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>
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>
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>
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>
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>
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>
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>
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>
Replace with PTE_HPHYS for the page table walk, and a direct call
to mmu_translate for the final stage2 translation. Hoist the check
for HF2_NPT_MASK out to get_physical_address, which avoids the
recursive call when stage2 is disabled.
We can now return all the way out to x86_cpu_tlb_fill before raising
an exception, which means probe works.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-5-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create TranslateParams for inputs, TranslateResults for successful
outputs, and TranslateFault for error outputs; return true on success.
Move stage1 error paths from handle_mmu_fault to x86_cpu_tlb_fill;
reorg the rest of handle_mmu_fault into get_physical_address.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-4-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use a boolean to control the call to get_hphys instead
of passing a null function pointer.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-3-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace int is_write1 and magic numbers with the proper
MMUAccessType access_type and enumerators.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221002172956.265735-2-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Restore pc_save while undoing any state change that may have
happened while decoding the instruction. Leave a TODO about
removing all of that when the table-based decoder is complete.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221016222303.288551-1-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add support for saving/restoring extended save states when signals
are delivered. This allows using AVX, MPX or PKRU registers in
signal handlers.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intel CPUs starting with Haswell-E implement a new MSR called
MSR_CORE_THREAD_COUNT which exposes the number of threads and cores
inside of a package.
This MSR is used by XNU to populate internal data structures and not
implementing it prevents virtual machines with more than 1 vCPU from
booting if the emulated CPU generation is at least Haswell-E.
This patch propagates the existing hvf logic from patch 027ac0cb51
("target/i386/hvf: add rdmsr 35H MSR_CORE_THREAD_COUNT") to TCG.
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Message-Id: <20221004225643.65036-2-agraf@csgraf.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-27-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Expand this function at each of its callers.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-26-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create a tcg global temp for this, and use it instead of explicit stores.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-25-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-24-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These functions have only one caller, and the logic is more
obvious this way.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-23-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These functions are always passed aflag, so we might as well
read it from DisasContext directly. While we're at it, use
a common subroutine for these two functions.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-22-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With gen_jmp_rel, we may chain between two translation blocks
which may only be separated because of TB size limits.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-21-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-20-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With gen_jmp_rel, we may chain to the next tb instead of merely
writing to eip and exiting. For repz, subtract cur_insn_len to
restart the current insn.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-19-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create a common helper for pc-relative branches. The jmp jb insn
was missing a mask for CODE32. In all cases the CODE64 check was
incorrectly placed, allowing PREFIX_DATA to truncate %rip to 16 bits.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-18-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We can set is_jmp early, using only one if, and let that
be overwritten by gen_rep*'s calls to gen_jmp_tb.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-17-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create helpers for loading the address of the next insn.
Use tcg_constant_* in adjacent code where convenient.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-16-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use i32 not int or tl for eip and cs arguments.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-15-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Drop the unused dest argument to gen_jr().
Remove most of the calls to gen_jr, and use DISAS_JUMP.
Remove some unused loads of eip for lcall and ljmp.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-14-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All callers pass s->base.pc_next and s->pc, which we can just
as well compute within the functions. Pull out common helpers
and reduce the amount of code under macros.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-13-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create common routines for computing the length of the insn.
Use tcg_constant_i32 in the new function, while we're at it.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-12-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace lone calls to gen_eob() with the new enumerator.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-11-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace sequences of gen_update_cc_op, gen_update_eip_next,
and gen_eob with the new is_jmp enumerator.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-10-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Set is_jmp properly in gen_movl_seg_T0, so that the callers
need to nothing special.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-9-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a few DISAS_TARGET_* aliases to reduce the number of
calls to gen_eob() and gen_eob_inhibit_irq(). So far,
only update i386_tr_translate_insn for exiting the block
because of single-step or previous inhibit irq.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-8-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Sync EIP before exiting a translation block.
Replace all gen_jmp_im that use s->pc.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-7-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like gen_update_cc_op, sync EIP before doing something
that could raise an exception. Replace all gen_jmp_im
that use s->base.pc_next.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-6-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All callers pass s->base.pc_next and s->pc, which we can just as
well compute within the function. Adjust to use tcg_constant_i32
while we're at it.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-5-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
All callers pass s->base.pc_next - s->cs_base, which we can just
as well compute within the function. Note the special case of
EXCP_VSYSCALL in which s->cs_base wasn't subtracted, but cs_base
is always zero in 64-bit mode, when vsyscall is used.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-4-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Instead of returning the new pc, which is present in
DisasContext, return true if an insn was translated.
This is false when we detect a page crossing and must
undo the insn under translation.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221001140935.465607-3-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The DisasContext member and the disas_insn local variable of
the same name are identical to DisasContextBase.pc_next.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221001140935.465607-2-richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The availability of tb->pc will shortly be conditional.
Introduce accessor functions to minimize ifdefs.
Pass around a known pc to places like tcg_gen_code,
where the caller must already have the value.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The "O" operand type in the Intel SDM needs to load an 8- to 64-bit
unsigned value, while insn_get is limited to 32 bits. Extract the code
out of disas_insn and into a separate function.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The later prefix wins if both are present, make it show in s->prefix too.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
INSERTQ is defined to not modify any bits in the lower 64 bits of the
destination, other than the ones being replaced with bits from the
source operand. QEMU instead is using unshifted bits from the source
for those bits.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Many instructions which load/store 128-bit values are supposed to
raise #GP when the memory operand isn't 16-byte aligned. This includes:
- Instructions explicitly requiring memory alignment (Exceptions Type 1
in the "AVX and SSE Instruction Exception Specification" section of
the SDM)
- Legacy SSE instructions that load/store 128-bit values (Exceptions
Types 2 and 4).
This change sets MO_ALIGN_16 on 128-bit memory accesses that require
16-byte alignment. It adds cpu_record_sigbus and cpu_do_unaligned_access
hooks that simulate a #GP exception in qemu-user and qemu-system,
respectively.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/217
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ricky Zhou <ricky@rzhou.org>
Message-Id: <20220830034816.57091-2-ricky@rzhou.org>
[Do not bother checking PREFIX_VEX, since AVX is not supported. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Right now translator stops right *after* the end of a page, which
breaks reporting of fault locations when the last instruction of a
multi-insn translation block crosses a page boundary.
An implementation, like the one arm and s390x have, would require an
i386 length disassembler, which is burdensome to maintain. Another
alternative would be to single-step at the end of a guest page, but
this may come with a performance impact.
Fix by snapshotting disassembly state and restoring it after we figure
out we crossed a page boundary. This includes rolling back cc_op
updates and emitted ops.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1143
Message-Id: <20220817150506.592862-4-iii@linux.ibm.com>
[rth: Simplify end-of-insn cross-page checks.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pass these along to translator_loop -- pc may be used instead
of tb->pc, and host_pc is currently unused. Adjust all targets
at one time.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The only user can easily use translator_lduw and
adjust the type to signed during the return.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
AVX includes an additional set of comparison predicates, some of which
our softfloat implementation does not expose as separate functions.
Rewrite the helpers in terms of floatN_compare for future extensibility.
Signed-off-by: Paul Brook <paul@nowt.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220424220204.2493824-24-paul@nowt.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini