Commit Graph

209 Commits

Author SHA1 Message Date
Daniel P. Berrangé
3a841ab53f qapi: introduce x-query-jit QMP command
This is a counterpart to the HMP "info jit" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-11-02 15:57:20 +00:00
Ilya Leoshkevich
f025692c99 accel/tcg: Clear PAGE_WRITE before translation
translate_insn() implementations fetch instruction bytes piecemeal,
which can cause qemu-user to generate inconsistent translations if
another thread modifies them concurrently [1].

Fix by making pages containing translated instruction non-writable
right before loading instruction bytes from them.

[1] https://lists.nongnu.org/archive/html/qemu-devel/2021-08/msg00644.html

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20210805204835.158918-1-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-09-14 12:00:20 -07:00
Richard Henderson
c2ffd7549b accel/tcg: Record singlestep_enabled in tb->cflags
Set CF_SINGLE_STEP when single-stepping is enabled.
This avoids the need to flush all tb's when turning
single-stepping on or off.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-21 07:47:05 -10:00
Richard Henderson
04f5b647ed accel/tcg: Handle -singlestep in curr_cflags
Exchange the test in translator_use_goto_tb for CF_NO_GOTO_TB,
and the test in tb_gen_code for setting CF_COUNT_MASK to 1.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210717221851.2124573-6-richard.henderson@linaro.org>
2021-07-21 07:47:04 -10:00
Richard Henderson
78ff82bb1b accel/tcg: Reduce CF_COUNT_MASK to match TCG_MAX_INSNS
The space reserved for CF_COUNT_MASK was overly large.
Reduce to free up cflags bits and eliminate an extra test.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210717221851.2124573-2-richard.henderson@linaro.org>
2021-07-21 07:47:04 -10:00
Richard Henderson
a4390647f7 tcg: Move tb_phys_invalidate_count to tb_ctx
We can call do_tb_phys_invalidate from an iocontext, which has
no per-thread tcg_ctx.  Move this to tb_ctx, which is global.
The actual update still takes place with a lock held, so only
an atomic set is required, not an atomic increment.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/457
Tested-by: Viktor Ashirov <vashirov@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:38:33 -07:00
Liren Wei
834361efd9 tcg: Bake tb_destroy() into tcg_region_tree
The function is called only at tcg_gen_code() when duplicated TBs
are translated by different threads, and when the tcg_region_tree
is reset. Bake it into the underlying GTree as its value destroy
function to unite these situations.
Also remove tcg_region_tree_traverse() which now becomes useless.

Signed-off-by: Liren Wei <lrwei@bupt.edu.cn>
Message-Id: <8dc352f08d038c4e7a1f5f56962398cdc700c3aa.1625404483.git.lrwei@bupt.edu.cn>
[rth: Name the new tb_tc_cmp parameter correctly.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:38:33 -07:00
Liren Wei
f4cba756cb accel/tcg: Hoist tcg_tb_insert() up above tb_link_page()
TranslationBlocks not inserted into the corresponding region
tree shall be regarded as partially initialized objects, and
needs to be finalized first before inserting into QHT.

Signed-off-by: Liren Wei <lrwei@bupt.edu.cn>
Message-Id: <f9fc263f71e11b6308d8c1fbc0dd366bf4aeb532.1625404483.git.lrwei@bupt.edu.cn>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09 09:38:33 -07:00
Richard Henderson
42eb6dfcf1 tcg: Move tcg_init_ctx and tcg_ctx from accel/tcg/
These variables belong to the jit side, not the user side.

Since tcg_init_ctx is no longer used outside of tcg/, move
the declaration to tcg-internal.h.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-13 17:42:40 -07:00
Richard Henderson
fa79cde6ed accel/tcg: Merge tcg_exec_init into tcg_init_machine
There is only one caller, and shortly we will need access
to the MachineState, which tcg_init_machine already has.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11 09:26:28 -07:00
Richard Henderson
a76aabd37b tcg: Create tcg_init
Perform both tcg_context_init and tcg_region_init.
Do not leave this split to the caller.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11 09:26:28 -07:00
Richard Henderson
c46184a90a accel/tcg: Move alloc_code_gen_buffer to tcg/region.c
Buffer management is integral to tcg.  Do not leave the allocation
to code outside of tcg/.  This is code movement, with further
cleanups to follow.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11 09:26:28 -07:00
Richard Henderson
324b9d462e accel/tcg: Inline cpu_gen_init
It consists of one function call and has only one caller.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11 09:26:28 -07:00
Richard Henderson
b0a0794a0f tcg: Re-order tcg_region_init vs tcg_prologue_init
Instead of delaying tcg_region_init until after tcg_prologue_init
is complete, do tcg_region_init first and let tcg_prologue_init
shrink the first region by the size of the generated prologue.

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11 09:26:28 -07:00
Philippe Mathieu-Daudé
e5ceadff47 accel/tcg: Keep TranslationBlock headers local to TCG
Only the TCG accelerator uses the TranslationBlock API.
Move the tb-context.h / tb-hash.h / tb-lookup.h from the
global namespace to the TCG one (in accel/tcg).

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210524170453.3791436-3-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-05-26 15:33:59 -07:00
Philippe Mathieu-Daudé
824f4bac9f accel/tcg: Reduce 'exec/tb-context.h' inclusion
Only 2 headers require "exec/tb-context.h". Instead of having
all files including "exec/exec-all.h" also including it, directly
include it where it is required:
- accel/tcg/cpu-exec.c
- accel/tcg/translate-all.c

For plugins/plugin.h, we were implicitly relying on
  exec/exec-all.h -> exec/tb-context.h -> qemu/qht.h
which is now included directly.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210524170453.3791436-2-f4bug@amsat.org>
[rth: Fix plugins/plugin.h compilation]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-05-26 15:31:45 -07:00
Ilya Leoshkevich
0b00b0c1e0 accel/tcg: Assert that tb->size != 0 after translation
If arch-specific code generates a translation block of size 0,
tb_gen_code() may generate a spurious exception. Add an assertion in
order to catch such situations early.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210416154939.32404-5-iii@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2021-05-20 14:19:30 +02:00
Philippe Mathieu-Daudé
6c6a4a76ee accel/tcg: Align data dumped at end of TB
To better visualize the data dumped at the end of a TB, left-align it
(padding it with 0).  Print ".long" instead of ".quad" on 32-bit hosts.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210515104202.241504-1-f4bug@amsat.org>
[rth: Split the qemu_log and print .long for 32-bit hosts.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-05-16 09:05:14 -05:00
Thomas Huth
2068cabd3f Do not include cpu.h if it's not really necessary
Stop including cpu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-4-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-05-02 17:24:51 +02:00
Alex Bennée
277aed998a accel/tcg: avoid re-translating one-shot instructions
By definition a single instruction is capable of being an IO
instruction. This avoids a problem of triggering a cpu_io_recompile on
a non-recorded translation which then fails because it expects
tcg_tb_lookup() to succeed unconditionally. The normal use case
requires a TB to be able to resolve machine state.

The other users of tcg_tb_lookup() are able to tolerate a missing TB
if the machine state has been resolved by other means - which in the
single-shot case is always true because machine state is synced at the
start of a block.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210415162454.22056-1-alex.bennee@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-17 18:51:14 +01:00
Richard Henderson
eb42297a59 accel/tcg: Preserve PAGE_ANON when changing page permissions
Using mprotect() to change PROT_* does not change the MAP_ANON
previously set with mmap().  Our linux-user version of MTE only
works with MAP_ANON pages, so losing PAGE_ANON caused MTE to
stop working.

Reported-by: Stephen Long <steplong@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-12 11:06:24 +01:00
Richard Henderson
6cc9d67c6f accel/tcg: Precompute curr_cflags into cpu->tcg_cflags
The primary motivation is to remove a dozen insns along
the fast-path in tb_lookup.  As a byproduct, this allows
us to completely remove parallel_cpus.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-03-06 11:53:57 -08:00
Alex Bennée
bf253ac606 accel/tcg: drop the use of CF_HASH_MASK and rename params
We don't really deal in cf_mask most of the time. The one time it's
relevant is when we want to remove an invalidated TB from the QHT
lookup. Everywhere else we should be looking up things without
CF_INVALID set.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210224165811.11567-4-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-03-06 11:52:06 -08:00
Alex Bennée
c0ae396a81 accel/tcg: move CF_CLUSTER calculation to curr_cflags
There is nothing special about this compile flag that doesn't mean we
can't just compute it with curr_cflags() which we should be using when
building a new set.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210224165811.11567-3-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-03-06 11:50:50 -08:00
Alex Bennée
cfd405eae6 accel/tcg: allow plugin instrumentation to be disable via cflags
When icount is enabled and we recompile an MMIO access we end up
double counting the instruction execution. To avoid this we introduce
the CF_MEMI cflag which only allows memory instrumentation for the
next TB (which won't yet have been counted). As this is part of the
hashed compile flags we will only execute the generated TB while
coming out of a cpu_io_recompile.

While we are at it delete the old TODO. We might as well keep the
translation handy as it's likely you will repeatedly hit it on each
MMIO access.

Reported-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-21-alex.bennee@linaro.org>
2021-02-18 08:19:23 +00:00
Alex Bennée
c4afb3456c accel/tcg: remove CF_NOCACHE and special cases
Now we no longer generate CF_NOCACHE blocks we can remove a bunch of
the special case handling for them. While we are at it we can remove
the unused tb->orig_tb field and save a few bytes on the TB structure.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-20-alex.bennee@linaro.org>
2021-02-18 08:19:23 +00:00
Alex Bennée
873d64ac30 accel/tcg: re-factor non-RAM execution code
There is no real need to use CF_NOCACHE here. As long as the TB isn't
linked to other TBs or included in the QHT or jump cache then it will
only get executed once.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-19-alex.bennee@linaro.org>
2021-02-18 08:19:23 +00:00
Richard Henderson
eb56afdb15 target/sh4: Create superh_io_recompile_replay_branch
Move the code from accel/tcg/translate-all.c to target/sh4/cpu.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210208233906.479571-5-richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-14-alex.bennee@linaro.org>
2021-02-18 08:19:20 +00:00
Richard Henderson
95ab7c2291 target/mips: Create mips_io_recompile_replay_branch
Move the code from accel/tcg/translate-all.c to target/mips/cpu.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210208233906.479571-4-richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-13-alex.bennee@linaro.org>
2021-02-18 08:19:15 +00:00
Richard Henderson
d9bcb58a12 accel/tcg: Create io_recompile_replay_branch hook
Create a hook in which to split out the mips and
sh4 ifdefs from cpu_io_recompile.

[AJB: s/stoped/stopped/]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210208233906.479571-3-richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-12-alex.bennee@linaro.org>
2021-02-18 08:19:12 +00:00
Richard Henderson
3e8f1628e8 exec: Use cpu_untagged_addr in g2h; split out g2h_untagged
Use g2h_untagged in contexts that have no cpu, e.g. the binary
loaders that operate before the primary cpu is created.  As a
colollary, target_mmap and friends must use untagged addresses,
since they are used by the loaders.

Use g2h_untagged on values returned from target_mmap, as the
kernel never applies a tag itself.

Use g2h_untagged on all pc values.  The only current user of
tags, aarch64, removes tags from code addresses upon branch,
so "pc" is always untagged.

Use g2h with the cpu context on hand wherever possible.

Use g2h_untagged in lock_user, which will be updated soon.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-02-16 11:04:53 +00:00
Richard Henderson
d9c5858570 tcg: Introduce target-specific page data for user-only
This data can be allocated by page_alloc_target_data() and
released by page_set_flags(start, end, prot | PAGE_RESET).

This data will be used to hold tag memory for AArch64 MTE.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-02-16 11:04:52 +00:00
Richard Henderson
ae30e86661 tcg: Restart code generation when we run out of temps
Some large translation blocks can generate so many unique
constants that we run out of temps to hold them.  In this
case, longjmp back to the start of code generation and
restart with a smaller translation block.

Buglink: https://bugs.launchpad.net/bugs/1912065
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-24 08:03:27 -10:00
Roman Bolshakov
653b87eb36 tcg: Toggle page execution for Apple Silicon
Pages can't be both write and executable at the same time on Apple
Silicon. macOS provides public API to switch write protection [1] for
JIT applications, like TCG.

1. https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon

Tested-by: Alexander Graf <agraf@csgraf.de>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20210113032806.18220-1-r.bolshakov@yadro.com>
[rth: Inline the qemu_thread_jit_* functions;
 drop the MAP_JIT change for a follow-on patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-23 12:13:00 -10:00
Philippe Mathieu-Daudé
c03f041f12 accel/tcg: Restrict tb_gen_code() from other accelerators
tb_gen_code() is only called within TCG accelerator, declare it locally.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210117164813.4101761-4-f4bug@amsat.org>
[rth: Adjust vs changed tb_flush_jmp_cache patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-23 12:12:59 -10:00
Richard Henderson
0f4abea8ef accel/tcg: Move tb_flush_jmp_cache() to cputlb.c
Move and make the function static, as the only users
are here in cputlb.c.

Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-23 12:12:59 -10:00
Philippe Mathieu-Daudé
d9d699dd7c accel/tcg: Make cpu_gen_init() static
cpu_gen_init() is TCG specific, only used in tcg/translate-all.c.
No need to export it to other accelerators, declare it statically.

Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210117164813.4101761-2-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-23 12:12:59 -10:00
Richard Henderson
de2fac62d2 tcg: Remove TCG_TARGET_SUPPORT_MIRROR
Now that all native tcg hosts support splitwx, remove the define.
Replace the one use with a test for CONFIG_TCG_INTERPRETER.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:42 -10:00
Richard Henderson
d1861aa409 accel/tcg: Add mips support to alloc_code_gen_buffer_splitwx_memfd
Re-use the 256MiB region handling from alloc_code_gen_buffer_anon,
and replace that with the shared file mapping.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:42 -10:00
Richard Henderson
6f70ddee19 accel/tcg: Support split-wx for darwin/iOS with vm_remap
Cribbed from code posted by Joelle van Dyne <j@getutm.app>,
and rearranged to a cleaner structure.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:42 -10:00
Richard Henderson
a8c35b2cad accel/tcg: Support split-wx for linux with memfd
We cannot use a real temp file, because we would need to find
a filesystem that does not have noexec enabled.  However, a
memfd is not associated with any filesystem.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:42 -10:00
Richard Henderson
a35b3e1415 tcg: Add --accel tcg,split-wx property
Plumb the value through to alloc_code_gen_buffer.  This is not
supported by any os or tcg backend, so for now enabling it will
result in an error.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:41 -10:00
Richard Henderson
6bc144237a tcg: Use Error with alloc_code_gen_buffer
Report better error messages than just "could not allocate".
Let alloc_code_gen_buffer set ctx->code_gen_buffer_size
and ctx->code_gen_buffer, and simply return bool.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:41 -10:00
Richard Henderson
db0c51a380 tcg: Introduce tcg_splitwx_to_{rx,rw}
Add two helper functions, using a global variable to hold
the displacement.  The displacement is currently always 0,
so no change in behaviour.

Begin using the functions in tcg common code only.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:41 -10:00
Richard Henderson
4846cd37df tcg: Add in_code_gen_buffer
Create a function to determine if a pointer is within the buffer.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-01-07 05:09:41 -10:00
Paolo Bonzini
3b9bd3f46b remove TCG includes from common code
Enable removing tcg/$tcg_arch from the include path when TCG is disabled.
Move translate-all.h to include/exec, since stubs exist for the functions
defined therein.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-02 21:03:36 +01:00
Philippe Mathieu-Daudé
e76f68d3cc accel/tcg: Remove deprecated '-tb-size' option
The '-tb-size' option (replaced by '-accel tcg,tb-size') is
deprecated since 5.0 (commit fe17413247). Remove it.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201202112714.1223783-1-philmd@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20201210155808.233895-2-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-15 12:52:01 -05:00
Peter Maydell
1d705e8a5b accel/tcg: Add CPU_LOG_EXEC tracing for cpu_io_recompile()
When using -icount, it's useful for the CPU_LOG_EXEC logging
to include information about when cpu_io_recompile() was
called, because it alerts the reader of the log that the
tracing of a previous TB execution may not actually
correspond to an actually executed instruction. For instance
if you're using -icount and also -singlestep then a guest
instruction that makes an IO access appears in two
"Trace" lines, once in a TB that triggers the cpu_io_recompile()
and then again in the TB that actually executes.

(This is a similar reason to why the "Stopped execution of
TB chain before..." logging in cpu_tb_exec() is helpful
when trying to track execution flow in the logs.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20201013122658.4620-1-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-10-27 09:48:07 -07:00
Claudio Fontana
740b175973 cpu-timers, icount: new modules
refactoring of cpus.c continues with cpu timer state extraction.

cpu-timers: responsible for the softmmu cpu timers state,
            including cpu clocks and ticks.

icount: counts the TCG instructions executed. As such it is specific to
the TCG accelerator. Therefore, it is built only under CONFIG_TCG.

One complication is due to qtest, which uses an icount field to warp time
as part of qtest (qtest_clock_warp).

In order to solve this problem, provide a separate counter for qtest.

This requires fixing assumptions scattered in the code that
qtest_enabled() implies icount_enabled(), checking each specific case.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[remove redundant initialization with qemu_spice_init]
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[fix lingering calls to icount_get]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-05 16:41:22 +02:00
Richard Henderson
4c389f6edf disas: Move host asm annotations to tb_gen_code
Instead of creating GStrings and passing them into log_disas,
just print the annotations directly in tb_gen_code.

Fix the annotations for the slow paths of the TB, after the
part implementing the final guest instruction.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-10-03 04:25:14 -05:00
Stefan Hajnoczi
d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00
Alex Bennée
c83d628b7f accel/tcg: better handle memory constrained systems
It turns out there are some 64 bit systems that have relatively low
amounts of physical memory available to them (typically CI system).
Even with swapping available a 1GB translation buffer that fills up
can put the machine under increased memory pressure. Detect these low
memory situations and reduce tb_size appropriately.

Fixes: 600e17b261 ("accel/tcg: increase default code gen buffer size for 64 bit")
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Robert Foley <robert.foley@linaro.org>
Cc: BALATON Zoltan <balaton@eik.bme.hu>
Cc: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Message-Id: <20200724064509.331-7-alex.bennee@linaro.org>
2020-07-27 09:40:16 +01:00
Eric Blake
f9919116b8 osdep: Make MIN/MAX evaluate arguments only once
I'm not aware of any immediate bugs in qemu where a second runtime
evaluation of the arguments to MIN() or MAX() causes a problem, but
proactively preventing such abuse is easier than falling prey to an
unintended case down the road.  At any rate, here's the conversation
that sparked the current patch:
https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg05718.html

Update the MIN/MAX macros to only evaluate their argument once at
runtime; this uses typeof(1 ? (a) : (b)) to ensure that we are
promoting the temporaries to the same type as the final comparison (we
have to trigger type promotion, as typeof(bitfield) won't compile; and
we can't use typeof((a) + (b)) or even typeof((a) + 0), as some of our
uses of MAX are on void* pointers where such addition is undefined).

However, we are unable to work around gcc refusing to compile ({}) in
a constant context (such as the array length of a static variable),
even when only used in the dead branch of a __builtin_choose_expr(),
so we have to provide a second macro pair MIN_CONST and MAX_CONST for
use when both arguments are known to be compile-time constants and
where the result must also be usable as a constant; this second form
evaluates arguments multiple times but that doesn't matter for
constants.  By using a void expression as the expansion if a
non-constant is presented to this second form, we can enlist the
compiler to ensure the double evaluation is not attempted on
non-constants.

Alas, as both macros now rely on compiler intrinsics, they are no
longer usable in preprocessor #if conditions; those will just have to
be open-coded or the logic rewritten into #define or runtime 'if'
conditions (but where the compiler dead-code-elimination will probably
still apply).

I tested that both gcc 10.1.1 and clang 10.0.0 produce errors for all
forms of macro mis-use.  As the errors can sometimes be cryptic, I'm
demonstrating the gcc output:

Use of MIN when MIN_CONST is needed:

In file included from /home/eblake/qemu/qemu-img.c:25:
/home/eblake/qemu/include/qemu/osdep.h:249:5: error: braced-group within expression allowed only inside a function
  249 |     ({                                                  \
      |     ^
/home/eblake/qemu/qemu-img.c:92:12: note: in expansion of macro ‘MIN’
   92 | char array[MIN(1, 2)] = "";
      |            ^~~

Use of MIN_CONST when MIN is needed:

/home/eblake/qemu/qemu-img.c: In function ‘is_allocated_sectors’:
/home/eblake/qemu/qemu-img.c:1225:15: error: void value not ignored as it ought to be
 1225 |             i = MIN_CONST(i, n);
      |               ^

Use of MIN in the preprocessor:

In file included from /home/eblake/qemu/accel/tcg/translate-all.c:20:
/home/eblake/qemu/accel/tcg/translate-all.c: In function ‘page_check_range’:
/home/eblake/qemu/include/qemu/osdep.h:249:6: error: token "{" is not valid in preprocessor expressions
  249 |     ({                                                  \
      |      ^

Fix the resulting callsites that used #if or computed a compile-time
constant min or max to use the new macros.  cpu-defs.h is interesting,
as CPU_TLB_DYN_MAX_BITS is sometimes used as a constant and sometimes
dynamic.

It may be worth improving glib's MIN/MAX definitions to be saner, but
that is a task for another day.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200625162602.700741-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-26 09:39:39 -04:00
Emilio G. Cota
3f640eb881 translate-all: call qemu_spin_destroy for PageDesc
The radix tree is append-only, but we can fail to insert
a PageDesc if the insertion races with another thread.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Robert Foley <robert.foley@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200609200738.445-8-robert.foley@linaro.org>
Message-Id: <20200612190237.30436-11-alex.bennee@linaro.org>
2020-06-16 14:49:05 +01:00
Emilio G. Cota
938e897a66 tcg: call qemu_spin_destroy for tb->jmp_lock
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Robert Foley <robert.foley@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[RF: minor changes + remove tb_destroy_func]
Message-Id: <20200609200738.445-7-robert.foley@linaro.org>
Message-Id: <20200612190237.30436-10-alex.bennee@linaro.org>
2020-06-16 14:49:05 +01:00
Alex Bennée
5f0df0333b translate-all: include guest address in out_asm output
We already have information about where each guest instructions
representation starts stored in the tcg_ctx->gen_insn_data so we can
rectify the PC for faults. We can re-use this information to annotate
the out_asm output with guest instruction address which makes it a bit
easier to work out where you are especially with longer blocks. A
minor wrinkle is that some instructions get optimised away so we have
to scan forward until we find some actual generated code.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20200513175134.19619-11-alex.bennee@linaro.org>
2020-05-15 15:25:16 +01:00
Alex Bennée
e5ef4ec28b disas: include an optional note for the start of disassembly
This will become useful shortly for providing more information about
output assembly inline. While there fix up the indenting and code
formatting in disas().

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-Id: <20200513175134.19619-9-alex.bennee@linaro.org>
2020-05-15 15:25:16 +01:00
Richard Henderson
7d8cbbabcb accel/tcg: Relax va restrictions on 64-bit guests
We cannot at present limit a 64-bit guest to a virtual address
space smaller than the host.  It will mostly work to ignore this
limitation, except if the guest uses high bits of the address
space for tags.  But it will certainly work better, as presently
we can wind up failing to allocate the guest stack.

Widen our user-only page tree to the host or abi pointer width.
Remove the workaround for this problem from target/alpha.
Always validate guest addresses vs reserved_va, as there we
control allocation ourselves.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20200513175134.19619-7-alex.bennee@linaro.org>
2020-05-15 15:25:16 +01:00
Richard Henderson
64547a3bb6 tcg: Remove softmmu code_gen_buffer fixed address
The commentary talks about "in concert with the addresses
assigned in the relevant linker script", except there is no
linker script for softmmu, nor has there been for some time.

(Do not confuse the user-only linker script editing that was
removed in the previous patch, because user-only does not
use this code_gen_buffer allocation method.)

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-03-28 14:09:44 -07:00
Alex Bennée
600e17b261 accel/tcg: increase default code gen buffer size for 64 bit
While 32mb is certainly usable a full system boot ends up flushing the
codegen buffer nearly 100 times. Increase the default on 64 bit hosts
to take advantage of all that spare memory. After this change I can
boot my tests system without any TB flushes.

As we usually run more CONFIG_USER binaries at a time in typical usage
we aren't quite as profligate for user-mode code generation usage. We
also bring the static code gen defies to the same place to keep all
the reasoning in the comments together.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-Id: <20200228192415.19867-5-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-02-28 17:43:31 -08:00
Alex Bennée
21f2f447ad accel/tcg: only USE_STATIC_CODE_GEN_BUFFER on 32 bit hosts
There is no particular reason to use a static codegen buffer on 64 bit
hosts as we have address space to burn. Allow the common CONFIG_USER
case to use the mmap'ed buffers like SoftMMU.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-Id: <20200228192415.19867-4-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-02-28 17:43:25 -08:00
Alex Bennée
47a2def453 accel/tcg: remove link between guest ram and TCG cache size
Basing the TB cache size on the ram_size was always a little heuristic
and was broken by a1b18df9a4 which caused ram_size not to be fully
realised at the time we initialise the TCG translation cache.

The current DEFAULT_CODE_GEN_BUFFER_SIZE may still be a little small
but follow-up patches will address that.

Fixes: a1b18df9a4
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-Id: <20200228192415.19867-3-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-02-28 17:42:48 -08:00
Alex Bennée
a2fa63a8f5 accel/tcg: use units.h for defining code gen buffer sizes
It's easier to read.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200228192415.19867-2-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-02-28 17:42:39 -08:00
Philippe Mathieu-Daudé
dcb32f1d8f tcg: Search includes from the project root source directory
We currently search both the root and the tcg/ directories for tcg
files:

  $ git grep '#include "tcg/' | wc -l
  28

  $ git grep '#include "tcg[^/]' | wc -l
  94

To simplify the preprocessor search path, unify by expliciting the
tcg/ directory.

Patch created mechanically by running:

  $ for x in \
      tcg.h tcg-mo.h tcg-op.h tcg-opc.h \
      tcg-op-gvec.h tcg-gvec-desc.h; do \
    sed -i "s,#include \"$x\",#include \"tcg/$x\"," \
      $(git grep -l "#include \"$x\""); \
    done

Acked-by: David Gibson <david@gibson.dropbear.id.au> (ppc parts)
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200101112303.20724-2-philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2020-01-15 15:13:10 -10:00
Robert Foley
fc59d2d870 qemu_log_lock/unlock now preserves the qemu_logfile handle.
qemu_log_lock() now returns a handle and qemu_log_unlock() receives a
handle to unlock.  This allows for changing the handle during logging
and ensures the lock() and unlock() are for the same file.

Also in target/tilegx/translate.c removed the qemu_log_lock()/unlock()
calls (and the log("\n")), since the translator can longjmp out of the
loop if it attempts to translate an instruction in an inaccessible page.

Signed-off-by: Robert Foley <robert.foley@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20191118211528.3221-5-robert.foley@linaro.org>
2019-12-18 20:18:02 +00:00
Peter Maydell
68d8ef4ec5 TCG Plugins initial implementation
- use --enable-plugins @ configure
   - low impact introspection (-plugin empty.so to measure overhead)
   - plugins cannot alter guest state
   - example plugins included in source tree (tests/plugins)
   - -d plugin to enable plugin output in logs
   - check-tcg runs extra tests when plugins enabled
   - documentation in docs/devel/plugins.rst
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Merge remote-tracking branch 'remotes/stsquad/tags/pull-tcg-plugins-281019-4' into staging

TCG Plugins initial implementation

  - use --enable-plugins @ configure
  - low impact introspection (-plugin empty.so to measure overhead)
  - plugins cannot alter guest state
  - example plugins included in source tree (tests/plugins)
  - -d plugin to enable plugin output in logs
  - check-tcg runs extra tests when plugins enabled
  - documentation in docs/devel/plugins.rst

# gpg: Signature made Mon 28 Oct 2019 15:13:23 GMT
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-tcg-plugins-281019-4: (57 commits)
  travis.yml: enable linux-gcc-debug-tcg cache
  MAINTAINERS: add me for the TCG plugins code
  scripts/checkpatch.pl: don't complain about (foo, /* empty */)
  .travis.yml: add --enable-plugins tests
  include/exec: wrap cpu_ldst.h in CONFIG_TCG
  accel/stubs: reduce headers from tcg-stub
  tests/plugin: add hotpages to analyse memory access patterns
  tests/plugin: add instruction execution breakdown
  tests/plugin: add a hotblocks plugin
  tests/tcg: enable plugin testing
  tests/tcg: drop test-i386-fprem from TESTS when not SLOW
  tests/tcg: move "virtual" tests to EXTRA_TESTS
  tests/tcg: set QEMU_OPTS for all cris runs
  tests/tcg/Makefile.target: fix path to config-host.mak
  tests/plugin: add sample plugins
  linux-user: support -plugin option
  vl: support -plugin option
  plugin: add qemu_plugin_outs helper
  plugin: add qemu_plugin_insn_disas helper
  plugin: expand the plugin_init function to include an info block
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-30 14:10:32 +00:00
Emilio G. Cota
5025bb7fde translate-all: notify plugin code of tb_flush
Plugins might allocate per-TB data that then they get passed each
time a TB is executed (via the *userdata pointer).

Notify plugin code every time a code cache flush occurs, so
that plugins can then reclaim the memory of the per-TB data.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2019-10-28 15:12:38 +00:00
Emilio G. Cota
136094d0b2 translate-all: use cpu_in_exclusive_work_context() in tb_flush
tb_flush will be called by the plugin module from a safe
work environment. Prepare for that.

Suggested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 15:12:38 +00:00
Richard Henderson
fe9b676fb3 translate-all: Remove tb_alloc
Since 2ac01d6daf, this function does only two things: assert a
lock is held, and call tcg_tb_alloc.  It is used exactly once,
and its user has already done the assert.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Clement Deschamps <clement.deschamps@greensocs.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 10:35:23 +01:00
Clement Deschamps
1b1940026c translate-all: fix uninitialized tb->orig_tb
This fixes a segmentation fault in icount mode when executing
from an IO region.

TB is marked as CF_NOCACHE but tb->orig_tb is not initialized
(equals previous value in code_gen_buffer).

The issue happens in cpu_io_recompile() when it tries to invalidate orig_tb.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Clement Deschamps <clement.deschamps@greensocs.com>
Message-Id: <20191022140016.918371-1-clement.deschamps@greensocs.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 10:35:23 +01:00
Richard Henderson
ae57db63ac cputlb: Pass retaddr to tb_check_watchpoint
Fixes the previous TLB_WATCHPOINT patches because we are currently
failing to set cpu->mem_io_pc with the call to cpu_check_watchpoint.
Pass down the retaddr directly because it's readily available.

Fixes: 50b107c5d6
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:56:28 -07:00
Richard Henderson
5a7c27bb8a cputlb: Pass retaddr to tb_invalidate_phys_page_fast
Rather than rely on cpu->mem_io_pc, pass retaddr down directly.

Within tb_invalidate_phys_page_range__locked, the is_cpu_write_access
parameter is non-zero exactly when retaddr would be non-zero, so that
is a simple replacement.

Recognize that current_tb_not_found is true only when mem_io_pc
(and now retaddr) are also non-zero, so remove a redundant test.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:56:28 -07:00
Richard Henderson
ce9f5e2792 cputlb: Remove tb_invalidate_phys_page_range is_cpu_write_access
All callers pass false to this argument.  Remove it and pass the
constant on to tb_invalidate_phys_page_range__locked.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:56:28 -07:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Markus Armbruster
14a48c1d0d qemu-common: Move tcg_enabled() etc. to sysemu/tcg.h
Other accelerators have their own headers: sysemu/hax.h, sysemu/hvf.h,
sysemu/kvm.h, sysemu/whpx.h.  Only tcg_enabled() & friends sit in
qemu-common.h.  This necessitates inclusion of qemu-common.h into
headers, which is against the rules spelled out in qemu-common.h's
file comment.

Move tcg_enabled() & friends into their own header sysemu/tcg.h, and
adjust #include directives.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-2-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[Rebased with conflicts resolved automatically, except for
accel/tcg/tcg-all.c]
2019-06-11 20:22:09 +02:00
Richard Henderson
5e1401969b cpu: Move icount_decr to CPUNegativeOffsetState
Amusingly, we had already ignored the comment to keep this value
at the end of CPUState.  This restores the minimum negative offset
from TCG_AREG0 for code generation.

For the couple of uses within qom/cpu.c, without NEED_CPU_H, add
a pointer from the CPUState object to the IcountDecr object within
CPUNegativeOffsetState.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:42 -07:00
Richard Henderson
29a0af618d cpu: Replace ENV_GET_CPU with env_cpu
Now that we have both ArchCPU and CPUArchState, we can define
this generically instead of via macro in each target's cpu.h.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:34 -07:00
Richard Henderson
6e6c4efed9 tcg: Restart after TB code generation overflow
If a TB generates too much code, try again with fewer insns.

Fixes: https://bugs.launchpad.net/bugs/1824853
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-04-24 13:04:33 -07:00
Richard Henderson
8b86d6d258 tcg: Hoist max_insns computation to tb_gen_code
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.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-04-24 13:04:33 -07:00
Markus Armbruster
3de2faa9a8 tcg: Simplify how dump_exec_info() prints
dump_exec_info() takes an fprintf()-like callback and a FILE * to pass
to it.

Its only caller hmp_info_jit() passes monitor_fprintf() and the
current monitor cast to FILE *.  monitor_fprintf() casts it right
back, and is otherwise identical to monitor_printf().  The
type-punning is ugly.

Drop the callback, and call qemu_printf() instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-5-armbru@redhat.com>
2019-04-18 22:18:59 +02:00
Markus Armbruster
d4c51a0af3 tcg: Simplify how dump_opcount_info() prints
dump_opcount_info() takes an fprintf()-like callback and a FILE * to
pass to it.

Its only caller hmp_info_opcount() passes monitor_fprintf() and the
current monitor cast to FILE *.  monitor_fprintf() casts it right
back, and is otherwise identical to monitor_printf().  The
type-punning is ugly.

Drop the callback, and call qemu_printf() instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-4-armbru@redhat.com>
2019-04-18 22:18:59 +02:00
Thomas Huth
fb0343d5b4 tcg: Fix LGPL version number
It's either "GNU *Library* General Public version 2" or "GNU Lesser
General Public version *2.1*", but there was no "version 2.0" of the
"Lesser" library. So assume that version 2.1 is meant here.

Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1548252536-6242-5-git-send-email-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-01-30 11:01:52 +01:00
Peter Maydell
f7b78602fd accel/tcg: Add cluster number to TCG TB hash
Include the cluster number in the hash we use to look
up TBs. This is important because a TB that is valid
for one cluster at a given physical address and set
of CPU flags is not necessarily valid for another:
the two clusters may have different views of physical
memory, or may have different CPU features (eg FPU
present or absent).

We put the cluster number in the high 8 bits of the
TB cflags. This gives us up to 256 clusters, which should
be enough for anybody. If we ever need more, or need
more bits in cflags for other purposes, we could make
tb_hash_func() take more data (and expand qemu_xxhash7()
to qemu_xxhash8()).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20190121152218.9592-4-peter.maydell@linaro.org
2019-01-29 11:46:06 +00:00
Marc-André Lureau
444e20a36f build-sys: don't include windows.h, osdep.h does it
osdep.h will also define the available Windows API version for QEMU.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20181122110039.15972-2-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Richard Henderson
e09de0a20d cputlb: Count "partial" and "elided" tlb flushes
Our only statistic so far was "full" tlb flushes, where all mmu_idx
are flushed at the same time.

Now count "partial" tlb flushes where sets of mmu_idx are flushed,
but the set is not maximal.  Account one per mmu_idx flushed, as
that is the unit of work performed.

We don't actually count elided flushes yet, but go ahead and change
the interface presented to the monitor all at once.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:30 +00:00
Emilio G. Cota
fff42f183e tcg: access cpu->icount_decr.u16.high with atomics
Consistently access u16.high with atomics to avoid
undefined behaviour in MTTCG.

Note that icount_decr.u16.low is only used in icount mode,
so regular accesses to it are OK.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181010144853.13005-2-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 18:58:10 -07:00
Thomas Huth
dcf6760a64 accel/tcg: Remove dead code
The global cpu_single_env variable has been removed more than 5 years
ago, so apparently nobody used this dead debug code in that timeframe
anymore. Thus let's remove it completely now.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1537204134-15905-1-git-send-email-thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02 19:09:13 +02:00
Emilio G. Cota
78255ba2cc qht: drop ht argument from qht iterators
Accessing the HT from an iterator results almost always
in a deadlock. Given that only one qht-internal function
uses this argument, drop it from the interface.

Suggested-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>
2018-09-26 08:55:54 -07:00
Peter Maydell
9739e3767a accel/tcg: tb_gen_code(): Create single-insn TB for execution from non-RAM
If get_page_addr_code() returns -1, this indicates that there is no RAM
page we can read a full TB from. Instead we must create a TB which
contains a single instruction and which we do not cache, so it is
executed only once.

Since this means we can now have TBs which are not in any page list,
we also need to make tb_phys_invalidate() handle them (by not trying
to remove them from a nonexistent page list).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180710160013.26559-5-peter.maydell@linaro.org
2018-08-14 17:17:19 +01:00
Peter Maydell
c360a0fd71 accel/tcg: Handle get_page_addr_code() returning -1 in tb_check_watchpoint()
When we support execution from non-RAM MMIO regions, get_page_addr_code()
will return -1 to indicate that there is no RAM at the requested address.
Handle this in tb_check_watchpoint() -- if the exception happened for a
PC which doesn't correspond to RAM then there is no need to invalidate
any TBs, because the one-instruction TB will not have been cached.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180710160013.26559-4-peter.maydell@linaro.org
2018-08-14 17:17:19 +01:00
Stefan Weil
696c706642 accel: Fix typo and grammar in comment
The typo was found by codespell.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20180712194454.26765-1-sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-16 16:58:16 +02:00
Emilio G. Cota
ec7eb2ae77 translate-all: honour CF_NOCACHE in tb_gen_code
This fixes a record-replay regression introduced by 95590e2
("translate-all: discard TB when tb_link_page returns an existing
matching TB", 2018-06-15). The problem is that code using CF_NOCACHE
assumes that the TB returned from tb_gen_code is always a
newly-generated one. This assumption, however, was broken in
the aforementioned commit.

Fix it by honouring CF_NOCACHE, so that tb_gen_code always
returns a newly-generated TB when CF_NOCACHE is passed to it.
Do this by avoiding the TB hash table if CF_NOCACHE is set.

Reported-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Tested-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 1530806837-5416-1-git-send-email-cota@braap.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-09 16:14:36 +01:00
Emilio G. Cota
a688e73ba8 translate-all: fix locking of TBs whose two pages share the same physical page
Commit 0b5c91f ("translate-all: use per-page locking in !user-mode",
2018-06-15) introduced per-page locking. It assumed that the physical
pages corresponding to a TB (at most two pages) are always distinct,
which is wrong. For instance, an xtensa test provided by Max Filippov
is broken by the commit, since the test maps two virtual pages
to the same physical page:

	virt1: 7fff, virt2: 8000
	phys1 6000fff, phys2 6000000

Fix it by removing the assumption from page_lock_pair.
If the two physical page addresses are equal, we only lock
the PageDesc once. Note that the two callers of page_lock_pair,
namely page_unlock_tb and tb_link_page, are also updated so that
we do not try to unlock the same PageDesc twice.

Fixes: 0b5c91f74f
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1529944302-14186-1-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02 08:02:20 -07:00
Peter Maydell
109b25045b * "info mtree" improvements (Alexey)
* fake VPD block limits for SCSI passthrough (Daniel Barboza)
 * chardev and main loop fixes (Daniel Berrangé, Sergio, Stefan)
 * help fixes (Eduardo)
 * pc-dimm refactoring (David)
 * tests improvements and fixes (Emilio, Thomas)
 * SVM emulation fixes (Jan)
 * MemoryRegionCache fix (Eric)
 * WHPX improvements (Justin)
 * ESP cleanup (Mark)
 * -overcommit option (Michael)
 * qemu-pr-helper fixes (me)
 * "info pic" improvements for x86 (Peter)
 * x86 TCG emulation fixes (Richard)
 * KVM slot handling fix (Shannon)
 * Next round of deprecation (Thomas)
 * Windows dump format support (Viktor)
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* "info mtree" improvements (Alexey)
* fake VPD block limits for SCSI passthrough (Daniel Barboza)
* chardev and main loop fixes (Daniel Berrangé, Sergio, Stefan)
* help fixes (Eduardo)
* pc-dimm refactoring (David)
* tests improvements and fixes (Emilio, Thomas)
* SVM emulation fixes (Jan)
* MemoryRegionCache fix (Eric)
* WHPX improvements (Justin)
* ESP cleanup (Mark)
* -overcommit option (Michael)
* qemu-pr-helper fixes (me)
* "info pic" improvements for x86 (Peter)
* x86 TCG emulation fixes (Richard)
* KVM slot handling fix (Shannon)
* Next round of deprecation (Thomas)
* Windows dump format support (Viktor)

# gpg: Signature made Fri 29 Jun 2018 12:03:05 BST
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# 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

* remotes/bonzini/tags/for-upstream: (60 commits)
  tests/boot-serial: Do not delete the output file in case of errors
  hw/scsi: add VPD Block Limits emulation
  hw/scsi: centralize SG_IO calls into single function
  hw/scsi: cleanups before VPD BL emulation
  dump: add Windows live system dump
  dump: add fallback KDBG using in Windows dump
  dump: use system context in Windows dump
  dump: add Windows dump format to dump-guest-memory
  i386/cpu: make -cpu host support monitor/mwait
  kvm: support -overcommit cpu-pm=on|off
  hmp: obsolete "info ioapic"
  ioapic: support "info irq"
  ioapic: some proper indents when dump info
  ioapic: support "info pic"
  doc: another fix to "info pic"
  target-i386: Mark cpu_vmexit noreturn
  target-i386: Allow interrupt injection after STGI
  target-i386: Add NMI interception to SVM
  memory/hmp: Print owners/parents in "info mtree"
  WHPX: register for unrecognized MSR exits
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-06-29 12:30:29 +01:00
Paolo Bonzini
8bca9a03ec move public invalidate APIs out of translate-all.{c,h}, clean up
Place them in exec.c, exec-all.h and ram_addr.h.  This removes
knowledge of translate-all.h (which is an internal header) from
several files outside accel/tcg and removes knowledge of
AddressSpace from translate-all.c (as it only operates on ram_addr_t).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-28 19:05:30 +02:00
Stefan Hajnoczi
f18793b096 compiler: add a sizeof_field() macro
Determining the size of a field is useful when you don't have a struct
variable handy.  Open-coding this is ugly.

This patch adds the sizeof_field() macro, which is similar to
typeof_field().  Existing instances are updated to use the macro.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180614164431.29305-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-27 13:01:40 +01:00
Emilio G. Cota
0ac20318ce tcg: remove tb_lock
Use mmap_lock in user-mode to protect TCG state and the page descriptors.
In !user-mode, each vCPU has its own TCG state, so no locks needed.
Per-page locks are used to protect the page descriptors.

Per-TB locks are used in both modes to protect TB jumps.

Some notes:

- tb_lock is removed from notdirty_mem_write by passing a
  locked page_collection to tb_invalidate_phys_page_fast.

- tcg_tb_lookup/remove/insert/etc have their own internal lock(s),
  so there is no need to further serialize access to them.

- do_tb_flush is run in a safe async context, meaning no other
  vCPU threads are running. Therefore acquiring mmap_lock there
  is just to please tools such as thread sanitizer.

- Not visible in the diff, but tb_invalidate_phys_page already
  has an assert_memory_lock.

- cpu_io_recompile is !user-only, so no mmap_lock there.

- Added mmap_unlock()'s before all siglongjmp's that could
  be called in user-mode while mmap_lock is held.
  + Added an assert for !have_mmap_lock() after returning from
    the longjmp in cpu_exec, just like we do in cpu_exec_step_atomic.

Performance numbers before/after:

Host: AMD Opteron(tm) Processor 6376

                 ubuntu 17.04 ppc64 bootup+shutdown time

  700 +-+--+----+------+------------+-----------+------------*--+-+
      |    +    +      +            +           +           *B    |
      |         before ***B***                            ** *    |
      |tb lock removal ###D###                         ***        |
  600 +-+                                           ***         +-+
      |                                           **         #    |
      |                                        *B*          #D    |
      |                                     *** *         ##      |
  500 +-+                                ***           ###      +-+
      |                             * ***           ###           |
      |                            *B*          # ##              |
      |                          ** *          #D#                |
  400 +-+                      **            ##                 +-+
      |                      **           ###                     |
      |                    **           ##                        |
      |                  **         # ##                          |
  300 +-+  *           B*          #D#                          +-+
      |    B         ***        ###                               |
      |    *       **       ####                                  |
      |     *   ***      ###                                      |
  200 +-+   B  *B     #D#                                       +-+
      |     #B* *   ## #                                          |
      |     #*    ##                                              |
      |    + D##D#     +            +           +            +    |
  100 +-+--+----+------+------------+-----------+------------+--+-+
           1    8      16      Guest CPUs       48           64
  png: https://imgur.com/HwmBHXe

              debian jessie aarch64 bootup+shutdown time

  90 +-+--+-----+-----+------------+------------+------------+--+-+
     |    +     +     +            +            +            +    |
     |         before ***B***                                B    |
  80 +tb lock removal ###D###                              **D  +-+
     |                                                   **###    |
     |                                                 **##       |
  70 +-+                                             ** #       +-+
     |                                             ** ##          |
     |                                           **  #            |
  60 +-+                                       *B  ##           +-+
     |                                       **  ##               |
     |                                    ***  #D                 |
  50 +-+                               ***   ##                 +-+
     |                             * **   ###                     |
     |                           **B*  ###                        |
  40 +-+                     ****  # ##                         +-+
     |                   ****     #D#                             |
     |             ***B**      ###                                |
  30 +-+    B***B**        ####                                 +-+
     |    B *   *     # ###                                       |
     |     B       ###D#                                          |
  20 +-+   D  ##D##                                             +-+
     |      D#                                                    |
     |    +     +     +            +            +            +    |
  10 +-+--+-----+-----+------------+------------+------------+--+-+
          1     8     16      Guest CPUs        48           64
  png: https://imgur.com/iGpGFtv

The gains are high for 4-8 CPUs. Beyond that point, however, unrelated
lock contention significantly hurts scalability.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
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>
2018-06-15 08:18:48 -10:00
Emilio G. Cota
705ad1ff0c translate-all: remove tb_lock mention from cpu_restore_state_from_tb
tb_lock was needed when the function did retranslation. However,
since fca8a500d5 ("tcg: Save insn data and use it in
cpu_restore_state_from_tb") we don't do retranslation.

Get rid of the comment.

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>
2018-06-15 08:18:48 -10:00
Emilio G. Cota
194125e3eb translate-all: protect TB jumps with a per-destination-TB lock
This applies to both user-mode and !user-mode emulation.

Instead of relying on a global lock, protect the list of incoming
jumps with tb->jmp_lock. This lock also protects tb->cflags,
so update all tb->cflags readers outside tb->jmp_lock to use
atomic reads via tb_cflags().

In order to find the destination TB (and therefore its jmp_lock)
from the origin TB, we introduce tb->jmp_dest[].

I considered not using a linked list of jumps, which simplifies
code and makes the struct smaller. However, it unnecessarily increases
memory usage, which results in a performance decrease. See for
instance these numbers booting+shutting down debian-arm:
                      Time (s)  Rel. err (%)  Abs. err (s)  Rel. slowdown (%)
------------------------------------------------------------------------------
 before                  20.88          0.74      0.154512                 0.
 after                   20.81          0.38      0.079078        -0.33524904
 GTree                   21.02          0.28      0.058856         0.67049808
 GHashTable + xxhash     21.63          1.08      0.233604          3.5919540

Using a hash table or a binary tree to keep track of the jumps
doesn't really pay off, not only due to the increased memory usage,
but also because most TBs have only 0 or 1 jumps to them. The maximum
number of jumps when booting debian-arm that I measured is 35, but
as we can see in the histogram below a TB with that many incoming jumps
is extremely rare; the average TB has 0.80 incoming jumps.

n_jumps: 379208; avg jumps/tb: 0.801099
dist: [0.0,1.0)|▄█▁▁▁▁▁▁▁▁▁▁▁ ▁▁▁▁▁▁ ▁▁▁  ▁▁▁     ▁|[34.0,35.0]

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>
2018-06-15 08:18:48 -10:00
Emilio G. Cota
95590e24af translate-all: discard TB when tb_link_page returns an existing matching TB
Use the recently-gained QHT feature of returning the matching TB if it
already exists. This allows us to get rid of the lookup we perform
right after acquiring tb_lock.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
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>
2018-06-15 08:18:42 -10:00