It was found that running libquantum on riscv-linux qemu produced an
incorrect result. After investigation, FP registers are not saved
during context switch due to incorrect mstatus.FS.
In current implementation tb->flags merges all non-disabled state to
dirty. This means the code in mark_fs_dirty in translate.c that
handles initial and clean states is unreachable.
This patch fixes it and is successfully tested with:
libquantum
Thanks to Richard for pointing out the actual bug.
v3: remove the redundant condition
v2: root cause FS problem
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: ShihPo Hung <shihpo.hung@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
613fa160e1