Messages in this thread | | | Date | Tue, 22 Dec 2009 11:39:55 -0800 (PST) | From | Davide Libenzi <> | Subject | Re: [GIT PULL] AlacrityVM guest drivers for 2.6.33 |
| |
On Tue, 22 Dec 2009, Gregory Haskins wrote:
> On 12/22/09 1:53 PM, Avi Kivity wrote: > > I asked why the irqfd/ioeventfd mechanisms are insufficient, and you did not reply. > > > > BTW: the ioeventfd issue just fell through the cracks, so sorry about > that. Note that I have no specific issue with irqfd ever since the > lockless IRQ injection code was added. > > ioeventfd turned out to be suboptimal for me in the fast path for two > reasons: > > 1) the underlying eventfd is called in atomic context. I had posted > patches to Davide to address that limitation, but I believe he rejected > them on the grounds that they are only relevant to KVM.
I thought we addressed this already, in the few hundreds of email we exchanged back then :)
> 2) it cannot retain the data field passed in the PIO. I wanted to have > one vector that could tell me what value was written, and this cannot be > expressed in ioeventfd.
Like might have hinted in his reply, couldn't you add data support to the ioeventfd bits in KVM, instead of leaking them into mainline eventfd?
- Davide
| |