KVM: nVMX: do not use dangling shadow VMCS after guest reset
If a KVM guest is reset while running a nested guest, free_nested will
disable the shadow VMCS execution control in the vmcs01. However,
on the next KVM_RUN vmx_vcpu_run would nevertheless try to sync
the VMCS12 to the shadow VMCS which has since been freed.
This causes a vmptrld of a NULL pointer on my machime, but Jan reports
the host to hang altogether. Let's see how much this trivial patch fixes.
Reported-by: Jan Kiszka <jan.kiszka at siemens.com>
Cc: Liran Alon <liran.alon at oracle.com>
Cc: stable at vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
UnifiedSplitRaw
