This is a note to let you know that I've just added the patch titled KVM: s390: ioeventfd: ignore leftmost bits to the 3.13-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-s390-ioeventfd-ignore-leftmost-bits.patch and it can be found in the queue-3.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ff1f3cb4b3ac5d039f02679f34cb1498d110d241 Mon Sep 17 00:00:00 2001 From: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx> Date: Mon, 9 Dec 2013 18:30:01 +0100 Subject: KVM: s390: ioeventfd: ignore leftmost bits From: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx> commit ff1f3cb4b3ac5d039f02679f34cb1498d110d241 upstream. The diagnose 500 subcode 3 contains the 32 bit subchannel id in bits 32-63 (counting from the left). As for other I/O instructions, bits 0-31 should be ignored and thus not be passed to kvm_io_bus_write_cookie(). This fixes a bug where the guest passed non-zero bits 0-31 which the host tried to interpret, leading to ioeventfd notification failures. Signed-off-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx> Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx> Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/s390/kvm/diag.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -121,7 +121,7 @@ static int __diag_virtio_hypercall(struc * - gpr 4 contains the index on the bus (optionally) */ ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS, - vcpu->run->s.regs.gprs[2], + vcpu->run->s.regs.gprs[2] & 0xffffffff, 8, &vcpu->run->s.regs.gprs[3], vcpu->run->s.regs.gprs[4]); Patches currently in stable-queue which might be from dingel@xxxxxxxxxxxxxxxxxx are queue-3.13/kvm-s390-ioeventfd-ignore-leftmost-bits.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