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| author | Cornelia Huck <cornelia.huck@de.ibm.com> | 2013-07-03 18:30:54 +0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-07-18 14:29:24 +0400 |
| commit | 85dfe87e24326c472454cc92313ba8c3b4efe53b (patch) | |
| tree | 089985a2689fc17bd66a26518c77829bb9f78260 /arch/s390/kvm/diag.c | |
| parent | 126a5af520eff9b99a0bb1ca4bb4a0b7973f7d5a (diff) | |
| download | linux-85dfe87e24326c472454cc92313ba8c3b4efe53b.tar.xz | |
KVM: s390: use cookies for ioeventfd
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 <cornelia.huck@de.ibm.com>
[Small fix to a comment. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/s390/kvm/diag.c')
| -rw-r--r-- | arch/s390/kvm/diag.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index 3074475c8ae0..3a74d8af0d69 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -119,12 +119,21 @@ static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu) * 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], + vcpu->run->s.regs.gprs[4]); srcu_read_unlock(&vcpu->kvm->srcu, idx); - /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ + + /* + * 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] = ret; + /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */ return ret < 0 ? ret : 0; } |