linux-kernel - [PATCH V4 0/4] Fast MMIO eventfd fixes

lists.openwall.net		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 linux-cve-announce 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, 11 Sep 2015 11:17:33 +0800
From:	Jason Wang <jasowang@...hat.com>
To:	gleb@...nel.org, pbonzini@...hat.com, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc:	mst@...hat.com, cornelia.huck@...ibm.com,
	Jason Wang <jasowang@...hat.com>
Subject: [PATCH V4 0/4] Fast MMIO eventfd fixes

Hi:

This series fixes two issues of fast mmio eventfd:

1) A single iodev instance were registerd on two buses: KVM_MMIO_BUS
   and KVM_FAST_MMIO_BUS. This will cause double in
   ioeventfd_destructor()
2) A zero length iodev on KVM_MMIO_BUS will never be found but
   kvm_io_bus_cmp(). This will lead e.g the eventfd will be trapped by
   qemu instead of host.

1 is fixed by allocating two instances of iodev. 2 is fixed by ignore
the actual length if the length of iodev is zero in kvm_io_bus_cmp().

Please review.

Changes from V3:

- Don't do search on two buses when trying to do write on
  KVM_MMIO_BUS. This fixes a small regression found by vmexit.flat.
- Since we don't do search on two buses, change kvm_io_bus_cmp() to
  let it can find zero length iodevs.
- Fix the unnecessary lines in tracepoint patch.

Changes from V2:
- Tweak styles and comment suggested by Cornelia.

Changes from v1:
- change ioeventfd_bus_from_flags() to return KVM_FAST_MMIO_BUS when
  needed to save lots of unnecessary changes.

Jason Wang (4):
  kvm: factor out core eventfd assign/deassign logic
  kvm: fix double free for fast mmio eventfd
  kvm: fix zero length mmio searching
  kvm: add tracepoint for fast mmio

 arch/x86/kvm/trace.h |  18 ++++++++
 arch/x86/kvm/vmx.c   |   1 +
 arch/x86/kvm/x86.c   |   1 +
 virt/kvm/eventfd.c   | 124 ++++++++++++++++++++++++++++++---------------------
 virt/kvm/kvm_main.c  |   4 +-
 5 files changed, 96 insertions(+), 52 deletions(-)

-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/