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 and introduce a new capability for userspace. 2 is fixed by ignore the actual length if the length of iodev is zero in kvm_io_bus_cmp(). Please review. Changes from V5: - move patch of explicitly checking for KVM_MMIO_BUS to patch 1 and remove the unnecessary checks - even more grammar and typo fixes - rabase to kvm.git - document KVM_CAP_FAST_MMIO Changes from V4: - move the location of kvm_assign_ioeventfd() in patch 1 which reduce the change set. - commit log typo fixes - switch to use kvm_deassign_ioeventfd_id) when fail to register to fast mmio bus - change kvm_io_bus_cmp() as Paolo's suggestions - introduce a new capability to avoid new userspace crash old kernel - add a new patch that only try to register mmio eventfd on fast mmio bus 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 (6): kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd 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 kvm: add fast mmio capabilitiy Documentation/virtual/kvm/api.txt | 7 ++- arch/x86/kvm/trace.h | 18 ++++++ arch/x86/kvm/vmx.c | 1 + arch/x86/kvm/x86.c | 1 + include/uapi/linux/kvm.h | 1 + virt/kvm/eventfd.c | 124 ++++++++++++++++++++++---------------- virt/kvm/kvm_main.c | 20 +++++- 7 files changed, 118 insertions(+), 54 deletions(-) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
