On 12/28/22 10:54, David Woodhouse wrote:
Yes, I imagine that in practice you won't have running vCPUs during a
reset but the bug exists. Thanks!
If it's just kvm_xen_evtchn_reset() I can fix that — and have to
anyway, even if we switch the Xen code to its own lock.
But what is the general case lock ordering rule here? Can other code
call synchronize_srcu() while holding kvm->lock? Or is that verboten?
Nope, it's a general rule---and one that would extend to any other lock
taken inside srcu_read_lock(&kvm->srcu).
I have sent a patch to fix reset, and one to clarify the lock ordering
rules.
Paolo
