
Mirror the behavour of /proc/sys/abi/sve_default_vector_length under the real linux kernel. We have no way of passing along a real default across exec like the kernel can, but this is a decent way of adjusting the startup vector length of a process. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/482 Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20210723203344.968563-4-richard.henderson@linaro.org [PMM: tweaked docs formatting, document -1 special-case, added fixup patch from RTH mentioning QEMU's maximum veclen.] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>