Messages in this thread | | | Date | Sun, 24 Jun 2012 11:34:34 +0300 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH 2/4] kvm: Add missing KVM_IRQFD API documentation |
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On Fri, Jun 22, 2012 at 04:15:50PM -0600, Alex Williamson wrote: > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > > Documentation/virtual/kvm/api.txt | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 310fe50..9b4cb2b 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -1965,6 +1965,23 @@ return the hash table order in the parameter. (If the guest is using > the virtualized real-mode area (VRMA) facility, the kernel will > re-create the VMRA HPTEs on the next KVM_RUN of any vcpu.) > > +4.76 KVM_IRQFD > + > +Capability: KVM_CAP_IRQFD > +Architectures: x86 > +Type: vm ioctl > +Parameters: struct kvm_irqfd (in) > +Returns: 0 on success, -1 on error > + > +Allows setting an eventfd to directly trigger a guest interrupt > +kvm_irqfd.fd specifies the file descriptor to use as the eventfd and > +kvm_irqfd.gsi specifies the irqchip pin toggled by this event. By > +default this interface only supports edge triggered interrupts, > +meaning the specified gsi is asserted and immediately de-asserted > +when the eventfd is triggered.
That's a bit confusing. This assert/deassert only has effect for level. Do we or do we not want to maintain this assert/deassert behaviour for level irqfds? If yes we shouldn't say it's unsupported if no we should not document it.
Gleb, Avi, any thoughts?
> Specifying KVM_IRQFD_FLAG_DEASSIGN > +removes the previously set irqfd matching both kvm_irqfd.fd and > +kvm_irqfd.gsi. > + > > 5. The kvm_run structure > ------------------------
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