On Wed, Jan 04, 2023 at 01:20:13PM -0800, Ackerley Tng <ackerleytng@xxxxxxxxxx> wrote: > > I believe we should also have a handler for .msr_filter_changed. > > Without an .msr_filter_changed handler, a host crash can occur if we > first set up a vcpu for the TD, and then set an MSR filter. > > If we first set up a vcpu for the TD, and then set an MSR filter, upon > vcpu_enter_guest, the .msr_filter_changed handler (currently > vmx_msr_filter_changed()) will be invoked. to_vmx(vcpu) interprets the > containing struct of struct kvm_vcpu to be a struct vcpu_vmx instead of > a struct vcpu_tdx. > > In my case, I was working on a selftest and the missing handler caused a > NULL dereference in vmx_disable_intercept_for_msr() because > vmx->vmcs01.msr_bitmap is NULL. Nice catch. I'll fix it. -- Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
