On 09/12/2012 06:44 PM, Marcelo Tosatti wrote: > On Wed, Sep 12, 2012 at 06:34:33PM +0300, Avi Kivity wrote: >> On 09/11/2012 05:39 PM, Marcelo Tosatti wrote: >> > On Tue, Sep 11, 2012 at 12:18:22PM +0300, Avi Kivity wrote: >> >> > The same can happen with slot deletion, for example. >> >> > >> >> > Userspace (which performed the modification which can result in faults >> >> > to non-existant/read-only/.../new-tag memslot), must handle the faults >> >> > properly or avoid the possibility for reference to memslot information >> >> > from the past. >> >> > >> >> > I think its worthwhile to add a note about this in the API >> >> > documentation: "The user of this interface is responsible for handling >> >> > references to stale memslot information, either by handling >> >> > exit notifications which reference stale memslot information or not >> >> > allowing these notifications to exist by stopping all vcpus in userspace >> >> > before performing modifications to the memslots map". >> >> >> >> Or we can drop the new interface and rely on userspace to perform the >> >> lookup under its own locking rules. >> >> >> >> It's slow, but writes to ROM or ROM/device are rare anyway. >> > >> > Lookup what information? >> >> Where to dispatch the write. >> >> In fact userspace has to do that anyway if it's a ROM/device. There's >> no way userspace can guess that unless we pass in the slot number (which >> isn't synchronized with anything). > > Alright, do you prefer the details of this exit to be worked out later, > when necessary, then? > > That is, not merge this particular patch of the series? > Right. I think it is unneeded. -- error compiling committee.c: too many arguments to function -- 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
