Re: [RFC PATCH v5 026/104] KVM: TDX: x86: Add vm ioctl to get TDX systemwide parameters

From: Paolo Bonzini
Date: Tue Apr 05 2022 - 20:01:43 EST


On 3/4/22 20:48, isaku.yamahata@xxxxxxxxx wrote:
Implement a VM-scoped subcomment to get system-wide parameters. Although
this is system-wide parameters not per-VM, this subcomand is VM-scoped
because
- Device model needs TDX system-wide parameters after creating KVM VM.
- This subcommands requires to initialize TDX module. For lazy
initialization of the TDX module, vm-scope ioctl is better.

Since there was agreement to install the TDX module on load, please place this ioctl on the /dev/kvm file descriptor.

At least for SEV, there were cases where the system-wide parameters are needed outside KVM, so it's better to avoid requiring a VM file descriptor.

Thanks,

Paolo