On 11/4/20 1:35 AM, Philippe Mathieu-Daudé wrote: > If TARGET_PAGE_BITS_VARY is not supported, machines should not > intent to modify the target page size. > As set_preferred_target_page_bits() is supposed to return 'false' > on failure (documented in "qemu-common.h"), return false to > indicate failure if this ever happens. > > Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org> > --- > include/qemu-common.h | 4 +++- > exec-vary.c | 4 +++- > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/qemu-common.h b/include/qemu-common.h > index fda7dc6ca77..3ea616d4567 100644 > --- a/include/qemu-common.h > +++ b/include/qemu-common.h > @@ -70,7 +70,9 @@ void cpu_exec_step_atomic(CPUState *cpu); > * size may be smaller than any given CPU's preference). > * Returns true on success, false on failure (which can only happen > * if this is called after the system has already finalized its > - * choice of page size and the requested page size is smaller than that). > + * choice of page size and the requested page size is smaller than > + * that). Only target supporting variable page size should set a > + * preferred target page size. > */ > bool set_preferred_target_page_bits(int bits); > > diff --git a/exec-vary.c b/exec-vary.c > index ff905f2a8fb..4b0b7f193af 100644 > --- a/exec-vary.c > +++ b/exec-vary.c > @@ -86,8 +86,10 @@ bool set_preferred_target_page_bits(int bits) > } > init_target_page.bits = bits; > } > -#endif > return true; > +#else > + return false; > +#endif
I guess the only generic caller is the one in softmmu/vl.c, which is protected by machine_class->minimum_page_bits != 0. So this affects exactly one machine outside arm -- fuloong2e. Certainly we should not allow an impossible setting. I wonder if it is worth doing return bits == TARGET_PAGE_BITS? Either way, Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
