Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.13 071/140] KVM: s390: ioeventfd: ignore leftmost bits | Date | Tue, 4 Feb 2014 13:10:58 -0800 |
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3.13-stable review patch. If anyone has any objections, please let me know.
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From: Dominik Dingel <dingel@linux.vnet.ibm.com>
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@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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]);
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