.c:1201:16: error: format ‘%lx’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘tb_page_addr_t {aka unsigned int}’ [-Werror=format=]
printf("protecting code page: 0x" TARGET_FMT_lx "\n",
^
cc1: all warnings being treated as errors
/data/src/qemu/rules.mak:66: recipe for target 'accel/tcg/translate-all.o' failed
make[1]: *** [accel/tcg/translate-all.o] Error 1
Makefile:328: recipe for target 'subdir-mipsn32-linux-user' failed
make: *** [subdir-mipsn32-linux-user] Error 2
cota@flamenco:/data/src/qemu/build ((18f3fe1...) *$)$
Backports commit 67a5b5d2f6eb6d3b980570223ba5c478487ddb6f from qemu
We have object_get_objects_root() to keep user created objects, however
no place for objects that will be used internally. Create such a
container for internal objects.
Backports commit 7c47c4ead75d0b733ee8f2f51fd1de0644cc1308 from qemu
Provide helpers to convert bitmaps to little endian format. It can be
used when we want to send one bitmap via network to some other hosts.
One thing to mention is that, these helpers only solve the problem of
endianess, but it does not solve the problem of different word size on
machines (the bitmaps managing same count of bits may contains different
size when malloced). So we need to take care of the size alignment issue
on the callers for now.
Backports commit d7788151a0807d5d2d410e3f8944d8c8a651f8d2 from qemu
We already have several files that knowingly require assert()
to work, sometimes because refactoring the code for proper
error handling has not been tackled yet; there are probably
other files that have a similar situation but with no comments
documenting the same. In fact, we have places in migration
that handle untrusted input with assertions, where disabling
the assertions risks a worse security hole than the current
behavior of losing the guest to SIGABRT when migration fails
because of the assertion. Promote our current per-file
safety-valve to instead be project-wide, and expand it to also
cover glib's g_assert().
Note that we do NOT want to encourage 'assert(side-effects);'
(that is a bad practice that prevents copy-and-paste of code to
other projects that CAN disable assertions; plus it costs
unnecessary reviewer mental cycles to remember whether a project
special-cases the crippling of asserts); and we would LIKE to
fix migration to not rely on asserts (but that takes a big code
audit). But in the meantime, we DO want to send a message
that anyone that disables assertions has to tweak code in order
to compile, making it obvious that they are taking on additional
risk that we are not going to support. At the same time, leave
comments mentioning NDEBUG in files that we know still need to
be scrubbed, so there is at least something to grep for.
It would be possible to come up with some other mechanism for
doing runtime checking by default, but which does not abort
the program on failure, while leaving side effects in place
(unlike how crippling assert() avoids even the side effects),
perhaps under the name q_verify(); but it was not deemed worth
the effort (developers should not have to learn a replacement
when the standard C macro works just fine, and it would be a lot
of churn for little gain). The patch specifically uses #error
rather than #warn so that a user is forced to tweak the header
to acknowledge the issue, even when not using a -Werror
compilation.
Backports commit 262a69f4282e44426c7a132138581d400053e0a1 from qemu
Split out maybe_out_small_movi for use with other operations
that want to add to the constant pool.
Backports commit 28eef8aaece5e83df4568d9842ab9611ec130b2c from qemu
Replace the USE_DIRECT_JUMP ifdef with a TCG_TARGET_HAS_direct_jump
boolean test. Replace the tb_set_jmp_target1 ifdef with an unconditional
function tb_target_set_jmp_target.
While we're touching all backends, add a parameter for tb->tc_ptr;
we're going to need it shortly for some backends.
Move tb_set_jmp_target and tb_add_jump from exec-all.h to cpu-exec.c.
Backports commit a85833933628384d74ec412024d55cf012640287 from qemu
Define a new MachineClass field ignore_memory_transaction_failures.
If this is flag is true then the CPU will ignore memory transaction
failures which should cause the CPU to take an exception due to an
access to an unassigned physical address; the transaction will
instead return zero (for a read) or be ignored (for a write). This
should be set only by legacy board models which rely on the old
RAZ/WI behaviour for handling devices that QEMU does not yet model.
New board models should instead use "unimplemented-device" for all
memory ranges where the guest will attempt to probe for a device that
QEMU doesn't implement and a stub device is required.
We need this for ARM boards, where we're about to implement support for
generating external aborts on memory transaction failures. Too many
of our legacy board models rely on the RAZ/WI behaviour and we
would break currently working guests when their "probe for device"
code provoked an external abort rather than a RAZ.
Backports commit ed860129acd3fcd0b1e47884e810212aaca4d21b from qemu
Used later. An enum makes expected values explicit and
bounds the value space of switches.
Backports commit 77fc6f5e28667634916f114ae04c6029cd7b9c45 from qemu
This will allow some amount of cleanup to happen before
switching the backends over to enum DisasJumpType.
Backports commit 5dc66895b0113034cd37fd5e65911d7959fc26a9 from qemu
Currently we have a rather half-baked setup for allowing CPUs to
generate exceptions on accesses to invalid memory: the CPU has a
cpu_unassigned_access() hook which the memory system calls in
unassigned_mem_write() and unassigned_mem_read() if the current_cpu
pointer is non-NULL. This was originally designed before we
implemented the MemTxResult type that allows memory operations to
report a success or failure code, which is why the hook is called
right at the bottom of the memory system. The major problem with
this is that it means that the hook can be called even when the
access was not actually done by the CPU: for instance if the CPU
writes to a DMA engine register which causes the DMA engine to begin
a transaction which has been set up by the guest to operate on
invalid memory then this will casue the CPU to take an exception
incorrectly. Another minor problem is that currently if a device
returns a transaction error then this won't turn into a CPU exception
at all.
The right way to do this is to have allow the CPU to respond
to memory system transaction failures at the point where the
CPU specific code calls into the memory system.
Define a new QOM CPU method and utility function
cpu_transaction_failed() which is called in these cases.
The functionality here overlaps with the existing
cpu_unassigned_access() because individual target CPUs will
need some work to convert them to the new system. When this
transition is complete we can remove the old cpu_unassigned_access()
code.
Backports commit 0dff0939f6fc6a7abd966d4295f06a06d7a01df9 from qemu
Move the MemTxResult type to memattrs.h. We're going to want to
use it in cpu/qom.h, which doesn't want to include all of
memory.h. In practice MemTxResult and MemTxAttrs are pretty
closely linked since both are used for the new-style
read_with_attrs and write_with_attrs callbacks, so memattrs.h
is a reasonable home for this rather than creating a whole
new header file for it.
Backports commit 3114d092b1740f9db9aa559aeb48ee387011e1da from qemu
