On Thu, Aug 17, 2017 at 06:53:31PM +0200, Paolo Bonzini wrote: > On 11/08/2017 23:00, Nitesh Narayan Lal wrote: > > One way to go about > > this is to have my own function pointer pointing a to a function > > qemu_page_hinting() in virtio-balloon.c under QEMU. Now the part where I > > am not sure is how exactly I will ensure that when virtqueue_kick > > arrives in QEMU this function is invoked. (I am planning to use the same > > deflate_vq for my use-case). > > You can use a separate virtq as Michael mentioned. > > Another possibility is to extend virtio-balloon to support 64-bit values > in the virtqueues. Then when shifting PFNs right you have bits 52-63 > free, and you can put flags in there (e.g. bit 52=0 means deflate, bit > 52=1 means page hint). > > Of course, if your action is going to be MADV_DONTNEED, you don't need > to do anything special. > > Paolo Forgot to say: when you discuss virtio host/guest interface changes, please copy virtio-dev@xxxxxxxxxxxxxxxxxxxx. (Subscriber only, sorry about that). -- MST
