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>
This commit is contained in:
Richard Henderson 2020-11-04 15:31:43 -08:00
parent 793f738196
commit d1861aa409
1 changed files with 38 additions and 8 deletions

View File

@ -1137,24 +1137,40 @@ static bool alloc_code_gen_buffer_anon(size_t size, int prot,
static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp)
{
void *buf_rw, *buf_rx;
void *buf_rw = NULL, *buf_rx = MAP_FAILED;
int fd = -1;
#ifdef __mips__
/* Find space for the RX mapping, vs the 256MiB regions. */
if (!alloc_code_gen_buffer_anon(size, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS |
MAP_NORESERVE, errp)) {
return false;
}
/* The size of the mapping may have been adjusted. */
size = tcg_ctx->code_gen_buffer_size;
buf_rx = tcg_ctx->code_gen_buffer;
#endif
buf_rw = qemu_memfd_alloc("tcg-jit", size, 0, &fd, errp);
if (buf_rw == NULL) {
return false;
goto fail;
}
#ifdef __mips__
void *tmp = mmap(buf_rx, size, PROT_READ | PROT_EXEC,
MAP_SHARED | MAP_FIXED, fd, 0);
if (tmp != buf_rx) {
goto fail_rx;
}
#else
buf_rx = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0);
if (buf_rx == MAP_FAILED) {
error_setg_errno(errp, errno,
"failed to map shared memory for execute");
munmap(buf_rw, size);
close(fd);
return false;
goto fail_rx;
}
close(fd);
#endif
close(fd);
tcg_ctx->code_gen_buffer = buf_rw;
tcg_ctx->code_gen_buffer_size = size;
tcg_splitwx_diff = buf_rx - buf_rw;
@ -1163,6 +1179,20 @@ static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp)
qemu_madvise(buf_rw, size, QEMU_MADV_HUGEPAGE);
qemu_madvise(buf_rx, size, QEMU_MADV_HUGEPAGE);
return true;
fail_rx:
error_setg_errno(errp, errno, "failed to map shared memory for execute");
fail:
if (buf_rx != MAP_FAILED) {
munmap(buf_rx, size);
}
if (buf_rw) {
munmap(buf_rw, size);
}
if (fd >= 0) {
close(fd);
}
return false;
}
#endif /* CONFIG_POSIX */