diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/cacheflush.c | 4 | ||||
| -rw-r--r-- | util/coroutine-wasm.c | 127 | ||||
| -rw-r--r-- | util/meson.build | 4 | ||||
| -rw-r--r-- | util/oslib-posix.c | 28 |
4 files changed, 162 insertions, 1 deletions
diff --git a/util/cacheflush.c b/util/cacheflush.c index 1d12899..17c5891 100644 --- a/util/cacheflush.c +++ b/util/cacheflush.c @@ -229,6 +229,10 @@ static void __attribute__((constructor)) init_cache_info(void) /* Caches are coherent and do not require flushing; symbol inline. */ +#elif defined(EMSCRIPTEN) + +/* Wasm doesn't have executable region of memory. */ + #elif defined(__aarch64__) && !defined(CONFIG_WIN32) /* * For Windows, we use generic implementation of flush_idcache_range, that diff --git a/util/coroutine-wasm.c b/util/coroutine-wasm.c new file mode 100644 index 0000000..cb1ec92 --- /dev/null +++ b/util/coroutine-wasm.c @@ -0,0 +1,127 @@ +/* + * emscripten fiber coroutine initialization code + * based on coroutine-ucontext.c + * + * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws> + * Copyright (C) 2011 Kevin Wolf <kwolf@redhat.com> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.0 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include "qemu/coroutine_int.h" +#include "qemu/coroutine-tls.h" + +#include <emscripten/fiber.h> + +typedef struct { + Coroutine base; + void *stack; + size_t stack_size; + + void *asyncify_stack; + size_t asyncify_stack_size; + + CoroutineAction action; + + emscripten_fiber_t fiber; +} CoroutineEmscripten; + +/** + * Per-thread coroutine bookkeeping + */ +QEMU_DEFINE_STATIC_CO_TLS(Coroutine *, current); +QEMU_DEFINE_STATIC_CO_TLS(CoroutineEmscripten *, leader); +size_t leader_asyncify_stack_size = COROUTINE_STACK_SIZE; + +static void coroutine_trampoline(void *co_) +{ + Coroutine *co = co_; + + while (true) { + co->entry(co->entry_arg); + qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE); + } +} + +Coroutine *qemu_coroutine_new(void) +{ + CoroutineEmscripten *co; + + co = g_malloc0(sizeof(*co)); + + co->stack_size = COROUTINE_STACK_SIZE; + co->stack = qemu_alloc_stack(&co->stack_size); + + co->asyncify_stack_size = COROUTINE_STACK_SIZE; + co->asyncify_stack = g_malloc0(co->asyncify_stack_size); + emscripten_fiber_init(&co->fiber, coroutine_trampoline, &co->base, + co->stack, co->stack_size, co->asyncify_stack, + co->asyncify_stack_size); + + return &co->base; +} + +void qemu_coroutine_delete(Coroutine *co_) +{ + CoroutineEmscripten *co = DO_UPCAST(CoroutineEmscripten, base, co_); + + qemu_free_stack(co->stack, co->stack_size); + g_free(co->asyncify_stack); + g_free(co); +} + +CoroutineAction qemu_coroutine_switch(Coroutine *from_, Coroutine *to_, + CoroutineAction action) +{ + CoroutineEmscripten *from = DO_UPCAST(CoroutineEmscripten, base, from_); + CoroutineEmscripten *to = DO_UPCAST(CoroutineEmscripten, base, to_); + + set_current(to_); + to->action = action; + emscripten_fiber_swap(&from->fiber, &to->fiber); + return from->action; +} + +Coroutine *qemu_coroutine_self(void) +{ + Coroutine *self = get_current(); + + if (!self) { + CoroutineEmscripten *leaderp = get_leader(); + if (!leaderp) { + leaderp = g_malloc0(sizeof(*leaderp)); + leaderp->asyncify_stack = g_malloc0(leader_asyncify_stack_size); + leaderp->asyncify_stack_size = leader_asyncify_stack_size; + emscripten_fiber_init_from_current_context( + &leaderp->fiber, + leaderp->asyncify_stack, + leaderp->asyncify_stack_size); + leaderp->stack = leaderp->fiber.stack_limit; + leaderp->stack_size = + leaderp->fiber.stack_base - leaderp->fiber.stack_limit; + set_leader(leaderp); + } + self = &leaderp->base; + set_current(self); + } + return self; +} + +bool qemu_in_coroutine(void) +{ + Coroutine *self = get_current(); + + return self && self->caller; +} diff --git a/util/meson.build b/util/meson.build index 780b597..e5cd327 100644 --- a/util/meson.build +++ b/util/meson.build @@ -11,7 +11,9 @@ if host_os != 'windows' endif util_ss.add(files('compatfd.c')) util_ss.add(files('event_notifier-posix.c')) - util_ss.add(files('mmap-alloc.c')) + if host_os != 'emscripten' + util_ss.add(files('mmap-alloc.c')) + endif freebsd_dep = [] if host_os == 'freebsd' freebsd_dep = util diff --git a/util/oslib-posix.c b/util/oslib-posix.c index a697c60..4ff577e 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -58,6 +58,7 @@ #include <lwp.h> #endif +#include "qemu/memalign.h" #include "qemu/mmap-alloc.h" #define MAX_MEM_PREALLOC_THREAD_COUNT 16 @@ -210,11 +211,21 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared, const uint32_t qemu_map_flags = (shared ? QEMU_MAP_SHARED : 0) | (noreserve ? QEMU_MAP_NORESERVE : 0); size_t align = QEMU_VMALLOC_ALIGN; +#ifndef EMSCRIPTEN void *ptr = qemu_ram_mmap(-1, size, align, qemu_map_flags, 0); if (ptr == MAP_FAILED) { return NULL; } +#else + /* + * qemu_ram_mmap is not implemented for Emscripten. Use qemu_memalign + * for the anonymous allocation. noreserve is ignored as there is no swap + * space on Emscripten, and shared is ignored as there is no other + * processes on Emscripten. + */ + void *ptr = qemu_memalign(align, size); +#endif if (alignment) { *alignment = align; @@ -227,7 +238,16 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared, void qemu_anon_ram_free(void *ptr, size_t size) { trace_qemu_anon_ram_free(ptr, size); +#ifndef EMSCRIPTEN qemu_ram_munmap(-1, ptr, size); +#else + /* + * qemu_ram_munmap is not implemented for Emscripten and qemu_memalign + * was used for the allocation. Use the corresponding freeing function + * here. + */ + qemu_vfree(ptr); +#endif } void qemu_socket_set_block(int fd) @@ -588,7 +608,15 @@ bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, { static gsize initialized; int ret; +#ifndef EMSCRIPTEN size_t hpagesize = qemu_fd_getpagesize(fd); +#else + /* + * mmap-alloc.c is excluded from Emscripten build, so qemu_fd_getpagesize + * is unavailable. Fallback to the lower level implementation. + */ + size_t hpagesize = qemu_real_host_page_size(); +#endif size_t numpages = DIV_ROUND_UP(sz, hpagesize); bool use_madv_populate_write; struct sigaction act; |