This is groundwork for supporting multiple TCG contexts.
The naive solution here is to split code_gen_buffer statically
among the TCG threads; this however results in poor utilization
if translation needs are different across TCG threads.
What we do here is to add an extra layer of indirection, assigning
regions that act just like pages do in virtual memory allocation.
(BTW if you are wondering about the chosen naming, I did not want
to use blocks or pages because those are already heavily used in QEMU).
We use a global lock to serialize allocations as well as statistics
reporting (we now export the size of the used code_gen_buffer with
tcg_code_size()). Note that for the allocator we could just use
a counter and atomic_inc; however, that would complicate the gathering
of tcg_code_size()-like stats. So given that the region operations are
not a fast path, a lock seems the most reasonable choice.
The effectiveness of this approach is clear after seeing some numbers.
I used the bootup+shutdown of debian-arm with '-tb-size 80' as a benchmark.
Note that I'm evaluating this after enabling per-thread TCG (which
is done by a subsequent commit).
* -smp 1, 1 region (entire buffer):
qemu: flush code_size=83885014 nb_tbs=154739 avg_tb_size=357
qemu: flush code_size=83884902 nb_tbs=153136 avg_tb_size=363
qemu: flush code_size=83885014 nb_tbs=152777 avg_tb_size=364
qemu: flush code_size=83884950 nb_tbs=150057 avg_tb_size=373
qemu: flush code_size=83884998 nb_tbs=150234 avg_tb_size=373
qemu: flush code_size=83885014 nb_tbs=154009 avg_tb_size=360
qemu: flush code_size=83885014 nb_tbs=151007 avg_tb_size=370
qemu: flush code_size=83885014 nb_tbs=151816 avg_tb_size=367
That is, 8 flushes.
* -smp 8, 32 regions (80/32 MB per region) [i.e. this patch]:
qemu: flush code_size=76328008 nb_tbs=141040 avg_tb_size=356
qemu: flush code_size=75366534 nb_tbs=138000 avg_tb_size=361
qemu: flush code_size=76864546 nb_tbs=140653 avg_tb_size=361
qemu: flush code_size=76309084 nb_tbs=135945 avg_tb_size=375
qemu: flush code_size=74581856 nb_tbs=132909 avg_tb_size=375
qemu: flush code_size=73927256 nb_tbs=135616 avg_tb_size=360
qemu: flush code_size=78629426 nb_tbs=142896 avg_tb_size=365
qemu: flush code_size=76667052 nb_tbs=138508 avg_tb_size=368
Again, 8 flushes. Note how buffer utilization is not 100%, but it
is close. Smaller region sizes would yield higher utilization,
but we want region allocation to be rare (it acquires a lock), so
we do not want to go too small.
* -smp 8, static partitioning of 8 regions (10 MB per region):
qemu: flush code_size=21936504 nb_tbs=40570 avg_tb_size=354
qemu: flush code_size=11472174 nb_tbs=20633 avg_tb_size=370
qemu: flush code_size=11603976 nb_tbs=21059 avg_tb_size=365
qemu: flush code_size=23254872 nb_tbs=41243 avg_tb_size=377
qemu: flush code_size=28289496 nb_tbs=52057 avg_tb_size=358
qemu: flush code_size=43605160 nb_tbs=78896 avg_tb_size=367
qemu: flush code_size=45166552 nb_tbs=82158 avg_tb_size=364
qemu: flush code_size=63289640 nb_tbs=116494 avg_tb_size=358
qemu: flush code_size=51389960 nb_tbs=93937 avg_tb_size=362
qemu: flush code_size=59665928 nb_tbs=107063 avg_tb_size=372
qemu: flush code_size=38380824 nb_tbs=68597 avg_tb_size=374
qemu: flush code_size=44884568 nb_tbs=79901 avg_tb_size=376
qemu: flush code_size=50782632 nb_tbs=90681 avg_tb_size=374
qemu: flush code_size=39848888 nb_tbs=71433 avg_tb_size=372
qemu: flush code_size=64708840 nb_tbs=119052 avg_tb_size=359
qemu: flush code_size=49830008 nb_tbs=90992 avg_tb_size=362
qemu: flush code_size=68372408 nb_tbs=123442 avg_tb_size=368
qemu: flush code_size=33555560 nb_tbs=59514 avg_tb_size=378
qemu: flush code_size=44748344 nb_tbs=80974 avg_tb_size=367
qemu: flush code_size=37104248 nb_tbs=67609 avg_tb_size=364
That is, 20 flushes. Note how a static partitioning approach uses
the code buffer poorly, leading to many unnecessary flushes.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
While at it, also allocate temps_used directly as a bitmap of the
required size, instead of using a bitmap of TCG_MAX_TEMPS via
TCGTempSet.
Performance-wise we lose about 1.12% in a translation-heavy workload
such as booting+shutting down debian-arm:
Performance counter stats for 'taskset -c 0 arm-softmmu/qemu-system-arm \
-machine type=virt -nographic -smp 1 -m 4096 \
-netdev user,id=unet,hostfwd=tcp::2222-:22 \
-device virtio-net-device,netdev=unet \
-drive file=die-on-boot.qcow2,id=myblock,index=0,if=none \
-device virtio-blk-device,drive=myblock \
-kernel kernel.img -append console=ttyAMA0 root=/dev/vda1 \
-name arm,debug-threads=on -smp 1' (10 runs):
exec time (s) Relative slowdown wrt original (%)
---------------------------------------------------------------
original 20.213321616 0.
tcg_malloc 20.441130078 1.1270214
TCGContext 20.477846517 1.3086662
g_malloc 20.780527895 2.8061013
The other two alternatives shown in the table are:
- TCGContext: embed temps[TCG_MAX_TEMPS] and TCGTempSet used_temps
in TCGContext. This is simple enough but it isn't faster than using
tcg_malloc; moreover, it wastes memory.
- g_malloc: allocate/deallocate both temps and used_temps every time
tcg_optimize is executed.
Suggested-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is groundwork for supporting multiple TCG contexts.
To avoid scalability issues when profiling info is enabled, this patch
makes the profiling info counters distributed via the following changes:
1) Consolidate profile info into its own struct, TCGProfile, which
TCGContext also includes. Note that tcg_table_op_count is brought
into TCGProfile after dropping the tcg_ prefix.
2) Iterate over the TCG contexts in the system to obtain the total counts.
This change also requires updating the accessors to TCGProfile fields to
use atomic_read/set whenever there may be conflicting accesses (as defined
in C11) to them.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
Note that having n_tcg_ctxs is unnecessary. However, it is
convenient to have it, since it will simplify iterating over the
array: we'll have just a for loop instead of having to iterate
over a NULL-terminated array (which would require n+1 elems)
or having to check with ifdef's for usermode/softmmu.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
The core of this patch is this change to tcg/tcg.h:
> -extern TCGContext tcg_ctx;
> +extern TCGContext tcg_init_ctx;
> +extern TCGContext *tcg_ctx;
Note that for now we set *tcg_ctx to whatever TCGContext is passed
to tcg_context_init -- in this case &tcg_init_ctx.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Thereby decoupling the resulting translated code from the current state
of the system.
The tb->cflags field is not passed to tcg generation functions. So
we add a field to TCGContext, storing there a copy of tb->cflags.
Most architectures have <= 32 registers, which results in a 4-byte hole
in TCGContext. Use this hole for the new field.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This will enable us to decouple code translation from the value
of parallel_cpus at any given time. It will also help us minimize
TB flushes when generating code via EXCP_ATOMIC.
Note that the declaration of parallel_cpus is brought to exec-all.h
to be able to define there the "curr_cflags" inline.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Using the offset of a temporary, relative to TCGContext, rather than
its index means that we don't use 0. That leaves offset 0 free for
a NULL representation without having to leave index 0 unused.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The GET and MAKE functions weren't really specific enough.
We now have a full complement of functions that convert exactly
between temporaries, arguments, tcgv pointers, and indices.
The target/sparc change is also a bug fix, which would have affected
a host that defines TCG_TARGET_HAS_extr[lh]_i64_i32, i.e. MIPS64.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Transform TCGv_* to an "argument" or a temporary.
For now, an argument is simply the temporary index.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
While we're touching many of the lines anyway, adjust the naming
of the functions to better distinguish when "TCGArg" vs "TCGTemp"
should be used.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Copy s->nb_globals or s->nb_temps to a local variable for the purposes
of iteration. This should allow the compiler to use low-overhead
looping constructs on some hosts.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This avoids having to allocate external memory for each temporary.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
At the same time, drop the TCGContext argument and use tcg_ctx instead.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This avoids needing to test the index of a temp against nb_globals.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
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.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Will come in handy very soon.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
The hash table becomes read-only after it is filled in,
so we can save space by keeping just a global pointer to it.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Groundwork for supporting multiple TCG contexts.
Compile-tested for all targets on an x86_64 host.
Suggested-by: Richard Henderson <rth@twiddle.net>
Acked-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In preparation for adding tc.size to be able to keep track of
TB's using the binary search tree implementation from glib.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
It's not even clear what the interface REG and VAL32 were supposed to mean.
All uses had REG = 0 and VAL32 was the bitset assigned to the destination.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170911213328.9701-4-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This fixes building for ppc64 on ppc32 (changed in 5964fca8a1):
tcg/ppc/tcg-target.inc.c: In function 'tb_target_set_jmp_target':
include/qemu/compiler.h:86:30: error: static assertion failed: \
"not expecting: sizeof(*(uint64_t *)jmp_addr) > ATOMIC_REG_SIZE"
QEMU_BUILD_BUG_ON(sizeof(*ptr) > ATOMIC_REG_SIZE); \
^
tcg/ppc/tcg-target.inc.c:1377:9: note: in expansion of macro 'atomic_set'
atomic_set((uint64_t *)jmp_addr, pair);
^
Suggested-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170911204936.5020-1-f4bug@amsat.org>
[rth: Added commentary requested by pmm.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
changed in 659ef5cbb8, this fixes building with --enable-tcg-interpreter:
/home/travis/build/qemu/qemu/tcg/tcg.c:116:14: error: ‘tcg_out_ldst_finalize’ used but never defined [-Werror]
static bool tcg_out_ldst_finalize(TCGContext *s);
^
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20170911022839.23231-1-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
At this point the conversion is a wash. Loading of TB+ofs is
smaller, but the actual return address from exit_tb is larger.
There are a few more insns required to transition between TBs.
But the expectation is that accesses to the constant pool will
on the whole be smaller.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Move constants before all of the functions.
Move tcg_out_<format> functions before all
of the others. No functional change.
Signed-off-by: Richard Henderson <rth@twiddle.net>
We are not going to use ldrd for loading the comparator
for 32-bit guests, so don't limit cmp_off to 8 bits then.
This eliminates one insn in the tlb load for some guests.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Use UBFX to avoid limitation on CPU_TLB_BITS. Since we're dropping
the initial shift, we need to replace the page masking. We can use
MOVW+BIC to do this without shifting. The result is the same size
as the armv6 path with one less conditional instruction.
Signed-off-by: Richard Henderson <rth@twiddle.net>
We were passing in -2 instead of +2, but then ignoring
the actual contents of addend in the calculation.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Already it saves 2 bytes per call, but also the constant pool
entry may well be shared across multiple calls.
Signed-off-by: Richard Henderson <rth@twiddle.net>
A new shared header tcg-pool.inc.c adds new_pool_label,
for registering a tcg_target_ulong to be emitted after
the generated code, plus relocation data to install a
pointer to the data.
A new pointer is added to the TCGContext, so that we
dump the constant pool as data, not code.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Dispense with TCGBackendData, as it has never been used for more than
holding a single pointer. Use a define in the cpu/tcg-target.h to
signal requirement for TCGLabelQemuLdst, so that we can drop the no-op
tcg-be-null.h stubs. Rename tcg-be-ldst.h to tcg-ldst.inc.c.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Replace the USE_DIRECT_JUMP ifdef with a TCG_TARGET_HAS_direct_jump
boolean test. Replace the tb_set_jmp_target1 ifdef with an unconditional
function tb_target_set_jmp_target.
While we're touching all backends, add a parameter for tb->tc_ptr;
we're going to need it shortly for some backends.
Move tb_set_jmp_target and tb_add_jump from exec-all.h to cpu-exec.c.
This opens the possibility for TCG_TARGET_HAS_direct_jump to be
a runtime decision -- based on host cpu capabilities, the size of
code_gen_buffer, or a future debugging switch.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Missed being added as part of 71650df7b0.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This allows LOAD HALFWORD IMMEDIATE ON CONDITION,
eliminating one insn in some common cases.
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This allows using a 3-operand insn form for some arithmetic,
logicals and shifts.
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Use a switch instead of searching a table.
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Currently, we cannot use mttcg for running strong memory model guests
on weak memory model hosts due to missing ordering semantics.
We implicitly generate fence instructions for stronger guests if an
ordering mismatch is detected. We generate fences only for the orders
for which fence instructions are necessary, for example a fence is not
necessary between a store and a subsequent load on x86 since its
absence in the guest binary tells that ordering need not be
ensured. Also note that if we find multiple subsequent fence
instructions in the generated IR, we combine them in the TCG
optimization pass.
This patch allows us to boot an x86 guest on ARM64 hosts using mttcg.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <20170829063313.10237-4-bobby.prani@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We threatened to remove ia64 as host in v2.9.0. Its time has now come.
There are still some usages of defined(__ia64__) throughout the source
code that would be triggered if one were to enable TCI on an ia64 host.
Leave those alone for now.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
For a 64-bit ILP32 host, aligning to sizeof(long) is not enough.
Guess the minimum for any host is 8, as that covers uint64_t.
Qemu doesn't use a host long double or host vectors, except in
extremely limited circumstances.
Fixes a bus error for a sparc v8plus host.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Patch 85aa80813d changed the IF emitting the TST instruction,
but failed to change the ?: converting CMP to CMPEQ, so the
result of the TST is ignored.
Signed-off-by: Richard Henderson <rth@twiddle.net>
With the move of some docs/ to docs/devel/ on ac06724a71,
a couple of references were not updated.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Clang 3.9 passes the CONFIG_AVX2_OPT configure test. However, the
supplied <cpuid.h> does not contain the bit_AVX2 define that we use
when detecting whether the routine can be enabled.
Introduce a qemu-specific header that uses the compiler's definition
of __cpuid et al, but supplies any missing bit_* definitions needed.
This avoids introducing any extra ifdefs to util/bufferiszero.c, and
allows quite a few to be removed from tcg/i386/tcg-target.inc.c.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20170719044018.18063-1-rth@twiddle.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reserve a register for the guest_base using ppc code for reference.
By doing so, we do not have to recompute it for every memory load.
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1499677934-2249-1-git-send-email-jiang.biao2@zte.com.cn>
Every vCPU now uses a separate set of TBs for each set of dynamic
tracing event state values. Each set of TBs can be used by any number of
vCPUs to maximize TB reuse when vCPUs have the same tracing state.
This feature is later used by tracetool to optimize tracing of guest
code events.
The maximum number of TB sets is defined as 2^E, where E is the number
of events that have the 'vcpu' property (their state is stored in
CPUState->trace_dstate).
For this to work, a change on the dynamic tracing state of a vCPU will
force it to flush its virtual TB cache (which is only indexed by
address), and fall back to the physical TB cache (which now contains the
vCPU's dynamic tracing state as part of the hashing function).
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-id: 149915775266.6295.10060144081246467690.stgit@frigg.lan
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
When running a helloworld program with qemu-i386 in linux-user
mode on Loongson 3A3000, it will crash. This patch fix the bug.
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Message-Id: <1499669979-25904-1-git-send-email-jiang.biao2@zte.com.cn>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This patch enables the indirect jump path using an LDR (literal)
instruction. It will be interesting to test and see which performs
better among the two paths.
CC: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <20170630143614.31059-3-bobby.prani@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We use ADRP+ADD to compute the target address for goto_tb. This patch
introduces the NOP instruction which is used to align the above
instruction pair so that we can use one atomic instruction to patch
the destination offsets.
CC: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <20170630143614.31059-2-bobby.prani@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We can use a branch to register instruction for exit_tb for offsets
greater than 128MB.
CC: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Message-Id: <20170630143614.31059-1-bobby.prani@gmail.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The new placement of the TB means that we can use one insn
to load the goto_tb destination directly from the TB.
Signed-off-by: Richard Henderson <rth@twiddle.net>
