When the frontend device has no space for a read the fd is removed
from polling to allow time for the guest to read and clear the buffer.
Without the call to qemu_chr_fe_accept_input(), the poll will not be
broken out of when the guest has cleared the buffer causing significant
IO delays that get worse with smaller buffers.
Buglink: https://bugs.launchpad.net/qemu/+bug/1913341
Signed-off-by: Iris Johnson <iris@modwiz.com>
Message-id: 20210130184016.1787097-1-iris@modwiz.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
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