Make use of cookies for the virtio ccw notification hypercall to speed up lookup of devices on the io bus.
Signed-off-by: Cornelia Huck <[email protected]> --- arch/s390/kvm/diag.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index 3074475..2a467bf 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -108,22 +108,33 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu) static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu) { int ret, idx; + long cookie; /* No virtio-ccw notification? Get out quickly. */ if (!vcpu->kvm->arch.css_support || (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY)) return -EOPNOTSUPP; + cookie = vcpu->run->s.regs.gprs[4]; idx = srcu_read_lock(&vcpu->kvm->srcu); /* * The layout is as follows: * - gpr 2 contains the subchannel id (passed as addr) * - gpr 3 contains the virtqueue index (passed as datamatch) + * - gpr 4 contains the index on the bus (optionally) */ - ret = kvm_io_bus_write(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS, - vcpu->run->s.regs.gprs[2], - 8, &vcpu->run->s.regs.gprs[3]); + ret = kvm_io_bus_write_cookie(vcpu->kvm, KVM_VIRTIO_CCW_NOTIFY_BUS, + vcpu->run->s.regs.gprs[2], + 8, &vcpu->run->s.regs.gprs[3], + &cookie); srcu_read_unlock(&vcpu->kvm->srcu, idx); + + /* + * Return cookie in gpr 2, but don't overwrite the register if the + * diagnose will be handled by userspace. + */ + if (ret != -EOPNOTSUPP) + vcpu->run->s.regs.gprs[2] = cookie; /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ return ret < 0 ? ret : 0; } -- 1.8.2.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
