Commit Graph

272 Commits

Author SHA1 Message Date
Paolo Bonzini
3d304620ec target/i386: fix operand size of unary SSE operations
VRCPSS, VRSQRTSS and VCVTSx2Sx have a 32-bit or 64-bit memory operand,
which is represented in the decoding tables by X86_VEX_REPScalar.  Add it
to the tables, and make validate_vex() handle the case of an instruction
that is in exception type 4 without the REP prefix and exception type 5
with it; this is the cas of VRCP and VRSQRT.

Reported-by: yongwoo <https://gitlab.com/yongwoo36>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1377
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 10:44:35 +01:00
Joe Richey
b585edca34 i386: Emit correct error code for 64-bit IDT entry
When in 64-bit mode, IDT entiries are 16 bytes, so `intno * 16` is used
for base/limit/offset calculations. However, even in 64-bit mode, the
exception error code still uses bits [3,16) for the invlaid interrupt
index.

This means the error code should still be `intno * 8 + 2` even in 64-bit
mode.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1382
Signed-off-by: Joe Richey <joerichey@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 09:59:38 +01:00
Richard Henderson
8218c048be target/i386: Always completely initialize TranslateFault
In get_physical_address, the canonical address check failed to
set TranslateFault.stage2, which resulted in an uninitialized
read from the struct when reporting the fault in x86_cpu_tlb_fill.

Adjust all error paths to use structure assignment so that the
entire struct is always initialized.

Reported-by: Daniel Hoffman <dhoff749@gmail.com>
Fixes: 9bbcf37219 ("target/i386: Reorg GET_HPHYS")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221201074522.178498-1-richard.henderson@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1324
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-01 09:53:24 +01:00
Paolo Bonzini
38e65936a8 target/i386: allow MMX instructions with CR4.OSFXSR=0
MMX state is saved/restored by FSAVE/FRSTOR so the instructions are
not illegal opcodes even if CR4.OSFXSR=0.  Make sure that validate_vex
takes into account the prefix and only checks HF_OSFXSR_MASK in the
presence of an SSE instruction.

Fixes: 20581aadec ("target/i386: validate VEX prefixes via the instructions' exception classes", 2022-10-18)
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1350
Reported-by: Helge Konetzka (@hejko on gitlab.com)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-01 09:05:05 +01:00
Paolo Bonzini
35d95e4126 target/i386: hardcode R_EAX as destination register for LAHF/SAHF
When translating code that is using LAHF and SAHF in combination with the
REX prefix, the instructions should not use any other register than AH;
however, QEMU selects SPL (SP being register 4, just like AH) if the
REX prefix is present.  To fix this, use deposit directly without
going through gen_op_mov_v_reg and gen_op_mov_reg_v.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/130
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-11-15 09:34:42 +10:00
Paolo Bonzini
d1bb978ba1 target/i386: fix cmpxchg with 32-bit register destination
Unlike the memory case, where "the destination operand receives a write
cycle without regard to the result of the comparison", rm must not be
touched altogether if the write fails, including not zero-extending
it on 64-bit processors.  This is not how the movcond currently works,
because it is always followed by a gen_op_mov_reg_v to rm.

To fix it, introduce a new function that is similar to gen_op_mov_reg_v
but writes to a TCG temporary.

Considering that gen_extu(ot, oldv) is not needed in the memory case
either, the two cases for register and memory destinations are different
enough that one might as well fuse the two "if (mod == 3)" into one.
So do that too.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/508
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[rth: Add a test case ]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-11-15 09:34:42 +10:00
Stefan Hajnoczi
7f5acfcb66 * bug fixes
* reduced memory footprint for IPI virtualization on Intel processors
 * asynchronous teardown support (Linux only)
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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging

* bug fixes
* reduced memory footprint for IPI virtualization on Intel processors
* asynchronous teardown support (Linux only)

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* tag 'for-upstream' of https://gitlab.com/bonzini/qemu:
  target/i386: Fix test for paging enabled
  util/log: Close per-thread log file on thread termination
  target/i386: Set maximum APIC ID to KVM prior to vCPU creation
  os-posix: asynchronous teardown for shutdown on Linux
  target/i386: Fix calculation of LOCK NEG eflags

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-11-03 10:54:37 -04:00
Richard Henderson
03a60ae9ca target/i386: Fix test for paging enabled
If CR0.PG is unset, pg_mode will be zero, but it will also be zero
for non-PAE/non-PSE page tables with CR0.WP=0.  Restore the
correct test for paging enabled.

Fixes: 98281984a3 ("target/i386: Add MMU_PHYS_IDX and MMU_NESTED_IDX")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1269
Reported-by: Andreas Gustafsson <gson@gson.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221102091232.1092552-1-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-02 12:35:16 +01:00
Richard Henderson
6317933086 target/i386: Expand eflags updates inline
The helpers for reset_rf, cli, sti, clac, stac are
completely trivial; implement them inline.

Drop some nearby #if 0 code.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-11-01 08:31:41 +11:00
Richard Henderson
3d419a4dd2 accel/tcg: Remove will_exit argument from cpu_restore_state
The value passed is always true, and if the target's
synchronize_from_tb hook is non-trivial, not exiting
may be erroneous.

Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-11-01 08:31:41 +11:00
Qi Hu
1215317510 target/i386: Fix calculation of LOCK NEG eflags
After:

        lock negl -0x14(%rbp)
        pushf
        pop    %rax

%rax will contain the wrong value because the "lock neg" calculates the
wrong eflags.  Simple test:

        #include <assert.h>

        int main()
        {
          __volatile__ unsigned test = 0x2363a;
          __volatile__ char cond = 0;
          asm(
              "lock negl %0 \n\t"
              "sets %1"
              : "=m"(test), "=r"(cond));
          assert(cond & 1);
          return 0;
        }

Reported-by: Jinyang Shen <shenjinyang@loongson.cn>
Co-Developed-by: Xuehai Chen <chenxuehai@loongson.cn>
Signed-off-by: Xuehai Chen <chenxuehai@loongson.cn>
Signed-off-by: Qi Hu <huqi@loongson.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-31 09:46:34 +01:00
Richard Henderson
434382e640 target/i386: Convert to tcg_ops restore_state_to_opc
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-10-26 11:11:28 +10:00
Paolo Bonzini
2872b0f390 target/i386: implement FMA instructions
The only issue with FMA instructions is that there are _a lot_ of them (30
opcodes, each of which comes in up to 4 versions depending on VEX.W and
VEX.L; a total of 96 possibilities).  However, they can be implement with
only 6 helpers, two for scalar operations and four for packed operations.
(Scalar versions do not do any merging; they only affect the bottom 32
or 64 bits of the output operand.  Therefore, there is no separate XMM
and YMM of the scalar helpers).

First, we can reduce the number of helpers to one third by passing four
operands (one output and three inputs); the reordering of which operands
go to the multiply and which go to the add is done in emit.c.

Second, the different instructions also dispatch to the same softfloat
function, so the flags for float32_muladd and float64_muladd are passed
in the helper as int arguments, with a little extra complication to
handle FMADDSUB and FMSUBADD.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-22 09:05:54 +02:00
Paolo Bonzini
cf5ec6641e target/i386: implement F16C instructions
F16C only consists of two instructions, which are a bit peculiar
nevertheless.

First, they access only the low half of an YMM or XMM register for the
packed-half operand; the exact size still depends on the VEX.L flag.
This is similar to the existing avx_movx flag, but not exactly because
avx_movx is hardcoded to affect operand 2.  To this end I added a "ph"
format name; it's possible to reuse this approach for the VPMOVSX and
VPMOVZX instructions, though that would also require adding two more
formats for the low-quarter and low-eighth of an operand.

Second, VCVTPS2PH is somewhat weird because it *stores* the result of
the instruction into memory rather than loading it.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-20 15:16:18 +02:00
Paolo Bonzini
314d3eff66 target/i386: introduce function to set rounding mode from FPCW or MXCSR bits
VROUND, FSTCW and STMXCSR all have to perform the same conversion from
x86 rounding modes to softfloat constants.  Since the ISA is consistent
on the meaning of the two-bit rounding modes, extract the common code
into a wrapper for set_float_rounding_mode.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-20 15:16:13 +02:00
Paolo Bonzini
0d4bcac3ca target/i386: decode-new: avoid out-of-bounds access to xmm_regs[-1]
If the destination is a memory register, op->n is -1.  Going through
tcg_gen_gvec_dup_imm path is both useless (the value has been stored
by the gen_* function already) and wrong because of the out-of-bounds
access.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-20 15:15:50 +02:00
Paolo Bonzini
653fad2497 target/i386: remove old SSE decoder
With all SSE (and AVX!) instructions now implemented in disas_insn_new,
it's possible to remove gen_sse, as well as the helpers for instructions
that now use gvec.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
71a0891d61 target/i386: move 3DNow to the new decoder
This adds another kind of weirdness when you thought you had seen it all:
an opcode byte that comes _after_ the address, not before.  It's not
worth adding a new X86_SPECIAL_* constant for it, but it's actually
not unlike VCMP; so, forgive me for exploiting the similarity and just
deciding to dispatch to the right gen_helper_* call in a single code
generation function.

In fact, the old decoder had a bug where s->rip_offset should have
been set to 1 for 3DNow! instructions, and it's fixed now.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
57f6bba023 target/i386: implement VLDMXCSR/VSTMXCSR
These are exactly the same as the non-VEX version, but one has to be careful
that only VEX.L=0 is allowed.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
892544317f target/i386: implement XSAVE and XRSTOR of AVX registers
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
f8d19eec0d target/i386: reimplement 0x0f 0x28-0x2f, add AVX
Here the code is a bit uglier due to the truncation and extension
of registers to and from 32-bit.  There is also a mistake in the
manual with respect to the size of the memory operand of CVTPS2PI
and CVTTPS2PI, reported by Ricky Zhou.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
7170a17ec3 target/i386: reimplement 0x0f 0x10-0x17, add AVX
These are mostly moves, and yet are a total pain.  The main issue
is that:

1) some instructions are selected by mod==11 (register operand)
vs. mod=00/01/10 (memory operand)

2) stores to memory are two-operand operations, while the 3-register
and load-from-memory versions operate on the entire contents of the
destination; this makes it easier to separate the gen_* function for
the store case

3) it's inefficient to load into xmm_T0 only to move the value out
again, so the gen_* function for the load case is separated too

The manual also has various mistakes in the operands here, for example
the store case of MOVHPS operates on a 128-bit source (albeit discarding
the bottom 64 bits) and therefore should be Mq,Vdq rather than Mq,Vq.
Likewise for the destination and source of MOVHLPS.

VUNPCK?PS and VUNPCK?PD are the same as VUNPCK?DQ and VUNPCK?QDQ,
but encoded as prefixes rather than separate operands.  The helpers
can be reused however.

For MOVSLDUP, MOVSHDUP and MOVDDUP I chose to reimplement them as
helpers.  I named the helper for MOVDDUP "movdldup" in preparation
for possible future introduction of MOVDHDUP and to clarify the
similarity with MOVSLDUP.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
aba2b8ecb9 target/i386: reimplement 0x0f 0xc2, 0xc4-0xc6, add AVX
Nothing special going on here, for once.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
16fc5726a6 target/i386: reimplement 0x0f 0x38, add AVX
There are several special cases here:

1) extending moves have different widths for the helpers vs. for the
memory loads, and the width for memory loads depends on VEX.L too.
This is represented by X86_SPECIAL_AVXExtMov.

2) some instructions, such as variable-width shifts, select the vector element
size via REX.W.

3) VSIB instructions (VGATHERxPy, VPGATHERxy) are also part of this group,
and they have (among other things) two output operands.

3) the macros for 4-operand blends (which are under 0x0f 0x3a) have to be
extended to support 2-operand blends.  The 2-operand variant actually
came a few years earlier, but it is clearer to implement them in the
opposite order.

X86_TYPE_WM, introduced earlier for unaligned loads, is reused for helpers
that accept a Reg* but have a M argument.

These three-byte opcodes also include AVX new instructions, for which
the helpers were originally implemented by Paul Brook <paul@nowt.org>.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Richard Henderson
d4af67a27a target/i386: Use tcg gvec ops for pmovmskb
As pmovmskb is used by strlen et al, this is the third
highest overhead sse operation at %0.8.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[Reorganize to generate code for any vector size. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
7906847768 target/i386: reimplement 0x0f 0x3a, add AVX
The more complicated operations here are insertions and extractions.
Otherwise, there are just more entries than usual because the PS/PD/SS/SD
variations are encoded in the opcode rater than in the prefixes.

These three-byte opcodes also include AVX new instructions, whose
implementation in the helpers was originally done by Paul Brook
<paul@nowt.org>.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
6bbeb98d10 target/i386: reimplement 0x0f 0xd0-0xd7, 0xe0-0xe7, 0xf0-0xf7, add AVX
The more complicated ones here are d6-d7, e6-e7, f7.  The others
are trivial.

For LDDQU, using gen_load_sse directly might corrupt the register if
the second part of the load fails.  Therefore, add a custom X86_TYPE_WM
value; like X86_TYPE_W it does call gen_load(), but it also rejects a
value of 11 in the ModRM field like X86_TYPE_M.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
ce4fcb9478 target/i386: reimplement 0x0f 0x70-0x77, add AVX
This includes shifts by immediate, which use bits 3-5 of the ModRM byte
as an opcode extension.  With the exception of 128-bit shifts, they are
implemented using gvec.

This also covers VZEROALL and VZEROUPPER, which use the same opcode
as EMMS.  If we were wanting to optimize out gen_clear_ymmh then this
would be one of the starting points.  The implementation of the VZEROALL
and VZEROUPPER helpers is by Paul Brook.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
d1c1a4222c target/i386: reimplement 0x0f 0x78-0x7f, add AVX
These are a mixed batch, including the first two horizontal
(66 and F2 only) operations, more moves, and SSE4a extract/insert.

Because SSE4a is pretty rare, I chose to leave the helper as they are,
but it is possible to unify them by loading index and length from the
source XMM register and generating deposit or extract TCG ops.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
03b4588070 target/i386: reimplement 0x0f 0x50-0x5f, add AVX
These are mostly floating-point SSE operations.  The odd ones out
are MOVMSK and CVTxx2yy, the others are straightforward.

Unary operations are a bit special in AVX because they have 2 operands
for PD/PS operands (VEX.vvvv must be 1111b), and 3 operands for SD/SS.
They are handled using X86_OP_GROUP3 for compactness.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:05 +02:00
Paolo Bonzini
1d0efbdb35 target/i386: reimplement 0x0f 0xd8-0xdf, 0xe8-0xef, 0xf8-0xff, add AVX
These are more simple integer instructions present in both MMX and SSE/AVX,
with no holes that were later occupied by newer instructions.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
92ec056a6b target/i386: reimplement 0x0f 0x60-0x6f, add AVX
These are both MMX and SSE/AVX instructions, except for vmovdqu.  In both
cases the inputs and output is in s->ptr{0,1,2}, so the only difference
between MMX, SSE, and AVX is which helper to call.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
b98f886c8f target/i386: Introduce 256-bit vector helpers
The new implementation of SSE will cover AVX from the get go, because
all the work for the helper functions is already done.  We just need to
build them.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
620f75566a target/i386: provide 3-operand versions of unary scalar helpers
Compared to Paul's implementation, the new decoder will use a different approach
to implement AVX's merging of dst with src1 on scalar operations.  Adjust the
old SSE decoder to be compatible with new-style helpers.

The affected instructions are CVTSx2Sx, ROUNDSx, RSQRTSx, SQRTSx, RCPSx.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
f05f9789f5 target/i386: extend helpers to support VEX.V 3- and 4- operand encodings
Add to the helpers all the operands that are needed to implement AVX.

Extracted from a patch by Paul Brook <paul@nowt.org>.

Message-Id: <20220424220204.2493824-26-paul@nowt.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
1d0b926150 target/i386: move scalar 0F 38 and 0F 3A instruction to new decoder
Because these are the only VEX instructions that QEMU supports, the
new decoder is entered on the first byte of a valid VEX prefix, and VEX
decoding only needs to be done in decode-new.c.inc.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
55a3328669 target/i386: validate SSE prefixes directly in the decoding table
Many SSE and AVX instructions are only valid with specific prefixes
(none, 66, F3, F2).  Introduce a direct way to encode this in the
decoding table to avoid using decode groups too much.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
20581aadec target/i386: validate VEX prefixes via the instructions' exception classes
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paul Brook
608db8dbfb target/i386: add AVX_EN hflag
Add a new hflag bit to determine whether AVX instructions are allowed

Signed-off-by: Paul Brook <paul@nowt.org>
Message-Id: <20220424220204.2493824-4-paul@nowt.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
caa01fadbe target/i386: add CPUID feature checks to new decoder
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
268dc4648f target/i386: add CPUID[EAX=7,ECX=0].ECX to DisasContext
TCG will shortly implement VAES instructions, so add the relevant feature
word to the DisasContext.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
6ba13999be target/i386: add ALU load/writeback core
Add generic code generation that takes care of preparing operands
around calls to decode.e.gen in a table-driven manner, so that ALU
operations need not take care of that.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
b3e22b2318 target/i386: add core of new i386 decoder
The new decoder is based on three principles:

- use mostly table-driven decoding, using tables derived as much as possible
  from the Intel manual.  Centralizing the decode the operands makes it
  more homogeneous, for example all immediates are signed.  All modrm
  handling is in one function, and can be shared between SSE and ALU
  instructions (including XMM<->GPR instructions).  The SSE/AVX decoder
  will also not have duplicated code between the 0F, 0F38 and 0F3A tables.

- keep the code as "non-branchy" as possible.  Generally, the code for
  the new decoder is more verbose, but the control flow is simpler.
  Conditionals are not nested and have small bodies.  All instruction
  groups are resolved even before operands are decoded, and code
  generation is separated as much as possible within small functions
  that only handle one instruction each.

- keep address generation and (for ALU operands) memory loads and writeback
  as much in common code as possible.  All ALU operations for example
  are implemented as T0=f(T0,T1).  For non-ALU instructions,
  read-modify-write memory operations are rare, but registers do not
  have TCGv equivalents: therefore, the common logic sets up pointer
  temporaries with the operands, while load and writeback are handled
  by gvec or by helpers.

These principles make future code review and extensibility simpler, at
the cost of having a relatively large amount of code in the form of this
patch.  Even EVEX should not be _too_ hard to implement (it's just a crazy
large amount of possibilities).

This patch introduces the main decoder flow, and integrates the old
decoder with the new one.  The old decoder takes care of parsing
prefixes and then optionally drops to the new one.  The changes to the
old decoder are minimal and allow it to be replaced incrementally with
the new one.

There is a debugging mechanism through a "LIMIT" environment variable.
In user-mode emulation, the variable is the number of instructions
decoded by the new decoder before permanently switching to the old one.
In system emulation, the variable is the highest opcode that is decoded
by the new decoder (this is less friendly, but it's the best that can
be done without requiring deterministic execution).

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
a61ef762f9 target/i386: make rex_w available even in 32-bit mode
REX.W can be used even in 32-bit mode by AVX instructions, where it is retroactively
renamed to VEX.W.  Make the field available even in 32-bit mode but keep the REX_W()
macro as it was; this way, that the handling of dflag does not use it by mistake and
the AVX code more clearly points at the special VEX behavior of the bit.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Paolo Bonzini
12a2c9c72c target/i386: make ldo/sto operations consistent with ldq
ldq takes a pointer to the first byte to load the 64-bit word in;
ldo takes a pointer to the first byte of the ZMMReg.  Make them
consistent, which will be useful in the new SSE decoder's
load/writeback routines.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Richard Henderson
8629e77be5 target/i386: Use probe_access_full for final stage2 translation
Rather than recurse directly on mmu_translate, go through the
same softmmu lookup that we did for the page table walk.
This centralizes all knowledge of MMU_NESTED_IDX, with respect
to setup of TranslationParams, to get_physical_address.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-10-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Richard Henderson
4a1e9d4d11 target/i386: Use atomic operations for pte updates
Use probe_access_full in order to resolve to a host address,
which then lets us use a host cmpxchg to update the pte.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/279
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-9-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Richard Henderson
11b4e971dc target/i386: Combine 5 sets of variables in mmu_translate
We don't need one variable set per translation level,
which requires copying into pte/pte_addr for huge pages.
Standardize on pte/pte_addr for all levels.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-8-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Richard Henderson
726ea33531 target/i386: Use MMU_NESTED_IDX for vmload/vmsave
Use MMU_NESTED_IDX for each memory access, rather than
just a single translation to physical.  Adjust svm_save_seg
and svm_load_seg to pass in mmu_idx.

This removes the last use of get_hphys so remove it.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-7-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00
Richard Henderson
98281984a3 target/i386: Add MMU_PHYS_IDX and MMU_NESTED_IDX
These new mmu indexes will be helpful for improving
paging and code throughout the target.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-6-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-18 13:58:04 +02:00