>>> Juergen Gross <jgross@xxxxxxxx> 11/01/18 1:34 PM >>> >Currently the size of hypercall buffers allocated via >/dev/xen/hypercall is limited to a default of 64 memory pages. For live >migration of guests this might be too small as the page dirty bitmask >needs to be sized according to the size of the guest. This means >migrating a 8GB sized guest is already exhausting the default buffer >size for the dirty bitmap. > >There is no sensible way to set a sane limit, so just remove it >completely. The device node's usage is limited to root anyway, so there >is no additional DOS scenario added by allowing unlimited buffers. But is this setting of permissions what we want long term? What about a de-privileged qemu, which still needs to be able to issue at least dm-op hypercalls? Jan
