Andrew Morton wrote:
On Mon, 27 Apr 2009 14:33:24 -0400 Gregory Haskins <ghaskins@xxxxxxxxxx> wrote:
(Applies to kvm.git 41b76d8d0487c26d6d4d3fe53c1ff59b3236f096)
This series implements a mechanism called "irqfd". It lets you create
an eventfd based file-desriptor to inject interrupts to a kvm guest. We
associate one gsi per fd for fine-grained routing.
It'd be nice if the KVM weenies amongst us were to be told why one
would want to inject interrupts into a KVM guest. Monosyllabic words
would be preferred ;)
Interrupts are injected (better word, raised) into a guest because real
hardware has interrupts. This patchset does not add the ability to raise
interrupts (that existed from day 1); it adds an eventfd interface to do so.
An eventfd interface is useful, because it allows components to talk to
kvm guests without being tied to kvm internals; they signal an eventfd;
if the eventfd is terminated in kvm, it injects an interrupt. If the
eventfd is terminated in userspace, it returns from epoll().
We do not have a user of this interface in this series, though note
future version of virtual-bus (v4 and above) will be based on this.
So I assume that this patchset will be merged if/when a user of it is
merged?
This interface is applicable to both the kernel and userspace; userspace
users won't be merged.
But I certainly want to see how the whole thing works.
The first patch will require mainline buy-in, particularly from Davide
(cc'd). The last patch is kvm specific.
Three EXPORT_SYMBOL_GPL()s. Once the shouting has subsided I'd suggest
that this be merged via the KVM tree.
I think eventfd makes tons of sense as a generic 'wake me up' mechanism
that can be used from both sides of the kernel/user line.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
