Messages in this thread | | | Subject | Re: [PATCH v1 1/1] x86/tdx: Handle MWAIT, MONITOR and WBINVD | From | Xiaoyao Li <> | Date | Tue, 30 Mar 2021 12:56:41 +0800 |
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On 3/27/2021 8:18 AM, Kuppuswamy Sathyanarayanan wrote: > In non-root TDX guest mode, MWAIT, MONITOR and WBINVD instructions > are not supported. So handle #VE due to these instructions as no ops. > > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > Reviewed-by: Andi Kleen <ak@linux.intel.com> > --- > > Changes since previous series: > * Suppressed MWAIT feature as per Andi's comment. > * Added warning debug log for MWAIT #VE exception. > > arch/x86/kernel/tdx.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/arch/x86/kernel/tdx.c b/arch/x86/kernel/tdx.c > index e936b2f88bf6..fb7d22b846fc 100644 > --- a/arch/x86/kernel/tdx.c > +++ b/arch/x86/kernel/tdx.c > @@ -308,6 +308,9 @@ void __init tdx_early_init(void) > > setup_force_cpu_cap(X86_FEATURE_TDX_GUEST); > > + /* MWAIT is not supported in TDX platform, so suppress it */ > + setup_clear_cpu_cap(X86_FEATURE_MWAIT);
In fact, MWAIT bit returned by CPUID instruction is zero for TD guest. This is enforced by SEAM module.
Do we still need to safeguard it by setup_clear_cpu_cap() here?
> + > tdg_get_info(); > > pv_ops.irq.safe_halt = tdg_safe_halt;
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