Commit graph

2034 commits

Author SHA1 Message Date
Andrey Yurovsky e24890a580
arm: add Cortex A7 CPU parameters
Add the "cortex-a7" CPU with features and registers matching the Cortex-A7
MPCore Technical Reference Manual and the Cortex-A7 Floating-Point Unit
Technical Reference Manual. The A7 is very similar to the A15.

Backports commit dcf578ed8cec89543158b103940e854ebd21a8cf from qemu
2018-02-26 03:44:24 -05:00
Richard Henderson 552ef4b3e6
target-i386: Use struct X86XSaveArea in fpu_helper.c
This avoids a double hand-full of magic numbers in the
xsave and xrstor helper functions.

Backports commit 3f32bd21df655e62eb271182a5c63280d631c7b3 from qemu
2018-02-26 03:38:53 -05:00
Richard Henderson 2ab4b8fa4d
tcg/i386: Extend TARGET_PAGE_MASK to the proper type
TARGET_PAGE_MASK, as defined, has type "int". We need to extend
that to the proper target width before oring in an "unsigned".

Backports commit ebb90a005da67147245cd38fb04a965a87a961b7 from qemu
2018-02-26 03:32:38 -05:00
Pranith Kumar 16d71f0f10
tcg: Optimize fence instructions
This commit optimizes fence instructions. Two optimizations are
currently implemented: (1) unnecessary duplicate fence instructions,
and (2) merging weaker fences into a stronger fence.

[rth: Merge tcg_optimize_mb back into tcg_optimize, so that we only
loop over the opcode stream once. Merge "unrelated" weaker barriers
into one stronger barrier.]

Backports commit 34f939218ce78163171addd63750e1e0300376ab from qemu
2018-02-26 03:29:59 -05:00
Pranith Kumar 533e083495
target-i386: Generate fences for x86
Backports commit cc19e497a047193db5083425957d7292c8dd3226 from qemu
2018-02-26 03:28:31 -05:00
Pranith Kumar 32b7cee81e
target-aarch64: Generate fences for aarch64
Backports commit ce1bd93f94e8d4b7117744e49652d2f907bed99f from qemu
2018-02-26 03:26:35 -05:00
Pranith Kumar 7849f8d72a
target-arm: Generate fences in ARMv7 frontend
Backports commit 61e4c432ab26526bab0f3ef746c1861415b6da29 from qemu
2018-02-26 03:22:53 -05:00
Pranith Kumar 65a73763e3
tcg/sparc: Add support for fence
Backports commit f8f03b3707b49898052fb8cd75ee31d19c8161fc from qemu
2018-02-26 03:20:39 -05:00
Pranith Kumar a6fdc24e28
tcg/s390: Add support for fence
Backports commit c9314d610e0e5da4d2cd5a36f3563d102b3294e0 from qemu
2018-02-26 03:19:41 -05:00
Pranith Kumar bdd9cad15c
tcg/ppc: Add support for fence
Backports commit 7b4af5ee8a1336bc39714b6de47924ee71fba761 from qemu
2018-02-26 03:18:43 -05:00
Pranith Kumar 5f10101245
tcg/mips: Add support for fence
Backports commit 6f0b99104a396905870edc3049310ece29b6b8d6 from qemu
2018-02-26 03:17:34 -05:00
Pranith Kumar e29cbe9640
tcg/arm: Add support for fence
Backports commit 40f191ab8226fdada185efa49c44b60d8f494890 from qemu
2018-02-26 03:13:17 -05:00
Pranith Kumar 907060b865
tcg/aarch64: Add support for fence
Backports commit c7a59c2a92592e556b9361437c9c4229917bd1e3 from qemu
2018-02-26 03:11:03 -05:00
Pranith Kumar d49bd55f52
tcg/i386: Add support for fence
Generate a 'lock orl $0,0(%esp)' instruction for ordering instead of
mfence which has similar ordering semantics.

Backports commit a7d00d4effb58889ac6df64f98ac50c9d1594149 from qemu
2018-02-26 03:10:58 -05:00
Pranith Kumar 5e44ce9be8
Introduce TCGOpcode for memory barrier
This commit introduces the TCGOpcode for memory barrier instruction.

This opcode takes an argument which is the type of memory barrier
which should be generated.

Backports commit f65e19bc2c9e8358e634d309606144ac2a3c2936 from qemu
2018-02-26 03:02:41 -05:00
Richard Henderson 66d79ac959
tcg: Merge GETPC and GETRA
The return address argument to the softmmu template helpers was
confused. In the legacy case, we wanted to indicate that there
is no return address, and so passed in NULL. However, we then
immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero
value, indicating the presence of an (invalid) return address.

Push the GETPC_ADJ subtraction down to the only point it's required:
immediately before use within cpu_restore_state_from_tb, after all
NULL pointer checks have been completed.

This makes GETPC and GETRA identical. Remove GETRA as the lesser
used macro, replacing all uses with GETPC.

Backports commit 01ecaf438b1eb46abe23392c8ce5b7628b0c8cf5 from qemu
2018-02-26 02:54:44 -05:00
Richard Henderson 91f5cf0417
tcg: Support arbitrary size + alignment
Previously we allowed fully unaligned operations, but not operations
that are aligned but with less alignment than the operation size.

In addition, arm32, ia64, mips, and sparc had been omitted from the
previous overalignment patch, which would have led to that alignment
being enforced.

Backports commit 85aa80813dd9f5c1f581c743e45678a3bee220f8 from qemu
2018-02-26 02:47:26 -05:00
Stanislav Shmarov 5f9552657e
target-i386: Fixed syscall posssible segfault
In user-mode emulation env->idt.base memory is
allocated in linux-user/main.c with
size 8*512 = 4096 (for 64-bit).
When fake interrupt EXCP_SYSCALL is thrown
do_interrupt_user checks destination privilege level
for this fake exception, and tries to read 4 bytes
at address base + (256 * 2^4)=4096, that causes
segfault.

Privlege level was checked only for int's, so lets
read dpl from memory only for this case.

Backports commit 885b7c44e4f8b7a012a92770a0dba8b238662caa from qemu
2018-02-26 02:36:09 -05:00
Paolo Bonzini d8d0d08262
target-i386: fix ordering of fields in CPUX86State
Make sure reset zeroes TSC_AUX, XCR0, PKRU. Move XSTATE_BV from the
"vmstate only" section to the "KVM only" section.

Backports commit 7616f1c2da1c0f336a474a56ad6d32e15ccd666e from qemu
2018-02-26 02:34:22 -05:00
Ladi Prosek 7acc14da16
Remove unused function declarations
Unused function declarations were found using a simple gcc plugin and
manually verified by grepping the sources.

Backports commit d4b84d564ee3eb7a58e4585d671fb3c220b6c3b9 from qemu
2018-02-26 02:31:46 -05:00
Thomas Huth b581d4033f
tcg: Remove duplicate header includes
host-utils.h and timer.h are included twice in tcg.c.
One time should be enough.

Backports commit 347519eb9d68303a6c23a7663c0fa6c20a225191 from qemu
2018-02-26 02:29:38 -05:00
Lioncash 1ff9724b46
cutils: Remove unused vector ifdef block 2018-02-26 02:28:50 -05:00
Andrew Dutcher 26b36e5ff8
fpu: add mechanism to check for invalid long double formats
All operations that take a floatx80 as an operand need to have their
inputs checked for malformed encodings. In all of these cases, use the
function floatx80_invalid_encoding to perform the check. If an invalid
operand is found, raise an invalid operation exception, and then return
either NaN (for fp-typed results) or the integer indefinite value (the
minimum representable signed integer value, for int-typed results).

For the non-quiet comparison operations, this touches adjacent code in
order to pass style checks.

Backports cast correction portion of commit d1eb8f2acba579830cf3798c3c15ce51be852c56m from qemu
2018-02-26 02:27:40 -05:00
Pranith Kumar 9e6fec8741
atomics: Use __atomic_*_n() variant primitives
Use the __atomic_*_n() primitives which take the value as argument. It
is not necessary to store the value locally before calling the
primitive, hence saving us a stack store and load.

Backports commit 89943de17c4e276f2c47f05b4604e8816a6a636c from qemu
2018-02-26 02:16:48 -05:00
Fam Zheng 1a2c30abbf
rules.mak: Don't extract libs from .mo-libs in link command
For module build, .mo objects are passed to LINK and consumed in
process-archive-undefs. The reason behind that is documented in the
comment above process-archive-undefs.

Similarly, extract-libs should be called with .mo filtered out too.
Otherwise, the .mo-libs are added to the link command incorrectly,
spoiling the purpose of modularization.

Currently we don't have any .mo-libs usage, but it will be used soon
when we modularize more multi-source objects, like sdl and gtk.

Backports commit 5b1b6dbd94e2e2e98920f886cb32fcf4a1520b50 from qemu
2018-02-26 02:08:03 -05:00
Sergey Fedorov 58ff618708
tcg: rename tb_find_physical()
In fact, this function does not exactly perform a lookup by physical
address as it is descibed for comment on get_page_addr_code(). Thus
it may be a bit confusing to have "physical" in it's name. So rename it
to tb_htable_lookup() to better reflect its actual functionality.

Backports commit b34de45fc40d01c14b31d3a682e284180a2ed8c5 from qemu
2018-02-26 02:07:06 -05:00
Sergey Fedorov ab0c87bc6f
tcg: Merge tb_find_slow() and tb_find_fast()
These functions are not too big and can be merged together. This makes
locking scheme more clear and easier to follow.

Backports commit bd2710d5da06ad7706d4864f65b3f0c9f7cb4d7f from qemu
2018-02-26 02:05:19 -05:00
Sergey Fedorov 9b6f287488
tcg: Avoid bouncing tb_lock between tb_gen_code() and tb_add_jump()
Backports commit 74d356dd48b64eaa2a6104ac1493ca64cb31fa16 from qemu
2018-02-26 02:01:40 -05:00
Alex Bennée 09c3ef656e
tcg: cpu-exec: remove tb_lock from the hot-path
Lock contention in the hot path of moving between existing patched
TranslationBlocks is the main drag in multithreaded performance. This
patch pushes the tb_lock() usage down to the two places that really need
it:

- code generation (tb_gen_code)
- jump patching (tb_add_jump)

The rest of the code doesn't really need to hold a lock as it is either
using per-CPU structures, atomically updated or designed to be used in
concurrent read situations (qht_lookup).

To keep things simple I removed the #ifdef CONFIG_USER_ONLY stuff as the
locks become NOPs anyway until the MTTCG work is completed.

Backports commit 518615c6503ad78d3bb67ddf1cd848c4a41de02e from qemu
2018-02-26 01:58:33 -05:00
Alex Bennée 62aa0abd02
tcg: set up tb->page_addr before insertion
This ensures that if we find the TB on the slow path that tb->page_addr
is correctly set before being tested.

Backports commit 2e1ae44a4f4a6149fbb9dc812243522f07284700 from qemu
2018-02-26 01:50:04 -05:00
Paolo Bonzini 30845ae475
tcg: Prepare TB invalidation for lockless TB lookup
When invalidating a translation block, set an invalid flag into the
TranslationBlock structure first. It is also necessary to check whether
the target TB is still valid after acquiring 'tb_lock' but before calling
tb_add_jump() since TB lookup is to be performed out of 'tb_lock' in
future. Note that we don't have to check 'last_tb'; an already invalidated
TB will not be executed anyway and it is thus safe to patch it.

Backports commit 6d21e4208f382dd8ca1f7995a6dd9ea7ca281163 from qemu
2018-02-26 01:48:13 -05:00
Sergey Fedorov c0dda5fbe9
tcg: Prepare safe access to tb_flushed out of tb_lock
Ensure atomicity and ordering of CPU's 'tb_flushed' access for future
translation block lookup out of 'tb_lock'.

This field can only be touched from another thread by tb_flush() in user
mode emulation. So the only access to be sequential atomic is:
* a single write in tb_flush();
* reads/writes out of 'tb_lock'.

In future, before enabling MTTCG in system mode, tb_flush() must be safe
and this field becomes unnecessary.

Backports commit 118b07308a8cedc16ef63d7ab243a95f1701db40 from qemu
2018-02-25 23:33:58 -05:00
Sergey Fedorov 9eb02a540d
tcg: Prepare safe tb_jmp_cache lookup out of tb_lock
Ensure atomicity of CPU's 'tb_jmp_cache' access for future translation
block lookup out of 'tb_lock'.

Note that this patch does *not* make CPU's TLB invalidation safe if it
is done from some other thread while the CPU is in its execution loop.

Backports commit 89a16b1e4294e3664667a151c2f70c84dfac6fd9 from qemu
2018-02-25 23:29:18 -05:00
Sergey Fedorov 371101a184
tcg: Pass last_tb by value to tb_find_fast()
This is a small clean up. tb_find_fast() is a final consumer of this
variable so no need to pass it by reference. 'last_tb' is always updated
by subsequent cpu_loop_exec_tb() in cpu_exec().

This change also simplifies calling cpu_exec_nocache() in
cpu_handle_exception().

Backports commit 4b7e69509df2fcbfdab8c62c294dbfcfdab8a6e1 from qemu
2018-02-25 23:23:22 -05:00
Cao jin cc45b82472
timer/cpus: fix some typos and update some comments
Backports commit 3224e8786fcbe531746f1530c37210c425625213 from qemu
2018-02-25 23:21:57 -05:00
Paolo Bonzini 57fff7a94b
target-m68k: fix get_mac_extf helper
val is assigned twice; the second one should be combined with "|".
Reported by Coverity.

Backports commit 5ce747cfac697f61668ab4fa4a71c1dba15cc272 from qemu
2018-02-25 23:21:05 -05:00
Thomas Huth aed5df31b7
sparc: Use g_memdup() instead of g_new0() + memcpy()
There is no need to make sure that the memory is zeroed after the
allocation if we also immediatly fill the whole buffer afterwards
with memcpy(). Thus g_new0 should be g_new instead. But since we
are also doing a memcpy() here, we can also simply replace both
with g_memdup() instead.

Backports commit a337f295defad7eb977da4d6317cf70f7f2fa4b4 from qemu
2018-02-25 23:19:44 -05:00
Peter Maydell eb77f61bea
configure: Always compile with -fwrapv
QEMU's code relies on left shifts of signed integers always
being defined behaviour with the obvious 2s-complement
semantics. The only way to tell the compiler (and any
associated undefined-behaviour sanitizer) that we require a
C dialect with these semantics is to use the -fwrapv option.
This is a bit of a heavy hammer for the job as it also gives
us guaranteed semantics on integer arithmetic overflow which
in theory we don't require.

In an ideal world this would allow us to drop the warning
flag -Wno-shift-negative-value, but we must retain this to
avoid spurious warnings on clang versions predating the
fix to https://llvm.org/bugs/show_bug.cgi?id=25552.

Backports commit 2d31515bc0880a1cea86ce638d2a109f4f4e6f7d from qemu
2018-02-25 23:17:41 -05:00
Longpeng(Mike) 8b5400d675
target-i386: present virtual L3 cache info for vcpus
Some software algorithms are based on the hardware's cache info, for example,
for x86 linux kernel, when cpu1 want to wakeup a task on cpu2, cpu1 will trigger
a resched IPI and told cpu2 to do the wakeup if they don't share low level
cache. Oppositely, cpu1 will access cpu2's runqueue directly if they share llc.
The relevant linux-kernel code as bellow:

static void ttwu_queue(struct task_struct *p, int cpu)
{
struct rq *rq = cpu_rq(cpu);
......
if (... && !cpus_share_cache(smp_processor_id(), cpu)) {
......
ttwu_queue_remote(p, cpu); /* will trigger RES IPI */
return;
}
......
ttwu_do_activate(rq, p, 0); /* access target's rq directly */
......
}

In real hardware, the cpus on the same socket share L3 cache, so one won't
trigger a resched IPIs when wakeup a task on others. But QEMU doesn't present a
virtual L3 cache info for VM, then the linux guest will trigger lots of RES IPIs
under some workloads even if the virtual cpus belongs to the same virtual socket.

For KVM, there will be lots of vmexit due to guest send IPIs.
The workload is a SAP HANA's testsuite, we run it one round(about 40 minuates)
and observe the (Suse11sp3)Guest's amounts of RES IPIs which triggering during
the period:
No-L3 With-L3(applied this patch)
cpu0:	363890	44582
cpu1:	373405	43109
cpu2:	340783	43797
cpu3:	333854	43409
cpu4:	327170	40038
cpu5:	325491	39922
cpu6:	319129	42391
cpu7:	306480	41035
cpu8:	161139	32188
cpu9:	164649	31024
cpu10:	149823	30398
cpu11:	149823	32455
cpu12:	164830	35143
cpu13:	172269	35805
cpu14:	179979	33898
cpu15:	194505	32754
avg:	268963.6	40129.8

The VM's topology is "1*socket 8*cores 2*threads".
After present virtual L3 cache info for VM, the amounts of RES IPIs in guest
reduce 85%.

For KVM, vcpus send IPIs will cause vmexit which is expensive, so it can cause
severe performance degradation. We had tested the overall system performance if
vcpus actually run on sparate physical socket. With L3 cache, the performance
improves 7.2%~33.1%(avg:15.7%).

Backports commit 14c985cffa6cb177fc01a163d8bcf227c104718c from qemu
2018-02-25 23:16:14 -05:00
Lioncash 2d87095858
glib_compat: Amend header guard 2018-02-25 23:12:20 -05:00
Sergey Sorokin a882118050
target-arm: Fix lpae bit in FSR on an alignment fault
If an alignment fault occurred and target EL is using AArch32,
then DFSR/IFSR bit LPAE[9] must be set correctly.

Backports commit e0fe723c24562c8f909bb40f131bfdbe75650677 from qemu
2018-02-25 23:10:29 -05:00
Luwei Kang af7b3995dd
target-i386: Add more Intel AVX-512 instructions support
Add more AVX512 feature bits, include AVX512DQ, AVX512IFMA,
AVX512BW, AVX512VL, AVX512VBMI. Its spec can be found at:
https://software.intel.com/sites/default/files/managed/b4/3a/319433-024.pdf

Backports commit cc728d1493eee3e20c1547191862e43d3f55e714 from qemu
2018-02-25 23:09:18 -05:00
Alex Williamson fe66c2e088
memory: Don't use memcpy for ram_device regions
With a vfio assigned device we lay down a base MemoryRegion registered
as an IO region, giving us read & write accessors. If the region
supports mmap, we lay down a higher priority sub-region MemoryRegion
on top of the base layer initialized as a RAM device pointer to the
mmap. Finally, if we have any quirks for the device (ie. address
ranges that need additional virtualization support), we put another IO
sub-region on top of the mmap MemoryRegion. When this is flattened,
we now potentially have sub-page mmap MemoryRegions exposed which
cannot be directly mapped through KVM.

This is as expected, but a subtle detail of this is that we end up
with two different access mechanisms through QEMU. If we disable the
mmap MemoryRegion, we make use of the IO MemoryRegion and service
accesses using pread and pwrite to the vfio device file descriptor.
If the mmap MemoryRegion is enabled and results in one of these
sub-page gaps, QEMU handles the access as RAM, using memcpy to the
mmap. Using either pread/pwrite or the mmap directly should be
correct, but using memcpy causes us problems. I expect that not only
does memcpy not necessarily honor the original width and alignment in
performing a copy, but it potentially also uses processor instructions
not intended for MMIO spaces. It turns out that this has been a
problem for Realtek NIC assignment, which has such a quirk that
creates a sub-page mmap MemoryRegion access.

To resolve this, we disable memory_access_is_direct() for ram_device
regions since QEMU assumes that it can use memcpy for those regions.
Instead we access through MemoryRegionOps, which replaces the memcpy
with simple de-references of standard sizes to the host memory.

With this patch we attempt to provide unrestricted access to the RAM
device, allowing byte through qword access as well as unaligned
access. The assumption here is that accesses initiated by the VM are
driven by a device specific driver, which knows the device
capabilities. If unaligned accesses are not supported by the device,
we don't want them to work in a VM by performing multiple aligned
accesses to compose the unaligned access. A down-side of this
philosophy is that the xp command from the monitor attempts to use
the largest available access weidth, unaware of the underlying
device. Using memcpy had this same restriction, but at least now an
operator can dump individual registers, even if blocks of device
memory may result in access widths beyond the capabilities of a
given device (RTL NICs only support up to dword).

Backports commit 1b16ded6a512809f99c133a97f19026fe612b2de from qemu
2018-02-25 23:06:36 -05:00
Alex Williamson 5db45219c9
memory: Replace skip_dump flag with ram_device
Setting skip_dump on a MemoryRegion allows us to modify one specific
code path, but the restriction we're trying to address encompasses
more than that. If we have a RAM MemoryRegion backed by a physical
device, it not only restricts our ability to dump that region, but
also affects how we should manipulate it. Here we recognize that
MemoryRegions do not change to sometimes allow dumps and other times
not, so we replace setting the skip_dump flag with a new initializer
so that we know exactly the type of region to which we're applying
this behavior.

Backports commit ca83f87a66d19fdaabf23d4f5ebb49396fe232c1 from qemu
2018-02-25 23:00:45 -05:00
Pranith Kumar 1b19fe260a
softfloat: Fix warn about implicit conversion from int to int8_t
Change the flag type to 'uint8_t' to fix the implicit conversion error.

Backports commit dfd607671037ff46d5b16ade10e10efdf0d260be from qemu
2018-02-25 22:54:39 -05:00
Pranith Kumar 4c880fba9d
target-arm: Fix warn about implicit conversion
Clang warns about an implicit conversion as follows:

/mnt/devops/code/qemu/target-arm/neon_helper.c:1075:1: warning: implicit conversion from 'int' to 'int8_t' (aka 'signed char') changes value from 128 to -128 [-Wconstant-conversion]
NEON_VOP_ENV(qrshl_s8, neon_s8, 4)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/mnt/devops/code/qemu/target-arm/neon_helper.c:116:83: note: expanded from macro 'NEON_VOP_ENV'
uint32_t HELPER(glue(neon_,name))(CPUARMState *env, uint32_t arg1, uint32_t arg2) \
^
/mnt/devops/code/qemu/target-arm/neon_helper.c:106:5: note: expanded from macro '\
NEON_VOP_BODY'
NEON_DO##n; \
^~~~~~~~~~
<scratch space>:21:1: note: expanded from here
NEON_DO4
^~~~~~~~
/mnt/devops/code/qemu/target-arm/neon_helper.c:93:5: note: expanded from macro 'NEON_DO4'
NEON_FN(vdest.v1, vsrc1.v1, vsrc2.v1); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/mnt/devops/code/qemu/target-arm/neon_helper.c:1054:23: note: expanded from macro 'NEON_FN'
dest = (1 << (sizeof(src1) * 8 - 1)); \
~ ~~^~~~~~~~~~~~~~~~~~~~~~~~~

Fix it by casting to appropriate type.

Backports commit 6bbbb0ac136102098a70b97ab0c07bc7bf53131c from qemu
2018-02-25 22:44:43 -05:00
Richard Henderson ede1cae3dc
tcg: Lower indirect registers in a separate pass
Rather than rely on recursion during the middle of register allocation,
lower indirect registers to loads and stores off the indirect base into
plain temps.

For an x86_64 host, with sufficient registers, this results in identical
code, modulo the actual register assignments.

For an i686 host, with insufficient registers, this means that temps can
be (temporarily) spilled to the stack in order to satisfy an allocation.
This as opposed to the possibility of not being able to spill, to allocate
a register for the indirect base, in order to perform a spill.

Backports commit 5a18407f55ade924aa6397c9a043a9ffd59645fe from qemu
2018-02-25 22:32:28 -05:00
Richard Henderson 8a012ff6d3
tcg: Require liveness analysis
Backports commit c0ef05b5e62ab0c291a94022f14104e61e306f03 from qemu
2018-02-25 22:20:42 -05:00
Lioncash 541601edc4
util: Move qemu-log to utils 2018-02-25 22:17:44 -05:00
Richard Henderson 2aa46dd9a1
tcg: Include liveness info in the dumps
Backports commit bdfb460ef77500f7b186759b585f06ff2120929d from qemu
2018-02-25 22:13:08 -05:00
Richard Henderson e973e89a57
tcg: Compress dead_temps and mem_temps into a single array
We only need two bits per temporary. Fold the two bytes into one,
and reduce the memory and cachelines required during compilation.

Backports commit c70fbf0a9938baf3b4f843355a77c17a7e945b98 from qemu
2018-02-25 22:07:08 -05:00
Richard Henderson 690985a582
tcg: Fold life data into TCGOp
Reduce the size of other bitfields to make room.
This reduces the cache footprint of compilation.

Backports commit bee158cb4dde35c41632a3a129c869f14a32f8f0 from qemu
2018-02-25 21:49:42 -05:00
Lioncash b5e765d562
target-mips: Silence unused function warning 2018-02-25 21:47:22 -05:00
Richard Henderson 1547048a22
tcg: Reorg TCGOp chaining
Instead of using -1 as end of chain, use 0, and link through the 0
entry as a fully circular double-linked list.

Backports commit dcb8e75870e2de199db853697f8839cb603beefe from qemu
2018-02-25 21:44:50 -05:00
Richard Henderson b2e6e351c2
tcg: Compress liveness data to 16 bits
This reduces both memory usage and per-insn cacheline usage
during code generation.

Backports commit a1b3c48d2b23d6eaeb4529d3e1183d2648731bf8 from qemu
2018-02-25 21:27:24 -05:00
Eric Blake 30cbcafc05
osdep: Document differences in rounding macros
Make it obvious which macros are safe in which situations.

Useful since QEMU_ALIGN_UP and ROUND_UP both purport to do
the same thing, but differ on whether the alignment must be
a power of 2.
2018-02-25 21:05:21 -05:00
Leon Alrae bc434da124
target-mips: fix EntryHi.EHINV being cleared on TLB exception
While implementing TLB invalidation feature we forgot to modify
part of code responsible for updating EntryHi during TLB exception.
Consequently EntryHi.EHINV is unexpectedly cleared on the exception.

Backports commit 701074a6fc7470d0ed54e4a4bcd4d491ad8da22e from qemu
2018-02-25 21:02:31 -05:00
Igor Mammedov 943b9fc261
qdev: Fix object reference leak in case device.realize() fails
If device doesn't have parent assined before its realize
is called, device_set_realized() will implicitly set parent
to '/machine/unattached'.

However device_set_realized() may fail after that point at
several other points leaving not realized object dangling
in '/machine/unattached' and as result caller of

obj = object_new()
obj->ref == 1
object_property_set_bool(obj,..., true, "realized",...)
obj->ref == 2
if (fail)
object_unref(obj);
obj->ref == 1

will get object leak instead of expected object destruction.

Fix it by making device_set_realized() to cleanup after itself
in case of failure.

Backports commit 69382d8b3e8600b349c191394d761dcb480502cf from qemu
2018-02-25 21:00:26 -05:00
Igor Mammedov 62c89b9cd4
exec: Reduce CONFIG_USER_ONLY ifdeffenery
Backports commit 1bc7e522d9cf1b58f2de9c8f1737be0bb5129c35 from qemu
2018-02-25 20:57:48 -05:00
Igor Mammedov d30410dc9a
target-i386: Add x86_cpu_unrealizefn()
First remove VCPU from exec loop and only then remove lapic.

Backports commit c884776e9dc947105827bd6c22192863f97267d2 from qemu
2018-02-25 20:54:13 -05:00
Igor Mammedov 298b0e6529
target-i386: Fix apic object leak when CPU is deleted
Backports commit 67e55caa6dcb91c80428cee6fe463f8dd8a755ab from qemu
2018-02-25 20:48:40 -05:00
Igor Mammedov e15fb246ab
target-i386: cpu: Do not ignore error and fix apic parent
object_property_add_child() silently fails with error that it can't
create duplicate propery 'apic' as we already have 'apic' property
registered for 'apic' feature. As result generic device_realize puts
apic into unattached container.

As it's programming error, abort if name collision happens in future
and fix property name for apic_state to 'lapic', this way apic is
a child of cpu instance.

Backports commit 6816b1b3811e839540df22855d975b6d76ae438b from qemu
2018-02-25 20:47:46 -05:00
Paolo Bonzini 403021183d
target-i386: Add support for UMIP and RDPID CPUID bits
These are both stored in CPUID[EAX=7,EBX=0].ECX. KVM is going to
be able to emulate both (albeit with a performance loss in the case
of RDPID, which therefore will be in KVM_GET_EMULATED_CPUID rather
than KVM_GET_SUPPORTED_CPUID).

It's also possible to implement both in TCG, but this is for 2.8.

Backports commit c2f193b538032accb9db504998bf2ea7c0ef65af from qemu
2018-02-25 20:46:40 -05:00
Igor Mammedov 6714284211
target-i386: Add socket/core/thread properties to X86CPU
These properties will be used by as address where to plug
CPU with help -device/device_add commands.

Backports commit d89c2b8b98e097b9cad5104b0f178bde1cfa011b from qemu
2018-02-25 20:45:35 -05:00
Igor Mammedov 2ac9df3633
target-i386: Replace custom apic-id setter/getter with static property
Custom apic-id setter/getter doesn't do any property specific
checks anymore, so clean it up and use more compact static
property DEFINE_PROP_UINT32 instead.

Backports commit 2da00e3176abac34ca7a6aab1f5bbb94a0d03fc5 from qemu
2018-02-25 20:44:18 -05:00
Igor Mammedov 0525a9c9fa
pc: cpu: Consolidate apic-id validity checks in pc_cpu_pre_plug()
Machine code knows about all possible APIC IDs so use that
instead of hack which does O(n^2) complexity duplicate
checks, interating over global CPUs list.
As result duplicate check is done only once with O(log n) complexity.

Backports commit 4ec60c76d5ab513e375f17b043d2b9cb849adf6c from qemu
2018-02-25 20:38:43 -05:00
Dr. David Alan Gilbert 9ee1a82185
target-i386: Set physical address bits based on host
Add the host-phys-bits boolean property, if true, take phys-bits
from the hosts physical bits value, overriding either the default
or the user specified value.

We can also use the value we read from the host to check the users
explicitly set value and warn them if it doesn't match.

Note:
a) We only read the hosts value in KVM mode (because on non-x86
we get an abort if we try)
b) We don't warn about trying to use host-phys-bits in TCG mode,
we just fall back to the TCG default. This allows the machine
type to set the host-phys-bits flag if it wants and then to
work in both TCG and KVM.

Backports commit 11f6fee576680a2d482123535da920f8ceb33eb5 from qemu
2018-02-25 20:36:12 -05:00
Igor Mammedov 95cced34fb
pc: Add x86_topo_ids_from_apicid()
It's reverse of apicid_from_topo_ids() and will be used in follow up
patches to fill in data structures for query-hotpluggable-cpus and
for user friendly error reporting.

Backports commit 9f3aab58539b4cc716e42e772be8116dc2e7d159 from qemu
2018-02-25 20:31:36 -05:00
Igor Mammedov bc8dbd862d
target-i386: Use uint32_t for X86CPU.apic_id
Redo 9886e834 (target-i386: Require APIC ID to be explicitly set before
CPU realize) in another way that doesn't use int64_t to detect
if apic-id property has been set.

Use the fact that 0xFFFFFFFF is the broadcast
value that a CPU can't have and set default
uint32_t apic_id to it instead of using int64_t.

Later uint32_t apic_id will be used to drop custom
property setter/getter in favor of static property.

Backports commit d9c84f196970f78d4b55ab87e03cbcad7c65f86f from qemu
2018-02-25 20:30:31 -05:00
Dr. David Alan Gilbert 54851f7d74
target-i386: Fill high bits of mtrr mask
Fill the bits between 51..number-of-physical-address-bits in the
MTRR_PHYSMASKn variable range mtrr masks so that they're consistent
in the migration stream irrespective of the physical address space
of the source VM in a migration.

Backports commit fcc35e7ccaed771790940524f3b0eef7aebfc9b1 from qemu
2018-02-25 20:29:20 -05:00
Dr. David Alan Gilbert 78254267ff
target-i386: Allow physical address bits to be set
Currently QEMU sets the x86 number of physical address bits to the
magic number 40. This is only correct on some small AMD systems;
Intel systems tend to have 36, 39, 46 bits, and large AMD systems
tend to have 48.

Having the value different from your actual hardware is detectable
by the guest and in principal can cause problems;
The current limit of 40 stops TB VMs being created by those lucky
enough to have that much.

This patch lets you set the physical bits by a cpu property but
defaults to the same 40bits which matches TCGs setup.

I've removed the ancient warning about the 42 bit limit in exec.c;
I can't find that limit in there and no one else seems to know where
it is.

We use a magic value of 0 as the property default so that we can
later distinguish between the default and a user set value.

Backports commit af45907a132857cfd47acc998bf5f7c26cd13071 from qemu
2018-02-25 20:28:38 -05:00
Dr. David Alan Gilbert 7cb359cc19
target-i386: Provide TCG_PHYS_ADDR_BITS
Provide a constant for the number of address bits supported under TCG.

Backports commit 709787ee997f0a0ccab78e0edaf10d48929151ee from qemu
2018-02-25 20:23:25 -05:00
Eric Blake 23ab6d81f9
qapi: Implement boxed types for commands/events
Turn on the ability to pass command and event arguments in
a single boxed parameter, which must name a non-empty type
(although the type can be a struct with all optional members).
For structs, it makes it possible to pass a single qapi type
instead of a breakout of all struct members (useful if the
arguments are already in a struct or if the number of members
is large); for other complex types, it is now possible to use
a union or alternate as the data for a command or event.

The empty type may be technically feasible if needed down the
road, but it's easier to forbid it now and relax things to allow
it later, than it is to allow it now and have to special case
how the generated 'q_empty' type is handled (see commit 7ce106a9
for reasons why nothing is generated for the empty type). An
alternate type is never considered empty, but now that a boxed
type can be either an object or an alternate, we have to provide
a trivial QAPISchemaAlternateType.is_empty(). The new call to
arg_type.is_empty() during QAPISchemaCommand.check() requires
that we first check the type in question; but there is no chance
of introducing a cycle since objects do not refer back to commands.

We still have a split in syntax checking between ad-hoc parsing
up front (merely validates that 'boxed' has a sane value) and
during .check() methods (if 'boxed' is set, then 'data' must name
a non-empty user-defined type).

Generated code is unchanged, as long as no client uses the
new feature.

Backports commit c818408e449ea55371253bd4def1c1dc87b7bb03 from qemu
2018-02-25 20:22:03 -05:00
Eric Blake c65f056fbe
qapi: Plumb in 'boxed' to qapi generator lower levels
The next patch will add support for passing a qapi union type
as the 'data' of a command. But to do that, the user function
for implementing the command, as called by the generated
marshal command, must take the corresponding C struct as a
single boxed pointer, rather than a breakdown into one
parameter per member. Even without a union, being able to use
a C struct rather than a list of parameters can make it much
easier to handle coding with QAPI.

This patch adds the internal plumbing of a 'boxed' flag
associated with each command and event. In several cases,
this means adding indentation, with one new dead branch and
the remaining branch being the original code more deeply
nested; this was done so that the new implementation in the
next patch is easier to review without also being mixed with
indentation changes.

For this patch, no behavior or generated output changes, other
than the testsuite outputting the value of the new flag
(always False for now).

Backports commit 48825ca419fd9c8140d4fecb24e982d68ebca74f from qemu
2018-02-25 20:17:01 -05:00
Eric Blake 6ff318b839
qapi-event: Simplify visit of non-implicit data
Commit 7ce106a9 documented why we don't generated a visit_type_FOO()
for implicit types; and therefore events with an anonymous type for
'data' have to open-code a visit. Note that the open-coded visit in
qapi-event.c is slightly different from what is done in
qapi-visit.c for normal types, in part because we don't have to
check for *obj being NULL or free things on error. But where the
type is not implicit, it is nicer to reuse the normal visit instead
of open-coding a duplicate.

At the moment, the only event with a non-implicit 'data' is in the
testsuite, where test-qapi-event.c changes as follows:

|@@ -155,6 +155,7 @@ void qapi_event_send___org_qemu_x_event(
| __org_qemu_x_Struct param = {
| __org_qemu_x_member1, (char *)__org_qemu_x_member2, has_q_wchar_t, q_wchar_t
| };
|+ __org_qemu_x_Struct *arg = &param;
|
| emit = qmp_event_get_func_emit();
| if (!emit) {
|@@ -164,16 +165,7 @@ void qapi_event_send___org_qemu_x_event(
| qmp = qmp_event_build_dict("__ORG.QEMU_X-EVENT");
|
| v = qmp_output_visitor_new(&obj);
|-
|- visit_start_struct(v, "__ORG.QEMU_X-EVENT", NULL, 0, &err);
|- if (err) {
|- goto out;
|- }
|- visit_type___org_qemu_x_Struct_members(v, &param, &err);
|- if (!err) {
|- if (!err) {
|- visit_check_struct(v, &err);
|- }
|- visit_end_struct(v, NULL);
|+ visit_type___org_qemu_x_Struct(v, "__ORG.QEMU_X-EVENT", &arg, &err);
| if (err) {
| goto out;
| }

Backports commit 4d0b268fdb17a1fed10fe980e77fd388e5427bfd from qemu
2018-02-25 20:12:34 -05:00
Eric Blake b5220a6867
qapi: Drop useless gen_err_check()
Ever since commit 12f254f removed the last parameterization
of gen_err_check(), it no longer makes sense to hide the three
lines of generated C code behind a macro call. Just inline it
into the remaining users.

No change to generated code.

Backports commit fa274ed6fb788866ed3a2cfd54a2ddf78f04f2c0 from qemu
2018-02-25 20:10:45 -05:00
Eric Blake d7014c66df
qapi: Add type.is_empty() helper
In the near future, we want to lift our artificial restriction of
no variants at the top level of an event, at which point the
currently open-coded check for empty members will become
insufficient. Factor it out into a new helper method is_empty()
now, and future-proof it by checking variants, too, along with an
assert that it is not used prior to the completion of .check().
Update places that were checking for (non-)empty .members to use
the new helper.

All of the current callers assert that there are no variants (either
directly, or by qapi.py asserting that base types have no variants),
so this is not a semantic change.

No change to generated code.

Backports commit b6167706829c6e0d3572daa2b6769594ced276f7 from qemu
2018-02-25 20:07:43 -05:00
Eric Blake 4b39eaae33
qapi: Hide tag_name data member of variants
Clean up the only remaining external use of the tag_name field of
QAPISchemaObjectTypeVariants, by explicitly listing the generated
'type' tag for all variants in the testsuite (you can still tell
simple unions by the -wrapper types). Then we can mark the
tag_name field as private by adding a leading underscore to prevent
any further use.

Backports commit da9cb19385fc66b2cb2584bbbbcbf50246d057e2 from qemu
2018-02-25 20:06:15 -05:00
Eric Blake febeea5f4b
qapi: Special case c_name() for empty type
Commit 7ce106a rendered QAPISchemaObjectType.c_name() redundant,
since it now does nothing more than delegate to its superclass.
However, rather than deleting it, we can restore part of the
assertion that was removed in that commit, to prove that we never
emit the empty type directly in generated code, but rather
special-case it as a built-in that makes other aspects of code
generation easier to reason about.

Backports commit cd50a2564560986e865ff64fa73b59d2564076f0 from qemu
2018-02-25 20:05:16 -05:00
Eric Blake 8ccfff95fe
qapi: Require all branches of flat union enum to be covered
We were previously enforcing that all flat union branches were
found in the corresponding enum, but not that all enum values
were covered by branches. The resulting generated code would
abort() if the user passes the uncovered enum value.

We don't automatically treat non-present branches in a flat
union as empty types, for symmetry with simple unions (there,
the enum type is generated from the list of all branches, so
there is no way to omit a branch but still have it be part of
the union).

A later patch will add shorthand so that branches that are empty
in flat unions can be declared as 'branch':{} instead of
'branch':'Empty', to avoid the need for an otherwise useless
explicit empty type. [Such shorthand for simple unions is a bit
harder to justify, since we would still have to generate a
wrapper type that parses 'data':{}, rather than truly being an
empty branch with no additional siblings to the 'type' member.]

Backports commit d0b182392d0281ef780e3effcb82677a004f1f97 from qemu
2018-02-25 20:04:18 -05:00
Paolo Bonzini 674805745b
qapi: change QmpInputVisitor to QSLIST
This saves a lot of memory compared to a statically-sized array,
or at least 24kb could be considered a lot on an Atari ST.
It also makes the code more similar to QmpOutputVisitor.

This removes the limit on the depth of a QObject that can be processed
into a QAPI tree. This is not a problem because QObjects can be
considered trusted; the text received on the QMP wire is untrusted
input, but the JSON parser already takes pains to limit the QObject tree
it creates. We don't need the QMP input visitor to limit it again.

Backports commit 3d344c2aabb7bc9b414321e3c52872901edebdda from qemu
2018-02-25 20:02:09 -05:00
Paolo Bonzini b14f1d7a80
qapi: change QmpOutputVisitor to QSLIST
This saves a little memory compared to the doubly-linked QTAILQ.

Backports commit fc76ae8b38783e82c109834573ba5d6f080440b5 from qemu
2018-02-25 19:59:16 -05:00
Sergey Fedorov e39b9d0391
target-i386: Remove redundant HF_SOFTMMU_MASK
'HF_SOFTMMU_MASK' is only set when 'CONFIG_SOFTMMU' is defined. So
there's no need in this flag: test 'CONFIG_SOFTMMU' instead.

Backports commit da6d48e3348bbc266896cf8adf0c33f1eaf5b31f from qemu
2018-02-25 19:59:15 -05:00
Sergey Sorokin 4a904baaf5
target-arm: Add missed AArch32 TLBI sytem registers
Some PL2 related TLBI system registers are missed in AArch32
implementation. The patch fixes it.

Backports commit 541ef8c2e73fb99d173b125bef7c262fdd2fe33c from qemu
2018-02-25 19:59:15 -05:00
Peter Lieven 799bf1c3a5
exec: avoid realloc in phys_map_node_reserve
this is the first step in reducing the brk heap fragmentation
created by the map->nodes memory allocation. Since the introduction
of RCU the freeing of the PhysPageMaps is delayed so that sometimes
several hundred are allocated at the same time.

Even worse the memory for map->nodes is allocated and shortly
afterwards reallocated. Since the number of nodes it grows
to in the end is the same for all PhysPageMaps remember this value
and at least avoid the reallocation.

The large number of simultaneous allocations (about 450 x 70kB in
my configuration) has to be addressed later.

Backports commit 101420b886eec36990419bc9ed5b503622af8a0d from qemu
2018-02-25 19:32:40 -05:00
Paolo Bonzini a47c68164d
compiler: never omit assertions if using a static analysis tool
Assertions help both Coverity and the clang static analyzer avoid
false positives, but on the other hand both are confused when
the condition is compiled as (void)(x != FOO). Always expand
assertion macros when using Coverity or clang, through a new
QEMU_STATIC_ANALYSIS preprocessor symbol.

This fixes a couple false positives in TCG.

Backports commit 8bff06a0bbf257a2083223534c1607bf87d913e6 from qemu
2018-02-25 19:19:28 -05:00
Vijay 5608b53b6f
target-arm: Use Neon for zero checking
Use Neon instructions to perform zero checking of
buffer. This is helps in reducing total migration time.

Use case: Idle VM live migration with 4 VCPUS and 8GB ram
running CentOS 7.

Without Neon, the Total migration time is 3.5 Sec

Migration status: completed
total time: 3560 milliseconds
downtime: 33 milliseconds
setup: 5 milliseconds
transferred ram: 297907 kbytes
throughput: 685.76 mbps
remaining ram: 0 kbytes
total ram: 8519872 kbytes
duplicate: 2062760 pages
skipped: 0 pages
normal: 69808 pages
normal bytes: 279232 kbytes
dirty sync count: 3

With Neon, the total migration time is 2.9 Sec

Migration status: completed
total time: 2960 milliseconds
downtime: 65 milliseconds
setup: 4 milliseconds
transferred ram: 299869 kbytes
throughput: 830.19 mbps
remaining ram: 0 kbytes
total ram: 8519872 kbytes
duplicate: 2064313 pages
skipped: 0 pages
normal: 70294 pages
normal bytes: 281176 kbytes
dirty sync count: 3

Backports commit 7069532e3b944c25707d4f69998e68a739eabff9 from qemu
2018-02-25 19:17:38 -05:00
Richard Henderson d17dc29d2e
target-sparc: Elide duplicate updates to fprs
Backports commit f9c816c00cf4242542472ae6b2a579b11b7e86f1 from qemu
2018-02-25 19:14:59 -05:00
Richard Henderson 2215ef7e21
target-sparc: Use cpu_loop_exit_restore from helper_check_ieee_exceptions
This avoids needing to save state before every FP operation.

Backports commit 02c79d78853f07d519b3272d06e43041eb4a4105 from qemu
2018-02-25 19:12:36 -05:00
Richard Henderson 524e4af5ca
target-sparc: Use cpu_fsr in stfsr
Backports commit ba2397d1ca6546e8cf5bd9e2939923546ac3091a from qemu
2018-02-25 19:10:27 -05:00
Lioncash 17c54e2702
header_gen: alphabetize general symbols 2018-02-25 19:07:20 -05:00
Lioncash 4b8cae3f61
header_gen: alphabetize ARM symbols 2018-02-25 19:00:31 -05:00
Lioncash fa10382007
header_gen: alphabetize aarch64 symbols 2018-02-25 19:00:01 -05:00
Lioncash 3f8802fcf5
header_gen: alphabetize MIPS symbols 2018-02-25 18:59:49 -05:00
Richard Henderson 12eecc4939
target-sparc: Use explicit writes to cpu_fsr
By arranging for explicit writes to cpu_fsr after floating point
operations, we are able to mark the helpers as not writing to
tcg globals, which means that we don't need to invalidate the
integer register set across said calls.

Backports commit 7385aed20db5d83979f683b9d0048674411e963c from qemu
2018-02-25 18:55:07 -05:00
Richard Henderson 2e24c09db3
target-sparc: Remove helper_ldf_asi, helper_stf_asi
We've now implemented all fp asis inline, except for the no-fault
memory reads. The latter can be passed directly to helper_ld_asi.

Backports commit f2fe396f0fae6b389169f65abf294df9ae6cfee5 from qemu
2018-02-25 18:32:35 -05:00
Richard Henderson a921273a6c
target-sparc: Directly implement block and short ldf/stf asis
Backports commit ca5ce5723fb1ee3445f690004f63c209c15fb813 from qemu
2018-02-25 18:27:52 -05:00
Richard Henderson 333d88c9e6
target-sparc: Directly implement easy ldf/stf asis
Backports commit 7705091ca4a20c8c2d20e2af5d0a1bcb17296657 from qemu
2018-02-25 18:23:45 -05:00
Richard Henderson 9d47cda44c
target-sparc: Pass TCGMemOp constants to helper_ld/st_asi
Reduces the argument count for helper_ld_asi; do helper_st_asi
for consistency.

Backports commit 6850811e7c56403b0d225a1bffd096abf2ff06f9 from qemu
2018-02-25 18:19:42 -05:00
Richard Henderson 950aa89c7a
target-sparc: Fix obvious error in ASI_M_BFILL
Backports commit c095b83f9836cef80f64b32603fea240762a824b from qemu
2018-02-25 18:08:40 -05:00
Richard Henderson eb285aa281
target-sparc: Directly implement easy ldd/std asis
Backports commit e4dc0052a40d3e7b00ca0b008f345e2ed644aa20 from qemu
2018-02-25 18:07:51 -05:00
Richard Henderson 1ed7df7720
target-sparc: Introduce gen_check_align
Backports commit 35e94905ce4b39b358a673995f9bee11f46ec8be from qemu
2018-02-25 17:59:47 -05:00
Richard Henderson cef4ae5ca8
target-sparc: Use QT0 to return results from ldda
Also implement a few more twinx asis.

Backports commit 3f4288ebf6fca7b266fa42a74d9d99b961ba6844 from qemu
2018-02-25 17:56:08 -05:00
Richard Henderson 9e402493a9
target-sparc: Directly implement easy ld/st asis
Backports commit f0913be04be13cfb4f9341ae79e035fc8479fd28 from qemu
2018-02-25 17:49:16 -05:00
Richard Henderson e2d0ee1286
target-sparc: Use defines from asi.h
Backports commit 0cc1f4bf76a20c7fee0bab5c9bba9ad7302198b5 from qemu
2018-02-25 17:44:36 -05:00
Richard Henderson bd3b7a2537
target-sparc: Add UA2005 defines to asi.h
Backports commit 1d854963ea340855efe3f8a5b99c95a75bd717ae from qemu
2018-02-25 17:32:46 -05:00
Richard Henderson b9a65e0e79
target-sparc: Import linux/arch/sparc/include/uapi/asm/asi.h
Copied from tag v4.2, 64291f7db5bd8150a74ad2036f1037e6a0428df2.

Backports commit 68a03b8c8853c66724c6f200af3f821ae0d7e934 from qemu
2018-02-25 17:29:51 -05:00
Richard Henderson c509a5562d
target-sparc: Pass TCGMemOp to gen_ld/st_asi
Backports commit 1d65b0f5bb8f32500bbce09d922d226bb7cf4c68 from qemu
2018-02-25 17:26:34 -05:00
Richard Henderson 4bc53f223c
target-sparc: Introduce get_asi
Replace gen_get_asi, and use it for both 32-bit and 64-bit.
For v8, do supervisor and immediate checks here.

Also, move save_state and TB ending into the respective
subroutines, out of disas_sparc_insn.

Backports commit 7ec1e5ea4bd0700fa48da86bffa2fcc6146c410a from qemu
2018-02-25 17:23:20 -05:00
Richard Henderson 1dcd14d434
target-sparc: Store %asi in TB flags
Knowing the value of %asi at translation time means that we
can handle the common settings without a function call.

The steady state appears to be %asi == ASI_P, so that sparcv9
code can use offset forms of lda/sta. The %asi register gets
pushed and popped on entry to certain functions, but it rarely
takes on values other than ASI_P or ASI_AIUP. Therefore we're
unlikely to be expanding the set of TBs created.

Backports commit a6d567e523ed7e928861f3caa5d49368af3f330d from qemu
2018-02-25 05:17:21 -05:00
Richard Henderson 080281bc9c
target-sparc: Unify asi handling between 32 and 64-bit
We now have a single copy of gen_ld_asi, gen_st_asi,
gen_swap_asi, and everything uses gen_get_asi.

Backports commit 22e700607aeaff5f5e139d0fdc3d861e5502040c from qemu
2018-02-25 05:11:52 -05:00
Richard Henderson 847d65258b
target-sparc: Create gen_exception
This unifies quite a few duplicate code fragments.

Backports commit 4fbe00679000f9fd0c509c2d548d957b08ec6057 from qemu
2018-02-25 04:55:16 -05:00
Richard Henderson 39d1657fc3
target-sparc: Store mmu index in TB flags
Doing this instead of saving the raw PS_PRIV and TL. This means
that all nucleus mode TBs (TL > 0) can be shared. This fixes a
bug in that we didn't include HS_PRIV in the TB flags, and so could
produce incorrect TB matches for hypervisor state.

The LSU and DMMU states were unused by the translator. Including
them in TB flags meant unnecessary mismatches from tb_find_fast.

Backports commit 99a230638a3674e921224dbe628159c867d734b1 from qemu
2018-02-25 04:51:50 -05:00
Richard Henderson 395e00cdc5
target-sparc: Remove softint as a TCG global
The global is only ever read for one insn; we can just as well
use a load from env instead and generate the same code. This
also allows us to indicate the the associated helpers do not
touch TCG globals.

Backports commit e86ceb0d652baa5738e05a59ee0e7989dafbeaa1 from qemu
2018-02-25 04:49:27 -05:00
Richard Henderson dcd1d6f8ce
target-sparc: Mark more flags for helpers
Quite a few helpers do not modify tcg globals but did not so indicate.

Backports commit be72f9fcca742c5e9a949f5eac901ed6cc26a2a0 from qemu
2018-02-25 04:28:54 -05:00
Markus Armbruster c2ffbc575d
Clean up decorations and whitespace around header guards
Cleaned up with scripts/clean-header-guards.pl.

Backports commit 175de52487ce0b0c78daa4cdf41a5a465a168a25 from qemu
2018-02-25 04:26:02 -05:00
Markus Armbruster 1275b9b459
Clean up ill-advised or unusual header guards
Cleaned up with scripts/clean-header-guards.pl.

Backports commit 2a6a4076e117113ebec97b1821071afccfdfbc96 from qemu
2018-02-25 04:22:46 -05:00
Markus Armbruster 9ae2fc4d9e
Clean up header guards that don't match their file name
Header guard symbols should match their file name to make guard
collisions less likely. Offenders found with
scripts/clean-header-guards.pl -vn.

Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.

Backports commit 121d07125bb6d7079c7ebafdd3efe8c3a01cc440 from qemu
2018-02-25 04:18:42 -05:00
Markus Armbruster 25ec9ab016
tcg: Clean up tcg-target.h header guards
These use guard symbols like TCG_TARGET_$target.
scripts/clean-header-guards.pl doesn't like them because they don't
match their file name (they should, to make guard collisions less
likely).

Clean them up: use guard symbol $target_TCG_TARGET_H for
tcg/$target/tcg-target.h.

Backports commit 14e54f8ecfe9c5e17348f456781344737ed10b3b from qemu
2018-02-25 04:15:08 -05:00
Markus Armbruster 2b65f98538
target-*: Clean up cpu.h header guards
Most of them use guard symbols like CPU_$target_H, but we also have
__MIPS_CPU_H__ and __TRICORE_CPU_H__. They all upset
scripts/clean-header-guards.pl.

The script dislikes CPU_$target_H because they don't match their file
name (they should, to make guard collisions less likely). The others
are reserved identifiers.

Clean them all up: use guard symbol $target_CPU_H for
target-$target/cpu.h.

Backports commit 07f5a258750b3b9a6e10fd5ec3e29c9a943b650e from qemu
2018-02-25 04:12:46 -05:00
Markus Armbruster 60e8836b74
Use #include "..." for our own headers, <...> for others
Tracked down with an ugly, brittle and probably buggy Perl script.

Also move includes converted to <...> up so they get included before
ours where that's obviously okay.

Backports commit a9c94277f07d19d3eb14f199c3e93491aa3eae0e from qemu
2018-02-25 04:10:33 -05:00
Peter Maydell f6f843b4d4
bswap.h: Document cpu_to_* and *_to_cpu conversion functions
Add a documentation comment describing the functions for
converting between the cpu and little or bigendian formats.

Backports commit 7d820b766a2049f33ca7e078aa51018f2335f8c5 from qemu
2018-02-25 04:06:28 -05:00
Peter Maydell 1d7f813942
bswap.h: Remove unused cpu_to_*w() and *_to_cpup()
Now that all uses of cpu_to_*w() and *_to_cpup() have been replaced
with either ld*_p()/st*_p() or by doing direct dereferences and
using the cpu_to_*()/*_to_cpu() byteswap functions, we can remove
the unused implementations.

Backports commit f76bde702916d0230bf359d478bcac8d7f3b30ae from qemu
2018-02-25 04:04:46 -05:00
Sergey Sorokin d1e4ac0451
Fix confusing argument names in some common functions
There are functions tlb_fill(), cpu_unaligned_access() and
do_unaligned_access() that are called with access type and mmu index
arguments. But these arguments are named 'is_write' and 'is_user' in their
declarations. The patches fix the arguments to avoid a confusion.

Backports commit b35399bb4e9968296a12303b00f9f2066470e987 from qemu
2018-02-25 03:58:27 -05:00
Leon Alrae a465707a47
target-mips: enable 10-bit ASIDs in I6400 CPU
Backports commit cdc46fab07a122dfcc8a1054510a68d936ae3440 from qemu
2018-02-25 03:50:58 -05:00
Paul Burton 002b392a15
target-mips: support CP0.Config4.AE bit
The read-only Config4.AE bit set denotes extended 10 bits ASID.

Backports commit a0c8060841f2d56fb3504292c18522b957972e4c from qemu
2018-02-25 03:49:36 -05:00
Paul Burton ba4dcc8c2f
target-mips: change ASID type to hold more than 8 bits
ASID currently has uint8_t type which is too small since some processors
support more than 8 bits ASID. Therefore change its type to uint16_t.

Backports commit 2d72e7b047d800c9f99262466f65a98684ecca14 from qemu
2018-02-25 03:48:10 -05:00
Paul Burton ac27c881ff
target-mips: add ASID mask field and replace magic values
Backports commit 6ec98bd7b64ad75870c8e9d87a90fcd1a64b4942 from qemu
2018-02-25 03:44:26 -05:00
Leon Alrae 7e589c117b
target-mips: replace MIPS64R6-generic with the real I6400 CPU model
MIPS64R6-generic gradually gets closer to I6400 CPU, feature-wise. Rename
it to make it clear which MIPS processor it is supposed to emulate.

Backports commit 8f95ad1c79b4166350b982a6defe0e21faa04dac from qemu
2018-02-25 03:35:55 -05:00
Leon Alrae c0b3938b88
target-mips: add exception base to MIPS CPU
Replace hardcoded 0xbfc00000 with exception_base which is initialized with
this default address so there is no functional change here.
However, it is now exposed and consequently it will be possible to modify
it from outside of the CPU.

Backports commit 89777fd10fc3dd573c3b4d1b2efdd10af823c001 from qemu
2018-02-25 03:22:10 -05:00
Stanislav Shmarov 6f20d35cd1
translate-all: Fix user-mode self-modifying code in 2 page long TB
In user-mode emulation Translation Block can consist of 2 guest pages.
In that case QEMU also mprotects 2 host pages that are dedicated for
guest memory, containing instructions. QEMU detects self-modifying code
with SEGFAULT signal processing.

In case if instruction in 1st page is modifying memory of 2nd
page (or vice versa) QEMU will mark 2nd page with PAGE_WRITE,
invalidate TB, generate new TB contatining 1 guest instruction and
exit to CPU loop. QEMU won't call mprotect, and new TB will cause
same SEGFAULT. Page will have both PAGE_WRITE_ORG and PAGE_WRITE
flags, so QEMU will handle the signal as guest binary problem,
and exit with guest SEGFAULT.

Solution is to do following: In case if current TB was invalidated
continue to invalidate TBs from remaining guest pages and mark pages
as PAGE_WRITE. After that disable host page protection with mprotect.
If current tb was invalidated longjmp to main loop. That is more
efficient, since we won't get SEGFAULT when executing new TB.

Backports commit 7399a337e4126f7c8c8af3336726f001378c4798 from qemu
2018-02-25 03:14:22 -05:00
Samuel Damashek 670d81367b
cputlb: Fix for self-modifying writes across page boundaries
As it currently stands, QEMU does not properly handle self-modifying code
when the write is unaligned and crosses a page boundary. The procedure
for handling a write to the current translation block is to write-protect
the current translation block, catch the write, split up the translation
block into the current instruction (which remains write-protected so that
the current instruction is not modified) and the remaining instructions
in the translation block, and then restore the CPU state to before the
write occurred so the write will be retried and successfully executed.
However, since unaligned writes across pages are split into one-byte
writes for simplicity, writes to the second page (which is not the
current TB) may succeed before a write to the current TB is attempted,
and since these writes are not invalidated before resuming state after
splitting the TB, these writes will be performed a second time, thus
corrupting the second page. Credit goes to Patrick Hulin for
discovering this.

In recent 64-bit versions of Windows running in emulated mode, this
results in either being very unstable (a BSOD after a couple minutes of
uptime), or being entirely unable to boot. Windows performs one or more
8-byte unaligned self-modifying writes (xors) which intersect the end
of the current TB and the beginning of the next TB, which runs into the
aforementioned issue. This commit fixes that issue by making the
unaligned write loop perform the writes in forwards order, instead of
reverse order. This way, QEMU immediately tries to write to the current
TB, and splits the TB before any write to the second page is executed.
The write then proceeds as intended. With this patch applied, I am able
to boot and use Windows 7 64-bit and Windows 10 64-bit in QEMU without
KVM.

Per Richard Henderson's input, this patch also ensures the second page
is in the TLB before executing the write loop, to ensure the second
page is mapped.

The original discussion of the issue is located at
http://lists.nongnu.org/archive/html/qemu-devel/2014-08/msg02161.html.

Backports commit 81daabaf7a572f138a8b88ba6eea556bdb0cce46 from qemu
2018-02-25 03:12:11 -05:00
Samuel Damashek 04c423b081
cputlb: Add address parameter to VICTIM_TLB_HIT
Backports commit a390284b80d2b6581143cdb40666674e60e635ae from qemu
2018-02-25 03:03:36 -05:00
Richard Henderson 9e2422032a
cputlb: Move VICTIM_TLB_HIT out of line
There are currently 22 invocations of this function,
and we're about to increase that number.

Backports commit 7e9a7c50d9a400ef51242d661a261123c2cc9485 from qemu
2018-02-25 02:58:47 -05:00
Haozhong Zhang 2893a1c381
target-i386: Publish advised value of MSR_IA32_FEATURE_CONTROL via fw_cfg
It's a prerequisite that certain bits of MSR_IA32_FEATURE_CONTROL should
be set before some features (e.g. VMX and LMCE) can be used, which is
usually done by the firmware. This patch adds a fw_cfg file
"etc/msr_feature_control" which contains the advised value of
MSR_IA32_FEATURE_CONTROL and can be used by guest firmware (e.g. SeaBIOS).

Backports commit 217f1b4a72153cf8d556e9d45919e9222c38d25e from qemu
2018-02-25 02:49:42 -05:00
Ashok Raj b58f1fccce
target-i386: kvm: Add basic Intel LMCE support
This patch adds the support to inject SRAR and SRAO as LMCE, i.e. they
are injected to only one VCPU rather than broadcast to all VCPUs. As KVM
reports LMCE support on Intel platforms, this features is only available
on Intel platforms.

LMCE is disabled by default and can be enabled/disabled by cpu option
'lmce=on/off'.

Backports commit 87f8b626041ceaea9adcfdbd549359f0ca7b871d from qemu
2018-02-25 02:48:22 -05:00
Evgeny Yakovlev 49fdd75329
target-i386: Report hyperv feature words through qom
This change adds hyperv feature words report through qom rpc.

When VM is configured with hyperv features enabled
libvirt will check that required feature words are set
in cpuid leaf 40000003 through qom request.

Currently qemu does not report hyperv feature words
which prevents windows guests from starting with libvirt.

To avoid conflicting with current hyperv properties all added feature
words cannot be set directly with -cpu +feature yet.

Backports commit c35bd19a5c9140bce8b913cc5cefe6f071135bdb from qemu
2018-02-25 02:45:20 -05:00
Paolo Bonzini f39cc9e3b9
target-i386: Avoid using locals outside their scope
x86_cpu_parse_featurestr has a "val = num;" assignment just before num
goes out of scope. Push num up to fix the issue.

Backports commit cf2887c9738451eb989c6c102af070dee2dc172a from qemu
2018-02-25 02:30:06 -05:00
Paolo Bonzini 1be92ac243
target-i386: TCG can support CPUID.07H:EBX.erms
ERMS just says "rep movsb" and "rep stosb" are fast. It does not
imply any new instruction, so we can support it easily.

Backports commit 7eb24386dbfb0b66464c7f856c1074c606efccda from qemu
2018-02-25 02:29:00 -05:00
Igor Mammedov 78f9128dbb
target-sparc: Use sparc_cpu_parse_features() directly
Make SPARC target use sparc_cpu_parse_features() directly
so it won't get in the way of switching other propertified
targets to handling features as global properties.

Backports commit fb02d56e96d553088c5b4267a3c954a3e952a50a from qemu
2018-02-25 02:27:23 -05:00
Sergey Sorokin e4d123caa9
tcg: Improve the alignment check infrastructure
Some architectures (e.g. ARMv8) need the address which is aligned
to a size more than the size of the memory access.
To support such check it's enough the current costless alignment
check implementation in QEMU, but we need to support
an alignment size specifying.

Backports commit 1f00b27f17518a1bcb4cedca49eaec96a4d560bd from qemu
2018-02-25 02:23:28 -05:00
Richard Henderson 23586e2674
tcg: Optimize spills of constants
While we can store constants via constrants on INDEX_op_st_i32 et al,
we weren't able to spill constants to backing store.

Add a new backend interface, tcg_out_sti, which may store the constant
(and is allowed to fail). Rearrange the temp_* helpers so that we only
attempt to directly store a constant when the temp is becoming dead/free.

Backports commit 59d7c14eeff8d2ad7f61aed86ce5a176113bc153 from qemu
2018-02-25 01:45:29 -05:00
Richard Henderson 64fda683b1
tcg: Fix name for high-half register 2018-02-25 01:36:35 -05:00
Lioncash 532f840dc3
qapi: Add new clone visitor
We have a couple places in the code base that want to deep-clone
one QAPI object into another, and they were resorting to serializing
the struct out to QObject then reparsing it. A much more efficient
version can be done by adding a new clone visitor.

Since cloning is still relatively uncommon, expose the use of the
new visitor via a QAPI_CLONE() macro that takes care of type-punning
the underlying function pointer, rather than generating lots of
unused functions for types that won't be cloned. And yes, we're
relying on the compiler treating all pointers equally, even though
a strict C program cannot portably do so - but we're not the first
one in the qemu code base to expect it to work (hello, glib!).

The choice of adding a fourth visitor type deserves some explanation.
On the surface, the clone visitor is mostly an input visitor (it
takes arbitrary input - in this case, another QAPI object - and
creates a new QAPI object during the course of the visit). But
ever since commit da72ab0 consolidated enum visits based on the
visitor type, using VISITOR_INPUT would cause us to run
visit_type_str(), even though for cloning there is nothing to do
(we just copy the enum value across, without regards to its mapping
to strings). Also, since our input happens to be a QAPI object,
we can also satisfy the internal checks for VISITOR_OUTPUT. So in
the end, I settled with a new VISITOR_CLONE, and chose its value
such that many internal checks can use 'v->type & mask', sticking
to 'v->type == value' where the difference matters.

Note that we can only clone objects (including alternates) and lists,
not built-ins or enums. The visitor core hides integer width from
the actual visitor (since commit 04e070d), and as long as that's the
case, we can't clone top-level integers. Then again, those can
always be cloned by direct copy, since they are not objects with
deep pointers, so it's no real loss. And restricting cloning to
just objects and lists is cleaner than restricting it to non-integers.
As such, I documented that the clone visitor is for direct use only
by code internal to QAPI, and should not be used on incomplete objects
(other than a hack to work around the fact that we allow NULL in place
of "" in visit_type_str() in other output visitors). Note that as
written, the clone visitor will never fail on a complete object.

Scalars (including enums) not at the root of the clone copy just fine
with no additional effort while visiting the scalar, by virtue of a
g_memdup() each time we push another struct onto the stack. Cloning
a string requires deduplication of a pointer, which means it can also
provide the guarantee of an input visitor of never producing NULL
even when still accepting NULL in place of "" the way the QMP output
visitor does.

Cloning an 'any' type could be possible by incrementing the QObject
refcnt, but it's not obvious whether that is better than implementing
a QObject deep clone. So for now, we document it as unsupported,
and intentionally omit the .type_any() callback to let a developer
know their usage needs implementation.

Add testsuite coverage for several different clone situations, to
ensure that the code is working. I also tested that valgrind was
happy with the test.

Backports commit a15fcc3cf69ee3d408f60d6cc316488d2b0249b4 from qemu
2018-02-25 01:34:12 -05:00
Eric Blake 85af4b2030
qapi: Add new visit_complete() function
Making each output visitor provide its own output collection
function was the only remaining reason for exposing visitor
sub-types to the rest of the code base. Add a polymorphic
visit_complete() function which is a no-op for input visitors,
and which populates an opaque pointer for output visitors. For
maximum type-safety, also add a parameter to the output visitor
constructors with a type-correct version of the output pointer,
and assert that the two uses match.

This approach was considered superior to either passing the
output parameter only during construction (action at a distance
during visit_free() feels awkward) or only during visit_complete()
(defeating type safety makes it easier to use incorrectly).

Most callers were function-local, and therefore a mechanical
conversion; the testsuite was a bit trickier, but the previous
cleanup patch minimized the churn here.

The visit_complete() function may be called at most once; doing
so lets us use transfer semantics rather than duplication or
ref-count semantics to get the just-built output back to the
caller, even though it means our behavior is not idempotent.

Generated code is simplified as follows for events:

|@@ -26,7 +26,7 @@ void qapi_event_send_acpi_device_ost(ACP
| QDict *qmp;
| Error *err = NULL;
| QMPEventFuncEmit emit;
|- QmpOutputVisitor *qov;
|+ QObject *obj;
| Visitor *v;
| q_obj_ACPI_DEVICE_OST_arg param = {
| info
|@@ -39,8 +39,7 @@ void qapi_event_send_acpi_device_ost(ACP
|
| qmp = qmp_event_build_dict("ACPI_DEVICE_OST");
|
|- qov = qmp_output_visitor_new();
|- v = qmp_output_get_visitor(qov);
|+ v = qmp_output_visitor_new(&obj);
|
| visit_start_struct(v, "ACPI_DEVICE_OST", NULL, 0, &err);
| if (err) {
|@@ -55,7 +54,8 @@ void qapi_event_send_acpi_device_ost(ACP
| goto out;
| }
|
|- qdict_put_obj(qmp, "data", qmp_output_get_qobject(qov));
|+ visit_complete(v, &obj);
|+ qdict_put_obj(qmp, "data", obj);
| emit(QAPI_EVENT_ACPI_DEVICE_OST, qmp, &err);

and for commands:

| {
| Error *err = NULL;
|- QmpOutputVisitor *qov = qmp_output_visitor_new();
| Visitor *v;
|
|- v = qmp_output_get_visitor(qov);
|+ v = qmp_output_visitor_new(ret_out);
| visit_type_AddfdInfo(v, "unused", &ret_in, &err);
|- if (err) {
|- goto out;
|+ if (!err) {
|+ visit_complete(v, ret_out);
| }
|- *ret_out = qmp_output_get_qobject(qov);
|-
|-out:
| error_propagate(errp, err);

Backports commit 3b098d56979d2f7fd707c5be85555d114353a28d from qemu
2018-02-25 01:20:03 -05:00
Eric Blake ec53301cda
qmp-output-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
qmp_output_visitor_cleanup(); however, we still need to
expose the subtype for qmp_output_get_qobject().

Backports commit 1830f22a6777cedaccd67a08f675d30f7a85ebfd from qemu
2018-02-25 01:12:27 -05:00
Eric Blake f008d93ac0
qmp-input-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
qmp_input_visitor_cleanup(); which in turn means we no longer
need to return a subtype from qmp_input_visitor_new() nor a
public upcast function.

Generated code changes to qmp-marshal.c look like:

|@@ -52,11 +52,10 @@ void qmp_marshal_add_fd(QDict *args, QOb
| {
| Error *err = NULL;
| AddfdInfo *retval;
|- QmpInputVisitor *qiv = qmp_input_visitor_new(QOBJECT(args), true);
| Visitor *v;
| q_obj_add_fd_arg arg = {0};
|
|- v = qmp_input_get_visitor(qiv);
|+ v = qmp_input_visitor_new(QOBJECT(args), true);
| visit_start_struct(v, NULL, NULL, 0, &err);
| if (err) {
| goto out;

Backports commit b70ce1018a251c0c33498d9c927a07cade655a5e from qemu
2018-02-25 01:10:53 -05:00
Eric Blake e88a7e260b
string-input-visitor: Favor new visit_free() function
Now that we have a polymorphic visit_free(), we no longer need
string_input_visitor_cleanup(); which in turn means we no longer
need to return a subtype from string_input_visitor_new() nor a
public upcast function.

Backports commit 7a0525c7be6b38d32d586e3fd12e7377ded21faa from qemu
2018-02-25 01:08:04 -05:00
Eric Blake 7f741a6c9b
qapi: Add new visit_free() function
Making each visitor provide its own (awkwardly-named) FOO_cleanup()
is unusual, when we can instead have a polymorphic visit_free()
interface. Over the next few patches, we can use the polymorphic
functions to eliminate the need for a FOO_get_visitor() function
for accessing specific visitor functionality, once everything can
be accessed directly through the Visitor* interfaces.

The dealloc visitor is the first one converted to completely use
the new entry point, since qapi_dealloc_visitor_cleanup() was the
only reason that qapi_dealloc_get_visitor() existed, and only
generated and testsuite code was even using it. With the new
visit_free() entry point in place, we no longer need to expose
the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(),
and can get by with less generated code, with diffs that look like:

| void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj)
| {
|- QapiDeallocVisitor *qdv;
| Visitor *v;
|
| if (!obj) {
| return;
| }
|
|- qdv = qapi_dealloc_visitor_new();
|- v = qapi_dealloc_get_visitor(qdv);
|+ v = qapi_dealloc_visitor_new();
| visit_type_ACPIOSTInfo(v, NULL, &obj, NULL);
|- qapi_dealloc_visitor_cleanup(qdv);
|+ visit_free(v);
|}

Backports commit 2c0ef9f411ae6081efa9eca5b3eab2dbeee45a6c from qemu
2018-02-25 01:05:41 -05:00
Eric Blake 37ae4dfdfd
qapi: Add parameter to visit_end_*
Rather than making the dealloc visitor track of stack of pointers
remembered during visit_start_* in order to free them during
visit_end_*, it's a lot easier to just make all callers pass the
same pointer to visit_end_*. The generated code has access to the
same pointer, while all other users are doing virtual walks and
can pass NULL. The dealloc visitor is then greatly simplified.

All three visit_end_*() functions intentionally take a void**,
even though the visit_start_*() functions differ between void**,
GenericList**, and GenericAlternate**. This is done for several
reasons: when doing a virtual walk, passing NULL doesn't care
what the type is, but when doing a generated walk, we already
have to cast the caller's specific FOO* to call visit_start,
while using void** lets us use visit_end without a cast. Also,
an upcoming patch will add a clone visitor that wants to use
the same implementation for all three visit_end callbacks,
which is made easier if all three share the same signature.

For visitors with already track per-object state (the QMP visitors
via a stack, and the string visitors which do not allow nesting),
add an assertion that the caller is indeed passing the same
pointer to paired calls.

Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 00:57:54 -05:00