This patch fixes a translation bug for a subset of x86 BMI instructions
such as the following:
c4 e2 f9 f7 c0 shlxq %rax, %rax, %rax
Currently, these incorrectly generate an undefined instruction exception
when SSE is disabled via CR4, while instructions like "shrxq" work fine.
The problem appears to be related to BMI instructions encoded using VEX
and with a mandatory prefix of "0x66" (data). Instructions with this
data prefix (such as shlxq) are currently rejected. Instructions with
other mandatory prefixes (such as shrxq) translate as expected.
This patch removes the incorrect check in "gen_sse" that causes the
exception to be generated. For the non-BMI cases, the check is
redundant: prefixes are already checked at line 3696.
Buglink: https://bugs.launchpad.net/qemu/+bug/1748296
Backports 51909241d26fe6fe18a08def93ccc8273f61a8b3
For PDEP and PEXT, the mask is provided in the memory (mod+r/m)
operand, and therefore is loaded in s->T0 by gen_ldst_modrm.
The source is provided in the second source operand (VEX.vvvv)
and therefore is loaded in s->T1. Fix the order in which
they are passed to the helpers.
Backports 75b208c28316095c4685e8596ceb9e3f656592e2
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.
Backport d9ff33ada7f32ca59f99b270a2d0eb223b3c9c8f
We forgot to update cc_op before these branch insns,
which lead to losing track of the current eflags.
Buglink: https://bugs.launchpad.net/qemu/+bug/1888165
Backports commit 3cb3a7720b01830abd5fbb81819dbb9271bf7821 from qemu
In 32-bit mode, the higher 16 bits of the destination
register are undefined. In practice CR0[31:0] is stored,
just like in 64-bit mode, so just remove the "if" that
currently differentiates the behavior.
Backports commit c0c8445255b2b5b440c355431c8b01b7b7b7c8cf from qemu
The SSE instruction implementations all fail to raise the expected
IEEE floating-point exceptions because they do nothing to convert the
exception state from the softfloat machinery into the exception flags
in MXCSR.
Fix this by adding such conversions. Unlike for x87, emulated SSE
floating-point operations might be optimized using hardware floating
point on the host, and so a different approach is taken that is
compatible with such optimizations. The required invariant is that
all exceptions set in env->sse_status (other than "denormal operand",
for which the SSE semantics are different from those in the softfloat
code) are ones that are set in the MXCSR; the emulated MXCSR is
updated lazily when code reads MXCSR, while when code sets MXCSR, the
exceptions in env->sse_status are set accordingly.
A few instructions do not raise all the exceptions that would be
raised by the softfloat code, and those instructions are made to save
and restore the softfloat exception state accordingly.
Nothing is done about "denormal operand"; setting that (only for the
case when input denormals are *not* flushed to zero, the opposite of
the logic in the softfloat code for such an exception) will require
custom code for relevant instructions, or else architecture-specific
conditionals in the softfloat code for when to set such an exception
together with custom code for various SSE conversion and rounding
instructions that do not set that exception.
Nothing is done about trapping exceptions (for which there is minimal
and largely broken support in QEMU's emulation in the x87 case and no
support at all in the SSE case).
Backports commit 418b0f93d12a1589d5031405de857844f32e9ccc from qemu
Preparation for collapsing the two byte swaps, adjust_endianness and
handle_bswap, along the I/O path.
Target dependant attributes are conditionalized upon NEED_CPU_H.
Backports commit 14776ab5a12972ea439c7fb2203a4c15a09094b4 from qemu
We now have an interface for guest visible random numbers.
Backports commit 369fd5ca66810b2ddb16e23a497eabe59385eceb from qemu with
the actual RNG portion disabled for the time being.
Thereby decoupling the resulting translated code from the current state
of the system.
Backports commit b5e3b4c2aca8eb5a9cfeedfb273af623f17c3731 from qemu
In order to handle TB's that translate to too much code, we
need to place the control of the length of the translation
in the hands of the code gen master loop.
Backports commit 8b86d6d25807e13a63ab6ea879f976b9f18cc45a from qemu
Fix a TCG crash due to attempting an atomic increment
operation without having set up the address first.
This is a similar case to that dealt with in commit
e84fcd7f662a0d8198703, and we fix it in the same way.
Fixes: https://bugs.launchpad.net/qemu/+bug/1807675
Backports commit 8cb2ca3d7479748587313f0b34034a3f8aa08c92 from qemu
Fixes a TCG crash due to attempting the atomic operation without
having set up the address first. This does not attempt to fix
all of the other missing checks for LOCK.
Fixes: a7cee522f35
Fixes: https://bugs.launchpad.net/qemu/+bug/1803160
Backports commit e84fcd7f662a0d8198703f6f89416d7ac2c32767 from qemu
This patch fixes the checking of boundary crossing instructions.
In icount mode only first instruction of the block may cross
the page boundary to keep the translation deterministic.
These conditions already existed, but compared the wrong variable.
Backports commit 41d54dc09f1f327dedc79d5ba0b1b437ab7b0e94 from qemu
This flag will be used for KVM's nested VMX migration; the HF_GUEST_MASK name
is already used in KVM, adopt it in QEMU as well.
Backports commit f8dc4c645ec2956a6cd97e0ca0fdd4753181f735 from qemu
This was intentionally broken to make updating qemu as quick as possible
when it was woefully out of date, particularly because the interface of
qemu's TCG changed quite a bit, so this code would have needed to be
changed anyways.
Now that qemu is up to date for this variant of Unicorn, we can repair
this functionality and also--and I put massive emphasis on this, since
this wasn't done in the original Unicorn repo--*actually document what
the heck we're doing in this case*, so it's not a pain to change in the
future if we actually need to do that. It makes it much, much, simpler
for people not involved with qemu to understand what is going on in this
case.
These used to be necessary, as the relevant variables used to be void*,
thus making the casts necessary. Given they were changed to concrete
types over the course of backporting, these are unnecessary.
We need to terminate the translation block after STGI so that pending
interrupts can be injected.
This fixes pending NMI injection for Jailhouse which uses "stgi; clgi"
to open a brief injection window.
Backports commit df2518aa587a0157bbfbc635fe47295629d9914a from qemu
The implementation of these two instructions was swapped.
At the same time, unify the setup of eflags for the insn group.
Backports commit 13672386a93fef64cfd33bd72fbf3d80f2c00e94 from qemu
Do the cast to uintptr_t within the helper, so that the compiler
can type check the pointer argument. We can also do some more
sanity checking of the index argument.
Backports commit 07ea28b41830f946de3841b0ac61a3413679feb9 from qemu
While at it, use int for both num_insns and max_insns to make
sure we have same-type comparisons.
Backports commit b542683d77b4f56cef0221b267c341616d87bce9 from qemu
In commit 7073fbada733c8d10992f00772c9b9299d740e9b, the `andn` instruction
was implemented via `tcg_gen_andc` but passes the operands in the wrong
order:
- X86 defines `andn dest,src1,src2` as: dest = ~src1 & src2
- TCG defines `andc dest,src1,src2` as: dest = src1 & ~src2
The following simple test shows the issue:
int main(void) {
uint32_t ret = 0;
__asm (
"mov $0xFF00, %%ecx\n"
"mov $0x0F0F, %%eax\n"
"andn %%ecx, %%eax, %%ecx\n"
"mov %%ecx, %0\n"
: "=r" (ret));
printf("%08X\n", ret);
return 0;
}
This patch fixes the problem by simply swapping the order of the two last
arguments in `tcg_gen_andc_tl`.
Backports commit 5cd10051c2e02b7a86eae49919d6c65a87dbea46 from qemu
These gcc warnings are fixed:
target/i386/translate.c:4461:12: warning:
variable 'prefixes' might be clobbered by 'longjmp' or 'vfork' [-Wclobbered]
target/i386/translate.c:4466:9: warning:
variable 'rex_w' might be clobbered by 'longjmp' or 'vfork' [-Wclobbered]
target/i386/translate.c:4466:16: warning:
variable 'rex_r' might be clobbered by 'longjmp' or 'vfork' [-Wclobbered]
Tested with x86_64-w64-mingw32-gcc from Debian stretch.
Backports commit a4926d99129a1d8072fc4681cd4efdb214f65ed4 from qemu
In commit e3af7c788b73a6495eb9d94992ef11f6ad6f3c56 we
replaced direct calls to to cpu_ld*_code() with calls
to the x86_ld*_code() wrappers which incorporate an
advance of s->pc. Unfortunately we didn't notice that
in one place the old code was deliberately not incrementing
s->pc:
@@ -4501,7 +4528,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
static const int pp_prefix[4] = {
0, PREFIX_DATA, PREFIX_REPZ, PREFIX_REPNZ
};
- int vex3, vex2 = cpu_ldub_code(env, s->pc);
+ int vex3, vex2 = x86_ldub_code(env, s);
if (!CODE64(s) && (vex2 & 0xc0) != 0xc0) {
/* 4.1.4.6: In 32-bit mode, bits [7:6] must be 11b,
This meant we were mishandling this set of instructions.
Remove the manual advance of s->pc for the "is VEX" case
(which is now done by x86_ldub_code()) and instead rewind
PC in the case where we decide that this isn't really VEX.
Backports commit 817a9fcba8043faa467929e7b0193df6bdc92211 from qemu
When we used structures for TCGv_*, we needed a macro in order to
perform a comparison. Now that we use pointers, this is just clutter
Backports commit 11f4e8f8bfaa2caaab24bef6bbbb8a0205015119 from qemu
Rather than have a separate buffer of 10*max_ops entries,
give each opcode 10 entries. The result is actually a bit
smaller and should have slightly more cache locality.
Backports commit 75e8b9b7aa0b95a761b9add7e2f09248b101a392 from qemu
Besides being more correct, arbitrarily long instruction allow the
generation of a translation block that spans three pages. This
confuses the generator and even allows ring 3 code to poison the
translation block cache and inject code into other processes that are
in guest ring 3.
This is an improved (and more invasive) fix for commit 30663fd ("tcg/i386:
Check the size of instruction being translated", 2017-03-24). In addition
to being more precise (and generating the right exception, which is #GP
rather than #UD), it distinguishes better between page faults and too long
instructions, as shown by this test case:
int main()
{
char *x = mmap(NULL, 8192, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_ANON, -1, 0);
memset(x, 0x66, 4096);
x[4096] = 0x90;
x[4097] = 0xc3;
char *i = x + 4096 - 15;
mprotect(x + 4096, 4096, PROT_READ|PROT_WRITE);
((void(*)(void)) i) ();
}
... which produces a #GP without the mprotect, and a #PF with it.
Backports commit b066c5375737ad0d630196dab2a2b329515a1d00 from qemu
These take care of advancing s->pc, and will provide a unified point
where to check for the 15-byte instruction length limit.
Backports commit e3af7c788b73a6495eb9d94992ef11f6ad6f3c56 from qemu
It is unlikely that we will ever want to call this helper passing
an argument other than the current PC. So just remove the argument,
and use the pc we already get from cpu_get_tb_cpu_state.
This change paves the way to having a common "tb_lookup" function.
Backports commit 7f11636dbee89b0e4d03e9e2b96e14649a7db778 from qemu
