On Mon, 2024-03-25 at 16:10 -0700, Isaku Yamahata wrote: > > > My understanding is that Sean prefers to exit to userspace when KVM can't handle something, > > > versus > > > making up behavior that keeps known guests alive. So I would think we should change this patch > > > to > > > only be about not using the zapping roots optimization. Then a separate patch should exit to > > > userspace on attempt to use MTRRs. And we ignore the APIC one. > > > > > > This is trying to guess what maintainers would want here. I'm less sure what Paolo prefers. > > > > When we hit KVM_MSR_FILTER, the current implementation ignores it and makes it > > error to guest. Surely we should make it KVM_EXIT_X86_{RDMSR, WRMSR}, instead. > > It's aligns with the existing implementation(default VM and SW-protected) and > > more flexible. > > Something like this for "112/130 KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall" > Compile only tested at this point. Seems reasonable to me. Does QEMU configure a special set of MSRs to filter for TDX currently?