The tcg_cpu_FOO() names are x86 specific, so rename
them as x86_tcg_cpu_FOO() (as other names in this file)
to ease navigating the code.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Message-ID: <20240111120221.35072-5-philmd@linaro.org>
For PC-relative translation blocks, env->eip changes during the
execution of a translation block, Therefore, QEMU must be able to
recover an instruction's PC just from the TranslationBlock struct and
the instruction data with. Because a TB will not span two pages, QEMU
stores all the low bits of EIP in the instruction data and replaces them
in x86_restore_state_to_opc. Bits 12 and higher (which may vary between
executions of a PCREL TB, since these only use the physical address in
the hash key) are kept unmodified from env->eip. The assumption is that
these bits of EIP, unlike bits 0-11, will not change as the translation
block executes.
Unfortunately, this is incorrect when the CS base is not aligned to a page.
Then the linear address of the instructions (i.e. the one with the
CS base addred) indeed will never span two pages, but bits 12+ of EIP
can actually change. For example, if CS base is 0x80262200 and EIP =
0x6FF4, the first instruction in the translation block will be at linear
address 0x802691F4. Even a very small TB will cross to EIP = 0x7xxx,
while the linear addresses will remain comfortably within a single page.
The fix is simply to use the low bits of the linear address for data[0],
since those don't change. Then x86_restore_state_to_opc uses tb->cs_base
to compute a temporary linear address (referring to some unknown
instruction in the TB, but with the correct values of bits 12 and higher);
the low bits are replaced with data[0], and EIP is obtained by subtracting
again the CS base.
Huge thanks to Mark Cave-Ayland for the image and initial debugging,
and to Gitlab user @kjliew for help with bisecting another occurrence
of (hopefully!) the same bug.
It should be relatively easy to write a testcase that performs MMIO on
an EIP with different bits 12+ than the first instruction of the translation
block; any help is welcome.
Fixes: e3a79e0e87 ("target/i386: Enable TARGET_TB_PCREL", 2022-10-11)
Cc: qemu-stable@nongnu.org
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Richard Henderson <richard.henderson@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1759
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1964
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2012
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The PCREL patches introduced a bug when updating EIP in the !CF_PCREL case.
Using s->pc in func gen_update_eip_next() solves the problem.
Cc: qemu-stable@nongnu.org
Fixes: b5e0d5d22f ("target/i386: Fix 32-bit wrapping of pc/eip computation")
Signed-off-by: guoguangyao <guoguangyao18@mails.ucas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240115020804.30272-1-guoguangyao18@mails.ucas.ac.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With PCREL, we have a page-relative view of EIP, and an
approximation of PC = EIP+CSBASE that is good enough to
detect page crossings. If we try to recompute PC after
masking EIP, we will mess up that approximation and write
a corrupt value to EIP.
We already handled masking properly for PCREL, so the
fix in b5e0d5d2 was only needed for the !PCREL path.
Cc: qemu-stable@nongnu.org
Fixes: b5e0d5d22f ("target/i386: Fix 32-bit wrapping of pc/eip computation")
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240101230617.129349-1-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().
The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.
The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)
There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Acked-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The main difficulty here is that a page fault when writing to the destination
must not overwrite the flags. Therefore, the flags computation must be
inlined instead of using gen_jcc1*.
For simplicity, I am using an unconditional cmpxchg operation, that becomes
a NOP if the comparison fails.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
ALU instructions can write to both memory and flags. If the CC_SRC*
and CC_DST locations have been written already when a memory access
causes a fault, the value in CC_SRC* and CC_DST might be interpreted
with the wrong CC_OP (the one that is in effect before the instruction.
Besides just using the wrong result for the flags, something like
subtracting -1 can have disastrous effects if the current CC_OP is
CC_OP_EFLAGS: this is because QEMU does not expect bits outside the ALU
flags to be set in CC_SRC, and env->eflags can end up set to all-ones.
In the case of the attached testcase, this sets IOPL to 3 and would
cause an assertion failure if SUB is moved to the new decoder.
This mechanism is not really needed for BMI instructions, which can
only write to a register, but put it to use anyway for cleanliness.
In the case of BZHI, the code has to be modified slightly to ensure
that decode->cc_src is written, otherwise the new assertions trigger.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
gen_jcc() has been changed to accept a relative offset since the
new decoder was written. Adjust the J operand, which is meant
to be used with jump instructions such as gen_jcc(), to not
include the program counter and to not truncate the result, as
both operations are now performed by common code.
The result is that J is now the same as the I operand.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Similar to gen_setcc1, make gen_cmovcc1 receive TCGv. This is more friendly
to simultaneous implementation in the old and the new decoder.
A small wart is that s->T0 of CMOV is currently the *second* argument (which
would ordinarily be in T1). Therefore, the condition has to be inverted in
order to overwrite s->T0 with cpu_regs[reg] if the MOV is not performed.
This only applies to the old decoder, and this code will go away soon.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do not use gen_op, and pull the load from the accumulator into
disas_insn.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create a new temporary, to ease the register allocator's work.
Creation of the temporary is pushed into gen_ext_tl, which
also allows NULL as the first parameter now.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Just create a temporary for the occasion.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new x86 decoder wants the gen_* functions to compute EFLAGS before
writeback, which can be an issue for instructions with a memory
destination such as ARPL or shifts.
Extract code to compute the EFLAGS without clobbering CC_SRC, in case
the memory write causes a fault. The flags writeback mechanism will
take care of copying the result to CC_SRC.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new decoder would rather have the operand in T0 when expanding SCAS, rather
than use R_EAX directly as gen_scas currently does. This makes SCAS more similar
to CMP and SUB, in that CC_DST = T0 - T1.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new decoder likes to compute the address in A0 very early, so the
gen_lea_v_seg in gen_pop_T0 would clobber the address of the memory
operand. Instead use T0 since it is already available and will be
overwritten immediately after.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
decode->mem is only used if one operand has has_ea == true. String
operations will not use decode->mem and will load A0 on their own, because
they are the only case of two memory operands in a single instruction.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Usually the registers are just moved into s->T0 without much care for
their operand size. However, in some cases we can get more efficient
code if the operand fetching logic syncs with the emission function
on what is nicer.
All the current uses are mostly demonstrative and only reduce the code
in the emission functions, because the instructions do not support
memory operands. However the logic is generic and applies to several
more instructions such as MOVSXD (aka movslq), one-byte shift
instructions, multiplications, XLAT, and indirect calls/jumps.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
X86_SPECIAL_ZExtOp0 and X86_SPECIAL_ZExtOp2 are poorly named; they are a hack
that is needed by scalar insertion and extraction instructions, and not really
related to zero extension: for PEXTR the zero extension is done by the generation
functions, for PINSR the high bits are not used at all and in fact are *not*
filled with zeroes when loaded into s->T1.
Rename the values to match the effect described in the manual, and explain
better in the comments.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use _tl operations for 32-bit operands on 32-bit targets, and only go
through trunc and extu ops for 64-bit targets. While the trunc/ext
ops should be pretty much free after optimization, the optimizer also
does not like having the same temporary used in multiple EBBs.
Therefore it is nicer to not use tmpN* unless necessary.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The previous check erroneously allowed CMP to be modified with LOCK.
Instead, tag explicitly the instructions that do support LOCK.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
cpu_cc_compute_all() has an argument that is always equal to CC_OP for historical
reasons (dating back to commit a7812ae412, "TCG variable type checking.", 2008-11-17,
which added the argument to helper_cc_compute_all). It does not make sense for the
argument to have any other value, so remove it and clean up some lines that are not
too long anymore.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
gen_lea_v_seg (called by gen_add_A0_ds_seg) already zeroes any
bits of s->A0 beyond s->aflag. It does so before summing the
segment base and, if not in 64-bit mode, also after summing it.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
is_int is always 1, and error_code is always zero.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
OF is equal to the carry flag, so use the same CCPrepare.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Take advantage of the fact that there can be no 1 bits between SF and OF.
If they were adjacent, you could sum SF and get a carry only if SF was
already set. Then the value of OF in the sum is the XOR of OF itself,
the carry (which is SF) and 0 (the value of the OF bit in the addend):
this is OF^SF exactly.
Because OF and SF are not adjacent, just place more 1 bits to the
left so that the carry propagates, which means summing CC_O - CC_S.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In 32-bit mode, pc = eip + cs_base is also 32-bit, and must wrap.
Failure to do so results in incorrect memory exceptions to the guest.
Before 732d548732, this was implicitly done via truncation to
target_ulong but only in qemu-system-i386, not qemu-system-x86_64.
To fix this, we must add conditional zero-extensions.
Since we have to test for 32 vs 64-bit anyway, note that cs_base
is always zero in 64-bit mode.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2022
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20231212172510.103305-1-richard.henderson@linaro.org>
Instructions in VEX exception class 6 generally look at the value of
VEX.W. Note that the manual places some instructions incorrectly in
class 4, for example VPERMQ which has no non-VEX encoding and no legacy
SSE analogue. AMD does a mess of its own, as documented in the comment
that this patch adds.
Most of them are checked for VEX.W=0, and are listed in the manual
(though with an omission) in table 2-16; VPERMQ and VPERMPD check for
VEX.W=1, which is only listed in the instruction description. Others,
such as VPSRLV, VPSLLV and the FMA3 instructions, use VEX.W to switch
between a 32-bit and 64-bit operation.
Fix more of the class 4/class 6 mismatches, and implement the check for
VEX.W in TCG.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In preparation for adding more similar checks, move the VEX.L=0 check
and several X86_SPECIAL_* checks to a new field, where each bit represent
a common check on unused bits, or a restriction on the processor mode.
Likewise, many SVM intercepts can be checked during the decoding phase,
the main exception being the selective CR0 write, MSR and IOIO intercepts.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The implementation was validated with OpenSSL and with the test vectors in
https://github.com/rust-lang/stdarch/blob/master/crates/core_arch/src/x86/sha.rs.
The instructions provide a ~25% improvement on hashing a 64 MiB file:
runtime goes down from 1.8 seconds to 1.4 seconds; instruction count on
the host goes down from 5.8 billion to 4.8 billion with slightly better
IPC too. Good job Intel. ;)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit a908985971 ("target/i386/seg_helper: introduce tss_set_busy",
2023-09-26) failed to use the tss_selector argument of the new function,
which was therefore unused.
This shows up as a #GP fault when booting old versions of 32-bit
Linux.
Fixes: a908985971 ("target/i386/seg_helper: introduce tss_set_busy", 2023-09-26)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20231011135350.438492-1-pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Since we *might* have user emulation with softmmu,
replace the system emulation check by !user emulation one.
(target/ was cleaned from invalid CONFIG_SOFTMMU uses at
commit cab35c73be, but these files were merged few days
after, thus missed the cleanup.)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231004082239.27251-1-philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow the name 'cpu_env' to be used for something else.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The AccelCPUClass::cpu_realizefn handler is meant for target
specific code, rename it using '_target_' to emphasis it.
Suggested-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231003123026.99229-3-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Just remove the declaration. There is nothing in the function after the
switch statement, so it is safe to do.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* target/i386: fix BQL handling of the legacy FERR interrupts
* target/i386: fix memory operand size for CVTPS2PD
* target/i386: Add support for AMX-COMPLEX in CPUID enumeration
* compile plugins on Darwin
* configure and meson cleanups
* drop mkvenv support for Python 3.7 and Debian10
* add wrap file for libblkio
* tweak KVM stubs
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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging
* only build util/async-teardown.c when system build is requested
* target/i386: fix BQL handling of the legacy FERR interrupts
* target/i386: fix memory operand size for CVTPS2PD
* target/i386: Add support for AMX-COMPLEX in CPUID enumeration
* compile plugins on Darwin
* configure and meson cleanups
* drop mkvenv support for Python 3.7 and Debian10
* add wrap file for libblkio
* tweak KVM stubs
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# gpg: Signature made Thu 07 Sep 2023 07:44:37 EDT
# gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg: issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83
* tag 'for-upstream' of https://gitlab.com/bonzini/qemu: (51 commits)
docs/system/replay: do not show removed command line option
subprojects: add wrap file for libblkio
sysemu/kvm: Restrict kvm_pc_setup_irq_routing() to x86 targets
sysemu/kvm: Restrict kvm_has_pit_state2() to x86 targets
sysemu/kvm: Restrict kvm_get_apic_state() to x86 targets
sysemu/kvm: Restrict kvm_arch_get_supported_cpuid/msr() to x86 targets
target/i386: Restrict declarations specific to CONFIG_KVM
target/i386: Allow elision of kvm_hv_vpindex_settable()
target/i386: Allow elision of kvm_enable_x2apic()
target/i386: Remove unused KVM stubs
target/i386/cpu-sysemu: Inline kvm_apic_in_kernel()
target/i386/helper: Restrict KVM declarations to system emulation
hw/i386/fw_cfg: Include missing 'cpu.h' header
hw/i386/pc: Include missing 'cpu.h' header
hw/i386/pc: Include missing 'sysemu/tcg.h' header
Revert "mkvenv: work around broken pip installations on Debian 10"
mkvenv: assume presence of importlib.metadata
Python: Drop support for Python 3.7
configure: remove dead code
meson: list leftover CONFIG_* symbols
...
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
CVTPS2PD only loads a half-register for memory, unlike the other
operations under 0x0F 0x5A. "Unpack" the group into separate
emission functions instead of using gen_unary_fp_sse.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
CVTPS2PD only loads a half-register for memory, like CVTPH2PS. It can
reuse the "ph" packed half-precision size to load a half-register,
but rename it to "xh" because it is now a variation of "x" (it is not
used only for half-precision values).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All these files access the CPU LD/ST API declared in "exec/cpu_ldst.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230828221314.18435-4-philmd@linaro.org>
When CR0.TS=1, execution of x87 FPU, MMX, and some SSE instructions will
cause a Device Not Available (DNA) exception (#NM). System software uses
this exception event to lazily context switch FPU state.
Before this patch, enter_mmx helpers may be generated just before #NM
generation, prematurely resetting FPU state before the guest has a
chance to save it.
Signed-off-by: Matt Borgerson <contact@mborgerson.com>
Message-ID: <CADc=-s5F10muEhLs4f3mxqsEPAHWj0XFfOC2sfFMVHrk9fcpMg@mail.gmail.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
