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). -- 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
