[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] xen/x86: vpmu: Unmap per-vCPU PMU page when the domain is destroyed
On 26.11.2019 18:17, Paul Durrant wrote: > From: Julien Grall <jgrall@xxxxxxxxxx> > > A guest will setup a shared page with the hypervisor for each vCPU via > XENPMU_init. The page will then get mapped in the hypervisor and only > released when XEMPMU_finish is called. > > This means that if the guest is not shutdown gracefully (such as via xl > destroy), the page will stay mapped in the hypervisor. Isn't this still too weak a description? It's not the tool stack invoking XENPMU_finish, but the guest itself afaics. I.e. a misbehaving guest could prevent proper cleanup even with graceful shutdown. > @@ -2224,6 +2221,9 @@ int domain_relinquish_resources(struct domain *d) > if ( is_hvm_domain(d) ) > hvm_domain_relinquish_resources(d); > > + for_each_vcpu ( d, v ) > + vpmu_destroy(v); > + > return 0; > } I think simple things which may allow shrinking the page lists should be done early in the function. As vpmu_destroy() looks to be idempotent, how about leveraging the very first for_each_vcpu() loop in the function (there are too many of them there anyway, at least for my taste)? Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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