On Thu, Apr 07, 2022 at 01:51:38PM +1200, Kai Huang <kai.huang@xxxxxxxxx> wrote: > On Thu, 2022-04-07 at 09:29 +0800, Xiaoyao Li wrote: > > On 4/5/2022 8:58 PM, Paolo Bonzini wrote: > > > On 3/4/22 20:48, isaku.yamahata@xxxxxxxxx wrote: > > > > + td_params->attributes = init_vm->attributes; > > > > + if (td_params->attributes & TDX_TD_ATTRIBUTE_PERFMON) { > > > > + pr_warn("TD doesn't support perfmon. KVM needs to save/restore " > > > > + "host perf registers properly.\n"); > > > > + return -EOPNOTSUPP; > > > > + } > > > > > > Why does KVM have to hardcode this (and LBR/AMX below)? Is the level of > > > hardware support available from tdx_caps, for example through the CPUID > > > configs (0xA for this one, 0xD for LBR and AMX)? > > > > It's wrong code. PMU is allowed. > > > > AMX and LBR are disallowed because and the time we wrote the codes they > > are not supported by KVM. Now AMX should be allowed, but (arch-)LBR > > should be still blocked until KVM merges arch-LBR support. > > I think Isaku's idea is we don't support them in the first submission? > > If so as I suggested, we should add a TODO in comment.. Sure, will add a TODO comment. -- Isaku Yamahata <isaku.yamahata@xxxxxxxxx>