lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 15 May 2020 18:38:03 +0200
From:   Stefano Garzarella <>
To:     Jens Axboe <>
        Alexander Viro <>,,
Subject: [PATCH v2 0/2] io_uring: add a CQ ring flag to enable/disable eventfd

v1 -> v2:
 - changed the flag name and behaviour from IORING_CQ_NEED_EVENT to

The first patch adds the new 'cq_flags' field for the CQ ring. It
should be written by the application and read by the kernel.

The second patch adds a new IORING_CQ_EVENTFD_DISABLED flag that can be
used by the application to disable/enable eventfd notifications.

This feature can be useful if the application are using eventfd to be
notified when requests are completed, but they don't want a notification
for every request.
Of course the application can already remove the eventfd from the event
loop, but as soon as it adds the eventfd again, it will be notified,
even if it has already handled all the completed requests.

The most important use case is when the registered eventfd is used to
notify a KVM guest through irqfd and we want a mechanism to
enable/disable interrupts.

I also extended liburing API and added a test case here:

Stefano Garzarella (2):
  io_uring: add 'cq_flags' field for the CQ ring
  io_uring: add IORING_CQ_EVENTFD_DISABLED to the CQ ring flags

 fs/io_uring.c                 | 12 +++++++++++-
 include/uapi/linux/io_uring.h | 11 ++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)


Powered by blists - more mailing lists