Re: [libvirt] [PATCH 10/23] lib: Add API for setting the threshold size for VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD

On 03/15/2017 11:37 AM, Peter Krempa wrote: > The new API can be used to configure the threshold when > VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD should be fired. > ---

> + * This event allows to use thin-provisioned storage which needs management > + * tools to grow it without the need for polling of the data. > + * > + * Returns 0 if the operation has started, -1 on failure. > + */ > +int > +virDomainSetBlockThreshold(virDomainPtr domain, > + const char *dev, > + unsigned long long threshold, > + unsigned int flags) Hmm. Because the threshold resets once the event fires, we don't have a handy way to say 'set a threshold 100M or 10% further out than the last limit). That would be a reason for using flags, although I don't think we need to worry about it for now. Does setting the threshold lower than the current high-water mark (as reported by polling block status information) immediately fire an event, or will an event never fire in that situation?

> @@ -6048,6 +6056,13 @@ enum remote_procedure { > * @generate: both > * @acl: none > */ > - REMOTE_PROC_DOMAIN_EVENT_BLOCK_THRESHOLD = 385 > + REMOTE_PROC_DOMAIN_EVENT_BLOCK_THRESHOLD = 385, > + > + /** > + * @generate: both > + * @acl: domain:write This doesn't modify the domain. Why does it need domain:write; wouldn't domain:read be sufficient (namely, the same privileges you already require for polling block status information to learn the current high water mark)?