On Thu, Mar 28, 2024 at 01:24:27PM +0800, Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> wrote: > > > On 2/26/2024 4:26 PM, isaku.yamahata@xxxxxxxxx wrote: > > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> > > > > As TDP MMU is becoming main stream than the legacy MMU, the legacy MMU > > support for TDX isn't implemented. TDX requires KVM mmio caching. > > Can you add some description about why TDX requires mmio caching in the > changelog? Sure, will update the commit log. As the TDX guest is protected, the guest has to issue TDG.VP.VMCALL<MMIO> on VE. The VMM has to setup Shared-EPT entry to inject VE by setting the entry value with VE suppress bit cleared. KVM mmio caching is a feature to set the EPT entry to special value for MMIO GFN instead of the default value with suppress VE bit set. So TDX KVM wants to utilize it. Thanks, -- Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
