This is a note to let you know that I've just added the patch titled kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-don-t-try-to-register-to-kvm_fast_mmio_bus-for-non-mmio-eventfd.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8453fecbecae26edb3f278627376caab05d9a88d Mon Sep 17 00:00:00 2001 From: Jason Wang <jasowang@xxxxxxxxxx> Date: Tue, 15 Sep 2015 14:41:54 +0800 Subject: kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd From: Jason Wang <jasowang@xxxxxxxxxx> commit 8453fecbecae26edb3f278627376caab05d9a88d upstream. We only want zero length mmio eventfd to be registered on KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to make sure this. Cc: Gleb Natapov <gleb@xxxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- virt/kvm/eventfd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -846,7 +846,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, st /* When length is ignored, MMIO is also put on a separate bus, for * faster lookups. */ - if (!args->len && !(args->flags & KVM_IOEVENTFD_FLAG_PIO)) { + if (!args->len && bus_idx == KVM_MMIO_BUS) { ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS, p->addr, 0, &p->dev); if (ret < 0) @@ -901,7 +901,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, continue; kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev); - if (!p->length) { + if (!p->length && p->bus_idx == KVM_MMIO_BUS) { kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS, &p->dev); } Patches currently in stable-queue which might be from jasowang@xxxxxxxxxx are queue-4.1/kvm-fix-double-free-for-fast-mmio-eventfd.patch queue-4.1/kvm-fix-zero-length-mmio-searching.patch queue-4.1/kvm-factor-out-core-eventfd-assign-deassign-logic.patch queue-4.1/kvm-don-t-try-to-register-to-kvm_fast_mmio_bus-for-non-mmio-eventfd.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html