[ Upstream commit 767e33ca47dd8ace7769e0b0c19d7b0c38b2f72d ] _IOC() an internal helper that we should not use in driver code. In particular, we got the data direction wrong here, which breaks a number of tools, as having "_IOC_NONE" should never be paired with a nonzero size. Use _IOW() instead. Fixes: f8941e6c4c71 ("xen: privcmd: Add support for irqfd") Reported-by: Arnd Bergmann <arnd@kernel.org> Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmail.com/ Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/599ca6f1b9dd2f0e6247ea37bee3ea6827404b6d.1697439990.git.viresh.kumar@linaro.org Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>