On Mon, Mar 04, 2024 at 04:59:32PM +0800, Tao Su wrote: > On Mon, Mar 04, 2024 at 09:43:53AM +0100, Gerd Hoffmann wrote: > > > > + kvm_caps.guest_phys_bits = boot_cpu_data.x86_phys_bits; > > > > > > When KeyID_bits is non-zero, MAXPHYADDR != boot_cpu_data.x86_phys_bits > > > here, you can check in detect_tme(). > > > > from detect_tme(): > > > > /* > > * KeyID bits effectively lower the number of physical address > > * bits. Update cpuinfo_x86::x86_phys_bits accordingly. > > */ > > c->x86_phys_bits -= keyid_bits; > > > > This looks like x86_phys_bits gets adjusted if needed. > > If TDP is enabled and supports 5-level, we want kvm_caps.guest_phys_bits=52, > but c->x86_phys_bits!=52 here. Do you talk about EPT or NPT or both? > Maybe we need to set kvm_caps.guest_phys_bits > according to whether TDP is enabled or not, like leaf 0x80000008 in > __do_cpuid_func(). See patches 2+3 of this series. Maybe it is better to just not set kvm_caps.guest_phys_bits in generic kvm code and leave that completely to vmx / svm vendor modules. Or let the generic code handle the !tdp_enabled case and have the vendor modules override (considering EPT / NPT limitations) in case tdp is enabled. take care, Gerd
