On 22.06.2020 08:24, Max Filippov wrote:
On Fri, Jun 19, 2020 at 10:05 AM Peter Maydell <peter.mayd...@linaro.org> wrote:
I've just sent a patch that removes the target/arm gen_io_end() calls.
I had a quick look at sparc, xtensa and ppc, but they were too complicated
for a quick look to be sufficient :-)
I've checked the xtensa translator. The only gen_io_end() is for
opcodes that end TB when a full instruction is translated, because
they can change active interrupt requests. So it can be removed.
I'll send a patch.
One instance of gen_io_start is for the rsr.ccount opcode that reads
current cycle counter that translates to reading
QEMU_CLOCK_VIRTUAL clock.
Right, this is documented by Alex in the new document recently sent into
the mailing list:
https://lore.kernel.org/qemu-devel/7611429f-ec38-554d-3aec-e4a2f456a...@linaro.org/T/#mff14f2e3dc2cedd7cc6b1356985a0454e4772202
Looks like this adds one more case to the
following list:
As I understand it, the definition of "I/O insn" is anything that can
either:
- affect the icount deadline (e.g. by setting or removing a
QEMU_CLOCK_VIRTUAL timer)
- interrupt the current translation block with cpu_loop_exit,
cpu_restore_state or similar.
