On Thu, Nov 03, 2022, Paolo Bonzini wrote: > On 11/3/22 00:19, Sean Christopherson wrote: > > +- kvm_lock is taken outside kvm->mmu_lock > > Not surprising since one is a mutex and one is an rwlock. :) Heh, Signed-off-by: Captain Obvious <seanjc@xxxxxxxxxx> > You can drop this hunk as well as the "Opportunistically update KVM's locking > documentation" sentence in the commit message. Will do. > > - vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock > > - kvm->arch.mmu_lock is an rwlock. kvm->arch.tdp_mmu_pages_lock and > > @@ -216,15 +220,11 @@ time it will be set using the Dirty tracking mechanism described above. > > :Type: mutex > > :Arch: any > > :Protects: - vm_list > > - > > -``kvm_count_lock`` > > -^^^^^^^^^^^^^^^^^^ > > - > > -:Type: raw_spinlock_t > > -:Arch: any > > -:Protects: - hardware virtualization enable/disable > > -:Comment: 'raw' because hardware enabling/disabling must be atomic /wrt > > - migration. > > + - kvm_usage_count > > + - hardware virtualization enable/disable > > + - module probing (x86 only) > > What do you mean exactly by "module probing"? Is it anything else than what > is serialized by vendor_module_lock? Ooh, I forgot to update this patch after switching to vendor_module_lock. I added the above after fixing the first deadlock between kvm_lock and cpu_hotplug_lock, but later gave up on trying to use kvm_lock after deadlock #2, which is when I when I realized piggybacking kvm_lock was going to be a maintainance nightmare due.
