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2023-03-28tcg: use QTree instead of GTreeEmilio Cota
qemu-user can hang in a multi-threaded fork. One common reason is that when creating a TB, between fork and exec we manipulate a GTree whose memory allocator (GSlice) is not fork-safe. Although POSIX does not mandate it, the system's allocator (e.g. tcmalloc, libc malloc) is probably fork-safe. Fix some of these hangs by using QTree, which uses the system's allocator regardless of the Glib version that we used at configuration time. Tested with the test program in the original bug report, i.e.: ``` void garble() { int pid = fork(); if (pid == 0) { exit(0); } else { int wstatus; waitpid(pid, &wstatus, 0); } } void supragarble(unsigned depth) { if (depth == 0) return ; std::thread a(supragarble, depth-1); std::thread b(supragarble, depth-1); garble(); a.join(); b.join(); } int main() { supragarble(10); } ``` Resolves: https://gitlab.com/qemu-project/qemu/-/issues/285 Reported-by: Valentin David <me@valentindavid.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Emilio Cota <cota@braap.org> Message-Id: <20230205163758.416992-3-cota@braap.org> [rth: Add QEMU_DISABLE_CFI for all callback using functions.] Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-07-12tcg: Fix returned type in alloc_code_gen_buffer_splitwx_memfd()Shaobo Song
This fixes a bug in POSIX-compliant environments. Since we had allocated a buffer named 'tcg-jit' with read-write access protections we need a int type to combine these access flags and return it, whereas we had inexplicably return a bool type. It may cause an unnecessary protection change in tcg_region_init(). Cc: qemu-stable@nongnu.org Fixes: 7be9ebcf924c ("tcg: Return the map protection from alloc_code_gen_buffer") Signed-off-by: Shaobo Song <shnusongshaobo@gmail.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20220624150216.3627-1-shnusongshaobo@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-04-06Replace qemu_real_host_page variables with inlined functionsMarc-André Lureau
Replace the global variables with inlined helper functions. getpagesize() is very likely annotated with a "const" function attribute (at least with glibc), and thus optimization should apply even better. This avoids the need for a constructor initialization too. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-07osdep: Move memalign-related functions to their own headerPeter Maydell
Move the various memalign-related functions out of osdep.h and into their own header, which we include only where they are used. While we're doing this, add some brief documentation comments. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
2022-02-21include: Move qemu_[id]cache_* declarations to new qemu/cacheinfo.hPeter Maydell
The qemu_icache_linesize, qemu_icache_linesize_log, qemu_dcache_linesize, and qemu_dcache_linesize_log variables are not used in many files. Move them out of osdep.h to a new qemu/cacheinfo.h, and document them. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20220208200856.3558249-5-peter.maydell@linaro.org
2022-02-21include: Move qemu_mprotect_*() to new qemu/mprotect.hPeter Maydell
The qemu_mprotect_*() family of functions are used in very few files; move them from osdep.h to a new qemu/mprotect.h. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20220208200856.3558249-3-peter.maydell@linaro.org
2022-02-21include: Move qemu_madvise() and related #defines to new qemu/madvise.hPeter Maydell
The function qemu_madvise() and the QEMU_MADV_* constants associated with it are used in only 10 files. Move them out of osdep.h to a new qemu/madvise.h header that is included where it is needed. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20220208200856.3558249-2-peter.maydell@linaro.org
2021-09-21tcg/mips: Drop special alignment for code_gen_bufferRichard Henderson
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-07-09tcg: Move tb_phys_invalidate_count to tb_ctxRichard Henderson
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>
2021-07-09tcg: Bake tb_destroy() into tcg_region_treeLiren Wei
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>
2021-06-13tcg: When allocating for !splitwx, begin with PROT_NONERichard Henderson
There's a change in mprotect() behaviour [1] in the latest macOS on M1 and it's not yet clear if it's going to be fixed by Apple. In this case, instead of changing permissions of N guard pages, we change permissions of N rwx regions. The same number of syscalls are required either way. [1] https://gist.github.com/hikalium/75ae822466ee4da13cbbe486498a191f Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-13tcg: Merge buffer protection and guard page protectionRichard Henderson
Do not handle protections on a case-by-case basis in the various alloc_code_gen_buffer instances; do it within a single loop in tcg_region_init. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-13tcg: Round the tb_size default from qemu_get_host_physmemRichard Henderson
If qemu_get_host_physmem returns an odd number of pages, then physmem / 8 will not be a multiple of the page size. The following was observed on a gitlab runner: ERROR qtest-arm/boot-serial-test - Bail out! ERROR:../util/osdep.c:80:qemu_mprotect__osdep: \ assertion failed: (!(size & ~qemu_real_host_page_mask)) Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-13tcg: Sink qemu_madvise call to common codeRichard Henderson
Move the call out of the N versions of alloc_code_gen_buffer and into tcg_region_init. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-13tcg: Return the map protection from alloc_code_gen_bufferRichard Henderson
Change the interface from a boolean error indication to a negative error vs a non-negative protection. For the moment this is only interface change, not making use of the new data. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-13tcg: Allocate code_gen_buffer into struct tcg_region_stateRichard Henderson
Do not mess around with setting values within tcg_init_ctx. Put the values into 'region' directly, which is where they will live for the lifetime of the program. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11tcg: Move in_code_gen_buffer and tests to region.cRichard Henderson
Shortly, the full code_gen_buffer will only be visible to region.c, so move in_code_gen_buffer out-of-line. Move the debugging versions of tcg_splitwx_to_{rx,rw} to region.c as well, so that the compiler gets to see the implementation of in_code_gen_buffer. This leaves exactly one use of in_code_gen_buffer outside of region.c, in cpu_restore_state. Which, being on the exception path, is not performance critical. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-11tcg: Tidy split_cross_256mbRichard Henderson
Return output buffer and size via output pointer arguments, rather than returning size via tcg_ctx->code_gen_buffer_size. 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>
2021-06-11tcg: Tidy tcg_n_regionsRichard Henderson
Compute the value using straight division and bounds, rather than a loop. Pass in tb_size rather than reading from tcg_init_ctx.code_gen_buffer_size, 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>
2021-06-11tcg: Rename region.start to region.after_prologueRichard Henderson
Give the field a name reflecting its actual meaning. 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>
2021-06-11tcg: Replace region.end with region.total_sizeRichard Henderson
A size is easier to work with than an end point, particularly during initial buffer allocation. 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>
2021-06-11tcg: Move MAX_CODE_GEN_BUFFER_SIZE to tcg-target.hRichard Henderson
Remove the ifdef ladder and move each define into the appropriate header file. 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>
2021-06-11tcg: Introduce tcg_max_ctxsRichard Henderson
Finish the divorce of tcg/ from hw/, and do not take the max cpu value from MachineState; just remember what we were passed in tcg_init. 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>
2021-06-11accel/tcg: Pass down max_cpus to tcg_initRichard Henderson
Start removing the include of hw/boards.h from tcg/. Pass down the max_cpus value from tcg_init_machine, where we have the MachineState already. 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>
2021-06-11accel/tcg: Move alloc_code_gen_buffer to tcg/region.cRichard Henderson
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>
2021-06-11tcg: Split out region.cRichard Henderson
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>