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| author | Richard Henderson <richard.henderson@linaro.org> | 2021-06-11 23:08:28 -0700 |
|---|---|---|
| committer | Laurent Vivier <laurent@vivier.eu> | 2021-06-15 08:28:56 +0200 |
| commit | 228168cbb7cc40bfb1621b0b6868c018b522276a (patch) | |
| tree | b82f0e2af4188a3b465311b34e5b50d5ed28986b /linux-user/mmap.c | |
| parent | 1ea06abceec61b6f3ab33dadb0510b6e09fb61e2 (diff) | |
| download | focaccia-qemu-228168cbb7cc40bfb1621b0b6868c018b522276a.tar.gz focaccia-qemu-228168cbb7cc40bfb1621b0b6868c018b522276a.zip | |
linux-user: Set CF_PARALLEL when mapping shared memory
Signal the translator to use host atomic instructions for guest operations, insofar as it is possible. This is the best we can do to allow the guest to interact atomically with other processes. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/121 Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20210612060828.695332-1-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user/mmap.c')
| -rw-r--r-- | linux-user/mmap.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 7e3b245036..0e103859fe 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -451,6 +451,20 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, goto fail; } + /* + * If we're mapping shared memory, ensure we generate code for parallel + * execution and flush old translations. This will work up to the level + * supported by the host -- anything that requires EXCP_ATOMIC will not + * be atomic with respect to an external process. + */ + if (flags & MAP_SHARED) { + CPUState *cpu = thread_cpu; + if (!(cpu->tcg_cflags & CF_PARALLEL)) { + cpu->tcg_cflags |= CF_PARALLEL; + tb_flush(cpu); + } + } + real_start = start & qemu_host_page_mask; host_offset = offset & qemu_host_page_mask; |