Commit graph

3631 commits

Author SHA1 Message Date
Eric Blake c14d8226ab
qapi: Fix memleak in string visitors on int lists
Commit 7f8f9ef1 introduced the ability to store a list of
integers as a sorted list of ranges, but when merging ranges,
it leaks one or more ranges. It was also using range_get_last()
incorrectly within range_compare() (a range is a start/end pair,
but range_get_last() is for start/len pairs), and will also
mishandle a range ending in UINT64_MAX (remember, we document
that no range covers 2**64 bytes, but that ranges that end on
UINT64_MAX have end < begin).

The whole merge algorithm was rather complex, and included
unnecessary passes over data within glib functions, and enough
indirection to make it hard to easily plug the data leaks.
Since we are already hard-coding things to a list of ranges,
just rewrite the thing to open-code the traversal and
comparisons, by making the range_compare() helper function give
us an answer that is easier to use, at which point we avoid the
need to pass any callbacks to g_list_*(). Then by reusing
range_extend() instead of duplicating effort with range_merge(),
we cover the corner cases correctly.

Drop the now-unused range_merge() and ranges_can_merge().

Doing this lets test-string-{input,output}-visitor pass under
valgrind without leaks.

Backports commit db486cc334aafd3dbdaf107388e37fc3d6d3e171 from qemu
2018-02-25 00:20:34 -05:00
Eric Blake ef357d06bc
qapi: Simplify use of range.h
Calling our function g_list_insert_sorted_merged is a misnomer,
since we are NOT writing a glib function. Furthermore, we are
making every caller pass the same comparator function of
range_merge(): any caller that would try otherwise would break
in weird ways since our internal call to ranges_can_merge() is
hard-coded to operate only on ranges, rather than paying
attention to the caller's comparator.

Better is to fix things so that callers don't have to care about
our internal comparator, by picking a function name and updating
the parameter type away from a gratuitous use of void*, to make
it obvious that we are operating specifically on a list of ranges
and not a generic list. Plus, refactoring the code here will
make it easier to plug a memory leak in the next patch.

range_compare() is now internal only, and moves to the .c file.

Backports commit 7c47959d0cb05db43014141a156ada0b6d53a750 from qemu
2018-02-25 00:02:42 -05:00
Eric Blake 5e22c7e180
range: Create range.c for code that should not be inline
g_list_insert_sorted_merged() is rather large to be an inline
function; move it to its own file. range_merge() and
ranges_can_merge() can likewise move, as they are only used
internally. Also, it becomes obvious that the condition within
range_merge() is already satisfied by its caller, and that the
return value is not used.

The diffstat is misleading, because of the copyright boilerplate.

Backports commit fec0fc0a13ac7f1a1130433a6740cd850c3db34a from qemu
2018-02-24 23:59:13 -05:00
Eric Blake ebeb0e46f8
qapi: Fix crash on missing alternate member of QAPI struct
If a QAPI struct has a mandatory alternate member which is not
present on input, the input visitor reports an error for the
missing alternate without setting the discriminator, but the
cleanup code for the struct still tries to use the dealloc
visitor to clean up the alternate.

Commit dbf11922 changed visit_start_alternate to set *obj to NULL
when an error occurs, where it was previously left untouched.
Thus, before the patch, the dealloc visitor is blindly trying to
cleanup whatever branch corresponds to (*obj)->type == 0 (that is,
QTYPE_NONE, because *obj still pointed to zeroed memory), which
selects the default branch of the switch and sets an error, but
this second error is ignored by the way the dealloc visitor is
used; but after the patch, the attempt to switch dereferences NULL.

When cleaning up after a partial object parse, we specifically
check for !*obj after visit_start_struct() (see gen_visit_object());
doing the same for alternates fixes the crash. Enhance the testsuite
to give coverage for both missing struct and missing alternate
members.

Also add an abort - we expect visit_start_alternate() to either set an
error or to set (*obj)->type to a valid QType that corresponds to
actual user input, and QTYPE_NONE should never be reachable from valid
input. Had the abort() been in place earlier, we might have noticed
the dealloc visitor dereferencing bogus zeroed memory prior to when
commit dbf11922 forced our hand by setting *obj to NULL and causing a
fault.

Test case:

{'execute':'blockdev-add', 'arguments':{'options':{'driver':'raw'}}}

The choice of 'driver':'raw' selects a BlockdevOptionsGenericFormat
struct, which has a mandatory 'file':'BlockdevRef' in QAPI. Since
'file' is missing as a sibling of 'driver', this should report a
graceful error rather than fault. After this patch, we are back to:

{"error": {"class": "GenericError", "desc": "Parameter 'file' is missing"}}

Generated code in qapi-visit.c changes as:

|@@ -2444,6 +2444,9 @@ void visit_type_BlockdevRef(Visitor *v,
| if (err) {
| goto out;
| }
|+ if (!*obj) {
|+ goto out_obj;
|+ }
| switch ((*obj)->type) {
| case QTYPE_QDICT:
| visit_start_struct(v, name, NULL, 0, &err);
|@@ -2459,10 +2462,13 @@ void visit_type_BlockdevRef(Visitor *v,
| case QTYPE_QSTRING:
| visit_type_str(v, name, &(*obj)->u.reference, &err);
| break;
|+ case QTYPE_NONE:
|+ abort();
| default:
| error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
| "BlockdevRef");
| }
|+out_obj:
| visit_end_alternate(v);

Backports commit 9b4e38fe6a35890bb1d995316d7be08de0b30ee5 from qemu
2018-02-24 23:53:29 -05:00
Aleksandar Markovic f95e0e9e98
target-mips: Add FCR31's FS bit definition
Add preprocessor definition of FCR31's FS bit, and update related
code for setting this bit.

Backports commit 77be419980114d75605811e1681115d0919cfa1a from qemu
2018-02-24 21:32:10 -05:00
Aleksandar Markovic 4a540f88de
target-mips: Implement FCR31's R/W bitmask and related functionalities
This patch implements read and write access rules for Mips floating
point control and status register (FCR31). The change can be divided
into following parts:

- Add fields that will keep FCR31's R/W bitmask in procesor
definitions and processor float_status structure.

- Add appropriate value for FCR31's R/W bitmask for each supported
processor.

- Add function for setting snan_bit_is_one, and integrate it in
appropriate places.

- Modify handling of CTC1 (case 31) instruction to use FCR31's R/W
bitmask.

- Modify handling user mode executables for Mips, in relation to the
bit EF_MIPS_NAN2008 from ELF header, that is in turn related to
reading and writing to FCR31.

- Modify gdb behavior in relation to FCR31.

Backports commit 599bc5e89c46f95f86ccad0d747d041c89a28806 from qemu
2018-02-24 21:30:24 -05:00
Aleksandar Markovic 84b516d9db
target-mips: Add nan2008 flavor of <CEIL|CVT|FLOOR|ROUND|TRUNC>.<L|W>.<S|D>
New set of helpers for handling nan2008-syle versions of instructions
<CEIL|CVT|FLOOR|ROUND|TRUNC>.<L|W>.<S|D>, for Mips R6.

All involved instructions have float operand and integer result. Their
core functionality is implemented via invocations of appropriate SoftFloat
functions. The problematic cases are when the operand is a NaN, and also
when the operand (float) is out of the range of the result.

Here one can distinguish three cases:

CASE MIPS-A: (FCR31.NAN2008 == 1)

1. Operand is a NaN, result should be 0;
2. Operand is larger than INT_MAX, result should be INT_MAX;
3. Operand is smaller than INT_MIN, result should be INT_MIN.

CASE MIPS-B: (FCR31.NAN2008 == 0)

1. Operand is a NaN, result should be INT_MAX;
2. Operand is larger than INT_MAX, result should be INT_MAX;
3. Operand is smaller than INT_MIN, result should be INT_MAX.

CASE SoftFloat:

1. Operand is a NaN, result is INT_MAX;
2. Operand is larger than INT_MAX, result is INT_MAX;
3. Operand is smaller than INT_MIN, result is INT_MIN.

Current implementation of <CEIL|CVT|FLOOR|ROUND|TRUNC>.<L|W>.<S|D>
implements case MIPS-B. This patch relates to case MIPS-A. For case
MIPS-A, only return value for NaN-operands should be corrected after
appropriate SoftFloat library function is called.

Related MSA instructions FTRUNC_S and FTINT_S already handle well
all cases, in the fashion similar to the code from this patch.

Backports commit 87552089b62fa229d2ff86906e4e779177fb5835 from qemu
2018-02-24 21:14:04 -05:00
Aleksandar Markovic a411a12170
target-mips: Add abs2008 flavor of <ABS|NEG>.<S|D>
Updated handling of instructions <ABS|NEG>.<S|D>. Note that legacy
(pre-abs2008) ABS and NEG instructions are arithmetic (and, therefore,
any NaN operand causes signaling invalid operation), while abs2008
ones are non-arithmetic, always and only changing the sign bit, even
for NaN-like operands. Details on these instructions are documented
in [1] p. 35 and 359.

Implementation-wise, abs2008 versions are implemented without helpers,
for simplicity and performance sake.

[1] "MIPS Architecture For Programmers Volume II-A:
The MIPS64 Instruction Set Reference Manual",
Imagination Technologies LTD, Revision 6.04, November 13, 2015

Backports commit 6be77480052b1a71557081896e7080363a8a2f95 from qemu
2018-02-24 20:45:06 -05:00
Aleksandar Markovic ef9f33a345
target-mips: Activate IEEE 754-2008 signaling NaN bit meaning for MSA
Function msa_reset() is updated so that flag snan_bit_is_one is
properly set to 0.

By applying this patch, a number of incorrect MSA behaviors that
require IEEE 754-2008 compliance will be fixed. Those are behaviors
that (up to the moment of applying this patch) did not get the desired
functionality from SoftFloat library with respect to distinguishing
between quiet and signaling NaN, getting default NaN values (both
quiet and signaling), establishing if a floating point number is NaN
or not, etc.

Two examples:

* FMAX, FMIN will now correctly detect and propagate NaNs.
* FCLASS.D ans FCLASS.S will now correcty detect NaN flavors

Backports commit 40bd6dd456e61a36e454fb9dd2cc739b67c224cf from qemu
2018-02-24 20:41:48 -05:00
Aleksandar Markovic 3e9325f1e9
softfloat: Handle snan_bit_is_one == 0 in MIPS pickNaNMulAdd()
Only for Mips platform, and only for cases when snan_bit_is_one is 0,
correct the order of argument comparisons in pickNaNMulAdd().

For more info, see [1], page 53, section "3.5.3 NaN Propagation".

[1] "MIPS Architecture for Programmers Volume IV-j:
The MIPS32 SIMD Architecture Module",
Imagination Technologies LTD, Revision 1.12, February 3, 2016

Backports commit c27644f0e9659471e1c9355da5b667960d311937 from qemu
2018-02-24 20:40:11 -05:00
Aleksandar Markovic 33833b6605
softfloat: For Mips only, correct default NaN values
Only for Mips platform, and only for cases when snan_bit_is_one is 0,
correct default NaN values (in their 16-, 32-, and 64-bit flavors).

For more info, see [1], page 84, Table 6.3 "Value Supplied When a New
Quiet NaN Is Created", and [2], page 52, Table 3.7 "Default NaN
Encodings".

[1] "MIPS Architecture For Programmers Volume II-A:
The MIPS64 Instruction Set Reference Manual",
Imagination Technologies LTD, Revision 6.04, November 13, 2015

[2] "MIPS Architecture for Programmers Volume IV-j:
The MIPS32 SIMD Architecture Module",
Imagination Technologies LTD, Revision 1.12, February 3, 2016

Backports commit a7c04d545a97126c9df9d96623747d8613aaf7db from qemu
2018-02-24 20:38:23 -05:00
Aleksandar Markovic 33ee9429b2
softfloat: Clean code format in fpu/softfloat-specialize.h
fpu/softfloat-specialize.h is the most critical file in SoftFloat
library, since it handles numerous differences between platforms in
relation to floating point arithmetics. This patch makes the code
in this file more consistent format-wise, and hopefully easier to
debug and maintain.

Backports commit a59eaea64686c8966b7653303660f8c26f285c77 from qemu
2018-02-24 20:35:05 -05:00
Aleksandar Markovic 6eb4fa54f6
softfloat: Implement run-time-configurable meaning of signaling NaN bit
This patch modifies SoftFloat library so that it can be configured in
run-time in relation to the meaning of signaling NaN bit, while, at the
same time, strictly preserving its behavior on all existing platforms.

Background:

In floating-point calculations, there is a need for denoting undefined or
unrepresentable values. This is achieved by defining certain floating-point
numerical values to be NaNs (which stands for "not a number"). For additional
reasons, virtually all modern floating-point unit implementations use two
kinds of NaNs: quiet and signaling. The binary representations of these two
kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally,
the first bit of mantissa).

Up to 2008, standards for floating-point did not specify all details about
binary representation of NaNs. More specifically, the meaning of the bit
that is used for distinguishing between signaling and quiet NaNs was not
strictly prescribed. (IEEE 754-2008 was the first floating-point standard
that defined that meaning clearly, see [1], p. 35) As a result, different
platforms took different approaches, and that presented considerable
challenge for multi-platform emulators like QEMU.

Mips platform represents the most complex case among QEMU-supported
platforms regarding signaling NaN bit. Up to the Release 6 of Mips
architecture, "1" in signaling NaN bit denoted signaling NaN, which is
opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture
adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of
that, Mips architecture for SIMD (also known as MSA, or vector instructions)
also specifies signaling bit in accordance to IEEE standard. MSA unit can be
implemented with both pre-Release 6 and Release 6 main processor units.

QEMU uses SoftFloat library to implement various floating-point-related
instructions on all platforms. The current QEMU implementation allows for
defining meaning of signaling NaN bit during build time, and is implemented
via preprocessor macro called SNAN_BIT_IS_ONE.

On the other hand, the change in this patch enables SoftFloat library to be
configured in run-time. This configuration is meant to occur during CPU
initialization, at the moment when it is definitely known what desired
behavior for particular CPU (or any additional FPUs) is.

The change is implemented so that it is consistent with existing
implementation of similar cases. This means that structure float_status is
used for passing the information about desired signaling NaN bit on each
invocation of SoftFloat functions. The additional field in float_status is
called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE.

IMPORTANT:

This change is not meant to create any change in emulator behavior or
functionality on any platform. It just provides the means for SoftFloat
library to be used in a more flexible way - in other words, it will just
prepare SoftFloat library for usage related to Mips platform and its
specifics regarding signaling bit meaning, which is done in some of
subsequent patches from this series.

Further break down of changes:

1) Added field snan_bit_is_one to the structure float_status, and
correspondent setter function set_snan_bit_is_one().

2) Constants <float16|float32|float64|floatx80|float128>_default_nan
(used both internally and externally) converted to functions
<float16|float32|float64|floatx80|float128>_default_nan(float_status*).
This is necessary since they are dependent on signaling bit meaning.
At the same time, for the sake of code cleanup and simplicity, constants
<floatx80|float128>_default_nan_<low|high> (used only internally within
SoftFloat library) are removed, as not needed.

3) Added a float_status* argument to SoftFloat library functions
XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_),
XXX_maybe_silence_nan(XXX a_). This argument must be present in
order to enable correct invocation of new version of functions
XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128>
here)

4) Updated code for all platforms to reflect changes in SoftFloat library.
This change is twofolds: it includes modifications of SoftFloat library
functions invocations, and an addition of invocation of function
set_snan_bit_is_one() during CPU initialization, with arguments that
are appropriate for each particular platform. It was established that
all platforms zero their main CPU data structures, so snan_bit_is_one(0)
in appropriate places is not added, as it is not needed.

[1] "IEEE Standard for Floating-Point Arithmetic",
IEEE Computer Society, August 29, 2008.

Backports commit af39bc8c49224771ec0d38f1b693ea78e221d7bc from qemu
2018-02-24 20:27:12 -05:00
Alexey Kardashevskiy 096ca207af
memory: Add reporting of supported page sizes
Every IOMMU has some granularity which MemoryRegionIOMMUOps::translate
uses when translating, however this information is not available outside
the translate context for various checks.

This adds a get_min_page_size callback to MemoryRegionIOMMUOps and
a wrapper for it so IOMMU users (such as VFIO) can know the minimum
actual page size supported by an IOMMU.

As IOMMU MR represents a guest IOMMU, this uses TARGET_PAGE_SIZE
as fallback.

This removes vfio_container_granularity() and uses new helper in
memory_region_iommu_replay() when replaying IOMMU mappings on added
IOMMU memory region.

Backports the relevant parts of commit f682e9c244af7166225f4a50cc18ff296bb9d43e from qemu
2018-02-24 19:23:28 -05:00
Lluís Vilanova 2297527755
exec: [tcg] Track which vCPU is performing translation and execution
Information is tracked inside the TCGContext structure, and later used
by tracing events with the 'tcg' and 'vcpu' properties.

The 'cpu' field is used to check tracing of translation-time
events ("*_trans"). The 'tcg_env' field is used to pass it to
execution-time events ("*_exec").

Backports commit 7c2550432abe62f53e6df878ceba6ceaf71f0e7e from qemu
2018-02-24 19:21:39 -05:00
Eduardo Habkost 0f6513ef62
error: Remove unnecessary local_err variables
This patch simplifies code that uses a local_err variable just to
immediately use it for an error_propagate() call.

Coccinelle patch used to perform the changes added to
scripts/coccinelle/remove_local_err.cocci.

Backports commit 6b62d961373e0327f2af8fb77d6d5d6308864180 from qemu
2018-02-24 19:12:25 -05:00
Peter Maydell 5ae787f895
target-arm: Provide hook to tell GICv3 about changes of security state
The GICv3 CPU interface needs to know when the CPU it is attached
to makes an exception level or mode transition that changes the
security state, because whether it is asserting IRQ or FIQ can change
depending on these things. Provide a mechanism for letting the GICv3
device register a hook to be called on such changes.

Backports commit bd7d00fc50c9960876dd194ebf0c88889b53e765 from qemu
2018-02-24 19:09:22 -05:00
Peter Maydell eec3a5f843
target-arm: Define new arm_is_el3_or_mon() function
The GICv3 system registers need to know if the CPU is AArch64
in EL3 or AArch32 in Monitor mode. This happens to be the first
part of the check for arm_is_secure(), so factor it out into a
new arm_is_el3_or_mon() function that the GIC can also use.

Backports commit 712058764da29b2908f6fbf56760ca4f15980709 from qemu
2018-02-24 19:04:27 -05:00
Peter Maydell f893dacef0
bitops.h: Implement half-shuffle and half-unshuffle ops
A half-shuffle operation takes a word with zeros in the high half:
0000 0000 0000 0000 ABCD EFGH IJKL MNOP
and spreads the bits out so they are in every other bit of the word:
0A0B 0C0D 0E0F 0G0H 0I0J 0K0L 0M0N 0O0P
A half-unshuffle performs the reverse operation.

Provide functions in bitops.h which implement these operations
for 32-bit and 64-bit inputs, and add tests for them.

Backports commit b355438de52d0782983bf4bdc47936189a0c988b from qemu
2018-02-24 19:02:36 -05:00
Bharata B Rao 851dec945d
qom: API to get instance_size of a type
Add an API object_type_get_size(const char *typename) that returns the
instance_size of the give typename.

Backports commit 3f97b53a682d2595747c926c00d78b9d406f1be0 from qemu
2018-02-24 19:00:16 -05:00
Thomas Huth aee5c93f58
configure: Enable -Werror for MinGW builds, too
MinGW seems to compile currently without warnings, so it should
be safe to enable -Werror now for this environment, too.

Backports commit e4650c81b3d15ba67236815defbb475c4bdf8690 from qemu
2018-02-24 18:56:05 -05:00
Eduardo Habkost b918dd95f3
target-i386: Consolidate calls of object_property_parse() in x86_cpu_parse_featurestr
Backports commit f6750e959a397dea988efd4e488e1ff813011065 from qemu
2018-02-24 18:53:55 -05:00
Igor Mammedov 800b28483b
target-i386: Move features logic that requires CPUState to realize time
Making x86_cpu_parse_featurestr() a pure convertor
of legacy feature string into global properties, needs
it to be called before a CPU instance is created so
parser shouldn't modify CPUState directly or access
it at all. Hence move current hack that directly pokes
into CPUState, to set/unset +-feats, from parser to
CPU's realize method.

Backports commit dc15c0517b010a9444a2c05794dae980f2a2cbd9 from qemu
2018-02-24 18:47:46 -05:00
Eduardo Habkost b9ca5c4d33
target-i386: Remove xlevel & hv-spinlocks option fixups
The "fixup will be removed in future versions" warnings are
present since QEMU 1.7.0, at least, so users should have fixed
their scripts and configurations, already.

In the case of libvirt users, libvirt doesn't use the "xlevel"
option, and already rejects HyperV spinlock retry count < 0xFFF.

Backports commit c19b85216b5d47d922ac010931d4c7b2d79b2f68 from qemu
2018-02-24 18:33:32 -05:00
Radim Krčmář 610a52e9c7
target-i386: Implement CPUID[0xB] (Extended Topology Enumeration)
I looked at a dozen Intel CPU that have this CPUID and all of them
always had Core offset as 1 (a wasted bit when hyperthreading is
disabled) and Package offset at least 4 (wasted bits at <= 4 cores).

QEMU uses more compact IDs and it doesn't make much sense to change it
now. I keep the SMT and Core sub-leaves even if there is just one
thread/core; it makes the code simpler and there should be no harm.

Backports commit 5232d00a041c8f3628b3532ef35d703a1f0dac19 from qemu
2018-02-24 18:31:14 -05:00
Eduardo Habkost 8991e8bf0b
target-i386: add Skylake-Client cpu model
Introduce Skylake-Client cpu mode which inherits the features from
Broadwell and supports some additional features that are: MPX,
XSAVEC, and XGETBV1.

Backports commit f6f949e9295889fb272698aea763dcea77d616ce from qemu
2018-02-24 18:25:50 -05:00
Peter Maydell 9bdf310d49
target-arm: Don't permit ARMv8-only Neon insns on ARMv7
The Neon instructions VCVTA, VCVTM, VCVTN, VCVTP, VRINTA, VRINTM,
VRINTN, VRINTP, VRINTX, and VRINTZ were only introduced with ARMv8,
so they need a guard to make them UNDEF if the CPU only supports ARMv7.
(We got this right for all the other new-in-v8 insns, but forgot
it for these Neon 2-reg-misc ops.)

Backports commit fe8fcf3d642b4de1369841bf6acac13e0ec8770d from qemu
2018-02-24 18:20:00 -05:00
Peter Maydell a9fb399490
target-arm: Fix reset and migration of TTBCR(S)
Commit 6459b94c26dd666badb3 broke reset and migration of the AArch32
TTBCR(S) register if the guest used non-LPAE page tables. This is
because the AArch32 TTBCR register definition is marked as ARM_CP_ALIAS,
meaning that the AArch64 variant has to handle migration and reset.
Although AArch64 TCR_EL3 doesn't need to care about the mask and
base_mask fields, AArch32 may do so, and so we must use the special
TTBCR reset and raw write functions to ensure they are set correctly.

This doesn't affect TCR_EL2, because the AArch32 equivalent of that
is HTCR, which never uses the non-LPAE page table variant.

Backports commit 811595a2d4ab8c6354857a50ffd29fafce52a892 from qemu
2018-02-24 18:18:24 -05:00
Shannon Zhao 51c9e12605
target-arm: kvm64: set guest PMUv3 feature bit if supported
Check if kvm supports guest PMUv3. If so, set the corresponding feature
bit for vcpu.

Backports commit 5c0a3819f009639f67ce0453dff6ec7211bfee54 from qemu
2018-02-24 18:17:11 -05:00
Emilio G. Cota ae3e22a689
tb hash: hash phys_pc, pc, and flags with xxhash
For some workloads such as arm bootup, tb_phys_hash is performance-critical.
The is due to the high frequency of accesses to the hash table, originated
by (frequent) TLB flushes that wipe out the cpu-private tb_jmp_cache's.
More info:
https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg05098.html

To dig further into this I modified an arm image booting debian jessie to
immediately shut down after boot. Analysis revealed that quite a bit of time
is unnecessarily spent in tb_phys_hash: the cause is poor hashing that
results in very uneven loading of chains in the hash table's buckets;
the longest observed chain had ~550 elements.

The appended addresses this with two changes:

1) Use xxhash as the hash table's hash function. xxhash is a fast,
high-quality hashing function.

2) Feed the hashing function with not just tb_phys, but also pc and flags.

This improves performance over using just tb_phys for hashing, since that
resulted in some hash buckets having many TB's, while others getting very few;
with these changes, the longest observed chain on a single hash bucket is
brought down from ~550 to ~40.

Tests show that the other element checked for in tb_find_physical,
cs_base, is always a match when tb_phys+pc+flags are a match,
so hashing cs_base is wasteful. It could be that this is an ARM-only
thing, though. UPDATE:
On Tue, Apr 05, 2016 at 08:41:43 -0700, Richard Henderson wrote:
> The cs_base field is only used by i386 (in 16-bit modes), and sparc (for a TB
> consisting of only a delay slot).
> It may well still turn out to be reasonable to ignore cs_base for hashing.

BTW, after this change the hash table should not be called "tb_hash_phys"
anymore; this is addressed later in this series.

This change gives consistent bootup time improvements. I tested two
host machines:
- Intel Xeon E5-2690: 11.6% less time
- Intel i7-4790K: 19.2% less time

Increasing the number of hash buckets yields further improvements. However,
using a larger, fixed number of buckets can degrade performance for other
workloads that do not translate as many blocks (600K+ for debian-jessie arm
bootup). This is dealt with later in this series.

Backports commit 42bd32287f3a18d823f2258b813824a39ed7c6d9 from qemu
2018-02-24 18:00:14 -05:00
Emilio G. Cota 9ef9de9cf8
exec: add tb_hash_func5, derived from xxhash
This will be used by upcoming changes for hashing the tb hash.

Add this into a separate file to include the copyright notice from
xxhash.

Backports commit dc8b295d05ec35a8c032f9abca421772347ba5d4 from qemu
2018-02-24 17:36:35 -05:00
Emilio G. Cota 8518f55df7
compiler.h: add QEMU_ALIGNED() to enforce struct alignment
Backports commit 911a4d2215b05267b16925503218f49d607c6b29 from qemu
2018-02-24 17:32:43 -05:00
Peter Maydell 48539e54da
target-i386: Move user-mode exception actions out of user-exec.c
The exception_action() function in user-exec.c is just a call to
cpu_loop_exit() for every target CPU except i386. Since this
function is only called if the target's handle_mmu_fault() hook has
indicated an MMU fault, and that hook is only called from the
handle_cpu_signal() code path, we can simply move the x86-specific
setup into that hook, which allows us to remove the TARGET_I386
ifdef from user-exec.c.

Of the actions that were done by the call to raise_interrupt_err():
* cpu_svm_check_intercept_param() is a no-op in user mode
* check_exception() is a no-op since double faults are impossible
for user-mode
* assignments to cs->exception_index and env->error_code are no-ops
* assigning to env->exception_next_eip is unnecessary because it
is not used unless env->exception_is_int is true
* cpu_loop_exit_restore() is equivalent to cpu_loop_exit() since
pc is 0
which leaves just setting env_>exception_is_int as the action that
needs to be added to x86_cpu_handle_mmu_fault().

Backports commit 0c33682d5f29b0a4ae53bdec4c8e52e4fae37b34 from qemu
2018-02-24 17:27:08 -05:00
Peter Maydell fa2679ba96
target-i386: Add comment about do_interrupt_user() next_eip argument
Add a comment to do_interrupt_user() along the same lines as the
existing one for do_interrupt_all() noting that the next_eip
argument is not used unless is_int is true or intno is EXCP_SYSCALL.

Backports commit 33271823323483b4ede1ae99de83d33b25875402 from qemu
2018-02-24 17:26:18 -05:00
Peter Maydell d7dccff836
cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc()
The function cpu_resume_from_signal() is now always called with a
NULL puc argument, and is rather misnamed since it is never called
from a signal handler. It is essentially forcing an exit to the
top level cpu loop but without raising any exception, so rename
it to cpu_loop_exit_noexc() and drop the useless unused argument.

Backports commit 6886b98036a8f8f5bce8b10756ce080084cef11b from qemu
2018-02-24 17:25:28 -05:00
Peter Maydell b2013255aa
user-exec: Push resume-from-signal code out to handle_cpu_signal()
Since the only caller of page_unprotect() which might cause it to
need to call cpu_resume_from_signal() is handle_cpu_signal() in
the user-mode code, push the longjump handling out to that function.

Since this is the only caller of cpu_resume_from_signal() which
passes a non-NULL puc argument, split the non-NULL handling into
a new cpu_exit_tb_from_sighandler() function. This allows us
to merge the softmmu and usermode implementations of the
cpu_resume_from_signal() function, which are now identical.

Backports commit f213e72f2356b77768b9cb73814a3b26ad5a0099 from qemu
2018-02-24 17:21:06 -05:00
Peter Maydell 37b7538d85
translate-all.c: Don't pass puc, locked to tb_invalidate_phys_page()
The user-mode-only function tb_invalidate_phys_page() is only
called from two places:
* page_unprotect(), which passes in a non-zero pc, a puc pointer
and the value 'true' for the locked argument
* page_set_flags(), which passes in a zero pc, a NULL puc pointer
and a 'false' locked argument

If the pc is non-zero then we may call cpu_resume_from_signal(),
which does a longjmp out of the calling code (and out of the
signal handler); this is to cover the case of a target CPU with
"precise self-modifying code" (currently only x86) executing
a store instruction which modifies code in the same TB as the
store itself. Rather than doing the longjump directly here,
return a flag to the caller which indicates whether the current
TB was modified, and move the longjump to page_unprotect.

Backports commit 75809229bbf28b371afce14921ff5be98ddc5faa from qemu
2018-02-24 17:11:30 -05:00
Paolo Bonzini 1db22b5889
Makefile: add dependency on scripts/create_config
Make sure that config-host.h and config-target.h are rebuilt whenever
there is a change in the scripts that generates them; add the dependency
to the pattern rule as suggested by Peter.

Backports commit 553350156d80c18d0127c742f47b7adbd642f3ef from qemu
2018-02-24 17:05:03 -05:00
Fam Zheng c17a3070ea
Makefile: Add a FORCE target
Backports commit d41d4da3c5d702b505d74265900a13fae2c8d0e0 from qemu
2018-02-24 17:03:51 -05:00
Peter Maydell 8d0faac1dc
qemu-common.h: Drop WORDS_ALIGNED define
The WORDS_ALIGNED #define is not used anywhere, and hasn't been since
2013 when commit 612d590ebc6cef rewrote the various ld<type>_<endian>_p
functions to not use it. Remove the #define and the comment describing it.
Also remove the line in the comment about TARGET_WORDS_ALIGNED, since
it has never actually existed.

Backports commit 0d5c21f2b3bf1e0b562a2c74e353d2e03f2f50ef from qemu
2018-02-24 17:01:55 -05:00
Stefan Weil 4470900f3b
configure: Use instead of deprecated
This fixes these warnings from shellcheck:

^-- SC2006: Use $(..) instead of deprecated `..`

Backports commit 89138857619b2a023c32200e9af780792ccaa8c3 from qemu
2018-02-24 16:59:40 -05:00
Sergey Sorokin c05902eddd
target-arm: Fix TTBR selecting logic on AArch32 Stage 2 translation
Address size is 40-bit for the AArch32 stage 2 translation,
and t0sz can be negative (from -8 to 7),
so we need to adjust it to use the existing TTBR selecting logic.

Backports commit 6e99f762612827afeff54add2e4fc2c3b2657fed from qemu
2018-02-24 16:54:32 -05:00
Peter Maydell 806d72035e
target-arm: Don't try to set ESR IL bit in arm_cpu_do_interrupt_aarch64()
Remove some incorrect code from arm_cpu_do_interrupt_aarch64()
which attempts to set the IL bit in the syndrome register based
on the value of env->thumb. This is wrong in several ways:
* IL doesn't indicate Thumb-vs-ARM, it indicates instruction
length (which may be 16 or 32 for Thumb and is always 32 for ARM)
* not every syndrome format uses IL like this -- for some IL is
always set, and for some it is always clear
* the code is changing esr_el[new_el] even for interrupt entry,
which is not supposed to modify ESR_ELx at all

Delete the code, and instead rely on the syndrome value in
env->exception.syndrome having already been set up with the
correct value of IL.

Backports commit 78f1edb19fe11fa0c5d0bf484db59a384f455d3c from qemu
2018-02-24 16:49:53 -05:00
Peter Maydell dc8bf22d88
target-arm: Set IL bit in syndromes for insn abort, watchpoint, swstep
For some exception syndrome types, the IL bit should always be set.
This includes the instruction abort, watchpoint and software step
syndrome types; add the missing ARM_EL_IL bit to the syndrome
values returned by syn_insn_abort(), syn_swstep() and syn_watchpoint().

Backports commit 04ce861ea545477425ad9e045eec3f61c8a27df9 from qemu
2018-02-24 16:48:59 -05:00
Edgar E. Iglesias 8aee797956
target-arm: A64: Create Instruction Syndromes for Data Aborts
Add support for generating the ISS (Instruction Specific Syndrome) for
Data Abort exceptions taken from AArch64.
These syndromes are used by hypervisors for example to trap and emulate
memory accesses.

We save the decoded data out-of-band with the TBs at translation time.
When exceptions hit, the extra data attached to the TB is used to
recreate the state needed to encode instruction syndromes.
This avoids the need to emit moves with every load/store.

Based on a suggestion from Peter Maydell.

Backports commit aaa1f954d4cab243e3d5337a72bc6d104e1c4808 from qemu
2018-02-24 16:46:44 -05:00
Alistair Francis 25daa5363e
target-arm: Add the HSTR_EL2 register
Add the Hypervisor System Trap Register for EL2.

This register is used early in the Linux boot and without it the kernel
aborts with a "Synchronous Abort" error.

Backports commit 2a5a9abd4bc45e2f4c62c77e07aebe53608c6915 from qemu
2018-02-24 16:24:57 -05:00
Fam Zheng 495c39300c
rules.mak: Add COMMA constant
Using "," literal in $(call quiet-command, ...) arguments is awkward.
Add this constant to make it at least doable.

Backports commit 2f4e4dc237261c76734d8ae1d8e09d2983d2f1ca from qemu
2018-02-24 16:20:31 -05:00
Paolo Bonzini 8df5ad80b1
exec: hide mr->ram_addr from qemu_get_ram_ptr users
Let users of qemu_get_ram_ptr and qemu_ram_ptr_length pass in an
address that is relative to the MemoryRegion. This basically means
what address_space_translate returns.

Because the semantics of the second parameter change, rename the
function to qemu_map_ram_ptr.

Backports commit 0878d0e11ba8013dd759c6921cbf05ba6a41bd71 from qemu
2018-02-24 16:17:49 -05:00
Paolo Bonzini b2e1b34bcc
memory: split memory_region_from_host from qemu_ram_addr_from_host
Move the old qemu_ram_addr_from_host to memory_region_from_host and
make it return an offset within the region. For qemu_ram_addr_from_host
return the ram_addr_t directly, similar to what it was before
commit 1b5ec23 ("memory: return MemoryRegion from qemu_ram_addr_from_host",
2013-07-04).

Backports commit 07bdaa4196b51bc7ffa7c3f74e9e4a9dc8a7966a from qemu
2018-02-24 16:06:49 -05:00
Paolo Bonzini 918c626847
exec: remove ram_addr argument from qemu_ram_block_from_host
Of the two callers, one does not use it, and the other can compute
it itself based on the other output argument (offset) and the RAMBlock.

Backports commit f615f39616c4fd1a3a3b078af8d75bb4be6390de from qemu
2018-02-24 03:37:40 -05:00