diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2024-02-19 17:31:51 +0000 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2024-02-29 11:35:36 -1000 |
| commit | 62bcba836cb199bb0d9b5aa160919c863393859f (patch) | |
| tree | 6aa2388c2d9e3f85f9d5ca13d0a6174b1d0ecbde /accel | |
| parent | 7f89fdf8ebe6ef8df48f0a05f44e1020c713a94e (diff) | |
accel/tcg: Set can_do_io at at start of lookup_tb_ptr helper
If a page table is in IO memory and lookup_tb_ptr probes
the TLB it can result in a page table walk for the instruction
fetch. If this hits IO memory and io_prepare falsely assumes
it needs to do a TLB recompile.
Avoid that by setting can_do_io at the start of lookup_tb_ptr.
Link: https://lore.kernel.org/qemu-devel/CAFEAcA_a_AyQ=Epz3_+CheAT8Crsk9mOu894wbNW_FywamkZiw@mail.gmail.com/#t
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240219173153.12114-2-Jonathan.Cameron@huawei.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'accel')
| -rw-r--r-- | accel/tcg/cpu-exec.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 977576ca14..52239a441f 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -396,6 +396,14 @@ const void *HELPER(lookup_tb_ptr)(CPUArchState *env) uint64_t cs_base; uint32_t flags, cflags; + /* + * By definition we've just finished a TB, so I/O is OK. + * Avoid the possibility of calling cpu_io_recompile() if + * a page table walk triggered by tb_lookup() calling + * probe_access_internal() happens to touch an MMIO device. + * The next TB, if we chain to it, will clear the flag again. + */ + cpu->neg.can_do_io = true; cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); cflags = curr_cflags(cpu); |