Messages in this thread | | | Date | Wed, 2 Mar 2022 17:35:35 +0000 | From | Sean Christopherson <> | Subject | Re: [PATCH v3 22/28] KVM: x86/mmu: Zap defunct roots via asynchronous worker |
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On Wed, Mar 02, 2022, Paolo Bonzini wrote: > However, I think we now need a module_get/module_put when creating/destroying > a VM; the workers can outlive kvm_vm_release and therefore any reference > automatically taken by VFS's fops_get/fops_put.
Haven't read the rest of the patch, but this caught my eye. We _already_ need to handle this scenario. As you noted, any worker, i.e. anything that takes a reference via kvm_get_kvm() without any additional guarantee that the module can't be unloaded is suspect. x86 is mostly fine, though kvm_setup_async_pf() is likely affected, and other architectures seem to have bugs.
Google has an internal patch that addresses this. I believe David is going to post the fix... David?
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