> -----Original Message----- > From: Jan Beulich [mailto:jbeul...@suse.com] > Sent: Friday, October 28, 2016 9:19 PM > To: Wu, Feng <feng...@intel.com> > Cc: andrew.coop...@citrix.com; dario.faggi...@citrix.com; > george.dun...@eu.citrix.com; Tian, Kevin <kevin.t...@intel.com>; xen- > de...@lists.xen.org > Subject: Re: [PATCH v6 2/7] VMX: Properly handle pi when all the assigned > devices are removed > > >>> On 28.10.16 at 04:37, <feng...@intel.com> wrote: > > @@ -215,11 +220,21 @@ void vmx_pi_hooks_assign(struct domain *d) > > /* This function is called when pcidevs_lock is held */ > > void vmx_pi_hooks_deassign(struct domain *d) > > { > > + struct vcpu *v; > > + > > if ( !iommu_intpost || !has_hvm_container_domain(d) ) > > return; > > > > ASSERT(d->arch.hvm_domain.vmx.vcpu_block); > > > > + /* > > + * Pausing the domain can make sure the vCPU is not > > + * running and hence not calling the hooks simultaneously > > + * when deassigning the PI hooks and removing the vCPU > > + * from the blocking list. > > + */ > > + domain_pause(d); > > There's one additional caveat here which no-one of us so far thought > of: Currently there's nothing preventing the domctl-s under which > this sits from being issued by the control domain for itself. Various > other domctl-s, however, guard against this case when intending > to pause the target domain. The same needs to be done for the > ones leading here.
Thanks for the comments! Could you share in which case can a domain attach/detach a device for itself? Thanks! Thanks, Feng > > Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
