On Fri, 2023-07-21 at 13:18 -0700, Sean Christopherson wrote: > Attempt to disable virtualization during an emergency reboot if and only > if there is a registered virt callback, i.e. iff a hypervisor (KVM) is > active. If there's no active hypervisor, then the CPU can't be operating > with VMX or SVM enabled (barring an egregious bug). > > Checking for a valid callback instead of simply for SVM or VMX support > can also eliminates spurious NMIs by avoiding the unecessary call to > nmi_shootdown_cpus_on_restart(). > > Note, IRQs are disabled, which prevents KVM from coming along and > enabling virtualization after the fact. > > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> > Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>
